Growth inhibition of CD20-positive B lymphoma cell lines by IDEC-C2B8 anti-CD20 monoclonal antibody

Treatment with IDEC-C2B8 (C2B8), the chimeric anti-CD20 antibody, was shown in a phase I-II study to be very effective for the treatment of low-grade B-cell lymphoma, in contrast to the results of most previous immunotherapies with monoclonal antibodies. In a study designed to elucidate the reason for this efficacy, two cell lines derived from lymphomas with BCL2 gene rearrangement (SU-DHL-4 and SU-DHL-6) showed remarkable growth inhibition and cell-death, and two other cell lines derived from a diffuse lymphoma (RC-K8) and a mantle cell lymphoma (SP-49) showed moderate growth inhibition, but neither a CD20 weakly positive cell line (NALL-1) nor a negative cell line (MOLT-4) showed any growth inhibition. An examination of the intensity of cell-surface CD20 expression showed no correlation between intensity and degree of growth inhibition among the four cell lines showing growth inhibition. Morphological examination revealed condensed and fragmented nuclei and budding of the plasma membrane, both characteristic of apoptosis, with some cells in these cell lines showing growth inhibition by C2B8. Such apoptosis was also confirmed by flow cytometric analysis, suggesting that, at least in part, apoptosis plays a role in this growth inhibition. This growth-inhibitory mechanism may thus account for the effectiveness of C2B8 antibody therapy.     

In vitro and in vivo biologic effects of interleukin-3 (IL-3) in follicular low-grade lymphoma

We have taken an enhancer trap approach to identify genes that are expressed in hematopoietic cells and tissues of Drosophila. We conducted a molecular analysis of two P-element insertion strains that have reporter gene expression in embryonic hemocytes, strain 197 and vikingICO. This analysis has determined that viking encodes a collagen type IV gene, alpha2(IV). The viking locus is located adjacent to the previously described DCg1, which encodes collagen alpha1(IV), and in the opposite orientation. The alpha2(IV) and alpha1(IV) collagens are structurally very similar to one another, and to vertebrate type IV collagens. In early development, viking and DCg1 are transcribed in the same tissue-specific pattern, primarily in the hemocytes and fat body cells. Our results suggest that both the alpha1 and alpha2 collagen IV chains may contribute to basement membranes in Drosophila. This work also provides the foundation for a more complete genetic dissection of collagen type IV molecules and their developmental function in Drosophila.     

Mucocutaneous autoimmune syndrome following fludarabine therapy for low-grade non-Hodgkin's lymphoma of B-cell type (B-NHL)

A 40-year-old patient with low-grade B-NHL developed a generalized macular-papular rash following the first cycle of fludarabine treatment which progressed to a complete epidermal necrolysis following the second cycle. Clinical symptoms and the results of the direct and indirect immunofluorescence were consistent with a mucocutaneous autoimmune syndrome (pemphigus). Immunohistochemical analysis demonstrated a dense epidermal infiltration of CD8+ lymphocytes associated with the histological features of single-cell necrosis of keratinocytes. Early and aggressive immunosuppressive treatment with steroids, cyclophosphamide, and high-dose immunoglobulins resulted in regression of symptoms and complete reconstitution of epidermal integrity. The malignant lymphoma has completely regressed. The findings suggest a fludarabine-induced defect in immunosurveillance--resulting in the uncontrolled activation of autoaggressive T-cell clones--as a pathogenetic mechanism of this life-threatening dermatological complication.     

Cladribine in the treatment of advanced relapsed or refractory low and intermediate grade non-Hodgkin's lymphoma

BACKGROUND: Cladribine (2-chlorodeoxyadenosine) is a purine nucleoside analog with cytotoxic activity against both resting and proliferating cells. Clinical studies with cladribine have reported antitumor activity against various hematologic malignancies. METHODS: The authors studied responses to cladribine among patients with low and intermediate grade non-Hodgkin's lymphoma that had been refractory to or relapsed after prior chemotherapy. Cladribine was given intravenously over 2 hours at a dose of 0.14 mg/kg daily for 5 consecutive days, repeated every 4 weeks. RESULTS: Twenty-eight patients (16 males, 12 females) with a median age of 58 years (range, 41-75 years) were accrued. Twenty-three patients had low grade and 5 had intermediate grade lymphoma. Stage IV disease was present in 22 (79%), and 17 (61%) had systemic B-symptoms. The majority (57%) had received 2 or more prior chemotherapy regimens (median, 2; range, 1-5); 6 had had prior fludarabine therapy. Major responses were documented in 32% (9 of 28 patients), with 4 complete remissions (CR) and 5 partial remissions (PR) after a median of 4 cycles (range, 1-9). One CR occurred in one patient with intermediate grade diffuse large cell lymphoma, and three of six patients who had had prior fludarabine therapy experienced CR or PR with cladribine. Severe hematologic toxicities included reversible neutropenia, protracted thrombocytopenia, and lymphopenia. Other reported adverse effects included mild-to-moderate fatigue, nausea, and diarrhea. CONCLUSIONS: Cladribine is an active single agent in the treatment of patients with refractory or relapsed advanced stage indolent lymphoma, with major responses in one third of patients.     

In vitro testing of calcium channel blockers and cytotoxic chemotherapy in B-cell low-grade non-Hodgkin's lymphoma

The flux of calcium forms an important intracellular messenger system. The bcl-2 oncoprotein is thought to make cells resistant to a variety of insults, including cytotoxic drugs, by the suppression of apoptosis, which appears to involve the repartitioning of intracellular calcium. Three drugs that affect calcium pathways and may influence this repartitioning, i.e. dantrolene, azumolene (a water-soluble dantrolene analogue) and nimodipine, were studied in cell culture, using both a transformed follicle centre lymphoma cell line and primary culture of lymphoma cells in vitro in a manner that resulted in a growth pattern closely resembling that of the malignancy in vivo. Dantrolene and azumolene were potent inducers of cell death in both systems reducing the viable cell count by 70-90% in comparison with normal controls. Nimodipine, in comparison, appeared to have no significant effect. These results obtained in an in vitro setting suggest that further evaluation of dantrolene and azumolene for the treatment of low-grade non-Hodgkin's lymphoma is warranted.     

Prognostic value of serum IL-10 and soluble IL-2 receptor levels in aggressive non-Hodgkin's lymphoma

We investigated the prognostic significance of interleukin-10 (IL-10) and soluble interleukin-2 receptor (sIL-2r) levels in the pretreatment serum of 105 individuals with newly-diagnosed aggressive non-Hodgkin's lymphoma (NHL). Commercially available enzyme-linked immunoassay kits were used for cytokine and receptor measurements. Detectable levels of IL-10 were found in 42 (40%) patients at diagnosis, with no correlation with clinico-haematological parameters, but in no control samples (P < 0.001). Pretreatment concentrations of sIL-2r were markedly increased in individuals with NHL when compared to controls (2614 +/- 893 U/ml v 219 +/- 65 U/ml, P < 0.001), patients with stage III/IV presenting higher values than those with stage II disease (3885 +/- 1196 U/ml v 1732 +/- 646 U/ml, P < 0.001). No single parameter was associated with the achievement of complete remission, but the combination of elevated IL-10 and of sIL-2r greater than 3000 U/ml selected a subset of patients with a high probability of failing induction therapy (P < 0.001). Life-table analysis also indicated that patients with these characteristics have a significantly shorter event-free survival. In a multivariate analysis the combination of IL-10 with sIL-2r was found to have greater predictive strength than the combination of IL-10 with beta 2-microglobulin. We conclude that IL-10 and sIL-2r measurements can be expected to improve existing methods of risk assignment in aggressive NHL.     

Detection of occult low-grade b-cell non-Hodgkin's lymphoma in patients with chronic hepatitis C infection and mixed cryoglobulinemia

Hepatitis C virus (HCV) is both hepatotropic and lymphotropic and has been shown to be associated with the benign lymphoproliferative disorder, mixed cryoglobulinemia (MC). Preliminary studies suggest that there may be an association between chronic hepatitis C, MC, and non-Hodgkin's lymphoma (NHL). The aim of this study was to determine whether patients with chronic HCV and MC have occult bone marrow NHL. Sixteen patients with chronic HCV and clinically active MC underwent bone marrow biopsy and aspiration. Flow cytometry was performed looking for abnormal B-cell lineage. Molecular genetic studies were performed to identify B-cell monoclonality. Nine of 16 patients (56%) had abnormal marrow morphology, 7 (44%) were interpreted as suspicious for lymphoma, and 2 (13%) as consistent with lymphoma. Flow cytometry on 13 patients identified 5 (39%) with increased B-cell populations. Molecular analysis on 13 patients identified 3 (23%) with monoclonal proliferation of the B-cell lineage. All 13 patients tested for Epstein-Barr virus were negative by polymerase chain reaction (PCR). Four of 16 patients (25%) had marrow morphology and evidence of a monoclonal B-cell population by flow cytometry and/or molecular studies, consistent with B-cell NHL. These findings confirm the presence of lymphoproliferative disorders in patients with chronic HCV and MC. Some of these disorders meet the morphological and molecular criteria for the diagnosis of malignant lymphoma.     

BCL-6 and other genomic alterations in non-Hodgkin's lymphoma (NHL)

This study reports on the frequency and disease association pattern of a number of gene rearrangements in a large panel of lymphoid tumours (n = 94). We detected the t(11;14) translocation, involving rearrangement of the BCL-1 locus, in 60% of mantle cell lymphomas. The BCL-2 gene, located at band 18q21, was rearranged in 42% of follicle centre lymphomas (FCL) and in 15% of diffuse large B-cell (DLBC) lymphomas. In this study, 80% of the c-MYC rearrangements were detected in aggressive diffuse lymphoma subsets but, interestingly, 9% of FCL showed involvement of t(8q24) translocation. In our study, rearrangements of the BCL-6 gene at band 3q27 were found in 31% of DLBC lymphomas. Interestingly, 50% of the BCL-6 rearrangement positive lymphoma cases had coexisting gene rearrangements involving all of the aforementioned gene loci. The molecular dissection of these genes will improve our understanding of the genesis of the diverse clinicopathological subtypes.     

Association of the subtype 2 of the Epstein-Barr virus with T-cell non-Hodgkin's lymphoma of the midline granuloma type

Lethal midline granuloma (LMG) is associated with Epstein-Barr virus (EBV). The latter has at least two subtypes with different biological properties. The subtypes can be identified by their genomic configuration. Using EBV-RNA (EBER) in situ hybridization and EBV polymerase chain reaction (PCR), we have looked for the presence of EBV in six LMGs and six non-Hodgkin's lymphomas (NHLs) located in the nasopharyngeal region, and determined the subtype of EBV. Six of six LMGs were positive by PCR and EBER in situ hybridization, whereas NHLs were either negative or, in three of six cases, showed few EBER-positive cells considered to be nonneoplastic lymphocytes. The subtype 2 was found in LMG lesions of three of six patients; the remaining three of six patients with LMG had the generally occurring subtype 1. The results indicate that the association of EBV with NHL may depend more on tumor type than on its localization. The occurrence of the rare subtype 2 in LMG may relate to a covert immune defect.     

Epirubicin (CEOP-Bleo) versus idaurubicin (CIOP-Bleo) in the treatment of elderly patients with aggressive non-Hodgkin's lymphoma: dose escalation studies

One hundred and sixty nine untreated elderly patients (median age 69 years old; range 60-89 years old) with high or high-intermediate clinical risk non-Hodgkin's lymphoma were enrolled in a controlled clinical trial to evaluate escalated doses of epirubicin in a CEOP-Bleo regimen (cyclophosphamide, vincristine, epirubicin, prednisone and bleomycin), compared to escalated doses of idaurubicin in an CIOP-Bleo regimen (idaurubicin instead of epirubicin). Overall, 71% of the patients in the CEOP-Bleo arm achieved a complete response compared to only 48% in the CIOP-Bleo regimen (p < 0.01). At actuarial 3 year, 72% of the patients treated with the CEOP-Bleo regimen remained alive and free of disease, compared to 34% in the CIOP-Bleo arm (p < 0.01). Dose intensity was 0.86 in the epirubicin regimen, similar to 0.82 in the idaurubicin arm. Toxicities were more frequent and severe in the CEOP-Bleo regimen; however, no death-related treatment was observed in either groups. Cardiac toxicity was also similar in both arms. We conclude that treatment of elderly paitents with aggressive non-Hodgkin's lymphoma should be considered a curative attempt and not only palliative. The use of full doses of chemotherapy should be contemplated in elderly patients. Epirubicin, in escalating doses, is a drug with mild toxicity and improvement in outcome in this setting is observed. We cannot confirm the usefulness of idaurubicin, including escalating doses, in the treatment of patients with aggressive malignant lymphoma, because the complete response rate and survival were worse than other chemotherapy regimens. We feel that the CEOP-Bleo regimen with escalated doses of epirubicin is a useful option in the treatment of elderly patients with aggressive non-Hodgkin's lymphoma.     

Efficacy and toxicity of 2-Chlorodeoxyadenosine (Cladribine)--2 h infusion for 5 days--as first-line treatment for advanced low grade non-Hodgkin's lymphoma

2-Chlorodeoxyadenosine (Cladribine) is a new purine analogue with high activity in pretreated low grade non-Hodgkin's lymphoma (NHL). To evaluate the efficacy of this drug in untreated patients with advanced NHL, we performed a prospective multicentre trial. Cladribine (0.12 mg/kg) was administered intravenously daily for 5 consecutive days in an out-patient setting. The treatment was repeated every 28 days for four cycles. Included were patients with a histological diagnosis of low grade NHL according to the Kiel classification and stage III or IV disease. Stage II patients were included when radiotherapy had failed. 55 patients were entered into the study. 50 patients were evaluable. The remission rate was 44/50 (88%; 95% confidence interval 82-100%), including complete remissions (CR) in 14 (28%) patients. Only 2 patients showed progression while on Cladribine treatment. The estimated overall survival, and time to treatment failure (TTF) were 85% and 51%, respectively, after a median observation time of 92 weeks. 11 (22%) patients showed grade 3 or 4 toxicity according to the WHO grading. Haematological toxicity was responsible for 86% of the overall toxicity and 100% of grade 3 and 4 toxicity. 7 patients (14%) had an infection, two of which were opportunistic. 12 (24%) patients did not experience any toxicity during the treatment. The results of this study clearly demonstrate the safety and considerable activity of this regimen. Cladribine is very effective even at lower doses than have been used so far.     

Recombinant human erythropoietin in the anemia associated with multiple myeloma or non-Hodgkin's lymphoma: dose finding and identification of predictors of response

Previous phase I-II clinical trials have shown that recombinant human erythropoietin (rHuEpo) can ameliorate anemia in a portion of patients with multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL). Therefore, we performed a randomized controlled multicenter study to define the optimal initial dosage and to identify predictors of response to rHuEpo. A total of 146 patients who had hemoglobin (Hb) levels < or = 11 g/dL and who had no need for transfusion at the time of enrollment entered this trial. Patients were randomized to receive 1,000 U (n = 31), 2,000 U (n = 29), 5,000 U (n = 31), or 10,000 U (n = 26) of rHuEpo daily subcutaneously for 8 weeks or to receive no therapy (n = 29). Of the patients, 84 suffered from MM and 62 from low- to intermediate-grade NHL, including chronic lymphocytic leukemia; 116 of 146 (79%) received chemotherapy during the study. The mean baseline Hb level was 9.4 +/- 1.0 g/dL. The median serum Epo level was 32 mU/mL, and endogenous Epo production was found to be defective in 77% of the patients, as judged by a value for the ratio of observed-to-predicted serum Epo levels (O/P ratio) of < or = 0.9. An intention-to-treat analysis was performed to evaluate treatment efficacy. The median average increase in Hb levels per week was 0.04 g/dL in the control group and -0.04 (P = .57), 0.22 (P = .05), 0.43 (P = .01), and 0.58 (P = .0001) g/dL in the 1,000 U, 2,000 U, 5,000 U, and 10,000 U groups, respectively (P values versus control). The probability of response (delta Hb > or = 2 g/dL) increased steadily and, after 8 weeks, reached 31% (2,000 U), 61% (5,000 U), and 62% (10,000 U), respectively. Regression analysis using Cox's proportional hazard model and classification and regression tree analysis showed that serum Epo levels and the O/P ratio were the most important factors predicting response in patients receiving 5,000 or 10,000 U. Approximately three quarters of patients presenting with Epo levels inappropriately low for the degree of anemia responded to rHuEpo, whereas only one quarter of those with adequate Epo levels did so. Classification and regression tree analysis also showed that doses of 2,000 U daily were effective in patients with an average platelet count greater than 150 x 10(9)/L. About 50% of these patients are expected to respond to rHuEpo. Thus, rHuEpo was safe and effective in ameliorating the anemia of MM and NHL patients who showed defective endogenous Epo production. From a practical point of view, we conclude that the decision to use rHuEpo in an individual anemic patient with MM or NHL should be based on serum Epo levels, whereas the choice of the initial dosage should be based on residual marrow function.     

Analysis of ploidy and proliferative activity in childhood non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD)

We have performed DNA analysis by means of fluorescence-activated cell cytometry on paraffin-embedded tissue from the diagnostic biopsy specimens in 40 cases of non-Hodgkin's lymphoma (NHL) and 25 of Hodgkin's disease (HD) and from 50 normal tonsils as controls. For HD cases, aneuploidy was found in 7 of 25 (28%), a higher proportion than in two previous studies of mainly adult patients. Diploid tumors showed S-phase fractions (SPFs) similar to those of controls. In the NHL cases aneuploidy was found in 12 of 40 (30%) with no significant association with site, stage, histopathology, immunophenotype, or prognosis. SPFs were highest in abdominal and chest primary sites but were not related to stage. Burkitt's lymphomas had the highest SPFs relative to lymphoblastic (P < .01) and centroblastic lymphomas (P < .05). Significantly higher SPFs were found in B cell than in T cell tumors (P < .001). There was considerable heterogeneity for SPFs within each NHL subgroup. Survival was worse at 5 years for those with high SPFs compared with those with normal SPFs (P = .04). These results suggest that tumor DNA analysis may be useful in the evaluation of children with NHL. Larger studies are needed to define its role as an independent prognostic variable.     

Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in dura

The study was designed to clarify the difference in pharmacokinetics of monoclonal antibodies (mAb) in animal models and humans, and to elucidate the applicability of animal models. 99mTc-labeled murine mAb -- against carcinoembryonic antigen (designated BW431/26), and neural cell adhesion molecule (NE150) -- and one chimeric mouse/human mAb against nonspecific cross-reacting antigen (chNCA) were administered i.v. to normal mice and athymic mice (370 kBq, 400 ng) xenografted with human cancer cells expressing antigens, and into patients with tumor (925 MBq, 1 mg). The biodistribution of two of the three mAb (not 99mTc-BW431/26) differed clearly in mice and patients. 99mTc-NE150 showed specific uptake in xenografted tumor and otherwise a normal biodistribution; however, clinical examination showed increased uptake in the liver with rapid blood clearance (mean alpha half-life = 31.1 min) compared with 99mTc-BW431/26 (28.4 h). 99mTc-chNCA demonstrated increased blood clearance and renal excretion in both normal and athymic mice, with accumulation in tumors. Clinical examination showed rapid blood clearance (mean alpha half-life = 6.4 min) and increased uptake in the liver. High-performance liquid chromatographic analysis of 99mTc-chNCA revealed the immune complex in blood, suggesting uptake of the complex by the reticuloendothelial cells. The biodistribution of radiolabeled mAb in animal and human models was variable and specific for each of the three mAb. The results of animal studies with mAb should be evaluated carefully before being extrapolated to humans, on the basis of the nature of the mAb and interacting substances.     

Anti-CD45 and anti-CD52 (Campath) monoclonal antibodies effectively eliminate systematically disseminated human non-Hodgkin's lymphoma B cells in Scid mice

Severe combined immunodeficient (Scid) mice inoculated with the human (t(14;18)-positive B cell lines DoHH2 and BEVA develop lethal systemically disseminated lymphoma (de Kroon et al., Leukemia 8:1385, and Blood 80 [suppl 1]:436). These models were used to study the therapeutic effect of rat-anti-human CD52 (Campath-1G) or CD45 monoclonal antibodies (mAbs) on systemically disseminated tumor cells and on tumor cells present in solid tumor masses. Both mAbs were effective in inhibiting growth of systemically disseminated malignant cells. When treatment with anti-CD52 or anti-CD45 mAbs at a dose of 30 micrograms/mouse/d for 4 days was started 24 hours after intravenous inoculation of human DoHH2 or BEVA cells, a 3-log kill of tumor cells was observed as measured by prolonged survival. After treatment, surviving animals injected with high numbers of BEVA cells showed tumor masses in liver, kidney, and mesenteric lymph nodes. In contrast to nontreated animals, however, only low numbers of malignant cells were found in peripheral blood, and bone marrow was free of tumor cells. Similarly, after mAb treatment of mice inoculated subcutaneously (sc) with DoHH2 cells, no tumor cells could be found in the bone marrow, and few DoHH2 cells could be detected in the peripheral blood, spleen, liver, kidney, or lung. In contrast, tumor cells present in subcutaneous tumors and axillary lymph nodes were relatively unaffected by mAb therapy. The presence of rat immunoglobulin (Ig) could be demonstrated on surviving tumor cells. The presence of murine macrophages in areas in these tumors that were depleted of DoHH2 cells suggested that the mAb-mediated antitumor effect observed in the Scid mouse model is mediated by cellular mechanisms. Apparently these mechanisms were not sufficient to eliminate the fast-growing tumor cells present in the protected sites. Our results indicate that treatment with anti-CD52 or anti-CD45 mAbs potentially may be useful as adjuvant immunotherapy for systemically disseminated B cell lymphoma.     

Prognostic significance of t(14;18) and bcl-2 gene expression in follicular small cleaved cell lymphoma and diffuse large cell lymphoma

Affected and unaffected members of a Caucasian family with Werner syndrome were analyzed for mutations in the recently described Werner syndrome (WRN) gene and for their relevance to phenotypic expression of chromosomal instability and x-ray hypersensitivity. Two distinct molecular alterations were documented in the family. Analysis of the genomic DNA revealed a single-base exchange from A to T at an intron-exon boundary in the otherwise strongly conserved 5' donor splice site. Consequently, exon 30 is spliced together with the intron. The ensuing structure could be confirmed by the presence and calculated size of the resulting RNA fragments. The patients, all compound heterozygotes, had a 1-bp deletion in the first third of the coding sequence in the other allele. The genotypes of the family members for these mutations were determined and consequences for the cellular phenotype of the otherwise unaffected heterozygotes are documented.