Patterns of Ganglioside Expression in B Cell Neoplasms

Twenty seven B cell neoplasms were examined by high performance thin layer chromatography (HPTLC) and immune thin layer chromatography (ITLC) to determine ganglioside expression. Patterns of expression in the cells were compared with conventional morphology, genotype, and glycoprotein immunophenotype. Patterns of ganglioside expression were found for each of the tumor types analyzed (5 acute lymphoblastic lymphomas (ALL), 5 Burkitt's Lymphomas (BL), 4 chronic lymphocytic leukemias (CLL), 3 diffuse poorly differentiated lymphomas (DPDL), 7 diffuse histiocytic lymphomas (DHL), and 3 multiple myelomas (MM). GM3 was the predominant ganglioside found in all B cell neoplasms except multiple myeloma where GM2 was equivalent to GM3. GM1 was detected by ITLC in all B cell tumors, but significant amounts were found by HPTLC only in ALL, CLL, and DHL. Small amounts of GD3 and GD2 were found in several B cell neoplasms. Significant amounts of other gangliosides were not found. The expression of GM2 on the MM cell lines, a cell type derived from outside of the nervous system, is unusual. This high level of expression was also seen in metabolic labeling studies. GM2 was readily detectable in the SKMM1 human multiple myeloma cell line by flow cytometry and served as a target for human complement-mediated cytotoxicity. Although the functions of gangliosides are largely unknown, the patterns of gangliosides found for this system of human B cell malignancies may serve to provide targets for specific immunotherapy and clues to their functions.     

Richter's and prolymphocytic transformation of chronic lymphocytic leukemia are associated with high mRNA expression of activation-induced cytidine deaminase and aberrant somatic hypermutation.

Chronic lymphocytic leukemia (CLL) is an indolent B-cell non-Hodgkin's lymphoma that may transform into higher-grade lymphoma. The transformation involves an increased number of prolymphocytic cells, termed prolymphocytic transformation (PLT) or the development of diffuse large B-cell lymphoma (DLBL), also referred to as Richter's transformation (RT). To analyze whether activation-induced cytidine deaminase (AID), which is essential for somatic hypermutation (SHM) of normal B-cells, and malfunction of SHM termed aberrant somatic hypermutation (ASHM) are associated with higher-grade transformation of CLL, AID mRNA expression and the mutation pattern of c-MYC, PAX-5 and RhoH genes were analyzed in eight cases of CLL without transformation and in 21 cases that showed RT or PLT. Chronic lymphocytic leukemia cases, which showed no transformation or eventually transformed into higher-grade lymphoma, showed low levels of AID mRNA expression and low frequency of mutations of c-MYC, PAX-5 and RhoH genes. In both RT and PLT, high-levels of AID mRNA expression and high-frequency mutations of c-MYC, PAX-5 and RhoH genes were detected. These results indicate that AID expression and ASHM are associated with higher-grade transformation of CLL and provide further evidences that AID expression and ASHM may be activated during the clonal history of B-cell lymphomas.     

Detection of 14q32.33 translocation and t(11;14) in interphase nuclei of chronic B-cell leukemia/lymphomas by in situ hybridization

Abnormalities of chromosome 14 involving band q32.33 are among the most commonly observed cytogenetic alterations in B-cell malignancies. To assess the incidence and pathogenetic implications of 14q32.33 translocation in chronic B-cell leukemia/lymphomas, we performed fluorescence in situ hybridization (FISH) analysis with variable region (V_H) and gamma constant region (Cγ) gene probes in 37 patients with these disorders. Chromosome 14q32.33 translocation was detected in 2 of 18 patients with chronic lymphocytic leukemia (CLL), 1 of 2 with CLL of mixed cell types (CLL/PL), 1 of 2 with pro-lymphocytic leukemia (PLL), 5 of 6 with leukemic mantle-cell lymphoma (MCL), 2 of 7 with splenic B-cell leukemia/lymphoma of possible marginal zone origin (SBLL) and 2 with leukemic follicular lymphoma (FL). To further characterize 14q32.33 translocations in these patients, we developed a new procedure using double-color FISH with PRAD1, BCL2, V_H and Cγ gene probes. Chromosome t(11;14) was detected in 1 patient with CLL/PL, 1 with PLL and 5 with MCL. Chromosome t(14;18) was detected in 2 patients with FL. In a PLL patient with t(11;14), the cosmid CPP29 containing the PRAD1 gene and its 5′-flanking region split and co-localized with both Cγ and V_H gene probes, thus spanning the breakpoint. In CLL and SBLL patients, donor chromosomes were other than chromosomes 2, 11, 18 and 19, suggesting the involvement of a novel oncogene(s) in the pathogenesis of these diseases. Interphase FISH rapidly detected 14q32.33 translocation, t(11;14) and t(14;18) in B-cell malignancies with low mitotic activity at the single-cell level, facilitating the correlation of the molecular features of these translocations with clinical characteristics. Int. J. Cancer 72:31–38, 1997. © 1997 Wiley-Liss Inc.     

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma With Secondary Acquisition of t(11;14)(q13;q32)/CCND1-IGH: A Rare Variant Of Richter Transformation to Mantle Cell Lymphoma

IntroductionChronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) occasionally undergoes Richter transformation, mostly to diffuse large B-cell lymphoma, but its evolution to other types of B-cell lymphoma is rare. We report a CLL evolved to mantle cell lymphoma by acquiring t(11;14)(q13;q32); CCND1-IGH.MethodA Retrospective review of clinical and laboratory data.ResultsA 39-year-old male patient was diagnosed with CLL/SLL, and was initially followed without specific treatment, but subsequently received chlorambucil/fludarabine/rituximab due to exacerbated lymphocytosis. While his CLL/SLL waned and waxed, the immunophenotype and genotype of neoplastic B-cells remained unchanged, without cyclin D1 expression and CCND1-IGH fusion. Eleven years after the diagnosis, the patient's disease showed evidence of progression. Bone marrow examination demonstrated “CLL” with the morphology and immunophenotype similar to those seen in the previous biopsies. Unexpectedly, the neoplastic B-cells demonstrated cyclin D1 expression and harbored t(11;14)(q13;q32); CCND1-IGH, suggesting a clonal evolution to mantle cell lymphoma. He subsequently received cytoreductive chemotherapy followed by allogenic bone marrow transplant and remained in remission since then.ConclusionThe retention of immunophenotype suggests a clonal relationship between CLL/SLL and mantle cell lymphoma. While the acquisition of t(11;14)(q13;q32); CCND1-IGH likely alters the disease course, the pathogenesis of this illegitimate translocation in CLL remains to be studied.     

Chromosome abnormalities in malignant lymphoma in patients from Kurashiki: histological and immunophenotypic correlations

Clonal chromosomal abnormalities were found in tumor tissue of 43 (84%) of 51 patients with non-Hodgkin's lymphoma (B-cell, 32; T-cell, 15) from an adult T-cell leukemia/lymphoma-nonendemic area in western mainland Japan. Four tumors were tetraploid, and the other 39 had a chromosome number in the diploid range. Trisomies 3, 5, 7, 18, and X, monosomy 13, and loss of an X in female and a Y in male were found in more than three patients each. Structural abnormalities in arms 1p, 1q, 2q, 3q, 13q, 14q, and 18q were found in eight or more patients each. Clustering of breaks occurred in 3q25-29 (ten patients, nine of whom with a B-cell tumor), 11q13 (five patients), dir dup(12)(q13-15----q21-24) (four patients), 14q32 (12 patients), and 18q21 (seven patients). The 14q32 translocations were all associated with B-cell tumors. t(8;14) was seen in a small noncleaved cell lymphoma, t(11;14)(q13;q32) in one follicular and three intermediately differentiated lymphocytic lymphomas, and t(14;18)(q32;q21) in two follicular lymphomas and one diffuse small cleaved cell tumor. The translocation partner of 14q could not be determined in the other four patients, three of whom had der(18)t(18;?)(q21;?). The seven 18q21 abnormalities, including a novel translocation t(2;18)(p11;q21.3), all occurred in B-cell tumors; even in the absence of t(14;18), they were closely associated with lymphomas of follicular center cell origin (six of seven).     

Cytoplasmic IgM in leukemic B cells by flow cytometry

The presence of intracellular cytoplasmic immunoglobulin M (IgM) in leukemic cells from patients with acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) was investigated by flow cytometry. The objective of the study was to develop a reproducible flow cytometric method. A Burkitt's lymphoma-derived B-cell line, Daudi, and a pre-B ALL, Nalm-6, served as prototypes. Normal B cells and cells from patients with chronic myelogenous leukemia (CML) were used as negative controls. Cytoplasmic mu was expressed in 77.3 +/- 7.5% (n = 10) of Nalm-6 cells. CALLA+ ALL and CML cells lacked cytoplasmic mu. The surface-membrane immunoglobulin on the viable B cells was blocked with purified goat anti-human IgM. Subsequently, the B cells were fixed in cold absolute methanol and stained with a fluorescein-conjugated goat anti-human IgM to demonstrate cytoplasmic IgM. After the surface-membrane IgM was blocked, normal B cells had no cytoplasmic IgM (0.3-0.5% positive cells) detectable by flow cytometry. However, the peripheral blood lymphocytes from five patients with CLL and the Daudi cells contained cytoplasmic IgM, ranging from 7.8 to 76.7% and 45.7 to 89.3%, respectively. We conclude that cytoplasmic mu in Nalm-6, CLL, and Daudi cells can be easily and rapidly demonstrated by flow cytometry.     

Monoclonal antibody studies in B(non-T)-cell malignancies

Tumor cells suspensions prepared from 129 B- or non-T cell malignancieswere investigated with a panel of 10 monoclonal antibodies andconventional surface marker techniques. Surface immunoglobulin(slg) and Bl antigen proved to be the most useful markers forB-cell lineage. Six major subtypes of acute lymphoblastic leukemia(ALL) of non-T cell nature are now recognized by these immunologicaltechniques, including null-ALL, la-ALL, lymphoid stem cell ALL,pre-pre-B ALL, pre-B ALL and B-ALL. In cases of chronic leukemias and lymphomas of non-T cell nature,80% of the tumor was defined by slg and 88% by Bl antigen asdefinitely of B-cell lineage. The clonal character was alsodefined in 68% of the tumor on the basis of the detection ofpredominant single light chain in slg. Ia-like antigen was detectedin almost all cases (96%). Leukemic cells from all cases of chronic lymphocytic leukemia(CLL), chronic lymphosarcoma cell leukemia (CLsCL) and hairycell leukemia (HCL) reacted with OKlal and anti-Bl, and leukemiccells from most of them with anti-pan T monoclonal antibody(10.2). In more than half of CLL and CLsCL, leukemic cells werereactive with J5, OKM1, 9.6 and OKT8, but not with OKT3, OKT4and OKT6. HCL cells had almost the same reactivity with thesemonoclonal antibodies as CLL and CLsCL cells except that J5remained unreactive. These results indicated that Japanese CLL,CLsCL and HCL were different from Western ones at least withrespect to surface marker characteristics. In cases of lymphomas, heavy chains of sIg were expressed inpolyclonal fashion, especially in follicular lymphoma and diffuselymphomas of medium sized cell type and large cell type, indicatingthat lymphomas of these types may originate from follicularcenter cells of the heavy chain switching stage. Anti-T monoclonalswere also reactive with lymphoma cells. In about half of follicularlymphomas and diffuse lymphomas of the medium sized cell type,lymphoma cells reacted with 10.2, and less frequently with 9.6,OKT4 and OKT3. On the other hand, only in one or two cases ofdiffuse lymphoma of the large cell type and of immunoblasticsarcoma (IBS), did tumor cells react with 10.2 and 9.6, butthis was exceptional. In more than 25% of IBS, tumor cells alsoreacted with OKT8, but not with 0KT4 and OKT3. These resultsindicated that anti-T monoclonals are no longer specific forT-cell lineage. It must be recognized that, in B- or non-T celllymphoma as well as chronic leukemia, tumor cells are sometimesreactive with several anti-T monoclonals. These results cancause confusion. Therefore, it is still necessary to performconventional marker studies in addition to monoclonal antibodystudies in the case of B- or non-T cell malignancies. Furtherdevelopment of useful anti-B monoclonals is strongly desired. ^* Present address: Department of Internal Medicine, Iwaki KyoritsuGeneral Hospital, 16, Kuzehara, Mimaya-machi, Uchigo, Iwaki973, Fukushima. ^** Present address: Department of Pediatrics, National ShikokuCancer Center, 13, Horinouchi, Matsuyama 790, Ehime.     

Differential diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma and other indolent lymphomas,including mantle cell lymphoma

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) accounts for approximately 1% of all lymphomas in our department. In this article, we describe the differential diagnosis of CLL/SLL from other indolent lymphomas, with special reference to follicular lymphoma, marginal zone B-cell lymphoma, lymphoplasmacytic lymphoma, and mantle cell lymphoma, although the latter is considered to be aggressive. CLL/SLL often exhibits proliferation centers, similar to follicular lymphoma. Immunohistological examination can easily distinguish these two lymphomas. The most important characteristic of CLL/SLL is CD5 and CD23 positivity. Mantle cell lymphoma is also CD5-positive and there are some CD23-positive cases. Such cases should be carefully distinguished from CLL/SLL. Some marginal zone lymphomas are also positive for CD5 and such cases are often disseminated. Lymphoplasmacytic lymphoma should also be a differential diagnosis for CLL/SLL. It frequently demonstrates MYD88 L265P, which is a key differential finding. By immunohistological examination, the expression of lymphoid enhancer-binding factor 1 is specific for CLL/SLL and can be a good marker in the differential diagnosis.     

CD148 and CD27 are expressed in B cell lymphomas derived from both memory and naïve B cells

CD148 and CD27 are activation antigens involved in B cell and T cell activation and development. They have been recently proposed as markers of normal human memory B cells corresponding to the presence of somatically hypermutated IgV genes. We undertook an immunohistochemical study of CD148 and CD27 expression on neoplastic B cells in 116 cases of B cell non-Hodgkin's lymphoma. All cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), mantle cell lymphoma, Burkitt's lymphoma, and the vast majority of cases of marginal zone B cell lymphoma and most cases of plasmacytoma/myeloma expressed CD148 and CD27. Follicular lymphoma and diffuse large B cell lymphoma were also immunoreactive for CD148 and CD27 with some variation and discordance in expression. Cases of precursor B-lymphoblastic lymphoma/leukemia did not express CD148 or CD27. Our findings demonstrate that CD148 and CD27 are expressed in a wide range of B cell non-Hodgkin's lymphomas, and, therefore, do not serve to distinguish between neoplastic cells of na?ve and memory B cell derivation.     

Surface phenotyping, histology and the nature of non-Hodgkin lymphoma in 157 patients.

In a study of 157 patients with lymphoid malignancy, the phenotype of the tumour cells was correlated with the histological classification of the tumour using the Rappaport and the Kiel classifications. The markers used included E, Fc gamma, Fc micron (IgM) and C3d rosetting, estimation of SIg and CyIg, and tests for the expression of HTLA, Ia and ALL. Repeat biopsy specimens were studied in 23 of these patients. The phenotypic features of lymphoblastic malignancy indicated B-cell, T-cell and ALL-positive null-cell tumours in this group. Immunoblastic lymphomas were predominantly of non-capping B-cell type, but T-cell immunoblastic lymphoma occurred in 2 patients. Immunoblastic lymphomas of receptor-silent cells occur, and are ALL- and HTLA-negative. In the category of diffuse, poorly differentiated lymphocytic lymphomas, most cases are of centroblastic and centrocytic tumour of diffuse type, but pure centrocytic tumours and centroblastic tumours occur. The dominant phenotype in this group is of B cells expressing C3d receptors. Nodular poorly differentiated lymphocytic lymphomas (Rappaport) are classified as centroblastic and centrocytic follicular (Kiel) and most express SIg+ C3d+ phenotype. The frequency of this phenotype appeared the same in both diffuse and nodular poorly differentiated lymphocytic neoplasms. The Rappaport group of diffuse well-differentiated lymphocytic lymphoma includes 2 Kiel categories, malignant lymphoma lymphocytic, and malignant lymphoma lymphoplasmacytoid. Cells of the former tumour were considered to be immature B cells resembling those seen in CLL, and characteristically expressing SIg weakly, with a high frequency of single kappa light chain. Cells of the latter tumour are by contrast mature, and are related to the centroblastic and centrocytic follicular tumour by their histogenesis and phenotypic features. Repeat biopsy examinations indicate that T-cell predominance occurs in the prodromal phase of B-cell-predominant tumours of SIg+ C3d+ phenotype. It is concluded that non-Hodgkin lymphoma can be divided into 2 categories: (1) tumours of immature immunologically incompetent cells of lymphoblastic histology and with phenotypic features akin to T, B and Null-cell ALL, and (2) tumours of differentiated lymphocytes expressing the phenotypic features of B lymphocytes, with maturation arrested at one of several stages of an antigen-dependent immune response.     

Increased incidence of IgA antibodies to the Epstein-Barr virus-associated viral capsid antigen and early antigens in patients with chronic lymphocytic leukemia

Antibody titers to Epstein-Barr virus (EBV)-associated early antigens (EA) and the viral capsid antigen (VCA) were determined by ELISA on 263 sera obtained from healthy donors, patients with Hodgkin's disease (HD), non-Hodgkin lymphomas (NHL), infectious mononucleosis (IM), Burkitt's lymphoma (BL), and nasopharyngeal carcinoma (NPC). As expected, most lymphoma patients showed markedly elevated anti-VCA IgG and anti-EA IgG antibody titers. Only one patient in the NHL group (n = 56) consisting of patients with lymphomas other than chronic lymphocytic leukemia (CLL) and hairy-cell leukemia (HCL), and 3 patients with HCL (n = 19) had high antibody titers of the IgA class to VCA and EA. Seventeen out of 48 patients (36%) with CLL had high IgA anti-VCA titers and 10 of these sera (21%) also contained IgA anti-EA. The geometric mean titer (GMT) of IgA anti-VCA was 2,510, the GMT of IgA anti-EA was 780. These antibody titers were about 10 times lower than the corresponding GMT of the NPC patients investigated in this study. The elevated IgG and IgA antibody titers to VCA and EA in CLL and HCL patients seem to reflect an immunodeficiency secondary to the malignant disease leading to reactivation of latent EBV infection. The possibility that at least some of these B-cell lymphomas are associated with EBV cannot be excluded.     

Cytogenetics of pre-B-cell acute lymphoblastic leukemia with emphasis on prognostic implications of the t(1;19)

In earlier studies of the cytogenetic characteristics of leukemic lymphoblasts from children with pre-B-cell acute lymphoblastic leukemia (ALL), we concluded that certain chromosomal abnormalities explain, in part, the increased presence of high-risk features at diagnosis and the less favorable response to therapy among patients with this immunologic subclass of ALL. With extended follow-up and a larger patient population, we have further evaluated the biologic and clinical aspects of pre-B leukemia. Of 686 cases of ALL with adequate immunophenotyping, 150 were classified as pre-B cell. Seventy-seven (69%) of the 112 pre-B cases with fully banded karyotypes had a translocation. The t(1;19) accounted for 28 (25%) of these pre-B cases and 31 (6.5%) of all 480 consecutively banded ALL cases. Three (2.6%) of the pre-B cases had a novel dicentric (7;9)(p1?3;p11) translocation. A t(9;22)(q34;q11) and a t(4;11)(q21;q23) were observed in seven (6%) and three (2.6%) of the cases, respectively. Within the pre-B subgroup, comparison of t(1;19) cases (n = 28) with those having other translocations (n = 49) or no identifiable translocations (n = 35) indicated that higher leukocyte counts (P = .002), absence of DNA indexes greater than 1.16 (P = .02), higher serum lactate dehydrogenase levels (P less than .0001), and a higher frequency of nonwhite race (P = .006) were significantly related to the t(1;19). Both the t(1;19) and other chromosomal translocations were associated with an adverse prognosis in the subset of patients treated from 1979 to 1984 (Total Therapy study X). In a more recent and more intensive chemotherapy program (Total Therapy study XI), neither the t(1;19) nor other chromosomal translocations has conferred an inferior outcome, suggesting that effective treatment can offset the negative impact of chromosomal rearrangements in cases of childhood pre-B ALL.     

Expression of inhibitor of apoptosis proteins in B-cell non-Hodgkin and Hodgkin lymphomas

BACKGROUND: Inhibitor of apoptosis proteins (IAPs) inhibit apoptosis by binding specific caspases, and possibly by other mechanisms. Eight IAPs have been identified in humans, of which cIAP1, cIAP2, and XIAP are well known. IAPs are being investigated as potential treatment targets in cancer patients. METHODS: cIAP1, cIAP2, and XIAP were assessed in lymphoma cell lines, 240 B-cell non-Hodgkin lymphoma (NHL) tumors, and 40 Hodgkin lymphoma (HL) tumors. RESULTS: All IAPs were expressed in most NHL and all HL cell lines. In NHL tumors, cIAP1 was expressed in 174 (73%), cIAP2 in 115 (48%), and XIAP in 37 (15%). cIAP1 was positive in all precursor B-cell lymphoblastic lymphoma/leukemia (LBL) and nodal marginal zone B-cell lymphoma (MZL), over 90% of follicular lymphoma and diffuse large B-cell lymphoma (DLBCL), and approximately 50% to 60% of myeloma, Burkitt lymphoma (BL), lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (LPL/WM), small lymphocytic lymphoma/ chronic lymphocytic leukemia (SLL/CLL), extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT-lymphoma), splenic MZL, and mantle cell lymphoma. cIAP2 was positive in all MALT-lymphoma, over 90% of precursor B-cell LBL (94%), most BL (75%), LPL/WM (71%), and SLL/CLL (67%), and approximately 40% to 60% of follicular lymphoma, myeloma, and DLBCL. XIAP was positive most cases of precursor B-cell LBL (57%) and approximately 30% to 40% of nodal MZL, BL, and DLBCL. In HL tumors, cIAP1 was positive in 30 (75%), cIAP2 in 27 (68%), and XIAP in 23 (58%), and did not correlate with histologic type. CONCLUSIONS: Differential expression of IAPs in B-cell lymphomas suggests differences in pathogenesis that may have implications for novel treatment strategies targeting IAPs.     

Trisomy 12-associated, t(11;14)-negative mature B-cell leukemia with gene expression profile resembling mantle cell lymphoma

Trisomy 12 can be seen in many different lymphoid neoplasms. However, many or most mature B-cell leukemias associated with isolated trisomy 12 are reported in the literature as chronic lymphocytic leukemia (CLL) or 'atypical CLL'. This study reports a case of a mature B-cell leukemia, morphologically and immunophenotypically similar to cases previously published as atypical CLL, in which cytogenetic evaluation revealed an isolated clonal trisomy 12 but no evidence of the mantle cell lymphoma-associated t(11;14)(q13;q32). Further analysis confirmed absence of cyclin-D1 expression. Subsequent lymph node biopsy revealed evidence of large cell transformation of the underlying chronic lymphoproliferative disorder. Gene expression profiling of the initial peripheral blood sample using a cDNA micro-array of ∼10,000 expressed genes revealed a close resemblance between the reported case and 2 cases of known mantle cell lymphoma. When further compared to 7 known 'typical' CLL cases, the reported case was classified as mantle cell lymphoma by hierarchical cluster analysis. The case reported here raises interesting questions regarding the nature of cases reported previously as trisomy 12-associated CLL and reinforces the fact that other leukemic lymphoproliferative disorders should be included in the differential diagnosis of such cases. Further study is indicated to elucidate the nature and diversity of disorders previously reported as trisomy 12-associated chronic lymphocytic leukemia.     

Expression of leucocyte-common antigen and large sialoglycoprotein on leukemic cells in B-cell chronic lymphocytic leukemia and non-Hodgkin's lymphoma

Patterns of leucocyte-common antigen (L-CA) and large sialoglycoprotein (LSGP) expression on leukemic peripheral blood lymphocytes of 13 patients with chronic lymphocytic leukemia (CLL), 17 with non-Hodgkin's lymphoma (NHL) in leukemic phase and one with hairy cell leukemia (HCL) have been examined by means of surface labelling and electrophoresis in 5% polyacrylamide gels. The 13 CLL, 10 of the 11 diffuse NHL and the six nodular poorly differentiated lymphocytic lymphoma (PDLL) patients fell into three groups according to expression of 210, 198 and 185k forms of L-CA. Group 1 (210 less than 198 less than 185k L-CA) included eight CLL and one diffuse NHL; Group 2 (210 greater than or equal to 198 and 185k L-CA) included four CLL, three diffuse NHL and four nodular PDLL; Group 3 (mainly 210k L-CA) included one CLL, six diffuse NHL and two nodular PDLL. A patient with diffuse large cell lymphoma and the HCL patient both had patterns of multiple, diffuse, very high Mr labelled glycoproteins. LSGP on these cells varied from nil to very high and levels were not related to L-CA patterns. Lymph node cells from five patients were also studied and were found to express larger numbers of L-CA forms and less LSGP than corresponding peripheral blood lymphocytes. Possible relationships of L-CA forms and LSGP to lymphocyte function and disease patterns are discussed.     

Pre-B-cell leukemia with a t(8; 14) and a t(14; 18) translocation is preceded by follicular lymphoma

We have performed gene rearrangement studies on the leukemic blasts of a patient with acute pre-B-cell leukemia. The patient had a 5 year history of follicular lymphoma, which developed into acute pre-B-cell leukemia. The leukemic blasts revealed a karyotype with two translocations, t(8; 14) and t(14; 18), characteristic for Burkitt's lymphoma and follicular lymphoma. The cells are TdT positive, do not possess surface immunoglobulin, and they show immunoglobulin gene rearrangement. The mu heavy chain and kappa light chain constant (C mu and C kappa) loci are deleted, while the gamma and lambda light chain constant (C gamma and C lambda) region genes are rearranged. Both alleles of the heavy chain joining segment (JH) are rearranged on chromosome 14q+, one of them with the bcl-2 oncogene from chromosome 18. The breakpoint of the t(14; 18) translocation occurs in the major breakpoint cluster region in the 3' untranslated region of bcl-2. On chromosome 8 a c-myc rearrangement was mapped immediately 5' to the c-myc first exon in a region involved in sporadic Burkitt lymphoma. The data are consistent with our previous hypothesis on the evolution of B-cell malignancies: a rare pre-B cell develops a t(14; 18) translocation during immunoglobulin VDJ joining that results in an expansion of a follicular lymphoma clone carrying an activated bcl-2 gene. Within the clone of pre-B cells a second translocation, t(8; 14), occurs during heavy chain isotype switching that results in the deregulation of the c-myc involved in the translocation.     

Expression of DNA mismatch repair proteins in transformed non-Hodgkin's lymphoma: relationship to smoking

It has been hypothesized that defects in DNA-mismatch repair are associated with smoking in certain types of transformed non-Hodgkin lymphoma (NHL). We have analyzed biopsy samples from two indolent B-cell lymphomas, follicular lymphoma (FL) and chronic lymphocytic leukemia/small lymphocytic leukemia (CLL/SLL), that have transformed to diffuse-large B-cell lymphoma (DLBCL). We correlated the presence or absence of DNA-mismatch repair enzymes by immunostaining as well as the p53 status to smoking history. Of all patients (n = 30), 37% showed negative immunostaining of MLH1, 16% showed negative immunostaining of MSH2 and 63% had p53 mutations and/or protein expression. Eighteen out of 20 transformed follicular lymphomas and seven out of 10 CLL/SLL that have transformed to DLBCL (Richter's syndrome) were informative for smoking histories. We found that the relative risk of negative immunostaining for either MLH1 or MSH2 was 2.2 times higher in smokers than non-smokers (relative risk = 2.2041, 95% confidence interval: 0.89714, 5.41491). No direct correlation was found between smoking and the mutations in the p53 gene. These results suggest that cigarette smoking may play a role in the development of transformed lymphomas through defective mismatch repair.     

Induction of Differentiation of African Burkitt's Lymphoma Cells by Phorbol Ester: Possible Relation with Early B Cells

The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) was used to examine the phenotypic changes in three African Burkitt's lymphoma cell lines, P3HR1, Daudi, and Raji. Cells were cultured with a nanogram concentration of TPA for up to seven days and then analyzed by flow cytometry and an immunoperoxidase staining method. The cells were stained with a panel of monoclonal antibodies reactive with B lymphocytes or B cell leukemia/lymphomas, and an antibody to the enzyme terminal deoxynucleotidyl transferase (Tdt). All three cell lines were found to express more HLA-linked DC/DS (Leu 10) antigen, while demonstrating a concomitant decrease in the expression of common acute lymphoblastic leukemia antigen (CALLA) and terminal deoxynucleotidyl transferase after TPA induction. The other antigens including Ig, BA1, BA2, Tac, Leu 8, Leu 1, C3bR, Leu 12, and Leu M5 showed no significant changes. The marker expression and differentiation pattern of these African Burkitt's lymphoma lines are very similar to those of pre-B cells except for the surface IgM expression observed in Daudi cells. The expression of CALLA and Tdt in African Burkitt's lymphoma is probably not the result of an Epstein-Barr virus infection, but may in fact reflect the true nature or origin of tumor cells. We conclude that African Burkitt's lymphoma cells are derived from an early stage of B-cell differentiation closely related to, but more mature than pre-B cells.