Dalton de Alencar Fischer Chamone

Prevalence, incidence, and residual risk of human immunodeficiency virus among community and replacement first-time blood donors in São Paulo, Brazil

BACKGROUND:  Concerted efforts have been directed toward recruitment of community rather than replacement donors in Brazil. Time trends and demographic correlates of human immunodeficiency (HIV) prevalence and incidence among first‐time (FT) donors in Brazil were examined by donation type. HIV residual risk from FT‐donor transfusions, and projected yield of p24 antigen and nucleic acid test (NAT) screening were estimated.

Descarte de bolsas de sangue e prevalência de doenças infecciosas em doadores de sangue da Fundação Pró-Sangue/Hemocentro de São Paulo

OBJETIVO: Analisar a evolucao, de 1991 a 2001, do descarte sorologico na Fundacao Pro-Sangue/Hemocentro de Sao Paulo, o maior banco de sangue da America Latina, e verificar a prevalencia de doencas infecciosas entre doadores dessa instituicao no ano de 2001. METODOS: Foram compilados os dados de descarte sorologico relativos aos anos de 1991 a 2001. Para determinar a prevalencia de doencas infecciosas, foram analisadas 9 942 amostras triadas em novembro de 2001, sendo as amostras reativas submetidas a testes confirmatorios. RESULTADOS: Foi encontrada uma diminuicao percentual significativa de descarte, de 20% em 1991 para 9% em 2001. A prevalencia de doencas infecciosas entre doadores em 2001 foi de 0,04% para virus da imunodeficiencia humana (VIH); 0,21% para virus da hepatite C (VHC); 0,06% para virus T-linfotropico humano (HTLV); para virus da hepatite B (VHB), as prevalencias foram de 0,14% para anti-HBc + HBsAg, 1,68% para anti-HBc + anti-HBs e 1,67% para anti-HBc isolado; 1,10% para sifilis; e 0,14% para doenca de Chagas. CONCLUSAO: A diminuicao no descarte e a prevalencia de doencas infecciosas entre doadores da Fundacao Pro-Sangue/Hemocentro de Sao Paulo em 2001 refletem o aumento na porcentagem de doadores de repeticao nesse banco de sangue.

Human immunodeficiency virus test-seeking motivation in blood donors, São Paulo, Brazil

Background and Objective  Previous studies have shown that volunteer, community‐recruited donors have a higher prevalence of human immunodeficiency virus (HIV) infection in São Paulo, Brazil, than replacement donors. One hypothesis which may explain this unexpected finding is that some individuals donate blood because they are seeking HIV testing. The objective of this study was to characterize test‐seeking blood donors and to determine whether they are at higher risk for HIV infection compared with other donors.

Granulocyte-colony stimulating factor or granulocyte-colony stimulating factor associated to stem cell intracoronary infusion effects in non ischemic refractory heart failure.

We prospectively studied bone marrow stem cell (BMSC) therapy in 23 patients with non ischemic refractory heart failure(HF) in comparison with a HF control group with 17 patients. BMSC patients randomly underwent granulocyte-colony stimulating factor (G-CSF) administration (14 patients) or G-CSF associated to BMSC intracoronary infusion (eight patients). After the first month all BMSC patients received G-CSF with one-month interval between each one. CD34+ cell peaks (per mm(3)) in BMSC patients were 19+/-12 and in normal control 60+/-20 (p=0.003). In BMSC patients after the 1st G-CSF left ventricular(LV) ejection fraction (EF) increased from 21.4+/-4.7% to 23.6+/-7.7%(p=.048), peak VO(2) (ml/kg/min) from 9.9+/-2.4 to 11.6+/-3 (p=.04), functional class and quality of life improved whereas in the HF control group LVEF, RFEF and functional class were unchanged. Both BMSC subgroups presented improvement of LV function evaluated by DTI velocities. Evaluations after the first month in BMSC patients showed improvements in LVEF (p=.001), right VEF (p=0.01), DTI velocities (p=.009), peak VO(2) (p=0.04), functional class (p<0.001) and quality of life (p<0.001). In conclusion, CD34+ mobilization is impaired in HF. Stem cell therapy can improve HF. Randomized trials should be developed to confirm our results.

Factors affecting hematopoietic progenitor cell mobilization: an analysis of 307 patients.

We reviewed the data of 307 patients treated with autologous bone marrow transplantation with the aim to identify factors associated with poor hematopoietic stem cell (HSC) mobilization after administration of cyclophosphamide and granulocyte-colony stimulating factor. Success in mobilization was defined when > or = 2.0 x 10(6) CD34+ cells/kg weight could be collected with < or = 3 leukapheresis procedures. Success was observed in 260 patients (84.7%) and nonsuccess in 47 patients (15.3%). According to the stepwise regression model: diagnosis, chemotherapy load, treatment with mitoxantrone and platelet count before mobilization were found to be independent predictive factors for HSC mobilization. These results could help in the previous recognition of patients at risk for non response to mobilization and allow to plan an alternative protocol for this group of patients.

Significance of isolated hepatitis B core antibody in blood donors from São Paulo

The clinical significance of isolated anti-HBc is still a challenge. To elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. One hundred and twelve isolated anti-HBc seropositive blood donors underwent clinical evaluation and retesting of HBV markers. Those who presented repeatedly reactive isolated anti-HBc, received a single dose of hepatitis B recombinant vaccine to verify anti-HBs early response. A HBV-DNA determination by PCR was done for those who did not test positive to anti-HBs after vaccine. The level of anti-HBc was recorded as a ratio of the sample-to-cut-off values (S:C ratio) in 57 candidates at donation. Comparing true and false-positive anti-HBc results, the different S:C ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. A high percent of false-positive results (16.07%) was verified after anti-HBc retesting. HBV immunity was characterized in 49.11%, either by anti-HBs detection in retesting (15.18%), or after a single dose HBV vaccination (33.93%). HBV-DNA was negative in all tested donors. In conclusion, this algorithm was useful to clarify the meaning of isolated anti-HBc in most of our blood donors.

Immunohematological Findings in Myelodysplastic Syndrome

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.

Circulating platelet aggregates indicative of in vivo platelet activation in pulmonary hypertension

The authors investigated the existence of circulating cellular aggregates in 12 patients with moderate to severe pulmonary hypertension, using scanning elec tron microscopy. Peripheral venous blood was collected in the presence of 11.5 mM buffered ethylenediaminetetraacetic acid, in order to disperse freshly formed disaggregable aggregates. Irreversible aggregates represented by plate let clusters and/or platelet attachment to either leukocytes or red cells were identified in 7 patients with pulmonary hypertension. Endogenous platelet acti vation was further confirmed by a significant increase in plasma levels of beta- thromboglobulin in comparison with controls (33.8 ± 14.1 vs 22.7 ± 11.5 ng/mL respectively, p < 0.025). The presence of irreversible aggregates in the blood stream strongly suggests that cell-cell interactions actually occur in vivo in these patients. If so, therapeutic measures aimed at preventing in situ thrombosis and its consequences may be beneficial in this disorder.

Addition of low-dose busulfan to cyclophosphamide in aplastic anemia patients prior to allogeneic bone marrow transplantation to reduce rejection

Summary:Busulfan was added at the dose of 4 mg/kg to 200 mg/kg cyclophosphamide in 81 patients (3–53 years, median 24) with aplastic anemia to reduce graft rejection. Graft-versus-host disease (GVHD) prophylaxis comprised cyclosporine–methotrexate. The number of prior transfusions was 0–276 (median 26), and 48% had received prior immunosuppressive therapy. Two patients experienced primary graft failure, and 10 secondary rejection at 28–1001 days (median 317 days). The cumulative incidence of rejection was 22%; for heavily transfused patients (⩾50 U) it was 43% compared to 16% for the rest (P=0.06). Overall survival rate at 8 years was 56%; patients who received ⩽15 and >15 transfusions was 78 and 50%, respectively (P=0.01), whereas it was 67 and 28% for ⩽50 and >50 transfusions, respectively (P=0.002). In multivariate analysis, higher number of prior transfusions, shorter period of immunosuppression with cyclosporine and GVHD were associated with inferior survival; moreover, a higher risk of graft rejection were associated with a higher number of prior transfusions and a trend was observed for a shorter cyclosporine administration. Low-dose busulfan is feasible and may be helpful in patients exposed to <50 transfusions. However, rejection remains a significant problem, mainly in heavily transfused patients.

Trends in the profile of blood donors at a large blood center in the city of São Paulo, Brazil

OBJECTIVE To describe the trends in the profile of blood donors from 1995 through 2001 at a large blood center in the city of São Paulo, Brazil, particularly following the initiation in 1998 of marketing strategies aimed at substituting replacement donors with altruistic repeat donors. METHODS Using an information system that had been established at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo) in 1994, we collected information on sex, age, and type of donation for the years 1995-2001. We classified blood donors as either replacement blood donors (if they stated that the reason for donating was that they had a friend or relative in the hospital) or as altruistic donors. First-time blood donors were those who had not donated in our institution since the establishment of the information system. RESULTS The percentage of repeat altruistic blood donors increased over time as first-time replacement donors declined for both genders. The proportion of altruistic donors climbed from 20% of all blood donors in 1995 to 57% in 2001. In 2001, first-time blood donors represented only 52% of all donors, as contrasted to 88% in 1995. Female donors increased from 20% to 37% of the donors over the period studied. CONCLUSIONS 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.