Coexpression of CD15 and CD20 by Reed-Sternberg cells in Hodgkin''s disease.

The immunophenotype of the Reed-Sternberg cells in Hodgkin's disease is heterogeneous among different cases; this heterogeneity has contributed to the continuing uncertainty regarding the normal counterpart of the Reed-Sternberg cell. In this study, the authors demonstrate coexpression of the B-cell marker, CD20, and the granulocyte associated antigen, CD15, by Reed-Sternberg cells in three of 20 cases of nodular sclerosis and mixed cellularity Hodgkin's disease using a double-labelling technique in one case and staining of serial sections in three cases. Additionally, the authors found that expression of CD20 occurred more often in tumors with a monomorphous proliferation of mononuclear and binucleate Hodgkin's and Reed-Sternberg cells, without numerous eosinophils or polymorphonuclear neutrophils. In contrast, expression of CD15 by Reed-Sternberg cells was associated with a greater granulocyte infiltrate. The presence or absence of fibrosis, plasma cells, and histiocytes did not correlate with antigen expression. These results suggest that there may be a continuum of antigen expression by Reed-Sternberg cells, with some cells expressing CD20, some CD15, and others expressing both antigens; cells coexpressing both CD15 and CD20 may represent an unstable intermediate in the process of antigen switching. The possibility that antigen expression by the neoplastic cells in a given case may modulate depending on the background infiltrate could explain the heterogeneity of immunophenotype among cases of Hodgkin's disease.     

Monoclonal antibodies reactive in routinely processed tissue sections of malignant lymphoma, with emphasis on T-cell lymphomas

The immunoreactivity of eight monoclonal antibodies was evaluated on 45 routinely processed lymphomas (22 T-cell lymphomas, 11 B-cell lymphomas, and 12 cases of Hodgkin's disease). Two antibodies reactive with leukocyte common (T200) antigens (PD7/26 and 2B11) stained most of the B- and T-cell lymphomas but did not stain the Reed-Sternberg cells and variants in Hodgkin's disease. Two antibodies known to stain B cells (LN-1 and LN-2) reacted with some of the B-cell lymphomas, but LN-2 also reacted with the neoplastic cells in six of 22 T-cell lymphomas and with the Reed-Sternberg variants in eight of 12 cases of Hodgkin's disease. The granulocyte antibody anti-Leu M1 reacted with most cases of Hodgkin's disease but also reacted with two of 11 B-cell non-Hodgkin's lymphomas. An antibody to epithelial membrane antigen (anti-EMA) stained some cases of T-cell lymphoma, B-cell lymphoma, and Hodgkin's disease. Leu 7 was expressed in one T-cell lymphoma and in one case of Hodgkin's disease. A novel antibody reactive with T cells (L60) stained all cases of T-cell lymphoma but also stained some cases of B-cell lymphoma and one case of Hodgkin's disease. We conclude that none of these antibodies, when used alone on routinely fixed paraffin-embedded material, is completely sensitive and specific for T-cell lymphoma, B-cell lymphoma, or Hodgkin's disease. However, a panel of antibodies is useful in distinguishing Hodgkin's disease from non-Hodgkin's lymphoma and in suggesting the B- or T-cell phenotype of non-Hodgkin's lymphomas.     

Expression of vimentin and epithelial membrane antigen in human malignant lymphomas

Immunoreactivity with monoclonal antibodies against the intermediate filament protein, vimentin, and epithelial membrane antigen (EMA) was examined in 330 cases of lymphoma (317 non-Hodgkin's and 13 Hodgkin's lymphomas), 12 reactive lymph nodes and mononuclear cells of the peripheral blood using either indirect immunoperoxidase staining or the avidin-biotin immunoperoxidase complex technique. The cell origin of each tumor was established using a panel of monoclonal antibodies against lymphocyte differentiation antigens. There were 41 T-cell, 247 B-cell and 29 undetermined lymphomas, and 13 cases of Hodgkin's disease in the series. Vimentin was expressed in 24 T-cell lymphomas (58.5%) and 60 B-cell lymphomas (24.2%). This difference in frequency was statistically significant. Vimentin expression in follicular lymphomas was less frequent than in diffuse B-cell lymphomas. In diffuse lymphomas, small and medium cell types were more reactive with anti-vimentin than large cell types. Reed-Sternberg cells (R-S cells) in Hodgkin's disease were positive for vimentin in 11 cases (84.6%). The frequency of EMA reactivity in lymphomas was low, particularly in T-cell lymphomas. No positive cases were found among follicular lymphomas. In diffuse non-Hodgkin's lymphomas, EMA was expressed only in mixed and large cell types, but never in smaller ones. In conclusion, monoclonal antibodies against vimentin and EMA appear to be of limited usefulness for the diagnosis of non-Hodgkin's lymphomas, but anti-vimentin antibody may be used as an adjunct to the diagnosis of R-S cells in Hodgkin's disease.     

Rare expression of T-cell markers in classical Hodgkin's lymphoma.

Hodgkin's and Reed-Sternberg cells of classical Hodgkin's lymphoma are primarily of B-cell origin, although there are instances of T-cell antigen expression suggesting T-cell origin. We comprehensively analyzed expression of various T-cell antigens in 259 classical Hodgkin's lymphoma cases using the tissue microarray technique. Expression of the T-cell antigens CD2, CD3, CD4, CD5, CD7 and CD8 was assessed by immunohistochemistry. Hodgkin's and Reed-Sternberg cells of T-cell marker-positive cases were microdissected and analyzed by a multiplex polymerase chain reaction for clonal immunoglobulin heavy chain- and T-cell receptor gamma gene rearrangements. In all, 12 cases (5%) expressed at least one T-cell marker in the following order: CD2 in 11 cases, CD4 in five, CD3 in two, and CD5 and CD8 in one case each; there were no CD7-positive cases, and five cases (2%) expressed more than one T-cell antigen. In positive cases, a mean fraction of 40% of the Hodgkin's and Reed-Sternberg cells (range 20-100%) expressed the analyzed T-cell markers. Two cases (<1%) evidenced clonal T-cell receptor gamma gene rearrangement. Phenotypic expression of T-cell antigens in Hodgkin's and Reed-Sternberg cells of classical Hodgkin's lymphoma is rare (5%), while genotypically, less than 1% of classical Hodgkin's lymphomas are of possible T-cell origin. Therefore, T-cell antigen expression on Hodgkin's and Reed-Sternberg cells is aberrant in the majority of cases and only infrequently classical Hodgkin's lymphomas are of T-cell origin.     

Cadherins in reactive lymph nodes and lymphomas: high expression in anaplastic large cell lymphomas

Using a polyclonal pan-cadherin antibody and a monoclonal E-cadherin antibody (HECD-1) we have investigated cadherin expression in lymphomas and reactive lymph nodes. Routinely processed tissue from nine reactive lymph nodes and 48 lymphomas (six T-cell, six high-grade B-cell, 15 low-grade B-cell, 13 anaplastic large cell and eight Hodgkin's disease) were immunostained. The reactive cases showed pan-cadherin membrane associated staining of endothelium and epithelioid granulomas. No staining of lymphoid cells was seen. Pan-cadherin immunostaining was present in three of six T-cell lymphomas, two of six high-grade B-cell lymphomas, 12 of 13 anaplastic large cell lymphomas and three of eight cases of Hodgkin's disease. No staining of low-grade B-cell lymphomas was identified with the pan-cadherin antibody. E-cadherin was not detected in any of the lymphomas that showed pan-cadherin expression. The frequent and strongest cadherin expression in anaplastic large cell is noteworthy. The tumour cells of this lymphoma subtype are characterized by copious cytoplasm and a cohesive appearance, features which impart a superficial resemblance to carcinoma cells. Since cadherin molecules are known to have major morpho-regulatory functions our data suggests that the expression of cadherin molecules by anaplastic large cell lymphomas may play an important role in determining their characteristic epithelioid phenotype.     

Expression of B-cell antigens by Hodgkin''s and Reed-Sternberg cells.

Twenty frozen and 55 paraffin sections of lymphnode specimens from 55 patients with pretreatment Hodgkin's disease (nodular sclerosis Hodgkin's disease, n = 45; mixed cellularity Hodgkin's disease, n = 10) were studied by immunohistochemistry and molecular analysis to determine the phenotype of Hodgkin's and Reed-Sternberg cells (HRS). In all cases the HRS cells were CD45-, and CD30+, and in 43/55 (78%) cases they were CD15+. In 48/55 cases (87%) HRS cells were reactive with at least one B-cell marker (CD19, CD20, CD22, CDw75, MB2), 8/55 cases (14.5%) showed reactivity (mainly cytoplasmic) of a subpopulation of HRS cells with the T-cell markers CD3 and beta F1. All cases that expressed T-cell antigens were also reactive with at least one B-cell marker. In frozen sections, a minority of HRS cells in each case studied showed cytoplasmic positivity for bcl-2 protein. Rearrangement of immunoglobulin heavy chain genes was detected in one case and of T-cell receptor beta chain genes in none. The authors were unable to confirm previous reports of bcl-2 gene rearrangement in Hodgkin's disease. The results strongly support a B lymphocytic origin of HRS cells.     

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma: a clonal T-cell lymphoproliferative disorder with indolent behavior.

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma, a provisional entity in the 2005 WHO-EORTC classification for cutaneous lymphomas, is not well characterized. Fifteen cases meeting the definition of this entity were identified. Fourteen represented solitary lesions on the head/neck (n=9), upper extremity (n=4), or trunk (n=1). One patient presented with multiple lesions on the trunk and extremities. Histologically, the infiltrate showed a nodular pattern in the dermis and subcutis without epidermotropism, and had a polymorphous composition with a predominance of small to medium-sized CD4-positive T cells. Most cases showed normal T-cell antigen expression; diminished/absent expression of CD7 was seen in three cases and CD2 expression was absent in one case. All cases showed a notable reactive infiltrate including frequent B cells, plasma cells, and histiocytes. Clonal TCR gene rearrangements were detected in each case. No clonal Ig gene rearrangements were detected. Out of the 11 patients with follow-up, none showed systemic disease. The majority resolved without relapse, one without treatment, four with excision, and four with radiation therapy. One patient developed local recurrence. The patient with multiple lesions had disease progression despite chemotherapy and stem cell transplant. These cases highlight the polymorphous histology and prominent reactive B-cell component of this entity. Diagnosis requires molecular genetic analysis, as prominent cytologic atypia and immunophenotypic aberrancy are rare. The differential diagnosis includes reactive lymphoid hyperplasia, mycosis fungoides and cutaneous B-cell lymphomas. In patients with isolated cutaneous lesions, the indolent behavior of this rare T-cell neoplasm should be recognized to avoid unnecessary treatment.     

Distribution of lymphocytes with interleukin-2 receptors (TAC antigens) in reactive lymphoproliferative processes, Hodgkin''s disease, and non-Hodgkin''s lymphomas. An immunohistologic study of 300 cases.

The authors investigated the distribution of interleukin-2 receptors (TAC antigen) in the lymph nodes of 300 patients with lymphoproliferative disorders. They used fresh-frozen sections to evaluate a possible correlation between the immunophenotype of specific lymphoid disorders and the presence or absence of TAC expression and to determine whether the TAC positivity of lymphoid cells contributes to the characterization of lymphoproliferative processes. All of the cases had previously been studied with a large screening panel of monoclonal antibodies and polyclonal antisera. Among 85 patients with a variety of benign reactive processes, the lymph nodes from 47 contained TAC-bearing lymphocytes in various patterns of distribution. Of 41 patients with Hodgkin's disease, 37 had TAC-bearing lymphocytes. Of 26 B-cell, well-differentiated lymphocytic lymphomas (WDL), 14 were diffusely TAC-positive and one had TAC-bearing cells in random distribution. Six cases of intermediate lymphocytic lymphoma were also studied, and three showed randomly distributed TAC-bearing lymphocytes. Of 19 patients with follicular or follicular and diffuse, poorly differentiated lymphocytic (PDL) lymphoma, 14 were TAC-positive. All 3 diffuse PDL lymphomas studied were TAC-negative. Among 23 cases of B-cell and 5 cases of T-cell mixed cell lymphoma, 15 and three, respectively, had TAC-positive lymphocytes. Of 39 large cell lymphomas (B-cell, 33; T-cell, 6), 14 were TAC-positive. All 13 cases of hairy cell leukemia were diffusely positive. Of 23 T-lymphoblastic lymphomas, only 1 showed positive TAC reactivity, which was focal. Of 5 cases of cutaneous T-cell lymphoma, 2 had TAC-bearing lymphocytes. Our study indicates that the TAC antigen is not lineage-specific, and that it may be expressed by lymphoid cells regardless of their phenotype.     

IL-2 receptor expression in human lymphoid lesions. Immunohistochemical study of 166 cases.

Interleukin-2 (IL-2) receptor expression is a feature of T-cell activation and T-cell neoplasia. Expression of the IL-2 receptor in human lymphoid lesions was studied in a series of 166 immunophenotyped cases, including nodal and extranodal reactive lymphoid proliferations (44 cases), low-grade B-cell lymphomas (27 cases), intermediate and high grade B cell lymphomas (42 cases), peripheral T-cell lymphomas (13 cases), Hodgkin's disease (12 cases), histiocytic proliferations (15 cases), nonhematopoietic tumors (16 cases), and miscellaneous lesions (7 cases). Low levels of receptor expression were seen in reactive lymphoid lesions, low-grade B-cell lymphomas, and nonhematopoietic tumors (20%, 7%, and 25% of cases, respectively, with greater than 10% positive cells). High levels of receptor expression were seen in cases of peripheral T-cell lymphoma and histiocytic proliferations (86% and 100% of cases, respectively, with greater than 10% positive cells). Intermediate levels of expression were seen in Hodgkin's disease (including Reed-Sternberg cells) and some cases of intermediate and high-grade B-cell lymphomas (58% and 50% of cases, respectively, with greater than 10% positive cells). IL-2 receptor expression is not confined to T-cell neoplasia, but is also a feature of neoplastic and nonneoplastic histiocytic proliferations, Hodgkin's disease, and some intermediate and high-grade B-cell lymphomas. Biologic and therapeutic implications are discussed.     

Expression of Vimentin and Epithelial Membrane Antigen in Human Malignant Lymphomas

Immunoreactivity with monoclonal antibodies against the intermediate filament protein, vimentin, and epithelial membrane antigen (EMA) was examined in 330 cases of lymphoma (317 non-Hodgkin's and 13 Hodgkin's lymphomas), 12 reactive lymph nodes and mononuclear cells of the peripheral blood using either indirect immunoperox-idase staining or the avidin-biotin immunoperoxidase complex technique. The cell origin of each tumor was established using a panel of monoclonal antibodies against lymphocyte differentiation antigens. There were 41 T cell, 247 B cell and 29 undetermined lymphomas, and 13 cases of Hodgkin's disease in the series. Vimentin was expressed in 24 T-cell lymphomas (58.5%) and 60 B cell lymphomas (24.2%). This difference in frequency was statistically significant. Vimentin expression in follicular lymphomas was less frequent than in diffuse B-cell lymphomas. In diffuse lymphomas, small and medium cell types were more reactive with anti-vimentin than large cell types. Reed-Sternberg cells (R-S cells) in Hodgkin's disease were positive for vimentin in 11 cases (84.6%). The frequency of EMA reactivity in lymphomas was low, particularly in T cell lymphomas. No positive cases were found among follicular lymphomas. In diffuse non Hodgkin's lymphomas, EMA was expressed only in mixed and large cell types, but never in smaller ones. In conclusion, monoclonal antibodies against vimentin and EMA appear to be of limited usefulness for the diagnosis of non Hodgkin's lymphomas, but anti vimentin antibody may be used as an adjunct to the diagnosis of R-S cells in Hodgkin's disease.     

CD 30 expression in follicular lymphoma

The CD30 antigen is a characteristic phenotypic feature of Sternberg-Reed and Hodgkin cells and is also found in a subset of large cell non-Hodgkin's lymphomas. The finding of CD30 positive cells in some centroblastic/centrocytic (cb/cc) follicular lymphomas prompted us to characterize the presence and distribution of CD30 positive cells in this type of lymphoma, using the monoclonal antibody BerH2. CD30 positive cells were present in 17/19 of the cases studied, located mainly at the edge of the neoplastic follicles, but also in some cases in perinodular or T-cell areas. This distribution resembles that found in reactive tonsils and lymph nodes. The majority of these CD30 positive cells in cb/cc lymphoma seem to be B-cells, as suggested by their reactivity with B-cell markers demonstrated by double immunostaining. The nature of these CD30 positive cells is unclear, but they should be taken into consideration in the differential diagnosis of cb/cc lymphoma with lymphocyte predominance Hodgkin's disease.     

T-cell/histiocyte-rich large B-cell lymphoma is a disseminated aggressive neoplasm: differential diagnosis from Hodgkin's lymphoma

AIMS: An accurate diagnosis of T-cell/histiocyte-rich large B-cell lymphoma needs to take into consideration those forms of Hodgkin's lymphoma also characterized by a predominance of small lymphocytes and histiocytes, i.e. nodular lymphocyte predominance Hodgkin's lymphoma and lymphocyte-rich classical Hodgkin's lymphoma. We have studied the clinical, phenotypic and genetic features of a series of 12 cases of T-cell/histiocyte-rich large B-cell lymphoma along with 18 cases of Hodgkin's lymphoma for comparative purposes. METHODS AND RESULTS: Of the Hodgkin's lymphoma cases, there were 11 lymphocyte predominance type and seven classic type. T-cell/histiocyte-rich large B-cell lymphomas presented usually in advanced stages (III or IV in 11/12 cases), frequently with 'B' symptoms (6/9 cases), and followed a more aggressive course than Hodgkin's lymphoma (4/8 patients died due to the tumour in T-cell/histiocyte-rich large B-cell lymphoma versus 0/15 in Hodgkin's lymphoma). T-cell/histiocyte-rich large B-cell lymphoma cases showed diffuse effacement of the nodal architecture by a proliferation of scattered large atypical B-cells obscured by a background of small T-lymphocytes (more CD8+, TIA1+ than CD57+). Five cases showed also a prominent histiocytic component. The large B-cells expressed CD45 and often EMA (6/10 cases). On the other hand, CD 30, CD15 and latent infection by Epstein-Barr virus (EBV) were generally lacking. bc l6 and CD10 were, respectively, detected in 6/6 and 1/5 cases. Conventional polymerase chain reaction (PCR) showed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements in all T-cell/histiocyte-rich large B-cell lymphomas studied (5/5), but did not detect any case with t(14;18) involving the major breakpoint region (0/4). CONCLUSIONS: The differential diagnosis of T-cell/histiocyte-rich large B-cell lymphoma from Hodgkin's lymphoma is facilitated by the integration of different immunophenotypic, molecular and clinical findings. T-cell/histiocyte-rich large B-cell lymphoma is a monoclonal neoplasm of bc l6+ B-cells with a phenotypic profile similar to lymphocyte predominance Hodgkin's lymphoma, suggesting a germinal centre origin and a possible relation to this disease. Therefore, in order to distinguish it from lymphocyte predominance Hodgkin's lymphoma, characterization of the reactive background, IgH gene rearrangement studies by conventional PCR and clinical features are more useful. In contrast, T-cell/histiocyte-rich large B-cell lymphoma can be distinguished from classical Hodgkin's lymphoma thanks to the presence of monoclonal IgH rearrangement and the CD 30-CD15-CD45+EMA+ immunophenotypic profile of the neoplastic cells in T-cell/histiocyte-rich large B-cell lymphoma.     

Expression of lymphoid-associated antigens on Hodgkin''s and Reed-Sternberg cells of Hodgkin''s disease. An immunocytochemical study on lymph node cytospins using monoclonal antibodies

The aim of this study was to elucidate the origin of Hodgkin's and Reed-Sternberg cells. Lymph node cytospins and frozen sections from 20 cases of Hodgkin's disease of different histological subtypes were immunostained by the immuno-alkaline phosphatase technique using a panel of monoclonal antibodies. As expected, the Hodgkin's and Reed-Sternberg cells of all cases were positive for the CD30 (Ki-1), CD15 (hapten X) and CD25 (Tac) antigens. In eight cases, a variable percentage of typical Hodgkin's and Reed-Sternberg cells showed a clear-cut cytoplasmic and/or surface positivity for the T-cell-associated antigens CD3, CD5, CD6 and CD4 (seven cases) or CD8 (one case), but consistently lacked B-cell and macrophage-associated markers. The best visualization of T-cell antigens was obtained in cytocentrifuge preparations and in areas of lymph node frozen sections that had been infiltrated by clusters of Hodgkin's and Reed-Sternberg cells. In two cases of Hodgkin's disease (nodular sclerosis, mixed cellularity) the neoplastic cells weakly expressed the B-cell antigens CD19 and CD22, but not T-cell or macrophage-associated markers. In 10 cases, Hodgkin's and Reed-Sternberg cells were negative for all the lymphoid- and macrophage-associated antigens. These results suggest a lymphoid (either T or B) rather than histiocytic origin for the Hodgkin's and Reed-Sternberg cells in a number of Hodgkin's disease cases.     

Expression of CD95 antigen and Bcl-2 protein in non-Hodgkin's lymphomas and Hodgkin's disease.

CD95 (APO-1/Fas) is a member of the superfamily that includes the nerve growth factor and tumor necrosis factor receptors, OX40, CD27, CD30, and CD40. Present on a minority of resting blood lymphocytes, CD95 expression is upregulated on activated T and B lymphocytes and natural killer cells, where binding of the antigen by anti-Fas and anti-APO-1 antibodies has been shown to induce apoptosis. This CD95-mediated apoptosis is at least partially inhibited by expression of the Bcl-2 protooncogene. To evaluate possible roles of CD95 and Bcl-2 in growth regulation of lymphoid neoplasms, we studied by immunohistochemistry the expression of CD95 and Bcl-2 in 67 B- and 5 T-cell lymphomas, and 10 cases of Hodgkin's disease. In all, 29 B and 2 T cell lymphomas, and 9 cases of Hodgkin's disease expressed CD95. Compared with diffuse large B-cell and Burkitt-like lymphomas, lowgrade B-cell lymphomas more frequently expressed CD95 (52% versus 26%; P < .005). None of the B-cell small lymphocytic lymphomas or mantle cell lymphomas expressed CD95, whereas the majority of follicle center lymphomas, extranodal marginal zone B-cell lymphomas, and immunocytomas were CD95+. Of the 29 CD95+ B-cell lymphomas, only 33% of the high-grade group coexpressed Bcl-2, compared with 87% of the low-grade group (P < .04). Two of three peripheral T-cell lymphomas--including one anaplastic large cell lymphoma--expressed CD95. Staining for CD95 was seen in 9 of 10 cases of Hodgkin's disease. The infrequent expression of CD95 in high-grade B-cell lymphomas suggests an association between loss of CD95 expression/function and a more aggressive tumor grade. Whereas frequent coexpression of Bcl-2 with CD95 may protect low-grade B-cell lymphomas against CD95-mediated apoptosis, in the high-grade group such coexpression is infrequent, and other regulators besides Bcl-2 may be involved in modulating the apoptosis signal delivered by CD95.     

流式细胞术在抗原异常表达淋巴瘤/白血病诊断中的应用

目的 探讨流式细胞免疫分型在抗原异常表达淋巴瘤诊断及鉴别诊断中的作用。方法 应用流式细胞术对伴有抗原异常表达的淋巴瘤3例,B淋巴细胞性白血病8例,T淋巴细胞性白血病1例及伴有淋巴细胞分化抗原表达的急性非淋巴细胞白血病17例,急性粒细胞白血病累及淋巴结1例的免疫表型进行回顾性分析,每例均作胞质CD3ε、CD79a、髓过氧化物酶(MP0)的En Vision两步法染色。结果 11例B细胞淋巴瘤／白血病胞质CD79a阳性,胞质CD3ε及MP0阴性,其中5例伴CD5表达,2例同时伴CD5及1-2项髓系分化抗原表达;1例T淋巴细胞白血病胞质CD3ε阳性,胞质CD79a及MP0阴性,伴CD13、CD33表达;18例急性非淋巴细胞白血病(包括1例急性粒细胞白血病累及淋巴结)胞质髓过氧化物酶(MP0)均阳性,胞质CD3ε及C1979a均阴性,其中8例(包括1例急性粒细胞白血病累及淋巴结)伴T细胞分化抗原表达,8例伴B细胞分化抗原表达,2例同时伴T细胞及B细胞分化抗原表达。结论流式细胞免疫分型不仅能发现淋巴瘤／白血病抗原异常的表达,而且可通过表面免疫标记及胞质CD3s、CD79a、MP0的表达来确定抗原异常表达淋巴瘤／白血病的细胞来源,对抗原异常表达淋巴瘤／白血病的诊断及鉴别诊断具有十分重要价值。     

The expression of the B-cell marker mb-1 (CD79a) in Hodgkin's disease

Recent evidence indicates that membrane-bound immunoglobulin on B lymphocytes is associated with a molecule which comprises the products of the mb-1 and B29 genes. This molecule is a highly specific marker for B-cells, presumably because of its central functional role in antigen triggering, and has recently been clustered as CD79a at the 5th Leucocyte Workshop. Recently there has been controversy surrounding reports of B-cell antigen expression by Reed–Sternberg and related cells, and we have therefore studied 108 cases of Hodgkin's disease immunohistochemically using a novel antibody which detects mb-1 protein in paraffin sections. The results were compared with those achieved using antibody L26 to detect CD20. The mb-1 protein was present in the neoplastic cells in all 14 cases of lymphocyte predominance Hodgkin's disease studied, and CD20 immunoreactivity was also found in seven of the eight cases of this subtype studied. Of the non-lymphocyte predominance cases, 20% (19/94) expressed mb-1 and 30% (20/67) CD20 in the Reed–Sternberg cells, but the cells positive for either of these two markers usually constituted only a very small proportion of the neoplastic population. However, in occasional cases (one of 94 for mb-1 and five of 67 for CD20), more than 50% of the neoplastic cells expressed one or both B-cell antigens. These results confirm the B-cell origin of the neoplastic cells in lymphocyte predominance Hodgkin's disease, but they also indicate that, contrary to our previous study, mb-1 expression may occasionally be found in what appears, on histological grounds, to be other types of Hodgkin's disease.     

CNA.42, a new monoclonal antibody directed against a fixative-resistant antigen of follicular dendritic reticulum cells.

A new monoclonal antibody (MAb), CNA.42, was generated using the CEM T-cell line. It recognizes a 120-kd formalin-resistant glycosylated antigen that is mainly expressed by follicular dendritic reticulum cells (FDRCs). This antigen is also expressed by a few mononuclear cells in the paracortical area of reactive lymph nodes and by some cortical thymocytes. Two hundred and eighty-nine cases of hematopoietic tumors of various types were tested with this antibody. They showed either intact FDRC networks or FDRC networks dispersed among malignant cells. In follicular lymphomas, the follicular pattern was highlighted by CNA.42 MAb. Expanded FDRC networks were found in angioimmunoblastic T-cell lymphomas. Neoplastic cells were positive in 43.6% (24/55) of T-cell and 4.6% (6/129) of B-cell lymphomas. The highest percentage of cases with positive neoplastic cells was found in anaplastic large-cell lymphomas (62.5%; 15/24). In Hodgkin's disease, FDRC networks, sometimes encasing Hodgkin and Reed-Sternberg (HRS) cells, were found. HRS cells were also stained by this antibody in 23 (21.9%) of the 105 cases examined. A variety of normal nonlymphoid tissues and nonhematopoietic tumors, such as some neurogenic tumors, carcinoma, and occasional sarcomas, were found to be positive. Analysis of the reactivity of CNA.42 antibody with FDRCs of lymphoid tissue from different animal species showed similar reactivity to that observed in humans, suggesting widespread evolutionary conservation of the antigen recognized by this antibody. In daily diagnostic practice, CNA.42 MAb seems to be a suitable FDRC marker and possibly has an auxiliary role in recognizing T-cell lymphomas.     

Paraffin section immunohistochemistry. II. Hodgkin''s disease and large cell anaplastic (Ki1) lymphoma

A panel of antibodies that recognize antigens that survive fixation and conventional processing have been applied to 43 cases of Hodgkin's disease and five cases of large cell anaplastic lymphoma. Reed-Sternberg cells in all five cases of nodular lymphocyte predominance Hodgkin's disease were positive with leucocyte common (CD45) and B-cell antibodies, and negative with LeuM1 (CD15) and BerH2 (CD30) antibodies. In other types of Hodgkin's disease, Reed-Sternberg cells were positive with BerH2 in all cases, positive with LeuM1 in 63% of cases (with enzymic predigestion), positive with at least one B-cell antibody in 29% of cases and positive for CD45 in 8% of cases. In 19% of all cases, Reed-Sternberg cells were positive for epithelial membrane antigen and in 93% they were positive with TAL1B5 (anti-class II MHC). No case showed immunoreactivity with anti-T-cell antibodies. The patterns of immunoreactivity of large cell anaplastic lymphoma were similar, except that none was positive with B-cell antibodies and three were positive with T-cell antibodies. All five were positive with BerH2 (CD30) and TAL1B5. Comparison of the results with those seen in other cases of non-Hodgkin's lymphoma indicates that, with the currently available reagents, this immunohistological profile cannot be used as the sole diagnostic discriminant of these conditions; this must still be based upon careful morphological assessment.