Anemia hemolítica autoinmune refractaria: tratamiento con Rituximab, anticuerpo monoclonal anti-CD20 / Refractory autoimmune hemolytic anemia: treatment with Rituximab, monoclonal anti-CD20 antibody

La anemia hemolítica autoinmune en la infancia se caracteriza, en ocasiones por un curso severo y refractario al tratamiento. En estos casos a veces es necesario realizar esplenectomía, lo que supone graves riesgos. Rituximab es un nuevo anticuerpo monoclonal anti CD20 que ya se ha utilizado con éxito en esta enfermedad. Presentamos un caso de un niño diagnosticado de AHAI que fue tratado con esteroides, gammaglobulina y al que se le practicó una es-, plenectomia sin éxito. Se le administró Rituximab a dosis de 375 mg/m2/ semanal durante 4 semanas y, simultaneamente, se inició pauta de descenso corticoidea. A los tres meses del tratamiento con Rituximab presentó un ascenso de la cifra de Hb de 3,5 g/dl y un descenso de la cifra de reticulocito del 67 por ciento. En el seguimiento posterior, durante 14 meses, el paciente se ha mantenido asintomático sin tratamiento ninguno. El tratamiento con Rituximab es una alternativa para esos pacientes refractarios al tratamiento antes de contemplar la esplenectomía (AU)

Criterios diagnósticos y diagnóstico diferencial de la púrpura trombótica trombocitopénica / Diagnostic criteria and differential diagnosis of thrombotic trombocytopenic purpura

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Posttransfusion hepatitis after induction chemotherapy in acute nonlymphoblastic leukemia: implications for long-term management and outcome.

BACKGROUND: The purpose of this study was to evaluate 1) the incidence of hepatitis and its influence on the clinical management of and outcome in acute nonlymphoblastic leukemia (ANLL) patients in first complete remission and 2) the impact of routine hepatitis C virus screening on the incidence of hepatitis in these patients. STUDY DESIGN AND METHODS: Clinical and blood bank charts were reviewed for 65 consecutive ANLL patients between 1985 and 1993 who achieved complete remission after a course of daunomycin and cytarabine (cytarabine: 200 mg/m2/day x 7 days in continuous infusion; daunomycin: 60 mg/m2/day for the first 3 days of the 7, as a bolus). RESULTS: Only 43 percent of patients who developed hepatitis completed the scheduled therapy. Hepatitis did not decrease the probability of relapse (66 +/- 9% vs. 66 +/- 11%), but patients with changes in planned treatment, due to hepatitis or other causes, tended to have a higher relapse rate than patients without changes in consolidation therapy (56.5% vs. 40.4%; p = 0.10). This did not result in a decrease in disease-free survival, however, because of the higher number of treatment-related deaths in the patients without hepatitis (who completed the therapy). Over the period from 1985 through 1989, the 6-month actuarial probability of developing hepatitis was 42 percent. However, since 1989, when hepatitis C screening of blood donors was implemented, the incidence was reduced to 12.5 percent (p < 0.05), in spite of greater transfusion support (172 +/- 46 vs. 89 +/- 53, p < 0.01). No new cases of hepatitis were observed after the introduction of second-generation hepatitis C virus assays. CONCLUSION: Hepatitis precludes the use of consolidation therapy in about half of ANLL patients, resulting, in the experience described here, in a trend toward a higher rate of relapse. Hepatitis C virus screening of blood components reduces the incidence of hepatitis in ANLL patients.

Circulating stem cell collection in lymphoma and myeloma after mobilization with cyclophosphamide and granulocyte colony-stimulating factor for autologous transplantation.

We report the results of 72 leukapheresis procedures performed for autologous peripheral blood stem cell collection in 18 patients with lymphoma and myeloma, after combined mobilization with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF). The numbers of mononuclear cells (MNCs), CD34+ cells and granulocyte-macrophage colony-forming units (CFU-GM) either in the peripheral circulation (preleukapheresis sample) or in the product obtained from leukapheresis (leukapheresis sample) were evaluated. A highly superior proportion of CD34+ cells (14-fold) and CFU-GM (5-fold) resulted from the mobilization therapy. CFU-GM and CD34+ cells were highly enriched with respect to all MNCs (relative recoveries: 2.13, range 0.3-41, and 1.08, range 0.2-8.5, respectively) due to an additional mobilization effect by the leukapheresis procedure. Also, a relatively strong linear correlation between the three different parameters was found in the leukapheresis product (CD34+:CFU-GM, r = 0.81; MNCs:CD34, r = 0.69; MNCs:CFU-GM, r = 0.75; CFU-GM:CD34+, and MNCs, r = 0.85). Our data suggest that the number of MNCs and CD34+ cells obtained after combined mobilization with cyclophosphamide and G-CSF can be used as predictor of the number of granulomonocytic progenitors.

Expression of phosphatidylinositol anchored membrane proteins in paroxysmal nocturnal haemoglobinuria after bone marrow transplantation.

A 20-year-old male with severe bone marrow failure associated with paroxysmal nocturnal haemoglobinuria (PNH) underwent an allogeneic bone marrow transplantation (BMT). Flow cytometric analysis of phosphatidylinositol (PI) anchored membrane proteins prior to BMT showed a markedly reduced expression of monocyte CD14 and neutrophil CD16 molecules. On day +17 after BMT expression of both antigens reached normal values and remained stable throughout a follow-up period of 10 months, thus confirming the eradication of the PNH clone. To date, this is the first case in which normal expression of PI-anchored proteins after BMT is reported.

Studies of in vitro red cell autoantibody production in normal donors and in patients with autoimmune hemolytic anemia.

The in vitro production of red cell autoantibodies (RBC AuAbs) has been investigated for better understanding of the pathogenesis of autoimmune hemolytic anemia (AIHA). Peripheral blood mononuclear cells (PBMNCs) were isolated and cultured for 14 days with or without added pokeweed mitogen (PWM), autologous RBCs, methyldopa, procainamide, and alpha-methylnorepinephrine. Also, isolated B cells were infected with Epstein-Barr virus (EBV) to produce polyclonal B-cell lines. Supernatants were tested for IgG and IgM RBC AuAbs by use of 125I-staphylococcal protein A (SPA). RBC AuAbs were detected in PBMNC cultures without additives to the culture medium of four of eight patients who had warm-antibody AIHA or a positive direct antiglobulin test (DAT) without hemolytic anemia. In two of these patients, RBC AuAb production was augmented by the addition of PWM, and in two additional patients, RBC AuAbs were detected only after the addition of PWM. Supernatants from PBMNC cultures from three of four normal donors produced RBC AuAbs independent of the presence of PWM; in two of these subjects, PWM augmented production of RBC AuAbs. PBMNC cultures from three DAT-negative patients with systemic lupus erythematosus produced RBC AuAbs, one in the presence of PWM and two in its absence. With one exception, there was no augmentation of AuAb production by the addition to the culture system of autologous RBCs or drugs. EBV infection of B cells from four patients with AIHA and four normal persons yielded B-cell lines secreting RBC AuAbs. The quantity of RBC AuAb after a 24-hour culture of EBV-transformed B cells was significantly greater in cultures from four patients who had AIHA than in cultures from four normal persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodialysis associated hypotension and dialysate temperature.

Incidence of intradialytic symptomatic hypotension was significantly reduced by lowering dialysate temperature from 37 degrees C to 35 degrees C. This improvement seems not to be mediated by temperature-induced changes in membrane biocompatibility, since leukocytes, platelets and complement activation were similar in both situations.

Characterization of an intracellular inhibitor of the carboxypeptidase R from Rhodotorula glutinis.

A peptidic inhibitor of the carboxypeptidase R from Rhodotorula glutinis has been identified and partially purified. A molecular weight of 31 000 was found by gel filtration. The inhibitor is reversibly separated from the carboxypeptidase by chaotropic agents. Removal of the inhibitor by an acid protease explains the osberved activation of the carboxypeptidase by incubation at acidic pH values.

Characterization of a carboxypeptidase from the yeast Rhodotorula glutinis.

A carboxypeptidase has been identified in Rhodotorula glutinis and partially purified. The enzyme is active on N-substituted dipeptides and tripeptides and also exhibits an esterolytic activity. Both activities are inhibited by (N-benzyloxycarbonyl-L-phenylalanyl)chloromethane and by a thermostable fraction present in extracts. The enzyme shows a pH optimum in the range 7.5 to 8.0 and has a molecular weight of 80000, determined by gel filtration.