Double labeling immunohistologic and flow cytometric analysis of human B cells with particular reference to Leu-8 expression

Detection of B-cell monoclonality in fine needle aspiration by PCR analysis

Cytologic examination of fine-needle aspiration (FNA) sometimes fails to diagnose the malignant nature of B-cell proliferations. In this study we analyzed the Ig gene rearrangement of 49 FNA samples by polymerase chain reaction (PCR) in order to evaluate whether molecular analyses can improve the accuracy of FNA. Twenty-six patients had non-Hodgkin's lymphoma, 11 had reactive lymphoid diseases, 5 had chronic inflammation and 7 had carcinoma. A semi-nested PCR was performed using an oligoprimer specific for consensus sequences of the V regions (FR3A) and two oligoprimers derived from conserved sequences of the J regions (LJH and VLJH). Histologic examination always followed the molecular and cytologic analysis. The sensitivity of PCR and FNA morphological examination in detecting a neoplastic pattern was 92% and 78%, respectively. When samples were considered inadequate for cytologic examination, PCR always reached a diagnosis consistent with the histologic features. Our results demonstrate that PCR analysis of FNA specimens is a reliable and sensitive method capable of enhancing the diagnostic accuracy of cytologic examination.

Heparin Induces Apoptosis in Lymphocytes from B-cell Chronic Lymphocytic Leukemia

It has been shown that glycosaminoglycans play a role in the regulation of immune response. In particular, heparin exerts an antiproliferative and apoptotic action in different cellular systems. In this study we evaluate whether heparin can also induce a naturally occurring programmed cell death in lymphocytes from B-chronic lymphocytic leukemia (B-CLL), a neoplastic lineage where apoptosis is blocked by the expression of the proto-oncogene bc1-2. Peripheral blood lymphocytes (PBL) from 7 cases of B-CLL patients in different stages were cultured with three different heparin sodium concentrations for 4 days. Apoptosis was evaluated by agarose gel electrophoresis and by cytofluorimetric analysis. Bcl-2 expression was tested by flow cytometric analysis and immunohistochemistry on cytospin preparations. Agarose gel electrophoresis showed the characteristic DNA fragmentation pattern of apoptosis in all the cases of B-CLL stage III and IV after heparin incubation. DNA from normal and neoplastic lymphocytes cultured without heparin did not undergo spontaneous apoptosis. Cytofluorimetric analysis confirmed the agarose gel pattern and found a level of apoptosis over 50% after culture of neoplastic PBL with heparin. In these cases bcl-2 expression was found to be significantly reduced after heparin incubation when comparing to bcl-2 level before incubation. Our data adds further evidence regarding the potential role of heparin in oncogene inhibition and in apoptosis induction. In particular, the induction of apoptosis in neoplastic lymphocytes by heparin may have a role in the complicated field of interactions between the immune system and the blood vessels by glycosaminoglycans.

CD25-negative hairy cell leukaemia: intracytoplasmic detection of Tac antigen and interferon-induced surface expression

Hairy cell leukaemia (HCL) is a chronic lymphoproliferative disease of B-cell lineage. One of the peculiar immunophenotypic markers is the strong expression of the p55 chain of the interleukin-2 receptor (IL2R), recognized by anti-CD25 (or anti-Tac) monoclonal antibody. However, it is known that in rare cases CD25 may not be detectable, even when variant forms of HCL are excluded. The possibility has not been investigated that in these situations CD25 is present in the cytoplasm of the neoplastic cells. This paper describes a case in which the clinical, histological, and electron microscopic features were consistent with a typical HCL. Immunophenotype analysis showed the whole spectrum of markers of HCL, except for the expression of IL2R. The soluble form of the molecule was, however, increased in the patient's serum. Cytospin staining of the neoplastic B cells with anti-CD25 clearly demonstrated the presence of IL2R in the cytoplasm of hairy cells. When the cells were cultivated in vitro in the presence of interferon-alpha 2b, CD25 was detectable at the membrane level. These findings suggest that at least some cases of CD25-negative HCL may express cytoplasmic IL2R.

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Practical suggestions for successful immunoenzyme double-staining experiments

Many methodologies exist to perform an immunoenzyme double staining. Hence, the practical problem arises as to which of these methods is optimal for one's own experimental design. A process of selection is described which is derived from our own practical experience. First, a general strategy is outlined for the handling of tissue sections to be used for multiple staining methods. Secondly, the selection of an appropriate immunoenzyme double-staining concept is made using a flow chart. Thereafter we give criteria for the definitive selection of an immunoenzyme double-staining protocol based on the characteristics of the tissue or cell type under study. Particular attention is given to the selection of appropriate detection systems, applying enzymes or gold particles, and good contrasting colour combinations. The problems of visualizing co-localization using immunoenzyme double staining are dealt with, and suggestions are made to adapt the method, if necessary, in order to optimize it.

Histogenesis of diffuse small cleaved cell lymphoma. An immunohistochemical and molecular genetic (bcl-2 gene) study with comparison to follicular small cleaved cell lymphoma and mantle zone lymphoma

Immunohistochemical and molecular genetic (bcl-2 gene) studies were performed on specimens from 24 patients with follicular small cleaved cell lymphoma (FSCCL), 24 patients with diffuse small cleaved cell lymphoma (DSCCL) and 4 patients with mantle zone lymphoma (MZL) to determine the cellular origin of the disease and whether or not DSCCL represents the diffuse counterpart of FSCCL. Two patients with FSCCL, 22 patients with DSCCL, and all of the patients with MZL had a phenotype of mantle zone (MZ) B-lymphocytes (SIgD+, Leu-1+, Leu-8+, positive alkaline phosphatase [ALPase+], and negative common acute lymphoblastic leukemia antigen [CALLA-]), and all the tested patients (2 patients with FSCCL, 13 patients with DSCCL, and 4 patients with MZL) had germlines of bcl-2 gene. Fourteen patients with FSCCL and 1 patient with DSCCL had a phenotype of follicular center cells (FCC) (CALLA+, SIgD-, Leu-1-, Leu-8- and negative ALPase), and 11 patients with FSCCL had bcl-2 gene rearrangements. These results indicate that FSCCL are almost always derived from FCC, whereas some FSCCL, most DSCCL, and all MZL are derived from MZ B-lymphocytes, and these lymphomas should be included in the same category as MZ B-lymphocyte-derived lymphomas. Histologically diagnosed DSCCL often may represent a diffuse counterpart of MZ B-lymphocyte-derived lymphoma. MZ B-lymphocyte-derived lymphomas histologically show a follicular (nodular), a follicular MZ, or a diffuse growth pattern and clinically show a high incidence of peripheral blood (PB) involvement or bone marrow (BM) involvement.

Venular endothelium binding molecules CD44 and LECAM-1 in normal and malignant B-cell populations. A comparative study

Lymphocytes leave the blood via post-capillary venules by binding initially to their specialized endothelium. CD44 is a 80-90 kDa hyaluronate-binding glycoprotein involved in binding to endothelium of high endothelial venules (HEV). LECAM-1 is a 75-85 kDa glycoprotein with lectin activity interacting with human peripheral lymph node vascular addressin (PNAd) on HEV. This immunohistochemical study shows that CD44 and LECAM-1 are essentially coordinately expressed on B-lymphocytes. The mode and level of CD44/LECAM-1 expression dissect the peripheral B-cell development into stages that are closely linked to morphologically defined B-cell compartments. Although statistically correlated in B-cell leukaemias (p < 0.0009) and extranodal B-cell lymphomas (p < 0.003), expression of both molecules was less stringently coordinated in 127 B-cell neoplasms examined. B-cell chronic lymphocytic leukaemia, hairy cell leukaemia and mantle zone lymphoma were CD44/LECAM-1 positive, thus corresponding to their reactive counterparts. Correspondingly, follicular centre cell-derived lymphomas were devoid of both markers. Conversely, CD44 and LEC-AM-1 were infrequently detectable in extranodal malignant B-cell neoplasms, irrespective of their maturational state. Presence versus absence of CD44 and LECAM-1, alone or together, determined neither the leukaemic versus aleukaemic state nor the nodal versus extranodal tumour-forming phenotype of a B-cell tumour.

Primary cutaneous B-cell lymphoma: a unique type of low-grade lymphoma. Clinicopathologic and immunologic study of 83 cases

The clinical presentation and course, and the morphoimmunologic features of primary cutaneous B-cell lymphoma (CBCL) were investigated in a series of 83 patients. Fifty-one patients were male and 32 were female (male-to-female ratio of 1.6:1); CBCL primarily involved the elderly (median age, 58 years). A locoregional extension of the disease was quite frequent (86.7%). The neoplastic cells showed a range of appearances reminiscent of the whole spectrum of follicular/parafollicular cells. The antigenic phenotype of tumor cells (CD19+, CD20+, CD22+, CD28+, CD10-, CD5-, MB2+, CD74+/-, CDw75+/-, MT2+/-, surface immunoglobulin + monoclonal/-) plus the presence of admixed CD14- dendritic reticulum cells suggest a mantle-zone nature for CBCL. The nonaggressive clinical behavior with a substantial tendency to remain localized to a limited area of the skin, the quite good response to nonaggressive treatment, and the dichotomy existing between the enhancement of morphoimmunologic atypism--which parallels the increasing age and growth rate of lesions--and the constant benign overall prognosis on long-term follow-up make CBCL a unique type of lymphoma of low-grade malignancy. Proper recognition of CBCL is mandatory to avoid possible undertreatment or overtreatment of the patients affected.

Report of an unusual small lymphocytic B-cell lymphoma selectively involving the B-zone of lymph node

Selective involvement of the B-cell compartment of lymph node by B-cell malignant lymphomas is an occasional finding related to early phases of lymph node infiltration. The authors have observed a unique case of diffuse small lymphocytic lymphoma that consisted of immunohistologically and genotypically proven B-clonal population exhibiting a repetitive pattern of infiltration in three lymph node samples obtained from the patient during a 9-year period. This pattern consisted of a selective and complete replacement of the B-areas with disappearance of follicles and widening of the medullary cords, an expanded T-zone showing features consistent with dermatopathic lymphadenitis and well-preserved sinuses. Clinically, multiple involved sites at presentation (lymph nodes, spleen, skin, bone marrow, and peripheral blood) and during the 9-year follow-up (testis) were detected, and the disease was associated with a relative indolent course like other low-grade lymphomas. The phenotypic profile of lymphoma cells studied by immunoperoxidase method, and by single-labeling and double-labeling flow cytometric analyses (SIg+, K+, LN2+, MB1+, MB2+, HLA-DR+, CD 9+, CD19+, CD 20+, CD 21+, CD 22+, CD 24+, Leu 8+, CD 5-, CD 10-, CD 11b-, CD 11c-, CD 25-, CD 38-, PCA-1-, FMC-7-, CD 23-) was consistent with a B-cell proliferation at an intermediate stage of differentiation but distinct from other well-defined B-cell neoplasms. Whether such unique B-zone pattern was due to an intrinsic property of this lymphoma or it is to be related to the coexisting reactive T-zone expansion remains controversial.

Leu-8/TQ1 is the human equivalent of the Mel-14 lymph node homing receptor

The human pan-leukocyte antigen Leu-8 has attracted wide interest because its presence or absence identifies suppressor-inducer and helper-inducer CD4+ T-lymphocyte subsets respectively. We report here that Leu-8 is the human homologue of the mouse Mel-14 homing receptor, a molecule that promotes the initial adhesion of blood-borne lymphocytes to the specialized post-capillary endothelium of peripheral lymph nodes. We also show that Leu-8 can adopt both conventional and phospholipid anchored forms, a finding that may have relevance in the context of antigen shedding following activation or homing. The assignment of lymphocytes to different functional classes based on lymph node homing potential may represent a more general association between lymphocyte function and tissue distribution.