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Biomedical subjects

J O Bordin

Publications and source records attributed to J O Bordin.

At least 19 recordsLinked to original sources
PubMed2005

Plasmablastic multiple myeloma is associated with increased vascular endothelial growth factor immunoexpression.

The biologic basis of the negative prognosis of plasmablastic myeloma is not fully understood. To determine whether histologically aggressive multiple myeloma (MM) is associated with a more angiogenic marrow environment, bone marrow samples from 50 recently diagnosed MM patients were evaluated. Twelve percent (6/50) of patients presented plasmablastic MM, and this feature correlated with moderate/strong intensity of vascular endothelial growth factor staining of plasma cells (P = 0.036). Although plasmablastic MM was not associated with increasing of microvessel density, this new evidence of increased expression of vascular endothelial growth factor on plasmablasts suggests that the adverse prognosis conferred by plasmablastic disease may be due, at least in part, to secretion of this angiogenic cytokine, also suggesting that the subset of MM patients with plasmablastic features may derive particular benefit from antiangiogenic therapies.

Adult↗
PubMed2005

Transfusions of CPDA-1 red blood cells stored for up to 28 days decrease donor exposures in very low-birth-weight premature infants.

The goal of this research was to study the safety and the efficacy of transfusing citrate-phosphate-adenine anticoagulant-preservative (CPDA-1) RBC stored for up to 28 days to reduce donor exposures in premature infants. A prospective randomized two-group study was conducted with very low-birth-weight premature infants that received at least one RBC transfusion during hospital stay. Neonates randomly assigned to Group 1 (26 infants) were transfused with CPDA-1 RBC stored for up to 28 days; those assigned to Group 2 (26 infants) received CPDA-1 RBC stored for up to 3 days. Demographic and transfusion-related data were collected. Neonates from both groups showed similar demographics and clinical characteristics. The number of transfusions per infant transfused was 4.4 +/- 4.0 in Group 1 and 4.2 +/- 3.1 in Group 2, and the number of donors per infant transfused was 1.5 +/- 0.8 (Group 1) and 4.3 +/- 3.4 (Group 2), P < 0.001. RBC transfusions containing 29.7 +/- 18.3 mmol L(-1) of potassium (RBC stored for up to 28 days) did not cause clinical or biochemical changes and reduced donor exposures by 70.2%, compared to transfusions containing 19.8 +/- 12.3 mmol L(-1) of potassium (RBC stored for up to 3 days), P < 0.001. In conclusion, RBC stored for up to 28 days safely reduced donor exposures in premature infants.

Adenine↗
PubMed2004

Gene frequencies of the HPA-15 (Gov) platelet alloantigen system in Brazilians.

The HPA-15 (Gov) alloantigen is a biallelic co-dominant system on human platelets, and its allele HPA-15a and HPA-15b differ by an A-->C single nucleotide polymorphism at nucleotide 2108 of the coding sequence resulting in a Tyr682Ser substitution in the mature CD109 glycoprotein. Employing the polymerase chain reaction-restriction fragment length polymorphism technique, we determined the HPA-15 gene frequencies among 276 subjects of distinct Brazilian ethnic groups including, 15 Caucasians, 15 African Brazilians, 15 Orientals, 106 Amazon Xikrin Indians, 31 Amazon Gavioes Indians and 94 blood donors. The calculated HPA-15a and HPA-15b allele frequencies found in Caucasians (0.53/0.47), African Brazilians (0.57/0.43), Orientals (0.57/0.43) and Brazilian blood donors (0.52/0.48) did not differ significantly. However, the HPA-15a and HPA-15b gene frequencies of Xikrin Indians (0.78/0.22) were significantly different from that of all other groups (P < 0.01). The HPA-15a/a, HPA-15a/b and HPA-15b/b genotype frequencies observed in Gavioes Indians were significantly different from those seen in African Brazilians (P = 0.04) and blood donors (P = 0.017). The present data showed that the distribution of the HPA-15 (Gov) system alleles observed among the Brazilian population is quite similar to the distributions already reported among Asian, Canadian and European populations. Moreover, the data indicated differences in the frequency of the HPA-15 system between Amazon Indians and other distinct Brazilian ethnic groups suggesting that Amerindians would be at higher risk of HPA-15 alloimmunization in the need of receiving blood components collected from blood donors of other ethnic groups.

Alleles↗
PubMed2003

Intracranial haemorrhage among a population of haemophilic patients in Brazil.

Intracranial haemorrhage (ICH) is a common cause of morbidity and mortality in haemophilic patients. The overall incidence of ICH has been reported to range from 2.2% to 7.5% in patients with haemophilia. From 1987 to 2001, 401 haemophilic patients from the Serviço de Hemofilia, Disciplina de Hematologia e Hemoterapia, Universidade Federal de São Paulo were evaluated. The episodes of ICH were documented by CT scan and the anatomic location, clinical presentation, relationship to trauma and clinical factors, including the presence of HIV infection and the presence of inhibitor, were reviewed. Among 401 haemophilic patients, 45 ICH episodes in 35 (8.7%) patients with age ranging from 4 days to 49 years (mean 10.6 years) were observed. A history of recent trauma was documented in 24 (53.3%) cases. Seventeen (37.8%) episodes occurred in more than one site of bleeding, 12 (26.7%) were subdural, seven (15.5%) subarachnoid, four (8.9%) epidural, two (4.4%) intracerebral and one (2.2%) intraventricular. The most frequent symptoms were headache and drowsiness. All patients were submitted to replacement therapy and neurosurgical intervention was performed in eight (17.8%) patients. Despite the treatment, three (8.6%) haemophilia A patients died due to the ICH event and three presented late sequelae. The most important aspect of ICH management is the early replacement therapy in haemophilic patients. This prompt treatment will increase the chances of a better prognosis. Another impact measure consists in the administration of the deficient coagulation factor after every head trauma, even when considered minor.

Adult↗
PubMed2003

Importance of combined-modality therapy for primary bone lymphoma.

Primary bone lymphoma (PBL) is a rare entity and comprises about 5% of all extranodal non-Hodgkin's lymphomas (NHL) and 7% of all primary bone tumors. To date there is no consensus about the optimal treatment for PBL. We retrospectively reviewed all cases of PBL treated at Hospital São Paulo, Brazil, over a 10-year-period (January 1992-January 2002). Medical records of 7 patients with PBL were reviewed and information on age at diagnosis, sex, NHL clinical staging (CS), treatment and response to treatment were retrieved. Five patients (72%) received combined-modality therapy (CMT) and all of them are in complete remission (CR) with a median follow up of 19 months (ranging from 12 to 144 months). We conclude that PBL is a potentially curable malignancy and treatment should be undertaken in a multiprofessional approach, in order to provide the best support which probably has to include chemotherapy, radiotherapy and, for patients with IPI higher than 2, consolidation with stem-cell transplantation.

Adult↗
PubMed2001

Aberrant phenotypes in acute myeloid leukemia: a high frequency and its clinical significance.

BACKGROUND AND OBJECTIVES: Immunophenotyping is an essential method for diagnosis and classification of acute myeloid leukemias (AML), and its extensive use could identify blast cell subpopulations with aberrant phenotypes rarely seen in normal myelopoiesis. The aberrant phenotypes have been correlated with clinical, morphological and prognostic features but their occurrence in AML differs in the various studies. DESIGN AND METHODS: In this study, we analyzed 35 cases of AML, examining them for aberrant phenotypes by multiparametric flow cytometry. Co-expression of lymphoid-associated markers in myeloblasts and asynchronous antigen expression were correlated with clinical features. RESULTS: Aberrant phenotypes were found in 88.6% of the cases studied. In this group, cross-lineage antigen expression was present in 34.3% and asynchronous expression in 82.4% of the cases. CD7 was the most frequent lymphoid-associated antigen. Among the cases of asynchronous antigen expression, the most frequent phenotype was CD117(+) and/or CD34(+) in association with CD11c(+), followed by CD15(+) and CD65(+), corresponding to 67.6%, 61.7 and 50.0% of the cases, respectively. Twenty out of 33 patients were available for complete remission assessment. The CD117(+) CD15(+) phenotype correlated significantly with complete remission achievement and with the lack of unfavorable chromosome associations. INTERPRETATION AND CONCLUSIONS: We conclude that aberrant phenotypes, as they are described here, are present in the great majority of cases of AML, asynchronous antigen expression being the most frequent example; and that CD117(+) CD15(+) phenotype shows a relevant association with clinical prognosis.

Acute Disease↗
PubMed2000

Platelet alloantigen frequencies in Amazon Indians and Brazilian blood donors.

The frequencies of human platelet-specific alloantigens (HPAs) vary between different ethnic groups, and genotyping using DNA techniques has been preferred over immunophenotyping methods for population studies. Using a polymerase chain reaction with allele-specific primers (PCR-ASP) method, we determined the allelic polymorphisms of five HPA systems among 174 unrelated individuals of two different Brazilian ethnic groups including Amazon Indians (n = 95) and blood donors (n = 79). Comparison of the calculated gene frequencies of the two alleles of HPA-1, -2, -3, -4 and -5 systems for Amazon Indians and Brazilian blood donors showed that gene frequencies obtained for the two alleles of HPA-1 (P<0.001), HPA-2 (P = 0.001) and HPA-5 (P<0.001) were significantly different between the two groups of individuals. All natives tested carried the HPA-2a and the HPA-5a alleles, but the HPA-1b and HPA-4b alleles are absent from the Indian population. It was also observed that all blood donors carried the HPA-1a, HPA-4a and HPA-5a alleles. In conclusion, the present data indicate differences in the frequency of the HPA systems between Amazon Indians and Brazilian subjects who present a high rate of racial admixture. While the frequencies of the HPA-1 and HPA-5 genes seen in Amazon Indians are similar to those reported for Oriental populations, the frequencies of the HPAs alleles in Brazilian blood donors are comparable to those reported for populations in North America and Europe.

Alleles↗
PubMed2000

Allelic polymorphisms of human fcgamma receptor IIa and Fcgamma receptor IIIb among distinct groups in Brazil.

BACKGROUND: The FcgammaRIIA gene is expressed in two polymorphic forms, R131 and H131, which differ by the replacement of histidine by arginine at position 131. The FCGR3B (FcgammaRIIIB) gene exists in two allelic isoforms, known as FCGR3B1 (FcgammaRIIIB-NA1) and FCGR3B2 (FcgammaRIIIB-NA2), which differ in nucleotides 141, 147, 227, 277, and 349. An additional polymorphism is the SH antigen that is associated with the FCGR3B3 (FcgammaRIIIB-SH) allele. STUDY DESIGN AND METHODS: By use of a PCR with allele-specific primers, the allelic polymorphisms of FcgammaRIIA and FcgammaRIIIB were determined among 263 unrelated Brazilian subjects, including Amazon Indians (n = 92), blood donors (n = 85), and patients with sickle cell disease (SCD) (n = 86). RESULTS: Amazon Indians had a significantly higher frequency of the R131 allele than did blood donors and SCD patients (0.91 vs. 0.55 vs. 0.55; p<0.001). NA1 and NA2 gene frequencies were found to be 0.67 and 0.21 for Amazon Indians, 0.58 and 0.42 for blood donors, and 0.61 and 0.39 for SCD patients, respectively. The FcgammaRIIIB-SH allele was absent from the Amazon Indians, but 9 (10.6%) blood donors and 10 (11.6%) SCD patients expressed this allele. CONCLUSION: Overall, the data indicate that the distribution of the FcgammaRIIIB alleles is significantly different in Amazon Indians from the distribution in Brazilian blood donors or African Brazilian patients with SCD, but that it is similar to the distributions reported in Asian populations. Moreover, the distribution of the FcgammaRIIA and FcgammaRIIIB alleles among Brazilian blood donors and SCD patients is comparable to the distributions reported in whites from the United States and Europe.

Alleles↗
PubMed1999

Delayed hemolytic transfusion reaction presenting as a painful crisis in a patient with sickle cell anemia.

CONTEXT: Patients with sickle cell anemia (SCA) are frequently transfused with red blood cells (RBC). Recently we reported that the calculated risk of RBC alloimmunization per transfussed unit in Brazilian patients with SCA is 1.15%. We describe a delayed hemolytic transfusion reaction (DHTR) presenting as a painful crisis in a patient with SCA. CASE REPORT: A 35-year-old Brazilian female with homozygous SCA was admitted for a program of partial exchange transfusion prior to cholecystectomy. Her blood group was O RhD positive and no atypical RBC alloantibody was detected using the indirect antiglobulin technique. Pre-transfusional hemoglobin (Hb) was 8.7 g/dL and isovolumic partial exchange transfusion was performed using 4 units of ABO compatible packed RBC. Five days after the last transfusion she developed generalized joint pain and fever of 39 degrees C. Her Hb level dropped from 12.0 g/dL to 9.3 g/dL and the unconjugated bilirrubin level rose to 27 mmol/L. She was jaundiced and had hemoglobinuria. Hemoglobin electrophoresis showed 48.7% HbS, 46.6% HbA1, 2.7% HbA2, and 2.0% HbF. The patient's extended RBC phenotype was CDe, K-k+, Kp(a-b+), Fy(a-b-), M+N+s+, Le(a+b-), Di(a-). An RBC alloantibody with specificity to the Rh system (anti-c, titer 1:16.384) was identified by the indirect antiglobulin test. The Rh phenotype of the RBC used in the last packed RBC transfusion was CcDEe. The patient was discharged, asymptomatic, 7 days after admission.

ABO Blood-Group System↗
PubMed1999

The effect of unmodified or prestorage white cell-reduced allogeneic red cell transfusions on the immune responsiveness in orthopedic surgery patients.

BACKGROUND: The immunomodulatory effects of allogeneic blood transfusions have been attributed to the white cells (WBCs) present in the cellular blood components transfused to patients. STUDY DESIGN AND METHODS: The effect of the transfusion of allogeneic red cells (RBCs) or allogeneic prestorage WBC-reduced RBCs (WBC-reduced RBCs) on host immune responsiveness was evaluated by measuring the lymphocyte subsets and the in-vitro cytokine production in response to phytohemagglutinin stimulation of WBCs of orthopedic surgery patients. Forty-seven patients undergoing hip replacement surgery were randomly assigned to receive allogeneic RBCs (n = 17) or WBC-reduced RBCs (n = 14; 99.95% WBC removal). Sixteen patients were not transfused. Patient blood samples taken before surgery and on Days 1 and 4 after surgery were tested for complete blood count, lymphocyte subset analysis, and measurement of cytokine levels. RESULTS: After surgery, the lymphocyte count was significantly decreased in patients transfused with > or = 3 units of allogeneic RBCs (2.0 +/- 0.5 vs. 1.3 +/- 0.3 x 10(9)/L; p = 0.017), but not in patients transfused with > or = 3 units of WBC-reduced RBCs (2.0 +/- 0.9 vs. 1.7 +/- 0.8 x 10(9)/L). Compared with preoperative levels, on Day 4 after surgery, patients transfused with > or = 3 units of allogeneic RBCs also had a decrease in the number of natural killer cells (0.07 +/- 0.05 vs. 0.04 +/- 0.03 x 10(9)/L; p = 0.018). Postoperatively, interleukin-2 was decreased in one patient who received WBC-reduced RBCs compared with that in four patients transfused with allogeneic RBCs (p = 0.32), and eight untransfused patients (p = 0.01). On Day 4, about 70 percent of patients transfused with allogeneic RBCs showed a 20-percent decrease in the interferon gamma level. CONCLUSION: Taken together, these data support the hypothesis that transfusion of > or = 3 units of allogeneic RBCs is associated with early postoperative lymphopenia in otherwise healthy individuals undergoing surgery. These findings were not observed in those individuals transfused with RBCs that had undergone prestorage WBC reduction.

Adult↗
PubMed1998

Renal dysfunction in patients with sickle cell anemia or sickle cell trait.

Patients with sickle cell anemia (Hb SS) or sickle cell trait (Hb AS) may present several types of renal dysfunction; however, comparison of the prevalence of these abnormalities between these two groups and correlation with the duration of disease in a large number of patients have not been thoroughly investigated. In a cross-sectional study using immunoenzymometric assays to measure tubular proteinuria, microalbuminuria, measurement of creatinine clearance, urinary osmolality and analysis of urine sediment, we evaluated glomerular and tubular renal function in 106 adults and children with Hb SS (N = 66) or Hb AS (N = 40) with no renal failure (glomerular filtration rate (GFR) > 85 ml/min). The percentage of individuals with microalbuminuria was higher among Hb SS than among Hb AS patients (30 vs 8%, P < 0.0001). The prevalence of microhematuria was similar in both groups (26 vs 30%, respectively). Increased urinary levels of retinol-binding protein or beta 2-microglobulin were detected in only 3 Hb SS and 2 Hb AS patients. Urinary osmolality was reduced in patients with Hb SS or with Hb AS; however, it was particularly evident in Hb SS patients older than 15 years (median = 393 mOsm/kg, range = 366-469) compared with Hb AS patients (median = 541 mOsm/kg, range = 406-722). Thus, in addition to the frequently reported early reduction of urinary osmolality and increased GFR, nondysmorphic hematuria was found in 26 and 30% of patients with Hb SS or Hb AS, respectively. Microalbuminuria is an important marker of glomerular injury in patients with Hb SS and may also be demonstrated in some Hb AS individuals. Significant proximal tubular dysfunction is not a common feature in Hb SS and Hb AS population at this stage of the disease (i.e., GFR > 85 ml/min).

Adolescent↗
PubMed1998

HTLV-I infection among relatives of patients with adult T-cell leukemia/lymphoma in Brazil: analysis of infection transmission.

We examined the presence of HTLV-I infection among 66 family members of 13 patients with well documented ATL to investigate the routes of HLTV-I transmission in a Southeast region of Brazil. HTLV-I infection was screened by an enzyme immunossay (ELISA) test and all repeatedly positive or indeterminate ELISA samples were further tested by a Western-Blot (WB) technique. Indeterminate and inconclusive WB samples were confirmed by a polymerase chain reaction (PCR). ELISA results showed that 40 (60.6%) individuals were not infected; 16 (24.2%) were positive; and 10 (15.2%) were undetermined. Among 16 ELISA positive subjects, 14 (87.5%) were confirmed to be positive by WB while 2 (12.5%) showed inconclusive results. Based on the laboratory data, questionnaire analysis, and family/epidemiological studies, we concluded that HTLV-I vertical transmission occurred in 6 of the 13 families. In 3 of these 6 families, the horizontal transmission also could be demonstrated. An isolated horizontal transmission was detected in one family, and in 6 families we did not find any infected family member. All HTLV-I-infected persons were clinically asymptomatic. The occurrence of an effective HTLV-I vertical transmission detected by the present study suggest that HTLV-I infection is endemic in the Southeast region of Brazil. Consistent with the modes of transmission, the HTLV-I antibody seroprevalence was greater in relatives of ATL patients than in the general blood donor Brazilian population (0.4%). In addition, the present data suggest that HTLV-I carries a high infectivity rate but a low virulence.

Adolescent↗
PubMed1997

Maternal immunization to Gov system alloantigens on human platelets.

BACKGROUND: Immunization to platelet alloantigens can occur during pregnancy or after the transfusion of blood components. Platelet alloantibodies can cause neonatal alloimmune thrombocytopenia and posttransfusion purpura. Transfusion-induced alloimmunization to a novel platelet alloantigen system, Gov, expressed on the 175-kDa glycosyl phosphatidylinositol-anchored platelet glycoprotein, CD109, was previously described. This report describes three unrelated patients who were alloimmunized to Gov(a) or Gov(b) during pregnancy. STUDY DESIGN AND METHODS: Platelets were typed by using radioimmunoprecipitation for HPA-1a, -3a, -5a, -5b, Gov(a), and Gov(b) and by polymerase chain reaction-restriction fragment length polymorphism for HPA-1a, -1b, -3a, and -3b. Maternal sera were screened for platelet antibodies by using radioimmunoprecipitation and the antigen capture assay. RESULTS: Patients 1 and 2 were investigated after the diagnosis of neonatal alloimmune thrombocytopenia in their children, and alloantibodies specific for Gov(b) and Gov(a), respectively, were detected in maternal serum. Serum from patient 3, who had mild idiopathic thrombocytopenia purpura with no detectable autoantibody, was found to contain alloantibodies to Gov(b) and to HPA-5b, presumably as a result of immunization during pregnancy. Platelet typings confirmed that the patients were at risk for alloimmunization to the respective antigen. CONCLUSION: This report of three cases of maternal alloimmunization to antigens in the Gov system indicates that immunization can occur via placental transfer of antigen and that Gov system alloantibodies may be associated with neonatal alloimmune thrombocytopenia.

Adult↗
PubMed1996

Red blood cell alloimmunization in sickle cell disease: the influence of racial and antigenic pattern differences between donors and recipients in Brazil.

Red blood cell (RBC) transfusions are widely used in the management of patients with sickle cell disease (SCD). However, repeated RBC transfusions are often complicated by RBC alloimmunization. To investigate whether the frequency of RBC alloimmunization could be accounted for by racial and RBC phenotype differences between donors and recipients in Brazil, in this study we compared the RBC phenotype of 100 SCD patients with that observed in 120 randomly selected blood donors. A comparison of the RBC phenotype between the two groups revealed a statistically significant increase in the frequency of the C antigen in the donor population (P < 0.01), but no significant difference was observed for the A,B,D,c,E,e,K,k,Fya,M,N,S,s, and Jka antigens. Using standard techniques (indirect antiglobulin test, enzyme treatment, and low-ionic-strength solution) we observed an RBC alloimmunization rate of 12.9% (11/85) in the SCD patients. Fifteen alloantibodies were detected in 11 patients, and most (80%) involved antigens in the Rhesus and Kell systems. This observed RBC alloimmunization rate in SCD patients in Brazil is lower than that reported by studies from North America, suggesting that the requirement for extended antigen-matched RBC transfusion for SCD patients in the setting of a RBC phenotype concordant donor-recipient population may not be cost-effective in some countries.

Adolescent↗
PubMed1996

Strategies for prevention of transfusion-associated Chagas' disease.

Available epidemiological data indicate that Chagas' disease, a zoonosis caused by the flagellate protozoan parasite T cruzi, is a very important medical and social problem in Latin America. More than 60% of T cruzi-infected individuals have migrated to urban areas, in both endemic and nonendemic countries. Thus, with the implementation and maintenance of regular vector control programs in some countries, allogeneic blood transfusions have been the main mechanism for the continuation of this endemy. The risk of infection after transfusion of a unit of T cruzi-infected blood product depends mainly on the amount of blood transfused, parasite concentration in the infected transfused blood unit, and the recipient's immunological status. Current strategies to prevent transfusion-associated Chagas' disease include the identification of T cruzi-infected blood donors by predonation questionnaire, serological tests for T cruzi antibodies, and the treatment of the blood collected with gentian violet. Because T cruzi infection is lifelong, and most infected persons are asymptomatic, the identification of high-risk blood donors by a predonation questionnaire is relevant in nonendemic countries but this strategy seems to be of limited usefulness for donor deferral in endemic areas. Because T cruzi antigens are shared by other parasites, the serological diagnosis of T cruzi infection is complex yielding both false-positive and false-negative results. Although sensitive, the tests currently available for the serodiagnosis of T cruzi infection lack specificity and a more specific, confirmatory test is still needed for the routine confirmation of T cruzi chronic infection. In areas of high endemicity or where serological screening is not available, the risk of T cruzi transmission by blood transfusion may be reduced by the addition of gentian violet to the collected blood. The use of gentian violet, alone or combined with ascorbic acid and light, effectively inactivate T cruzi present in donor blood; however, the long-term toxicity of this agent for blood recipients is still an open issue. In conclusion, the prevention of TA-CD is based on various strategies that are not mutually exclusive. Blood donor education, identification of putatively infectious blood donors by questionnaire or serological screening tests, and methods of parasite inactivation may significantly reduce the transmission of T cruzi by allogeneic blood transfusions.

Animals↗
PubMed1996

Fetal hemoglobin in patients with chronic renal disease.

To investigate-whether hemoglobin (Hb) synthesis is affected by different treatment protocols used for end-stage renal disease, we analyzed the electrophoretic pattern of hemoglobin in 136 adult patients with chronic renal failure. Forty-seven patients were not in a dialysis program (ND), 29 individuals were on continuous ambulatory peritoneal dialysis (CAPD), 33 patients were on hemodialysis (HD), and 27 subjects had received a kidney transplant (KT). We found 3.6% hemoglobin C, 1.4% hemoglobin S and 3.6% B-thalassemia minor as reported in other studies of Brazilian patients. In addition, we found increased fetal hemoglobin (Hb F) levels in 7.4% of the patients which contrasts with the reported 0.01% prevalence rate of hereditary persistence of Hb F in Brazil. Seven out of ten patients with elevated Hb F belonged to either the CAPD or the KT group. We postulate that stress erythropoiesis is probably the mechanism responsible for the Hb F increase in these patients. However, properly designed clinical studies are still necessary to clarify these questions.

Adult↗
PubMed1995

Prevention of transfusion-associated Chagas' disease by sterilization of Trypanosoma cruzi-infected blood with gentian violet, ascorbic acid, and light.

BACKGROUND: Allogeneic blood transfusions are the second most frequent route of Chagas' disease transmission in countries where the disease is endemic. The prevention of transfusion-associated Chagas' disease has been attempted through clinical and serologic screening of blood donors and/or by the addition of trypanomicidal substances such as gentian violet (GV) to stored blood for 24 hours. The present study describes an alternative method of chemoprophylaxis of transfusion-associated Chagas' disease that reduces the sterilization time by using a combination of low-concentration GV, ascorbic acid (AA), and photoradiation with visible light. STUDY DESIGN AND METHODS: To better reproduce the conditions of blood transfusion in developing areas, normal human blood was collected in blood collection bags, infected with different concentrations of Trypanosoma cruzi, and treated with GV, AA, and photoradiation. Mice were then inoculated with the T. cruzi-infected human blood that had been stored at different incubation intervals. Active parasites were sought in mouse blood for parasitologic diagnosis and serologic evaluation (mice inoculation, blood culture, and indirect immunofluorescence). RESULTS: The association of GV (250 micrograms/mL), and photoradiation with visible light (75W) sterilized T. cruzi-infected blood even after treatment for less than 30 minutes and even when chagasic blood was treated with low-concentration GV (62.5 micrograms/mL for 30 min). Moreover, the trypanomicidal activity of GV associated with AA and photoradiation with visible light was found even when blood was infected with a 10-fold parasite concentration. CONCLUSIONS: The proposed alternative prophylactic method is reproducible, easy to perform, and inexpensive, and it may have practical importance in endemic areas where serologic screening of donor blood is not always available. In addition, the reduction of the GV trypanomicidal concentration might further minimize the potential for GV-related side effects.

Animals↗