(American Journal of Pathology. 2001;159:915-924.)
© 2001 American Society for Investigative Pathology
Myeloperoxidase Expression by Histiocytes in Kikuchis and Kikuchi-Like Lymphadenopathy
Stefano A. Pileri*,
Fabio Facchetti
,
Stefano Ascani*,
Elena Sabattini*,
Simonetta Poggi*,
Milena Piccioli*,
Damiano Rondelli*,
Federica Vergoni
,
Pier Luigi Zinzani*,
Pier Paolo Piccaluga*,
Brunangelo Falini
and
Peter G. Isaacson
From the Pathology and Clinical Units,*
Institute of
Hematology and Clinical Oncology "L. & A. Seràgnoli," Bologna
University, Bologna, Italy; the Institute of Pathologic Anatomy and
Histopathology,
Brescia University, Brescia,
Italy; the Hematopathology Laboratory,
Institute of Hematology, Perugia University, Perugia, Italy; and the
Histopathology Department,
University College
London, London, United Kingdom
 |
Abstract
|
|---|
Forty-five examples of Kikuchis lymphadenitis (KL), 5
Kikuchi-like lupus erythematosus lymphadenopathies, 25
nonnecrotizing lymphadenitidies (5 toxoplasmic, 5
sarcoid-like, 6 dermatopathic, 4 suppurative, 3
tubercular, 2 with sinus histiocytosis), 4 examples of
hyaline-vascular Castleman disease (CD), 2 plasmacytoid
monocyte tumors (PM-Ts), and 61 accessory cell neoplasms were
studied by a panel of antibodies, including the PG-M1 (against
a macrophage-restricted CD68 epitope) and a polyclonal
anti-myeloperoxidase (MPO). In KL and Kikuchi-like lupus erythematosus
lymphadenopathies, 25 to 75% of CD68+ histiocytes
co-expressed MPO. This did not occur in nonnecrotizing
lymphadenitidies and accessory cell neoplasms.
MPO+/CD68+ elements corresponded to
nonphagocytosing mononuclear cells and some crescentic macrophages and
phagocytosing histiocytes. Typical PMs were
MPO-/CD68+ in all cases, including CD
and PM-T. Our observations suggest that in KL and KL-like
lymphadenopathies: 1) MPO+/CD68+ blood
monocytes might be attracted into tissues because of the lack or
paucity of granulocytes and the need of MPO for oxidative processes; 2)
PMs are more likely to be involved in the cytotoxic immune reaction
than in phagocytic phenomena; 3) the peculiar phenotype of the
histiocytic component can be usefully used for the differentiation from
malignant lymphoma and PM-T.
 |
Introduction
|
|---|
In 1972, Kikuchi1
and Fujimoto and
colleagues2
independently described an unusual and
idiopathic form of benign lymphadenitis that they, respectively, called
"lymphadenitis showing reticulum cell hyperplasia with nuclear debris
and phagocytosis" and "cervical subacute necrotizing
lymphadenitis." In 1982, Pileri and colleagues3
first
reported this condition outside Japan and termed it "histiocytic
necrotizing lymphadenitis without granulocytic infiltration," aiming
to differentiate it from other forms of necrotizing lymphadenitis with
variable amounts of granulocytes, such as those occurring in systemic
lupus erythematosus (LE), bacterial and viral infections, and
thrombosis of the afferent veins. Since then, several other cases,
generically referred to as Kikuchis lymphadenitis (KL), have been
observed in Western countries.4-11
Although, the etiology of the lesion has
still to be clearly established, an infectious cause is suggested by
the many associations with Epstein-Barr virus,12,13
human
herpesvirus (HHV)6,14,15
HHV8,16
parvovirus
B19,17
Toxoplasma gondii,18
and
Yersinia enterocolitica.5
Kikuchis
disease has also been described in HIV-19
and
HTLV-1-positive patients.20
Some authors favor an
autoimmune mechanism, and interestingly KL has also been described in
patients affected by connective tissue diseases.21-26
Clinically, KL is usually characterized by cervical adenopathy/ies,
mainly occurring in young women, and sometimes associated with fever
and transitory leukopenia. KL shows a benign clinical course with
resolution in few months, either spontaneously or after antibiotic
therapy. Rare reports exist of multicentric organ involvement, which
can be occasionally fatal,27
and extranodal locations,
mainly in the skin.28,29
Morphologically, the lesion affects the cortical and paracortical areas
of the node with foci that have "clear" appearance at low
magnification and are composed of varying amounts of
histiocytes,30
small- to medium-sized lymphocytes and
immunoblasts, abundant karyorhectic and granular eosinophilic debris,
and possible overt coagulative necrosis. By definition, neutrophils are
absent or sparse. On the basis of the proportion of the different
cytological components, Kuo31
has recently proposed three
different histological subtypes of KL: proliferative, necrotizing, and
xanthomatous. The diagnosis of KL is generally not difficult,
although early lesions lacking overt necrosis can be misdiagnosed as
malignant lymphoma, because of the presence of abundant
immunoblasts.32,33
At immunohistochemistry, the
histiocytic component is characterized by the expression of
the CD68 antigen, whereas the lymphoid component carries a T-cell
phenotype with a prevalence of CD8+ cytotoxic
cells.9,31,34-36
Plasmacytoid monocytes (PMs) are thought
to be an important cell component of early stages of
KL,3,5,8-10,29-32,34,37-39
and their identification is
considered helpful for diagnosis.31
PMs are medium-sized
cells with eccentric nuclei and clumped chromatin, which are regularly
found in the pulp of reactive lymph nodes, where they occur either as
large aggregates or as isolated, dispersed cells. They are closely
related to high endothelial venules. Although their phenotype has been
clearly defined (including positivity for CD4, CD31, CD36, CD43, CD68,
CD74, and CLA/HECA452),39-51
the exact nature of their
relationship to the myelomonocytic cell lineage still remains debated.
Recent reports suggest that PMs secrete large amounts of type I
interferon and drive a potent Th1 T-cell
polarization;52-54
in addition, they express the
interleukin-3 receptor
and CD40, and on stimulation with
interleukin-3 and CD40-ligand differentiate into dendritic
cells.51-55
In this study we report the occurrence of large numbers of histiocytes
expressing MPO in Kikuchis and Kikuchi-like lymphadenitis, and
discuss the nature of this peculiar histiocyte, its relationship to
other cell types occurring in KL, and its diagnostic relevance.
 |
Materials and Methods
|
|---|
Case Selection and Histological and Immunohistological Methods
Formalin-fixed, paraffin-embedded lymph node blocks of 45 Italian
KL patients were retrieved from the files of the Unit of Pathological
Anatomy and Hematopathology of Bologna University. The age and sex of
the patients, as well as the site of lymphadenopathy were known in all
instances. Three-µm-thick sections were cut from the paraffin blocks
and stained with hematoxylin and eosin (H&E), Giemsa, periodic
acid-Schiff (with and without diastase digestion), and Gomori silver
impregnation for reticulin fibers. Further sections were cut, coated on
naturally charged slides, stored at 56°C for at least 2 hours, and
then rinsed in water through repeated washes in Histoclear (National
Diagnostics, Atlanta, GA) and graded alcohols. These sections were used
for immunohistochemistry, which was performed by applying the following
antibodies: PG-M1/CD68 (Prof. B. Falini, Perugia University,
Italy), polyclonal anti-myeloperoxidase (MPO) (DAKO AS,
Denmark), Qbend10/CD34 (Menarini, Italy), L26/CD20 (DAKO),
JCB117/CD79a (Prof. D.Y. Mason, Oxford University, United
Kingdom), polyclonal anti-CD3 (DAKO), OPD4/CD45R0 (DAKO),
114B/CD8 (Prof. D.Y. Mason), Ber-H2/CD30 (Prof. B. Falini), Mib-1
(DAKO), TIA-1 (Coulter Immunology, FL, USA), G2b-7/Granzyme-B
(Kemiya Biochemical Company, WA, USA), and CLA/HECA425 (Pharmingen, San
Diego, CA). The antibodies were dispensed on a TechMate 500
immunostainer and detected by the alkaline phosphatase-anti
alkaline phosphatase (APAAP) technique or the
streptavidin-biotin-peroxidase complexes (SABC) method.56
Antigen retrieval was performed according to previously reported
experience.57
In particular, sections were placed in 1
mmol/L of ethylenediaminetetraacetic acid-NOH solution (pH 8.0),
microwaved for 5 minutes at 900 W twice and then left at room
temperature for 20 minutes. In all instances, positive and negative
controls were used to assess the reliability of the results, as
previously described.57
The results were graded in a
semiquantitative manner as follows: +, positivity in 75 to 100% of the
cells evaluated; +/-, positivity in 50 to 75% of the cells evaluated;
-/+, positivity in 25 to 50% of the cells evaluated; rare, positivity
in 10 to 25% of the cells evaluated; exceptional, positivity in 1 to
10% of the cells evaluated; and -, negativity in all of the cells
evaluated. The intensity of the staining and the pattern of positivity
(nuclear, cytoplasmic diffuse, dot-like, granular, membrane-bound, and
so forth) were also recorded.
In seven cases, double staining for CLA/HECA452 (used as a PM
marker)58
and MPO was performed. In particular, the rat
anti-human CLA/HECA425 and rabbit anti-human MPO antibodies were
respectively revealed by the immunoalkaline phosphatase (chromogen:
Fast Red or nitro blue tetrazolium) and the immunoperoxidase techniques
(chromogen: diaminobenzidine or amino-ethyl-carbazole).
The specificity of the MPO polyclonal antibody was tested in the course
of previously reported studies59,60
and in >1000 examples
of acute leukemia, malignant lymphoma, and nonhematopoietic tumors
tested in the laboratories of the senior authors of this paper (BF, FF,
PGI, SAP). Because no improper stains have ever been recorded, the
antibody has been adopted as an operational key marker by the Italian
Co-operative Study Group on Acute Leukemias and is used daily for the
diagnosis of these diseases in Italy.
Comparisons were made with 5 LE lymphadenopathies, 23 nonnecrotizing
lymphadenitidies (5 toxoplasmic, 5 sarcoid-like, 6 dermatopathic, 4
suppurative, 3 tubercular), 2 reactive lymphadenopathies with huge
mature sinus histiocytosis, 4 examples of hyaline-vascular Castleman
disease (CD), and 2 PM tumors (PMTs), retrieved from the files of the
Unit of Pathological Anatomy and Hematopathology of Bologna University,
the Histopathology Department of the University College London, or the
Institute of Pathological Anatomy and Histopathology of Brescia
University. All of the specimens were treated and immunohistochemically
studied as above. In addition, the series of tumors derived from
histiocytes and accessory dendritic cells (61 cases) recently studied
by the International Lymphoma Study Group61
was examined
as a further control.
Fluorescence-Actived Cell Sorting (FACS) Analysis Method
Blood samples from two normal individuals were obtained after
informed consent for FACS analysis. This was performed according to
previously reported procedures.62
The following mouse
monoclonal antibodies (mAbs) were used: anti-human MPO conjugated with
fluorescein isothiocyanate (clone MPO-7, DAKO) and anti-human CD14
conjugated with phycoerythrin (clone TÜK4, DAKO). The rabbit
anti-human MPO-unconjugated polyclonal antibody used for
immunohistochemistry was tested in parallel by indirect
immunofluorescence and a secondary swine anti-rabbit
immunoglobulin/fluorescein isothiocyanate (DAKO). Adequate isotype
controls were always applied. Briefly, appropriate amounts of
conjugated mAbs or unconjugated polyclonal antibody were added to 100
ml of whole blood and incubated for 15 minutes at room temperature. Red
cells were then lysed. For indirect immunofluorescence experiments, the
incubation with the primary antibody was followed by the application of
the secondary antibody for 15 minutes at room temperature. After
washing the samples twice, 10 to 20 x 104
events were acquired on a FACScalibur instrument (Becton-Dickinson,
Mountain View, CA) and analyzed by CellQuest software. Monocytes were
gated using linear side scatter and forward scatter characteristics to
exclude small lymphocytes as well as neutrophils.
 |
Results
|
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Thirty-three patients with KL were females and 12 were males
(male:female ratio, 1:2.75). Their age ranged from 16 to 51 years, the
mean and median values being 29.2 and 33.5 years, respectively. All
cases presented with laterocervical adenopathy, which was occasionally
associated with swelling of the axillary nodes (three cases) or with
adenopathies in the supraclavicular region (two cases) or axillary and
inguinal sites (two cases). Follow-up data were available for 30
patients, the length of observation ranging from 1 to 12 years; at the
time of writing, all these patients are alive and well, without signs
or symptoms either of KL or of collagen vascular disease, infection,
deep venous thrombosis, or malignancy.
Morphology
At low magnification, the normal lymph node architecture was
variably effaced because of the presence of patchy circumscribed or
confluent lesions that were located in the cortex and paracortex
(Figure 1)
. On
Giemsa staining, these lesions were grayish, strongly contrasting with
the deeply basophilic spared areas (Figure 1)
. The latter were
characterized by sparse follicles and expansion of the T zone, which
contained variable amounts of immunoblasts, as well as by occasional
clusters of PMs and scattered macrophages and dendritic cells producing
a mottled appearance.

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Figure 1. KL proliferative type. The lesion shows a large amount of histiocytes
intermingled with small lymphocytes, immunoblasts, and apoptotic bodies
(Giemsa staining; original magnification,
x400). Inset: Multiple lesions in
the cortex and paracortex that stain grayish at Giemsa and sharply
contrast with the deeply basophilic-spared portions of the node
(original magnification,
x50).
|
|
At closer examination (Table 1)
, 18 and
27 cases were, respectively, classified as proliferative and
necrotizing lesions, according to Kuo31
(Figures 1 and 5)
. No xanthomatous
forms31
were recorded. In all of the specimens examined,
neutrophils were absent or rare, whereas apoptotic bodies were easily
detected. In particular, the histiocytic componentthe composition of
which did not significantly vary with the proliferative or necrotizing
nature of the adenopathyconsisted of: 1) nonphagocytosing mononuclear
elements showing a moderate amount of cytoplasm, weakly stained by
Giemsa, and a round-oval or deeply indented nucleus with dispersed
chromatin; 2) variable numbers of morphologically recognizable PMs with
slightly basophilic cytoplasm and eccentric nuclei with clumped
chromatin; 3) crescentic macrophages;30
and 4)
phagocytosing histiocytes with a large rim of clear cytoplasm
containing abundant nuclear debris.

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Figure 5. KL-necrotizing type. The pattern is characterized by phenomena of
tissue necrosis, a rich histiocytic component and numerous apoptotic
bodies (H&E; original magnification,
x400).
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Immunohistochemistry
Lymphoid Component
Within the lesions, lymphoid cells showed mainly T-cell phenotype,
as revealed by their CD3 expression (Figure 2a)
. With the exception of a single case,
only rare CD79a+ elements were scattered
throughout. Most T lymphocytes carried the CD8 molecule (Figure 2b)
;
with one exception, the number of OPD4+ elements
was extremely low. These findings did not significantly vary between
the proliferative and necrotizing subgroups.31
The only
difference observed between the two histological subtypes consisted in
the slightly higher content of CD3+ T lymphocytes
in the proliferative form. The activation marker CD30 was determined in
40 samples: it was usually expressed by 10% or less of T cells, with
the exception of eight cases that showed values ranging from 25 to
55%. A variable number of T lymphocytes (10 to 80%) displayed a
distinct granular cytoplasmic positivity at the determination of the
cytotoxic markers TIA-1 and Granzyme B (Figure 2c)
, the staining of
which ran in parallel. No differences in terms of CD30, cytotoxic
markers, and Ki-67 antigen expression were found between the two
histological subtypes defined according to the criteria of
Kuo.31

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Figure 2. KL proliferative type. The lymphoid component mainly corresponds to
CD3+ peripheral T cells
(a), which
mostly express CD8 phenotype
(b) and carry
cytotoxic markers
(c), as shown
by the positivity at the determination of Granzyme B
(APAAP technique; Gills hematoxylin
counterstaining; original magnifications,
x400).
|
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Histiocytic Component
The PG-M1 mAbraised against a fixation-resistant epitope of the
CD68 molecule, specific to monocytes and
macrophages50
confirmed the amount and distribution of
histiocytes seen at conventional light microscopy within the
pathological foci (Table 1
; Figures 3 and 6
). The positivity was always restricted
to these elements, and further demonstrated their cytological
variability. Interestingly, in all of the cases tested, the polyclonal
antibody anti-MPO stained from 25 to 75% of the CD68-positive cells,
as assessed in serial sections, irrespective of the proliferative or
necrotizing nature of the lesion (Table 1
and Figures 4 and 7
).31
In particular,
positivity corresponded to the vast majority of nonphagocytosing
mononuclear cells and a proportion of crescentic macrophages and
phagocytosing histiocytes (Figure 8)
. In
contrast, morphologically recognizable PMs both within the lesions and
at some distance from them turned out to be MPO-negative (Table 1
;
Figure 9
). Double staining gave further
confirmation of the latter finding, showing that CLA/HECA425-positive
PMs were regularly MPO-negative (Figure 10)
.
Interestingly, variable numbers of MPO histiocytes were identified
around high endothelial venules or within PM clusters in areas of the
lymph node not directly involved by the proliferative or necrotizing
foci (Figure 11)
.

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Figure 3. KL proliferative type. CD68-staining pattern in the same case as Figure 1
(APAAP technique; Gills hematoxylin
counterstaining; original magnification, x300).
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Figure 6. KL-necrotizing type. The histiocytic component stains for CD68
(APAAP technique; Gills hematoxylin
counterstaining; original magnification, x300).
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Figure 4. KL proliferative type. In the same case the positivity for MPO
primarily corresponds to that for CD68. Inset: Exceptional
granulocytes express neutrophilic elastase
(APAAP technique; Gills hematoxylin
counterstaining; original magnification, x300).
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Figure 7. KL-necrotizing type. In the same case the positivity for MPO
primarily corresponds to that for CD68. Inset: Despite
tissue necrosis, there are rare granulocytes that express neutrophilic
elastase (APAAP technique; Gills hematoxylin
counterstaining; original magnification, x300).
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Figure 8. KL proliferative type. The morphological spectrum of MPO+
elements varies from mononuclear cells to crescentic and phagocytosing
(arrows)
histiocytes (SABC technique; hematoxylin
counterstaining; original magnification, x800).
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Figure 9. A plasmacytoid monocyte cluster at some distance from the lesions is
negative for MPO (APAAP technique; Gills
hematoxylin counterstaining; original magnification,
x250). Inset: Cytological details of
the cluster at Giemsa staining; note the presence of apoptotic bodies
(original magnification,
x400).
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Figure 10. Plasmacytoid monocytes expressing CLA/HECA425
(in red) are completely
negative for MPO; the latter molecule is carried by histiocytic
elements (in brown)
(double staining; original magnification,
x600).
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Figure 11. KL. A cluster of MPO+ histiocytes around a high endothelium
venule at distance from cortical lesions (SABC
technique; hematoxylin counterstaining; original magnification,
x500).
|
|
The antibody anti-neutrophilic elastase stained none of the histiocytes
co-expressing MPO and CD68 (Table 1)
: it revealed rare scattered
granulocytes in 15 cases (Figures 4 and 7)
. No elements were stained by
the Qbend10 mAb, CD34-positivity being restricted to vessel endothelia.
The Mib-1 antibody gave virtually negative results with the histiocytic
component.
Control Groups
The five cases of Kikuchi-like LE lymphadenopathy revealed
morphological changes corresponding to those observed in the
necrotizing form of KL; the only differences consisted in areas with
more extensive tissue necrosis (Figure 12)
and slightly higher numbers of
plasma cells and granulocytes in LE. In addition, the numbers of PM
admixed with the lesions and of PM aggregates in the spared lymph node
were usually less numerous than those found in KL. On
immunohistochemistry, most histiocytes showed co-expression of CD68 and
MPO (Figures 13 and 14)
.

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Figure 12. Kikuchi-like LE lymphadenitis. A focus with prominent necrotizing
features is shown (H&E; original magnification,
x500).
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Figure 13. Kikuchi-like LE lymphadenitis. The same histiocytic elements co-express
CD68 (Figure 13) and MPO (Figure 14
) (SABC
technique; hematoxylin counterstaining; original magnification, x600).
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Figure 14. Kikuchi-like LE lymphadenitis. The same histiocytic elements co-express
CD68 (Figure 13
) and MPO (Figure 14) (SABC
technique; hematoxylin counterstaining; original magnification, x600).
|
|
In the 25 examples of reactive lymphadenitis unrelated to KL, the
histiocytic population revealed regular expression of CD68, but
negativity for MPO, with the exception of occasional macrophages in
granulomatous-suppurative lymphadenitis. Occasional clusters of PMs,
more readily found in toxoplasma lymphadenitis, were clearly
CD68+ and MPO-, as were
those observed in the examples of CDs (Figures 15, 16, and 17)
and PMTs tested (Figures 18, 19, and 20)
. Finally, expression of MPO was
never observed in the 61 tumors of histiocytes and accessory dendritic
cells studied by the International Lymphoma Study Group.61

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Figure 15. Castleman disease. A plasmacytoid monocyte cluster located in the
bottom left corner (Giemsa; original
magnification, x100).
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Figure 16. Castleman disease. Plasmacytoid monocytes strongly express CD68
(APAAP technique; Gills hematoxylin
counterstaining; original magnification, x300).
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Figure 17. Castleman disease. Plasmacytoid monocytes lack MPO
(note some granulocytes in the surrounding,
which represent the internal control of the
reaction) (APAAP
technique; Gills hematoxylin counterstaining; original magnification,
x250).
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Figure 18. Plasmacytoid monocyte tumor. Cytological details at high magnification
(H&E; original magnification,
x400).
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Figure 19. Plasmacytoid monocyte tumor. Neoplastic cells express CD68
(SABC technique; hematoxylin counterstaining;
original magnification, x400).
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Figure 20. Plasmacytoid monocyte tumor. Double staining for CD45RA and MPO shows
the negativity of tumoral plasmacytoid monocytes for the latter
molecule (note the staining of some granulocytes
as an internal control)
(SABC technique; hematoxylin counterstaining;
original magnification, x500).
|
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FACS Analysis
When gating the monocyte fraction, a double staining for CD14 and
MPO was observed, irrespective of the anti-MPO antibody used (Figures 21
,,
22, and
23). In particular, the polyclonal
antibody showed the same reactivity and specificity as the fluorescein
isothiocyanate-conjugated reference monoclonal antibody.
 |
Discussion
|
|---|
Since the first description of KL in 1972,1,2
several
attempts have been made to understand its etiology and pathogenesis.
Although the identification of causative agent(s) is still a matter of
some debate,12-26
most studies agree on the fact that KL
is probably a cell-mediated phenomenon sustained by activated cytotoxic
CD8+ T lymphocytes.34-36
The latter
cells might be at the same time the cause and victims of the cell-death
process that occurs in KL.34-36
Our immunohistochemical
findings showing that most CD8+ T lymphocytes do
express TIA-1 and Granzyme B are consistent with this hypothesis.
However, although positivity for cytotoxic markers provides an
explanation for the large amounts of apoptotic cells and nuclear debris
typically observed in KL, it does not clarify all of the pathogenetic
mechanisms of the process. In particular, it does not explain why
granulocytic infiltration is strikingly absent in KL lesions, despite
the prominent necrotizing features.
Our study shows that the phenotypic profile of the histiocytic
component of KL is much more complex than was previously thought. In
particular, we observed that most histiocytes in KL co-express CD68 and
MPO. This result was totally unexpected, because we used the PG-M1
monoclonal antibody that detects a CD68 epitope that is restricted to
the monocyte/macrophage lineage and is absent in all steps of myeloid
differentiation.50
Indeed, unlike the anti-CD68 KP1
antibody, PG-M1 is useful for the differential diagnosis between M0-M3
and M4-M5 acute leukemias, which are PG-M1- and
PG-M1+, respectively.50,59,60
A similar cell composition was also identified in the examined cases of
KL-like (KL-L) lymphadenitis associated with LE, in which the
histiocytes within the necrotic foci co-expressed CD68/PG-M1 and MPO.
This observation further supports previous data indicating that KL and
KL-L conditions share important morphological and immunophenotypical
features, and probably constitute a single cellular
process.22-26
It could be argued that the results
observed in KL and LE might theoretically be because of a
cross-reactivity of the antibody against MPO; however, this possibility
is quite remote because the specificity of the reagent was supported by
proper internal positive and negative controls, as well as by
FACS-analysis experiments and previously reported
data.59,60
The latter showed that circulating monocytes
express MPO, and this expression was independent of the antibody used.
Our phenotypic and morphological findings both suggest that the
histiocytes of KL and KL-L conditions might primarily correspond to
CD68+/MPO+ peripheral blood
monocytes accumulating in the lymph node. This hypothesis is supported
by the recent observation that the MPO system of human monocytes can
substitute neutrophilic MPO for the production of advanced glycation
end products at sites of inflammation.63
Thus, peripheral
blood monocytes
(MPO+/CD68+) might be
attracted into tissues during particular inflammatory processessuch
as those occurring in Kikuchis and Kikuchi-like
lymphadenopathiesthat show lack or paucity of granulocytes, but
nevertheless require MPO. The peculiarity of the immune reaction
occurring in KL is further supported by the observation that the
CD68+/MPO+ tissue
histiocytes are not identified either in nonspecific reactive
lymphadenitis or in several granulomatous lymphadenitidies (whether or
not associated with necrosis and tissue neutrophilia) and in histiocyte
and accessory cell tumors.61
The data obtained in this study do not support the widely reported
concept that PMs represent a main cellular component in
KL.3,5,8-10,29-32,34,37-39
In fact, PM clusters were
frequently noticed in the lymph node parenchyma spared by the lesions.
They were usually sparse within both the proliferative and necrotic
lesions, and were easily recognizable by their morphology and
expression of CLA, along with their negativity for MPO. Therefore, PMs
seem to correspond to a minor component of KL. Their importance has
probably been overemphasized in the past because of their morphological
similarities with circulating monocytes attracted within the
necrotizing lesions.
What role, if any, PMs play in the immunological reaction that
characterizes KL remains to be established. Evidence is emerging that
PMs are neither terminally differentiated elements64
nor
precursors of phagocytosing histiocytes. They seem to correspond to the
natural type I interferon producing cells,51-55,65
originating in the bone marrow and migrating to peripheral organs,
where they eventually differentiate into dendritic cells or die,
depending on microenvironmental stimuli.51-55
We can
speculate that PMs may play a role in KL and KL-L LE by accumulating in
the lymph nodes and secreting large amounts of type I
interferon,66,67
thus activating a Th1 T-cell reaction and
a cytotoxic immune response,68
which typically occurs in
this condition.34,36,69
On clinical grounds, recognition of the peculiar phenotype of the
histiocytic component of KL should have important diagnostic
implications. Indeed knowledge of the distinctive KL phenotype can be
used to avoid a misdiagnosis of malignant lymphoma in patients bearing
the proliferative form of KL, an unfortunate error that has been
repeatedly reported in the literature.32,33
In addition,
this knowledge should be relevant for the differentiation of KL from
PMT, chloroma, or nodal colonization by acute nonlymphoid
leukemia.40
The exclusion of PMT is straightforward,
because in contrast to the histiocytic component of KL, PMT does not
express MPO. However, differential diagnosis with a myeloid tumor,
which is obviously MPO+, may be somewhat more
demanding: it should be resolved using the knowledge that the
histiocytic component of KL has a bland morphology, is basically
quiescent, is admixed with abundant cytotoxic T lymphocytes and
apoptotic bodies, and does not express neutrophilic elastase, TdT, or
CD34.59,60

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Figure 22. CD14-positive peripheral blood monocytes co-expressed MPO, when the
reference monoclonal antibody is applied.
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Acknowledgements
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|---|
We thank Mr. Luigi Chilli, Ms. Federica Sandri, and Ms. Silvana
Festa for their skillful technical assistance; Prof. David Y. Mason for
kindly providing the monoclonal antibodies JCB117 and 114B; and Mr.
Robin M. T. Cooke was responsible for editing the English.
 |
Footnotes
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Address reprint requests to Professor Stefano A. Pileri, Unità Operativa di Anatomia Patologica ed Ematopatologia, Istituto di Ematologia ed Oncologia Medica "L. e A. Seràgnoli," Università di Bologna, Policlinico S. Orsola, Via Massarenti 9, 40138 Bologna, Italia. E-mail:
pileri{at}almadns.unibo.it
Supported by grants from Associazione Italiana Ricerca sul Cancro (Milan), Ministero della Università e della Ricerca Scientifica e Tecnologica (Rome) and Associazone Bolognese per lo Studio dei Tumori Ematologici (Bologna).
Accepted for publication May 14, 2001.
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References
|
|---|
-
Kikuchi M: Lymphadenitis showing focal reticulum cell hyperplasia with nuclear debris and phagocytosis. Nippon Ketsueki Gakkai Zasshi 1972, 35:379-380
-
Fujimoto Y, Kozima Y, Yamaguchi K: Cervical subacute necrotizing lymphadenitis. A new clinicopathological entity. Naika 1972, 20:920-927
-
Pileri S, Kikuchi M, Helbron D, Lennert K: Histiocytic necrotizing lymphadenitis without granulocytic infiltration. Virchows Arch Pathol Anat 1982, 395:257-271
-
Turner RR, Martin J, Dorfman RF: Necrotizing lymphadenitis. A study of 30 cases. Am J Surg Pathol 1983, 7:115-123[Medline]
-
Feller AC, Lennert K, Stein H, Bruhn H-D, Wuthe H-H: Immunohistology and etiology of histiocytic necrotizing lymphadenitis: report of three instructive cases. Histopathology 1983, 7:825-839[Medline]
-
Ali MH, Horton LWL: Necrotising lymphadenitis without granulocytic infiltration (Kikuchis disease). J Clin Pathol 1985, 38:1252-1257[Abstract/Free Full Text]
-
Chan JKC, Saw D: Histiocytic necrotizing lymphadenitis (Kikuchis disease). A clinicopathologic study of 9 cases. Pathology 1986, 18:22-28[Medline]
-
Dorfman RF: Histiocytic necrotizing lymphadenitis of Kikuchi and Fujimoto. Arch Pathol Lab Med 1987, 111:1026-1029[Medline]
-
Rivano MT, Falini B, Stein H, Canino S, Ciani C, Gerdes J, Ribacchi R, Gobbi M, Pileri S: Histiocytic necrotizing lymphadenitis without granulocytic infiltration (Kikuchis lymphadenitis). Morphological and immunohistochemical study of eight cases. Histopathology 1987, 11:1013-1027[Medline]
-
Dorfman RF, Berry GJ: Kikuchis histiocytic necrotizing lymphadenitis: an analysis of 108 cases with emphasis on differential diagnosis. Semin Diagn Pathol 1988, 5:329-345[Medline]
-
Lorand Metze I, Vassallo J, Mori S: Histiocytic necrotizing lymphadenitis in Brazil: report of a case and review of the literature. Pathol Int 1994, 44:548-550[Medline]
-
Anagnostopoulos I, Hummel M, Korbjuhn P, Papadaki T, Anagnostou D, Stein H: Epstein-Barr virus in Kikuchi-Fujimoto disease. Lancet 1993, 341:893
-
Cho KJ, Lee SS, Khang SK: Histiocytic necrotizing lymphadenitis. A clinicopathologic study of 45 cases with in situ hybridization for Epstein-Barr virus and hepatitis B virus. J Korean Med Sci 1996, 11:409-414[Medline]
-
Eizuru Y, Minematu T, Minamishima Y, Kikuchi M, Yamanishi K, Takahashi M, Kurata T: Human herpes virus 6 in lymph node. Lancet 1989, :40
-
Sumiyoshi Y, Kikuchi M, Ohshima K, Joneda S, Kobari S, Takeshita M, Eizuru Y, Minamishima Y: Human herpesvirus-6 genomes in histiocytic necrotizing lymphadenitis (Kikuchis disease) and other forms of lymphadenitis. Am J Clin Pathol 1993, 99:609-614[Medline]
-
Huh J, Kang GH, Gong G, Kim SS, Ro JY, Kim CW: Kaposis sarcoma-associated herpesvirus in Kikuchis disease. Hum Pathol 1998, 29:1091-1096[Medline]
-
Yufu Y, Matsumoto M, Miyamura T, Nishimura J, Nawata H, Ohshima K: Parvovirus B19-associated haemophagocytic syndrome with lymphadenopathy resembling histiocytic necrotizing lymphadenitis (Kikuchis disease). Br J Haematol 1997, 96:868-871[Medline]
-
Kikuchi M, Yoshizumi T, Nakamura H: Necrotizing lymphadenitis: possible acute toxoplasmic infection. Virchows Arch A Pathol Anat Histopathol 1977, 19:99-113
-
Pileri SA, Sabattini E, Costigliola P, Poggi S, Ricchi E, Tumietto F, Chiodo F: Kikuchis lymphadenitis in HIV infection: a case report. AIDS 1991, 5:459-461[Medline]
-
Bataille V, Harland CC, Behrens J, Cook MG, Holden CA: Kikuchi disease (histiocytic necrotizing lymphadenitis) in association with HTLV1. Br J Dermatol 1997, 136:610-612[Medline]
-
Imamura M, Ueno H, Matsumura A, Kamija H, Suzuki T, Kikuchi K, Onoe T: An ultrastructural study of subacute necrotizing lymphadenitis. Am J Pathol 1982, 107:292-299[Abstract]
-
Ohta A, Mastumoto Y, Ohta T, Kaneoka H, Yamaguchi M: Stills disease associated with necrotizing lymphadenitis (Kikuchis disease). Report of 3 cases. J Rheumatol 1988, 15:981-983[Medline]
-
Lyberatos C: Two more cases of Stills disease and Kikuchis. J Rheumatol 1990, 17:568-569[Medline]
-
Tumiati B, Bellelli A, Portioli I, Prandi S: Kikuchis disease in systemic lupus erythematosus: an independent or dependent event? Clin Rheumatol 1991, 10:90-93[Medline]
-
el Ramahi KR, Karrar A, Ali MA: Kikuchi disease and its association with systemic lupus erythematosus. Lupus 1994, 5:406-411
-
Gourley I, Bell AL, Biggart D: Kikuchis disease as a presenting feature of mixed connective tissue disease. Clin Rheumatol 1995, 14:104-107[Medline]
-
Chan JKC, Wong K-C, Ng C-S: A fatal case of multicentric Kikuchis histiocytic necrotizing lymphadenitis. Cancer 1989, 63:1856-1862[Medline]
-
Sumiyoshi Y, Kikuchi M, Takeshita M, Yoneda S, Kobari S, Ohshima K: Immunohistological study of skin involvement in Kikuchis disease. Virchows Arch B Cell Pathol 1992, 62:263-269[Medline]
-
Spies J, Foucar K, Thompson CT, LeBoit PE: The histopathology of cutaneous lesions of Kikuchis disease (necrotizing lymphadenitis). A report of five cases. Am J Surg Pathol 1999, 23:1040-1047[Medline]
-
Tsang WYW, Chan JKC, Ng CS: Kikuchis lymphadenitis. A morphologic analysis of 75 cases with special reference to unusual features. Am J Surg Pathol 1994, 18:219-231[Medline]
-
Kuo T-T: Kikuchis disease (histiocytic necrotizing lymphadenitis). A clinicopathologic study of 79 cases with an analysis of histologic subtypes, immunohistology and DNA ploidy. Am J Surg Pathol 1995, 19:798-809[Medline]
-
Chamulak GA, Brynes RK, Nathwani BN: Kikuchi-Fujimoto disease mimicking malignant lymphoma. Am J Surg Pathol 1990, 14:514-523[Medline]
-
Menasce LP, Banerjee SS, Edmondson D, Harris M: Histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease): continuing diagnostic difficulties. Histopathology 1998, 33:248-254[Medline]
-
Takakuwa T, Ohnuma S, Koike J, Hoshikawa M, Koizumi H: Involvement of cell-mediated killing in apoptosis in histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease). Histopathology 1996, 28:41-48[Medline]
-
Felgar RE, Furth EE, Wasik MA, Gluckman SJ, Salhany KE: Histiocytic necrotizing lymphadenitis (Kikuchis disease): in situ end-labeling, immunohistochemical, and serologic evidence supporting cytotoxic lymphocyte-mediated apoptotic cell death. Mod Pathol 1997, 10:231-241[Medline]
-
Ohshima K, Shimazaki K, Kuma T, Suzumiya J, Kanda M, Kikuchi M: Perforin and Fas pathways of cytotoxic T-cells in histiocytic necrotizing lymphadenitis. Histopathology 1998, 33:471-478[Medline]
-
Facchetti F, de Wolf-Peeters C, van den Oord JJ, de Vos R, Desmet VJ: Plasmacytoid monocytes (so-called plasmacytoid T-cells) in Kikuchis lymphadenitis. An immunohistologic study. Am J Clin Pathol 1989, 92:42-50[Medline]
-
Hansmann M-L, Kikuchi M, Wacker HH, Radzun HJ, Nathwani BN, Hesse K, Parwaresch MR: Immunohistochemical monitoring of plasmacytoid cells in lymph node sections of Kikuchi-Fujimoto disease by a new pan-macrophage antibody Ki-M1P. Hum Pathol 1992, 23:676-680[Medline]
-
Sumiyoshi Y, Kikuchi M, Takeshita M, Ohshima K, Masuda Y, Parwaresch MR: Immunohistologic studies of Kikuchis disease. Hum Pathol 1993, 24:1114-1119[Medline]
-
Warnke RA, Weiss LM, Chan JKC, Cleary ML, Dorfman RF: Tumors of the lymph nodes and spleen. Atlas of Tumor Pathology, 3rd series, fascicle 14. 1994, :pp 375-378 Armed Forces Institute of Pathology Washington DC
-
Müller-Hermelink HK, Steinman G, Stein H, Lennert K: Malignant lymphoma of plasmacytoid T-cells. Morphologic and immunologic studies characterizing a special type of T-cell. Am J Surg Pathol 1983, 7:849-862[Medline]
-
Horny HP, Feller AC, Horst HA, Lennert K: Immunohistology of plasmacytoid T-cells: marker analysis indicates a unique phenotype of this enigmatic cells. Hum Pathol 1986, 18:28-32
-
Parwaresch MR, Radzun HJ, Kreipe H, Hansmann ML, Barth J: Monocyte/macrophage-reactive monoclonal antibody Ki-M6 recognizes an intracytoplasmic antigen. Am J Pathol 1986, 124:141-151
-
Kreipe H, Radzun HJ, Parwaresch MR, Haislip A, Hansmann ML: Ki-M7 monoclonal antibody specific for myelomonocytic cell lineage and macrophage in human. J Histochem Cytochem 1987, 35:1117-1126[Abstract]
-
Poppema S, Hollema H, Visser L, Vos H: Monoclonal antibodies (MT1, MT2, MB1, Mb2, MB3) reactive with leukocyte subsets in paraffin-embedded tissue sections. Am J Pathol 1987, 127:418-429[Abstract]
-
Facchetti F, De Wolf-Peeters C, Mason DY, Pulford K, van den Oord JJ, Desmet VJ: Plasmacytoid T-cells. Immunohistochemical evidence for their monocyte macrophage origin. Am J Pathol 1988, 133:15-21[Abstract]
-
Facchetti F, De Wolf-Peeters C, van den Oord JJ, De Vos R, Desmet VJ: Plasmacytoid T-cells: a cell population normally present in the reactive lymph node: an immunohistochemical and electronmicroscopic study. Hum Pathol 1988, 19:1085-1092[Medline]
-
Pulford KA, Rigney EM, Micklem KJ, Jones M, Stross WP, Getter KC, Mason DY: KP1: a monoclonal antibody detecting a new monocyte/macrophage associated antigen in routinely processed tissue sections. J Clin Pathol 1989, 42:414-421[Abstract/Free Full Text]
-
Koo CH, Mason DY, Miller R, Ben-Ezra J, Sheibani K, Rappaport H: Additional evidence that "plasmacytoid T-cell lymphoma" associated with chronic myeloproliferative disorders is of macrophage/monocyte origin. Am J Clin Pathol 1990, 93:822-827[Medline]
-
Falini B, Flenghi L, Pileri SA, Gambacorta M, Bigerna B, Dürkop H, Eitelbach F, Thiele J, Cavaliere A, Martelli MF, Poggi S, Sabattini E: PG-M1: a new monoclonal antibody directed against a fixative-resistant epitope on the macrophage-restricted form of the CD68 molecule. Am J Pathol 1993, 142:1359-1372[Abstract]
-
Facchetti F, Candiago E, Vermi W: Plasmacytoid monocyte express IL-3 receptor alpha and differentiate into dendritic cells. Histopathology 1999, 35:88-89[Medline]
-
Cella M, Jarossay D, Facchetti F, Alebardi O, Nakajima H, Lanzavecchia A, Colonna M: Plasmacytoid monocytes migrate to inflamed lymph nodes and produce high levels of type I interferon. Nat Med 1999, 5:919-922[Medline]
-
Cella M, Facchetti F, Lanzavecchia A, Colonna M: Plasmacytoid dendritic cells activated by influenza virus and CD40L drive a potent ThI polarization. Nature Immunol 2000, 1:305-310[Medline]
-
Kadowaki N, Antonenko S, Yiu-Nam Lau J, Liu Y-J: Natural interferon
/ß-producing cells link innate and adaptive immunity. J Exp Med 2000, 192:219-225[Abstract/Free Full Text]
-
Grouard G, Rissoan MC, Filgueira L, Durand I, Banchereau J, Liu YJ: The enigmatic plasmacytoid T cells develop into dendritic cells with interleukin (IL)-3 and CD40-ligand. J Exp Med 1997, 185:1101-1111[Abstract/Free Full Text]
-
Sabattini E, Bisgaard K, Ascani S, Poggi S, Piccioli M, Ceccarelli C, Pieri F, Fraternali-Orcioni G, Briskomatis A, Pileri SA: Envision Plus a new immunohistochemical method of choice for diagnostics and research. Critical comparison with the APAAP, ChemMate, CSA, LABC, and SABC techniques. J Clin Pathol 1998, 51:506-511[Abstract]
-
Pileri SA, Roncador G, Ceccarelli C, Piccioli M, Briskomatis A, Sabattini E, Ascani S, Santini D, Piccaluga PP, Leone O, Damiani S, Ercolessi C, Sandri F, Pieri F, Leoncini L, Falini B: Antigen retrieval techniques in immunohistochemistry: comparison among different methods. J Pathol 1997, 183:116-123[Medline]
-
Facchetti F, De Wolf-Peeters C, Van den Oord JJ, Meijer CJLM, Pals ST, Desmet VJ: Anti-high endothelial venule monoclonal antibody HECA-452 recognizes plasmacytoid T cells and delineates an "extranodular" compartment in the reactive lymph node. Immunol Lett 1989, 20:277-282[Medline]
-
Pileri SA, Ascani S, Piccioli M, Poggi S, Fraternali-Orcioni G, Sabattini E, Milani M, Falini B: Immunophenotyping of acute leukemias in paraffin sections: a powerful tool. Br J Haematol 1999, 105:394-401[Medline]
-
Breccia M, Petti MC, Fraternali-Orcioni G, Monarca B, Latagliata R, DElia GM, Mandelli F, Pileri SA: Granulocytic sarcoma with breast and skin presentation: a report of a case successfully treated by local radiation and systemic chemotherapy. Acta Haematol 2000, 104:34-37[Medline]
-
Pileri SA, Grogan TM, Harris NL, Weiss LM, Warnke RA, Chan JKC, Banks PM, Campo EG, Delsol G, De Wolf-Peeters C, Falini B, Dalla Favera R, Gascoyne RD, Gatter KC, Gaulard P, Issacson PG, Jaffe ES, Kluin P, Knowles DM, Mason DY, Mori S, Müller-Hermelink HK, Piris MA, Ralfkiaer E, Stein H, Su I-J: Tumors of histiocytes and accessory dendritic cells. A proposed classification from the International Lymphoma Study Group based on comprehensive evaluation of 61 cases. Histopathology, (in press)
-
Rondelli D, Lemoli RM, Ratta M, Fogli M, Re F, Curti A, Arpinati M, Tura S: Rapid induction of CD40 an a subset of granulocyte colony-stimulating factor-mobilized CD34(+) blood cells identifies myeloid committed progenitors and permits selection of nonimmunogenic CD40(-) progenitor cells. Blood 1999, 94:2293-2300[Abstract/Free Full Text]
-
Anderson MM, Requena JR, Crowley JR, Thorpe SR, Heinecke JW: The myeloperoxidase system of human phagocytes generates N
-(carboxymethyl)lysine on proteins: a mechanism for producing advanced glycation end products at sites of inflammation. J Clin Invest 1999, 104:103-113[Medline]
-
Lennert K: Malignant lymphomas other than Hodgkins disease. 1978:pp 31-33 Springer-Verlag, New York
-
Siegal FP, Kadowaki N, Shodell M, Fitzgerald Bocarsly PA, Shah K, Ho S, Antonenko S, Liu YJ: The nature of the principal type 1 interferon-producing cells in human blood. Science 1999, 284:1835-1837[Abstract/Free Full Text]
-
Sumiyoshi Y, Kikuchi M, Takeshita M, Ohshima K, Masuda Y: Alpha-interferon in Kikuchis disease. Virchows Arch B Cell Pathol 1991, 61:201-207[Medline]
-
Vallin H, Blomberg S, Alm GV, Cederblad B, Ronnblom L: Patients with systemic lupus erythematosus (SLE) have a circulating inducer of interferon-alpha (IFN-alpha) production acting on leucocytes resembling immature dendritic cells. Clin Exp Immunol 1999, 115:196-202[Medline]
-
Fitzgerald-Bocarsly P: Human natural interferon-
producing cells. Pharmac Ther 1993, 60:39-62[Medline]
-
Facchetti F, Vermi W, Fiorentini S, Chilosi M, Caruso A, Duse M, Notarangelo LD, Badolato R: Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions. Am J Pathol 1999, 154:145-152[Abstract/Free Full Text]
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