Interleukin-2 treatment in lymphoma: a phase II multicenter study [see comments]

A phase II study was undertaken to assess whether continuous infusion of high-dose recombinant interleukin-2 (rIL-2) alone was active against different histologic subtypes of heavily pretreated lymphoma. Sixty one lymphomas were included in the study. rIL-2 (Roussel UCLAF, Romainville, France) was administered by continuous infusion at 20 x 10(6) IU/m2 for three cycles of 5 days, 4 days, and 3 days, during the first week, third week, and fifth week, respectively. Twenty-four low- grade non-Hodgkin's lymphomas (NHL) were resistant to an anthracycline- containing regimen. Twenty-three intermediate and high-grade NHL were refractory to initial treatment or to salvage therapy. Seven Hodgkin's diseases were refractory to at least three regimens or relapsed after autologous bone marrow transplantation. Seven mycosis fungoides were refractory to chemotherapy. In low-grade NHL, one complete response (CR) was observed. In aggressive NHL, there were three CRs and two partial responses (PRs). No response was noted in Hodgkin's disease. One CR and four PRs were observed in mycosis fungoides. Complete response durations were 23, 20, 17, 12, and 4 months. Grade 4 toxicity was observed in 29 patients leading to arrest of therapy in 12 patients. The response to rIL-2 therapy in lymphoma differs according to histologic subtypes. Five responses were observed in 23 aggressive lymphomas. Five of seven mycosis fungoides responded; these preliminary results warrant testing of a larger number of patients.     

Interleukin-5 is an autocrine growth factor for Epstein-Barr virus-transformed B lymphocytes.

Because of the recent finding that interleukin-5 (IL-5) is produced by Epstein-Barr virus-transformed B lymphocytes (EBV-B cells), we performed studies to ascertain whether EBV-B cells might use IL-5 by an autocrine mechanism. EBV-B cells known to be IL-5 producers were capable of responding to addition of exogenous IL-5 by dose-related augmented proliferation. The addition of a neutralizing anti-IL-5 antibody reduced these effects and also dose-dependently inhibited proliferation and reduced viability of unsupplemented EBV-B cells, having a maximum effect at about 120 hours. In contrast, no stimulatory effect of IL-5 was noted on Burkitt's lymphoma cell lines, nor were these lines growth-inhibited by anti-IL-5 antibody. With biotinylated IL-5, (b-IL-5) second labeling with streptavidin-FITC, and flow cytometric analysis, binding of IL-5 to EBV-B cells cultured in fresh medium was demonstrated and could be competed for by excess unlabeled IL-5, suggesting the presence of IL-5-specific binding sites. Binding of IL-5 was reduced on cells cultured for longer periods before study but could be restored by extensively washing cells before labeling them with b-IL-5, suggesting that surface binding sites had become occupied by endogenously produced IL-5. These findings support a role for IL-5 in autocrine support of EBV-B cell growth.     

Activation of factor XI in plasma is dependent on factor XII [see comments]

The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable.     

Interleukin-10 is a growth factor for human myeloma cells by induction of an oncostatin M autocrine loop

We have a previously reported that interleukin-10 (IL-10) is a potent but IL-6-unrelated growth factor for freshly explanted myeloma cells (Lu et al, Blood 85:2521, 1995). We have also shown that exogenous IL- 10 supported the growth of XG-1 and XG-2 human myeloma cell lines (HMCL) through an IL-6-independent mechanism. (Lu et al, Blood 85:2521, 1995). Because the IL-10 receptor does not involve the gp 130 IL-6 transducer, we have attempted to elucidate the mechanisms of IL-10 action on myeloma cells. Our results indicate that the myeloma cell growth factor activity of IL-10 was abrogated by an antibody to the gp 130 IL-6 transducer, indicating that it was mediated through one of the gp 130-activating cytokines. We found that myeloma cells from XG-1 and XG-2 HMCL and from 5 of 6 patients' tumoral samples produced oncostatin M (OM) constitutively but failed to produce IL-6, IL-11 and leukemia- inhibitory factor (LIF). The autocrine OM was inactive in the absence of IL-10 due to lack of a functional OM receptor on myeloma cells. IL- 10, by inducing the receptor for LIF (LIFR), produced a functional autocrine OM loop in XG-1 and XG-2 cells and in primary myeloma cells from 2 patients. We also found that some myeloma cell lines (XG-4, XG- 6, and XG-7) an fresh myeloma cells from 3 of 6 patients produced an autocrine IL-10 and that these cells constitutively expressed LIFR. One HMCL (XG-7) produced IL-10, OM, and IL-6 an expressed LIFR. The XG-7 cells used OM and IL-6 as autocrine growth factors. We have previously shown that IL-10 could induce IL-11 receptor in myeloma cells and confer on them sensitivity to IL-11 (Lu et al, FEBS Lett 377:515, 1995). Taken together, these results show that IL-10 is a key cytokine for inducing the expression of LIFR and IL-11R and possibly another uncharacterized OM coreceptor on myeloma cells and that OM and IL-10 might be produced by myeloma cells. They also emphasize that all myeloma cell growth factors reported to data involve an activation of the gp130 IL-6 transducer.     

Splenectomy is safe and effective in human immunodeficiency virus- related immune thrombocytopenia [see comments]

Sixty-eight patients, followed in a prospective cohort study of 185 human immunodeficiency virus (HIV)-infected patients with severe immune thrombocytopenia (platelets < 50 x 10(9)/L), underwent splenectomy, 2 to 41 months (median: 10 months) after immune thrombocytopenic purpura (ITP) was diagnosed. The mean platelet count increased from 18 x 10(9)/L to 223 x 10(9)/L with a persistent increase in 56 (82%). It also led to a significant increase of the mean CD4 cell count from 475 x 10(6)/L to 725 x 10(6)/L within a mean delay of 10 months. In the whole cohort, with a mean follow-up of 63 months (range, 6 to 126), the 5-year estimated rate for progression to acquired immunodeficiency syndrome (AIDS) was 23% (95% confidence interval [CI], 15% to 31%) and the AIDS-free survival was 69% (95% CI, 61% to 77%). To investigate the potential impact of splenectomy, a Cox's multiple regression model was used; as splenectomy was not randomly assigned, it was incorporated as a time-dependent covariate. After adjustment on the CD4 cell count, no statistically significant differences were observed between the splenectomized and the nonsplenectomized patients: AIDS progression rate (P = 0.23), survival (P = 0.64) and AIDS-free survival (P = 0.72) were not influenced by splenectomy. Splenectomy is both effective and safe in the treatment of severe, refractory ITP associated with HIV infection.     

Graft-v-host disease is associated with autoimmune-like thrombocytopenia [see comments]

Persistent thrombocytopenia after allogeneic marrow transplantation is associated with poor patient survival. To identify the mechanisms of the thrombocytopenia, we studied platelet and fibrinogen kinetics and antiplatelet antibodies in 20 patients between 60 and 649 days (median 90) after transplantation. Seventeen patients had isolated thrombocytopenia (less than 100 X 10(9) platelets/L): the marrow cellularity was normal in five patients and slightly reduced in 12, and there was no discrepancy between thrombopoiesis and myeloerythropoiesis. Three patients had pancytopenia following marrow graft rejection (two) and relapse of leukemia (one). Only three patients had evidence of increased platelet production, indicating that in most cases there is a poor marrow response to thrombocytopenia early after marrow grafting. There was no correlation between platelet count and splenic pooling, suggesting that hypersplenism was an unlikely mechanism of the thrombocytopenia. Although there was a direct relationship between platelet count and platelet survival, the reduction in platelet survival was greater than what could be explained by the fixed platelet removal found in thrombocytopenic patients; this suggests increased platelet destruction. Seven patients had intercurrent infections that reduced both platelet and fibrinogen survivals. In addition, platelet antibodies bound to autologous or marrow donor platelets were present in five of the 12 patients studied. Patients with antiplatelet antibodies had lower platelet counts (30 +/- 10 X 10(9)/L v. 49.1 +/- 28.7 X 10(9)/L, P less than 0.05) and platelet survivals (1.32 +/- 0.92 days v. 3.58 +/- 2.02 days, P less than 0.05) than patients without antiplatelet antibodies. Furthermore, platelet- bound autoantibodies were present in five of six patients with grade II- IV acute or chronic graft-versus-host disease (GVHD), but were not present in six patients free of GVHD (P less than 0.01). We conclude that persistent thrombocytopenia after marrow transplantation is most often secondary to increased platelet destruction mediated by multiple mechanisms and that platelet autoantibodies are found in patients with acute or chronic GVHD.     

Interleukin-4 is an autocrine growth factor secreted by the L-428 Reed-Sternberg cell.

Recent evidence indicates that Reed-Sternberg (RS) cells from many cases of Hodgkin's disease have features of activated lymphocytes and that lymphokines from activated lymphocytes induce proliferation of L-428 RS cells. It is shown here that a lymphokine similar to a lymphokine secreted by activated lymphocytes is secreted by L-428 cells. This lymphokine has a molecular weight approximately equal to 68,000 daltons, identical to glycosylated recombinant interleukin-4 (rIL-4), and cross-reacts with monoclonal anti-IL-4 in Western immunoblotting. This Hodgkin's cell growth factor (HCGF) is 100% neutralized by polyclonal anti-IL-4 antibodies and competes for the IL-4 receptor. After acid-elution, the L-428 RS cell has been shown to have 3,396 +/- 120 high-affinity receptor sites/cell. HCGF competes with rIL-4 for this receptor and L-428 cells contain mRNA for IL-4. Although all evidence indicates that IL-4 is an important secreted autocrine growth factor for L-428 RS cells, anti-IL-4 has no effect on the sustained serum-free growth of these Hodgkin's cells, suggesting that either the IL-4 receptor and the IL-4 receptor-growth factor complex are protected from antibody inhibition or other mechanisms are responsible for the sustained proliferation of L-428 RS cells.     

Desmopressin: a nontransfusional form of treatment for congenital and acquired bleeding disorders [see comments]

Desmopressin (1-deamino-8-D-arginine vasopressin, abbreviated DDAVP) is a synthetic analogue of the antidiuretic hormone L-arginine vasopressin. Because it can raise circulating levels of factor VIII coagulant activity (FVIII) and von Willebrand factor and shorten the prolonged bleeding time, DDAVP is established as a nontransfusional form of treatment for mild and moderate hemophilia and von Willebrand disease. Recently, DDAVP has also been purported to be useful for shortening the prolonged skin bleeding times that occur with uremia, cirrhosis, and platelet dysfunctions of various etiologies. Finally, there is evidence from controlled clinical trials that DDAVP can reduce blood loss and transfusion requirements for hemostatically normal individuals undergoing spinal fusion surgery and for patients undergoing cardiopulmonary bypass surgery. The purpose of this report is to review the therapeutic applications of DDAVP in congenital and acquired bleeding disorders and to discuss areas in which further basic and clinical research is needed.     

Studies of the activation of factor VII bound to tissue factor [see comments]

Experiments were performed to evaluate activation of factor VII bound to relipidated tissue factor (TF) in suspension and to TF constitutively expressed on the surface of an ovarian carcinoma cell line (OC-2008). Activation was assessed by measuring cleavage of 125I- factor VII and by the ability of unlabeled factor VII to catalyze activation of a variant factor IX molecule that, after activation, cannot back-activate factor VII. Factor Xa was found to effectively activate factor VII bound to TF relipidated in either acidic or neutral phospholipid vesicles. Autoactivation of factor VII bound to TF in suspension was dependent on the preparation of TF apoprotein used and the technique of its relipidation. This highlights the need for caution in extrapolating data from TF in suspension to the activation of factor VII bound to cell surfaces during hemostasis. A relatively slow activation of factor VII bound to OC-2008 monolayers in the absence of added protease was observed consistently. Antithrombin in the presence or absence of heparin prevented this basal activation, whereas TF pathway inhibitor (TFPI/factor Xa complexes had only a limited inhibitory effect. Adding a substrate concentration of factor X markedly enhanced basal activation of factor VII, but both TFPI/factor Xa and antithrombin/heparin abolished this enhancement. Overall, our data are compatible with the hypothesis that not all factor VII/TF complexes formed at a site of tissue injury are readily activated to factor VIIa (VIIa)/TF complexes during hemostasis. The clinical significance of this is discussed.     

Human immunodeficiency virus infection of bone marrow endothelium reduces induction of stromal hematopoietic growth factors [see comments]

The majority of human immunodeficiency virus (HIV)-seropositive patients develop bone marrow abnormalities associated with hematopoietic malfunction during the progression of disease. One important manifestation of HIV-associated hematopoietic dysfunction is that after myelosuppression, bone marrow recovery, a process known to be mediated in part by the production of stromal cell-derived hematopoietic growth factors, is impaired. We sought to test the hypothesis that bone marrow stromal cells are infected by HIV-1 in vivo and that production of certain stromal cell-derived hematopoietic growth factors is deficient as a consequence. In this report, we demonstrate that bone marrow microvascular endothelial cells (MVEC), a key element of the stroma, are the predominant cells infected by HIV (5% to 20%) in bone marrow stromal cultures obtained from 11 consecutive HIV-seropositive patients. Although HIV-infected stromal cultures enriched for MVEC constitutively express normal levels of interleukin (IL)-4, IL-6, granulocyte (G)-colony-stimulating factor (CSF), granulocyte-macrophage (GM)-CSF, tumor necrosis factor (TNF)- alpha, transforming growth factor (TGF)-beta, and Steel factor, IL-1 alpha-induced release of IL-6 and G-CSF is significantly reduced in these cultures. These observations suggest that HIV infection of bone marrow MVEC reduces the capacity of hematopoietic stroma to respond to regulatory signals that normally augment blood cell production during periods of increased demand.     

Wegener's granulomatosis autoantigen is a novel neutrophil serine proteinase [see comments]

Circulating IgG autoantibodies that produce cytoplasmic immunofluorescence staining of ethanol-fixed normal neutrophils have recently been found in a large percentage of patients with active Wegener's granulomatosis. Such autoantibodies are rarely found in other diseases and are therefore virtually diagnostic of Wegener's granulomatosis. The nature of the neutrophil antigen defined by these autoantibodies is controversial and the roles of the antigen and/or autoantibodies in the pathogenesis of Wegener's granulomatosis are unknown. We studied serum samples that produce the cytoplasmic pattern of staining from 10 patients with a diagnosis of Wegener's granulomatosis. By Western blot analysis, all 10 sera reacted with a 29- Kd neutrophil protein (p29). We generated a mouse monoclonal antibody directed against this antigen. The monoclonal antibody produced the same immunofluorescence staining pattern as the serum autoantibodies and was used to affinity-purify p29. The purified antigen had a novel N- terminal sequence homologous to members of the serine proteinase family and bound to radiolabeled diisopropyl fluorophosphate (DFP). We conclude that the neutrophil antigen responsible for the cytoplasmic staining pattern produced by autoantibodies in patients with active Wegener's granulomatosis is a distinctive serine proteinase.     

Phase II trial of 2-chlorodeoxyadenosine for the treatment of cutaneous T-cell lymphoma [see comments]

We investigated the efficacy of 2-chlorodeoxyadenosine (2-CdA) therapy in patients with mycosis fungoides (MF) and the Sezary syndrome (SS). Between February 1991 and November 1993, 21 patients with relapsed or refractory MF/SS were treated with 2-CdA. 2-CdA was administered by continuous intravenous infusion at a dose of 0.1 mg/kg/d for 7 days initially (13 patients), but was subsequently reduced to 5 days (nine patients) due to hematologic toxicity. All patients had failed to respond to at least one prior treatment for MF/SS (median number of total prior therapies, five; median number of systemic prior therapies, three) and had an Eastern Cooperative Oncology Group performance status of two or better. Cycles were administered at 28-day intervals. Assessable patients received at least 5 days of 2-CdA. Fourteen patients received more than one cycle of 2-CdA. An overall response rate of 28% was achieved. Three patients (14%) had a complete response with a median duration of 4.5 months (range, 2.5 to 16). Three (14%) had a partial response with a median duration of 2 months (range, 2 to 4). Fifteen patients (72%) had no response. The most significant toxicities encountered were bone marrow suppression (62% of patients) and infectious complications (62% of patients). Thirty-eight percent of patients experienced no toxicity from 2-CdA. 2-CdA has activity as a single agent in patients with previously treated relapsed MF/SS. Studies in less heavily pretreated individuals with 2-CdA alone or in combination will be undertaken.     

Mitochondrial dysfunctions in circulating T lymphocytes from human immunodeficiency virus-1 carriers [see comments]

In several models of lymphocyte apoptosis, two alterations of mitochondrial function precede advanced DNA fragmentation: (1) a reduction of mitochondrial transmembrane potential (delta psi m) and (2) an increase in mitochondrial generation of superoxide anion. Here we show that two fluorochromes allow for the identification of analogous mitochondrial perturbations in circulating T lymphocytes from human immunodeficiency virus (HIV)-1+ donors. The first among these fluorochromes, the cationic lipophilic dye DiOC6(3), measures delta psi m; the second marker, hydroethidine (HE), is nonfluorescent, unless it is oxidized by superoxide anions to the product ethidium (Eth). CD4+ or CD8+ cells from clinically asymptomatic HIV-1 carriers contain a significantly elevated percentage of cells endowed with enhanced HE --> Eth conversion and/or reduced DiOC6(3) uptake as compared with normal controls. Phenotypic characterization of (HE --> Eth)high cells from HIV+ donors shows that these cells possess a low delta psi m, thus demonstrating a functional alteration of mitochondria. In addition, (HE --> Eth)high cells display a reduced incorporation of the cardiolipin- specific dye nonyl-acridine orange (NAO), showing a structural defect of the cardiolipin-containing inner mitochondrial membrane. Control experiments involving rotenone, an inhibitor of the respiratory chain complex I, indicate that the reactive oxygen species responsible for HE --> Eth conversion is generated during mitochondrial electron transport. In synthesis, it appears that mitochondrial alterations occur in a significant percentage of circulating T lymphocytes from HIV- 1 carriers. The extent of delta psi m reduction, as determined ex vivo, correlates with the frequency of cells undergoing DNA fragmentation after overnight in vitro culture. These observations may be important for the understanding and for the direct ex vivo quantitation of HIV- triggered lymphocyte destruction.     

Interleukin-6 functions as an autocrine growth factor in a cholangiocarcinoma cell line

Abstract The tumour cells of a human cholangiocarcinoma cell line, HuCC-T1, were found to express mRNA of interleukin-6 (IL-6) and to secrete a large amount of biologically active IL-6 in the culture medium at the concentration of 22.6 ng/mL. Interleukin-6 was demonstrated in the cytoplasm of the cells by immunohistochemical staining. Furthermore, these cells showed the presence of receptors for IL-6 on the surface, and DNA synthesis of the cells was stimulated by the exogenous addition of recombinant human IL-6 into the culture medium. The cell growth was significantly inhibited in the presence of anti-human IL-6 antibody in the culture medium. These findings indicate that IL-6 is one of the autocrine growth factors of this cell line in vitro.