HIV incidence and residual transfusion risk estimates are approximately 10 times higher in Brazil FT donors compared to US and European FT donors. Community FT donors had higher HIV prevalence than replacement FT donors. The yield of p24 antigen or RNA screening will be low in Brazilian donors, but substantially higher than in US donors.

No single test for Chagas' disease is sufficiently sensitive to prevent transfusion transmission of the disease in the urban centers of Brazil.

Blood transfusion is one of the principal routes of transmission of Chagas' disease, a major endemic disease in Latin America. Methods for blood screening are not accurate and may yield false results that lead to high social and economic costs. This study compares two methods of diagnosing Chagas' disease (indirect immunofluorescence and hemagglutination) and several enzyme-linked immunosorbent assays (ELISAs) with regard to specificity and sensitivity, by using human sera with known serologic and parasitologic characteristics, as well as samples with discrepant results on conventional serologic tests. An ELISA using recombinant antigens showed no cross-reactivity with sera that were positive for other diseases. All evaluated ELISAs performed well, and their use may lead to a reduction of more than 50 percent in the number of discordant sera. Further improvements are needed in view of the complexity of the serologic diagnosis of Chagas' disease.

Our data provide evidence that the São Paulo population has responded well to the marketing strategies that have been introduced in our institution. We believe that similar promotional efforts elsewhere in Brazil would produce comparable, positive results.

No abstract

The decrease in the discarding of blood units and in infectious diseases among donors at the Blood Center of São Paulo reflects the increase in the Center's percentage of repeat donors.

Our data show a clear improvement in performance of Brazilian blood banks testing for Chagas' disease.

Background: Few immunohematological studies have been done in myelodysplastic syndrome (MDS). Methods: Twenty-nine MDS patients were retrospectively evaluated with a direct antiglobulin test (DAT), antibody screening, serum electrophoresis and immunoelectrophoresis. Clinical and laboratory studies (hemoglobin level, reticulocyte count, DHL, total and indirect bilirubin) were done simultaneously, as well as the French-American-British subtype and bone marrow biopsy findings. Results: Alloantibodies were demonstrated in 17 patients (58.6%), autoantibodies in 10 (34.4%) patients and cold agglutinin in 18 (62%) patients. DAT was mediated by only IgG in 8 patients (80%), by IgG and C3 in 1 patient (10%) and by IgG, IgA and C3 in 1 (10%) patient. No hemolytic disease occurred in patients with autoantibodies. Increased serum gammaglobulin was observed in 16 (54.4%) patients. There was no correlation between the incidence of allo-/autoantibodies and the gammaglobulin level (p = 0.937) and the presence of lymphocyte infiltrates in bone marrow biopsies (p = 0.156). No significant difference was observed when the incidence of autoantibodies and number of red blood cell transfusions were compared (p = 0.334). Patients with refractory anemia and refractory anemia with ringed sideroblasts subtypes had a higher incidence of allo-/autoantibodies than other MDS subtypes (p = 0.03). Conclusion: Patients with MDS, in particular refractory anemia and refractory anemia with ringed sideroblasts have a high incidence of allo- and autoantibodies, probably related to intrinsic immune disorder, without clinical or laboratory hemolysis.