Cytochemically demonstrable B-glucuronidase activity in normal and neoplastic human lymphoid cells

Mononuclear cell suspensions were prepared from 40 normal peripheral blood and lymphoid tissue specimens and 42 neoplastic specimens obtained from patients with malignant lymphoma and lymphocytic leukemia. These suspensions were analyzed for la antigens, surface immunoglobulin (Slg), sheep erythrocyte (E) rosette formation and, in some instances, acid alpha-naphthyl acetate esterase (ANAE) activity. The results of these studies were correlated with the expression of cytochemically demonstrable BG activity. The percentage of BG+ lymphocytes was found to be comparable, within 10%, to the percentage of E+ (T) cells in the majority of normal, non-neoplastic peripheral blood, tonsil, spleen, and lymph node specimens examined. Occasionally, the percentage of E+ cells exceeded the percentage of BG+ cells by 20% or more, suggesting the presence of an E+BG- T cell subpopulation. BG+ B lymphocytes were only demonstrated in 1 of 40 non-neoplastic lymphoid specimens. The neoplastic B cells in each of 14 B cell (la+Slg+E-) lymphomas were BG-. However, a variable proportion of the neoplastic cells isolated from 6 cases of B cell chronic lymphocytic leukemia and neoplastic plasma cells isolated from 7 cases of multiple myeloma expressed BG activity. Thus, it appears that both normal and neoplastic BG- and BG+ B lymphocyte populations exist; the latter may be related to a state of activation or a stage of B cell differentiation. The neoplastic cells isolated from 4 T cell (la-Slg-E+) malignancies were BG+ while those isolated from 3 T cell malignancies were BG-. The variable expression of BG activity by T cell malignancies may be related to T cell differentiation. Investigation of BG expression by T cell derived malignancies may prove useful in sorting out T cell phenotypes.     

Differential metabolism of deoxyribonucleosides by leukaemic T cells of immature and mature phenotype

Experimental evidence has indicated that T lymphoblasts are more sensitive to deoxynucleoside toxicity than are B lymphoblasts. These data have led to the use of purine enzyme inhibitors as selective chemotherapeutic drugs in the treatment of T cell malignancies ranging from T cell acute lymphoblastic leukaemia to cutaneous T cell lymphomas. We have compared the toxicities of 2'-deoxyadenosine, 2'-deoxyguanosine, and thymidine for T cell lines derived from patients with T cell acute lymphoblastic leukaemia with those for mature T cell lines derived from patients with cutaneous T cell leukaemia/lymphoma. We have found that both deoxynucleosides are far less toxic to the mature T cell lies than to T lymphoblasts and that the mature cells accumulate much lower amounts of dATP and dGTP when exposed to deoxyadenosine and deoxyguanosine, respectively. Similar studies performed on peripheral blood cells from patients with T cell leukaemias of mature phenotype and on peripheral blood T cells demonstrate similar low amounts of deoxynucleotide accumulation. Measurements of the activities of several purine metabolizing enzymes that participate in deoxynucleoside phosphorylation or degradation do not reveal differences which would explain the toxicity of deoxynucleosides for immature, as compared to mature, T cells. We conclude that deoxynucleoside metabolism in leukaemic T cells varies with their degree of differentiation. These observations may be relevant to the design of chemotherapeutic regimes for T cell malignancies.     

Successful treatment of advanced natural killer cell lymphoma with high-dose chemotherapy and syngeneic peripheral blood stem cell transplantation.

CD56+ angiocentric lymphoma has currently been recognized as a distinct clinical entity which is the prototype of the putative NK cell lymphomas. A 16-year-old Japanese girl with advanced CD56+ angiocentric lymphoma received high-dose chemotherapy supported with syngeneic peripheral blood stem cell transplantation (PBSCT). Prior to syngeneic PBSCT, she received six cycles of conventional chemotherapy before transplantation, resulting in a partial response. PBSC were mobilized with granulocyte colony-stimulating factor (G-CSF) and collected from her identical twin. High-dose cyclophosphamide, MCNU, etoposide, and carboplatin were used for pretransplant conditioning. Syngeneic PBSCT was well tolerated. She achieved complete remission and is now surviving in continuous complete remission for more than 30 months after syngeneic PBSCT. Thus, marrow-ablative chemotherapy facilitated by autologous or allogeneic PBSCT should be considered as part of the primary therapy for poor prognosis NK cell lymphomas.     

Variable CD52 expression in mature T cell and NK cell malignancies: implications for alemtuzumab therapy

The anti-CD52 antibody alemtuzumab has been explored as a novel targeted therapy in T cell malignancies. To assess the suitability of alemtuzumab therapy, we carried out a comprehensive study of CD52 expression using flow cytometry (FC) in 78 untreated patients diagnosed with mature T/natural killer (NK) cell neoplasms, including 34 adult T cell leukaemia/lymphomas (ATLL), two anaplastic large cell lymphomas (ALCL), three angioimmunoblastic T cell lymphomas (AITL), 16 cutaneous T cell lymphomas (CTCL), four extra-nodal T/NK cell lymphomas (ENT/NKCL), four hepatosplenic T cell lymphomas (HSTCL), 13 peripheral T cell lymphomas, not otherwise specified (PTCL-NOS) and two T-prolymphocytic leukaemia (T-PLL). The level of CD52 expression was quantified using QuantiBRITE standard beads. The level of CD52 expression varied widely within each diagnostic category. All AITL, HSTCL and T-PLL cases were CD52-positive and the frequency of CD52 expression was high in PTCL-NOS (92·3%), ATLL (94·1%) and CTCL (87·5%), implying a rational role for alemtuzumab in the treatment of these diseases; however, CD52 expression was low in ALCL (50%) and ENT/NKCL (25%). FC testing for cell surface expression of CD52 is indicated in patients with T/NK cell malignancies being considered for alemtuzumab therapy. Further studies are necessary to determine if the level of CD52 expression correlates with response to therapy.     

Generation of CFU-C suppressor T cells in vitro. III. Failure of mitogen-primed T cells from patients with chronic granulocytic leukemia to inhibit the growth of normal CFU-C

T lymphocytes were derived by E rosetting from the peripheral blood (PB) and bone marrow (BM) of 15 patients with chronic granulocytic leukemia (CGL) in the chronic phase of their disease. T cells were also obtained from 12 healthy individuals. T cells were incubated overnight either in culture medium (RPMI) or RPMI plus pokeweed mitogen (PWM). The supernatants were then recovered and the cells washed in fresh RPMI. T cells from normal donors and from CGL patients were then cocultured with normal allogeneic marrow cells grown in soft agar for CFU-C colony formation. Target marrow cells were also grown in agar in the presence of T-derived supernatants. The results of this study can be summarized as follows. (1) Normal PB and BM T cells efficiently suppressed autologous and allogeneic CFU-C growth after PWM stimulation. (2) T cells derived from peripheral blood or marrow of CGL patients failed to inhibit CFU-C growth, whether pretreated with PWM or not. (3) The supernatants of PWM-treated normal T cells strongly inhibited CFU-C colony formation, whereas the supernatants of PWM- treated CGL T cells had no CFU-C/suppressor activity. These data indicate that T cells from CGL patients cannot be primed to become CFU- C suppressor cells after PWM: stimulation in vitro and cannot release a soluble inhibitor of granulopoiesis produced by PWM-primed normal T cells.     

Peripheral T‐cell lymphoma gene expression profiling and potential therapeutic exploitations

Peripheral T‐cell lymphomas constitute a heterogeneous group with regard to diagnosis, treatment and prognosis. Efforts have been made to combine novel techniques with cytology and immunochemistry in order to more precisely define these entities. Molecular profiling has contributed to novel insights in the biology of T‐cell lymphoma. Regarding anaplastic large cell lymphoma, low expression T‐cell receptor signalling and high STAT3 target signatures have been associated with the ALK‐positive subgroup. Gene expression profiling differentiates angioblastic T‐cell lymphoma from other T‐cell malignancies, suggests that the normal counterpart of lymphoma cells are follicular helper T cells, and supports the involvement of vascular endothelial growth factor deregulation in its physiopathology. In peripheral T‐cell lymphoma unspecified, gene profiling suggests the normal counterpart of tumour cells are activated CD4⁺ or CD8⁺ T‐lymphocytes, delineates prognostic groups depending on the proliferative signature, and suggests therapeutic options aimed at regulating nuclear factor‐κB and platelet‐derived growth factor receptor‐α phosphorylation. Gene expression profiling of primary cutaneous T cell lymphomas highlighted the importance of abnormal methylation patterns, suggested a pivotal role for JUNB/AP‐1, and defined a predictive model for response to interferon‐α. In conclusion, gene expression profiling is beginning to change the pathological classification, the prognosis profiles and the therapeutic approach in T‐cell lymphomas.     

Monocytes in rheumatoid arthritis. Regulatory, effector, and phenotypic properties

We reported that rheumatoid arthritis (RA) blood mononuclear cells (MNC) secreted less Ig and IgM rheumatoid factor (RF) than synovial cells. Since antibody elaboration is partly monocyte dependent, we compared regulatory, effector, and phenotypic properties of monocytes from 31 patients with RA with those of 21 normal subjects. RA IgG and IgM elaboration was less than normal. Monocyte, T or B cell numbers were comparable in RA and normal MNC and monocyte enriched/depleted preparations. RA and normal Ig production were monocyte dependent and this differed for IgG and IgM for RA and normals. IgM RF elaboration by stimulated RA MNC was also monocyte dependent and addition of normal monocytes/monocyte culture supernatants to RA monocyte depleted cultures and vice versa had inconsistent effects. RA MNC (Ficoll-Hypaque) phagocytosis was less than normal; killing (acridine orange fluorescent microscopy) was not. RA synovial monocyte phagocytosis - but not killing was also reduced. MNC from RA patients and normals contained similar numbers of monocytes; RA monocyte enriched populations (Percoll) showed less phagocytosis than normal; with similar killing. RA phagocytosis was reduced at 1,2,3,4 and 5 h and differed from normal at 3 and 5 h. Different sera - FCS, autologous, normal, RA - exhibited inconsistent effects on phagocytosis. RA and normal neutrophil phagocytosis and killing were comparable. Lastly, RA monocyte enriched preparations contained populations of OKM1, OKM3, OKM5, OKM6, Leu M1, Leu M2, Leu M3, and HLA-DR-positive cells (FACS analysis) comparable with normals. Regulatory and effector but not phenotypic properties of RA blood monocytes differed from normal and may contribute to inappropriate autoantibody production and chronic inflammation.     

Lipoteichoic acid derived from Enterococcus faecalis modulates the functional characteristics of both normal peripheral blood leukocytes and native human acute myelogenous leukemia blasts

OBJECTIVES: Several case reports have described complete hematological remissions for patients with otherwise untreated acute myelogenous leukemia (AML) who receive hematopoietic growth factor therapy during complicating bacterial infections. This may be caused by indirect cytokine effects, but direct effects of infecting agents on the malignant cells are also possible because bacterial molecules can bind to specific receptors expressed by normal and malignant leukocytes. Lipoteichoic acid (LTA) is a cell wall component of gram-positive bacteria, and it can activate normal immunocompetent cells through binding to specific cell membrane receptors. METHODS: We investigated effects of LTA derived from Enterococcus faecalis on in vitro cultured (i) normal peripheral blood mononuclear cells (PBMC); (ii) remaining T cells derived from patients with hematologic malignancies and chemotherapy-induced leukopenia; and (iii) native human AML cells. RESULTS: Increased interleukin 1beta (IL1beta) and IL8 release by in vitro cultured normal PBMC was observed after stimulation with LTA at concentrations > or =5 microg/mL; these levels were lower than for lipopolysaccharide (LPS)-stimulated cells and LTA antagonized LPS-induced cytokine release by normal PBMC. In most cases LTA did not alter T-cell proliferation for patients with chemotherapy-induced leukopenia. The LTA effects on AML blasts were investigated for 62 consecutive patients. LTA altered either cytokine (granulocyte-macrophage colony-stimulating factor + stem cell factor + IL3)-dependent proliferation or the release of IL1beta/IL8 for 23 patients; the effects were divergent but increased proliferation/cytokine levels were most commonly observed. CONCLUSION: The LTA derived from E. faecalis can modulate the functional characteristics of normal leukocytes and native human AML blasts.     

CD5-CD56+ T-cell receptor silent peripheral T-cell lymphomas are natural killer cell lymphomas [see comments]

Non-Hodgkin's lymphomas are divided into B- and T-cell neoplasms. The existence and the clinical relevance of lymphomas derived from the third lymphocyte lineage, ie, natural killer (NK) cells are still controversial. NK cells are lymphocytes that mediate cytotoxicity without prior sensitization. NK cells also have phenotypic and genotypic characteristics: they express the NK-related antigen CD56, T- cell markers such as CD2 and CD7, but do not express CD5 and T-cell receptor (TCR) proteins, and their TCR locus is not rearranged. Therefore, if NK cell lymphomas exist, they should express some T-cell markers, but not alpha beta or gamma delta TCR proteins. Such lymphomas are actually called TCR silent peripheral T cell lymphomas (PTCL). To detect and characterize NK cell lymphomas, we investigated the immunophenotype and immunogenotype of 35 patients with TCR silent PTCL. The first group included 16 patients with a lymphoma of CD5-CD56+ phenotype, which is identical to normal NK cells. These patients had either a nasal/nasopharyngeal lymphoma (11 cases) or a lymphoma with predominant non-nasal/non-nodal initial involvement (five cases). Eight of the nine cases for which immunogenotypic data were available lacked clonal rearrangement of the TCR gamma genes. Thus, these tumors are likely to be NK cell lymphomas. The second group of 15 cases had a CD5+ phenotype (14 were CD56-, and 1 was CD56+) and clonal rearrangement of TCR gamma genes, indicating that they were true PTCL with unproductive TCR rearrangement. The four remaining cases were CD5- CD56- lymphomas and disclosed either a clonal (two cases) or no clonal (two cases) rearrangements of the TCR gamma genes. Altogether these findings show that CD5-CD56+ so-called "TCR silent PTCL" bear the immunophenotype and immunogenotype of normal NK cells and display peculiar clinical features distinct from true PTCL.     

Concanavalin A receptors on the surface membrane of lymphocytes from patient's with Hodgkin's disease and other malignant lymphomas.

Concanavalin A (Con A) induces movement of its receptors on the cell surface membrane. This induction results in a concentration of Con A site complexes on one pole of the cell to form a cap. A marked difference was found in the mobility of Con A receptor between lymphocytes from normal persons and lymphocytes from patients with Hodgkin's disease and other malignant lymphomas. Lymphocytes isolated from tonsils of patients undergoing tonsillectomy and from axillary lymph nodes of breast cancer patients exhibited approximately 30% of cells with caps, which is identical with the cap formation ability of normal lymphocytes. In biopsy material from patients with Hodgkin's disease and other malignant lymphomas, a significant decrease in the ability of the lymphocytes to form caps was observed. This difference in the mobility of Con A sites was even more pronounced in lymphocytes isolated from the peripheral blood. In 123 patients with Hodgkin's disease and other malignant lymphomas, cap formation ranged between 3 and 12%. The ability of cells, from a normal donor or a lymphoma patient, to form caps was independent of the source from which the lymphocytes were isolated, e.g., lymph node, spleen, or blood. Lymphocytes from patients with lymphoma were also agglutinated by Con A to a higher degree than normal lymphocytes. These findings are discussed in relation to the association of the lymphocytes with these malignancies and as a possible aid in their differential diagnosis.     

Functional implications of hepatitis B surface antigen (HBsAg) in the T cells of chronic HBV carriers

This study was undertaken to investigate the role of T-lymphocyte-derived soluble factors in the maintenance of the hepatitis B virus (HBV) chronic carrier state. Cell-free supernatants from the peripheral blood T lymphocytes of chronic HBV carriers were produced by incubating them for 48h in tissue culture medium. These supernatants were added to in vitro hepatitis B s antibody (HBsAb)-producing cultures of peripheral blood mononuclear cells from hepatitis B surface antigen (HBsAg) vaccinees stimulated with HBsAg or pokeweed mitogen. T-cell supernatants from chronic carriers suppressed in vitro HBsAb antibody synthesis, whereas those from control subjects did not. This suppression was antigen specific as the supernatants did not suppress synthesis of total IgG or IgM. HBV viral sequences were demonstrable, by Southern and dot-blot hybridization, in the T cells secreting this factor. We also demonstrated the presence of HBsAg in T-cell supernatants derived from these cells. These results show that HBsAg of T-cell origin may have a role in suppressing HBsAb production. Our observations point to the role of HBsAg-specific cellular and humoral responses in favouring persistence of the chronic HBV carrier state.     

The expression of the Hodgkin's disease associated antigen Ki-1 in reactive and neoplastic lymphoid tissue: evidence that Reed-Sternberg cells and histiocytic malignancies are derived from activated lymphoid cells

Ki-1 is a monoclonal antibody (raised against a Hodgkin's disease- derived cell line) that, in biopsy tissue affected by Hodgkin's disease, reacts selectively with Reed-Sternberg cells. The expression of Ki-1 antigen has been analyzed by immunocytochemical techniques in a wide range of human tissue and cell samples, including fetal tissue, malignant lymphomas (290 cases), and mitogen- and virus-transformed peripheral blood lymphocytes. The antigen was detectable on a variable proportion of cells in all cases of lymphomatoid papulosis and angio- immunoblastic lymphadenopathy and in 28% of the cases of peripheral T cell lymphomas (including lympho-epithelioid lymphomas). It was also expressed (more strongly) on tumor cells in 45 cases of diffuse large- cell lymphoma, most of which had originally been diagnosed as malignant histiocytosis or anaplastic carcinoma, because of their bizarre morphology. However, all of these cases lacked macrophage and epithelial antigens. Thirty-five cases expressed T cell-related antigens (associated in nine cases with the coexpression of B cell- related antigens), seven bore B cell-related antigens alone, and three were devoid of T and B cell markers. DNA hybridization with a JH specific probe showed a germline configuration in 11 cases of T cell phenotype, in two cases lacking T and B cell antigens, and in one case of mixed T/B phenotype, while rearrangement was found in two cases of clear B cell type and in one mixed T/B case. Expression of the Ki-1 antigen could be induced, together with interleukin 2 (IL 2) receptor, on normal lymphoid cells of both T and B cell type by exposure to phytohemagglutinin, human T leukemia viruses, Epstein-Barr virus, or Staphylococcus aureus. The results obtained indicate that Ki-1 antigen is an inducible lymphoid-associated molecule that identifies a group of hitherto poorly characterized normal and neoplastic large lymphoid cells. Tumors comprised solely of these cells show both morphological and immunological similarities to the neoplastic cells in Hodgkin's disease. This suggests that both disorders represent the neoplastic proliferation of activated lymphoid cells of either T cell or, less commonly, B cell origin. Disorders in which only a minority of cells express Ki-1 antigen (lymphomatoid papulosis, angio-immunoblastic lymphadenopathy, and certain T cell lymphomas) probably represent lesions in which only some of the abnormal cells have transformed into an "activation state." In direct support of this view is the finding that the Ki-1 expression in these lesions is accompanied by the expression of HLA-DR and IL 2 receptors.     

Inhibition of leukemic cell proliferation by factor(s) released from irradiated lymphocytes of B-chronic lymphocytic leukemia patients

An attempt was made to clarify the mechanism by which splenic irradiation in patients with B-chronic lymphocytic leukemia (B-CLL) can induce a reduction in lymph node size. For this purpose peripheral blood lymphocytes from B-CLL patients were exposed to cobalt irradiation and were cultured for 1–8 days. The effect of the supernatants on the proliferation capacity of normal and malignant human cells was examined. A suppression of phytohemagglutinin (PHA)-induced proliferation of autologous and heterologous B-CLL lymphocytes was observed, whereas there was no effect on the proliferation of lymphocytes obtained from healthy volunteers. in addition, supernatants of irradiated B-CLL lymphocytes inhibited thymidine incorporation into blasts derived from patients with acute leukemia and the lymphoblastoid cell line Daudi, but they did not exert any effect on normal cells obtained from human embryonic liver. These results suggest the secretion of some factor(s) by irradiated B-CLL lymphocytes, which may inhibit the proliferation of malignant cells but has no effect on normal cells. © 1994 Wiley-Liss, Inc.     

Mechanism of activation of B lymphocytes in idiopathic UIP: evaluation of BCGF and BCDF-production from blood T lymphocytes

The activation of B lymphocytes and formation of immune complexes were suggested to play important roles in the pathogenesis of idiopathic UIP. To investigate the mechanism of the activation of B lymphocytes, we studied the production of B cell growth factor (BCGF) and B cell differentiation factor (BCDF) in patients with idiopathic UIP and those with IP-CVD, in comparison with healthy controls. Culture supernatants of peripheral blood mononuclear cells from patients with idiopathic UIP induced more IgM- and IgA-production than those from healthy controls, indicating a higher production of BCDF. Culture supernatants of peripheral blood mononuclear cells from patients with idiopathic UIP did not induce higher proliferation of B lymphocytes than those from healthy controls, indicating that production of BCGF was not enhanced in the patients. Increase of production of BCGF and BCDF from patients with IP-CVD was not observed. From these results, it was suggested that T lymphocytes that release lymphokines like BCDF are activated in patients with idiopathic UIP, but not in those with IP-CVD, and that the process of activation of B lymphocytes might be different between these fibrotic diseases.     

Impairment of T lymphocyte colony formation in Hodgkin's disease: effect of soluble inhibitory factors on normal T lymphocyte colony formation potential

PHA-induced T lymphocyte colonies from peripheral blood mononuclear cells of untreated Hodgkin's disease (HD) patients and normal healthy donors were assayed by one-step stimulation in microagar capillary cultures. A significant depression in the T cell colony formation was observed in HD patients in comparison with normal healthy donors. Clinical staging of the disease had no influence on this abnormality. Preincubation of HD lymphocytes for 24 h in tissue culture medium did not produce any appreciable recovery in the colony formation potential. However, in the presence of 24-hour culture supernatants of HD mononuclear cells, there was significant inhibition in the colony formation by lymphocytes obtained from normal healthy donors. Significance of these observations is discussed.     

Monoclonal B Cells in Peripheral Blood in Non-Hodgkin's Lymphoma. Correlation with Clinical Features and DNA Content

Peripheral blood from 69 patients with non-Hodgkin's lymphoma was examined with respect to B and T cell markers. Evidence for monoclonal B cell was found in 29 cases, 8 of ‘high grade’ and 21 of ‘low grade’ malignancy according to the Kiel classification. 17 out of the 29 patients had a normal lymphocyte count. Using conventional staging methods 4 cases of the 29 were in stages II and III, all others in stage IV. The proportion of S-phase cells in peripheral blood, determined by flow cytometry, was found to be elevated in cases with a monoclonal cell population. It is concluded that surface marker analysis of blood cells may be valuable as a diagnostic tool, as an indicator of prognosis and perhaps for the staging procedure of malignant lymphomas.     

Production of a glycosaminoglycan stimulatory factor by cloned human T lymphocytes activated in vitro

Supernatants of mitogen-activated mononuclear cells contain a factor which stimulates, up to fifteen-fold, the synthesis of glycosaminoglycan (GAG) by cultured normal dermal fibroblasts. To demonstrate that the GAG stimulatory factor is a product of T lymphocytes, we cloned normal peripheral blood T lymphocytes that were activated in mixed lymphocyte culture. Selected alloreactive T cell clones were expanded in the presence of original stimulator cells and T cell growth factor. Only supernatants of the clones that were reactivated with irradiated stimulators (allogeneic peripheral blood lymphocytes of B cell lines) were capable of increasing, 3-7-fold, the GAG synthesis by dermal fibroblasts. The production of GAG stimulatory activity by alloreactive T cells was restricted by HLA-DR allorecognition. Alloactivated T cell clones produced more GAG stimulatory activity on a per cell basis than did concanavalin A-activated mononuclear cells. These results show that cloned, activated T lymphocytes are capable of releasing soluble factors that modulate GAG synthesis by normal dermal fibroblasts.     

Frequency of a 30-base pair deletion in the latent membrane protein-1 gene in Epstein-Barr virus-associated lymphomas in Japan

The association of Epstein-Barr virus (EBV) with various lymphoid malignancies has been reported. The precise pathogenesis of EBV in malignancies has not yet been elucidated. Latent membrane protein-1 (LMP-1) and Epstein-Barr nuclear antigen-2 (EBNA-2) genes are suspected to be tumorigenic genes. Previous studies suggest that a deletion within the LMP-1 gene may increase the oncogenic potential of EBV. In this study, we analyzed the sequence within the carboxy terminal end of the LMP-1 gene in paraffin-embedded specimens from T-cell lymphomas, Hodgkin's disease (HD), and the buffy coat of peripheral blood from healthy individuals in Japan. Polymerase chain reaction (PCR) was performed using primers spanning the carboxy terminal region of the LMP-1 gene, and sequence analysis was performed to show the exact location of the deletion. The PCR product of the Raji cell line was 161 base pairs (bp), and the LMP-1 gene with deletion was 30 bp shorter in a direct sequence of PCR products. The 30-bp deletion was located in position 168285-168256 of the Raji cell. A deletion within the LMP-1 gene was found in 4 of 25 cases (16%) of EBV-positive T-cell lymphomas, 4 of 10 cases (40%) of EBV-positive HD cases, and 2 of 13 specimens (15%) with amplified PCR products from 49 healthy individuals. The incidence of the 30-bp deletion within the LMP-1 gene in HD was comparable to that of subjects in the United States and Brazil, but the deletion was not found in a high proportion of EBV-positive T-cell lymphoid malignancies. No statistical significance was found regarding the clinical outcome between patients with a deletion within the LMP-1 gene and patients with wild-type LMP. This deletion cannot be considered as simply causing the pathogenesis of EBV-associated lymphoid malignancies in Japan.     

Chromosome abnormalities in peripheral T-cell lymphoma

We have studied neoplastic lymph nodes from six patients histologically, immunologically and cytogenetically. Histologically all the cases were classified as peripheral T-cell lymphomas. These were subclassified as T-zone lymphomas in three, large cell 'pale cell' variant in one, large cell immunoblastic in one, and small cell, mycosis fungoides in one. Two had features of angioimmunoblastic lymphadenopathy (AILD). Immunologically all cases expressed CD2 (OKT11) and CD4 (T4). All six cases had clonal chromosome abnormalities, although in four cases the majority of cells were chromosomally normal. Chromosome 3 was most often involved in abnormalities, occurring in five patients. The most common single chromosome abnormality, trisomy 3, was seen in all three cases classified as T-zone lymphoma and in no other cases. In the two cases with features of AILD only numerical abnormalities were seen, whereas in the other cases complicated structural rearrangements were present. Recurring structural abnormalities involved bands 1p12or13, 1q32, 3p25 and 14q11. Our data suggest that cytogenetic analysis may assist in diagnosis and classification of the peripheral T-cell lymphomas.     

Interleukin-9 expression in human malignant lymphomas: unique association with Hodgkin's disease and large cell anaplastic lymphoma

To test the possibility that interleukin-9 (IL-9), the human homologue of the mouse T-cell growth factor P40, may be involved in the pathogenesis of human lymphomas, we examined IL-9 expression in a variety of tumors both by Northern blot analysis and by in situ hybridization. Of 18 B-cell non-Hodgkin's lymphomas and 11 peripheral T-cell lymphomas, none expressed IL-9 message. By contrast, IL-9 message was found in two of six cases of large cell anaplastic lymphoma (LCAL) and in 6 of 13 cases of Hodgkin's disease (HD). In HD the strongest signals were observed in Hodgkin (H) and Sternberg-Reed (SR) cells, but IL-9 mRNA was also detected in small lymphocytic cells. A search for IL-9 message in a panel of 20 cell lines derived both from hematopoietic and nonhematopoietic tumors confirmed the unique association of IL-9 expression with HD and LCAL in as much as the only two cell lines with IL-9 message were derived from cases of HD and LCAL. These results suggest that IL-9 is not involved as an autocrine growth factor in the pathogenesis of most B- and T-cell lymphomas, but that it may play a role in HD and LCAL.