RHD alleles in Brazilian blood donors with weak D or D-negative phenotypes.

The RHD gene is highly polymorphic and the existence of a large number of alleles results in RhD variant phenotypes. RHD genotyping has been used to distinguish normal D antigen from D variants due to limitations of serologic methods. The purpose of this study was to determine the phenotypic frequency of RhD and RhCE antigens and to investigate the RHD alleles present in samples with the weak D or D- phenotypes from Brazilian blood donors. A total of 2007 donors were phenotyped for D, C, c, E and e antigens. Samples phenotyped as D- were genotyped by polymerase chain reaction-sequence specific primers, and exon 10 and intron 4 of the RHD gene were analysed. D- samples containing the RHD gene or samples considered weak D were further characterised using genotyping platform or nucleotide sequencing. Using serologic methods we found that 87.3% of the donors were D+, 11.9% D- and 0.8% weak D. The frequency of RHD gene in D- individuals was 9.2%. Five RHD alleles from phenotypically D- donors were characterised in six molecular backgrounds: RHDΨ, RHD-CE-D(s), RHD-CE-(2-9)-D, RHD/RHDΨ, RHDΨ/RHD-CE-D(s) and RHD-CE(2)-D. The most common weak D antigens types found were 1, 3, 4.0/4.1 and 4.2, whereas the most prevalent weak D type was 4.2 (or DAR). The RHD genotyping proved to be a necessary tool to characterise RHD alleles in donors phenotyped as D- or weak D to increase the transfusion safety in highly racial mixed population.

Molecular studies reveal that A134T, G156A and G1333A SNPs in the CD177 gene are associated with atypical expression of human neutrophil antigen-2.

BACKGROUND AND OBJECTIVES: The human neutrophil antigen-2 (HNA-2) is expressed on a subpopulation of neutrophils as most subjects present a negative plus a positive HNA-2 population of neutrophils. The number of neutrophils expressing HNA-2 is variable and may increase in pregnancy, infections, myeloproliferative disorders and after G-CSF. This study investigated the presence of polymorphisms in the gene encoding HNA-2 (CD177) in individuals presenting different patterns of antigen expression and determined the association of single nucleotide polymorphisms (SNPs) with the heterogeneous HNA-2 expression. MATERIALS AND METHODS: Flow cytometry was employed to analyse the HNA-2 expression on neutrophils from 135 healthy subjects using two monoclonal antibodies (TAG4, 7D8). Sequencing reactions were performed on subjects whose antigen expression was low (< or = 50%), high (> or = 80%) or atypical (a nonreactive population plus two distinct positive cell populations). RESULTS: Five SNPs were detected, two of them (A793C, G1084A) were related to a low expression of HNA-2 (P = 0.031 and P = 0.004). Atypical antigen expression was observed in 5.9% (8/135) of the individuals, three nonpregnant women and five men. In these cases, the cDNA sequences revealed three SNPs (A134T, G156A and G1333A) strongly related to this atypical HNA-2 expression (P = 0.004, P = 0.006 and P < 0.0001, respectively). CONCLUSIONS: Our data show that polymorphisms in the CD177 are associated with variations in the HNA-2 expression and may be the cause of atypical expressions.

Human neutrophil alloantigen-1a, -1b, -2, -3a and -4a frequencies in Brazilians.

Human neutrophil reactive antibodies may cause clinical disorders such as transfusion-related acute lung injury, febrile transfusion reactions, alloimmune neonatal neutropenia, immune neutropenia after stem cell transplantation, refractoriness to granulocyte transfusion, drug-induced neutropenia and autoimmune neutropenia. Using the granulocyte immunofluorescence test by flow cytometry, the phenotypic frequencies of the human neutrophil alloantigens (HNA)-1a, -1b, -2, -3a and -4a were determined in 100 healthy Brazilian persons. Neutrophils were separated from blood samples by sedimentation, centrifugated and incubated with HNA-specific alloantibody plus fluorescein isothiocyanate-labeled F(ab')(2) fragments of anti-human IgG. The results showed that the phenotype frequencies of HNA-1a, -1b, -2a, -3a and -4a were 65%, 83%, 97%, 95% and 94%, respectively. We detected that neutrophils from 17% of Brazilians typed positive only with anti-HNA-1a (HNA-1a/a), 35% only with anti-HNA-1b (HNA-1b/b) and 48% reacted with both antibodies (HNA-1a/b). The frequencies found for HNA-1a and -1b were quite similar to that reported among Africans and American-Africans, but different from those found in Japanese and Chinese. In addition, our data showed that the frequencies of HNA-2, -3a and -4a in Brazilians were comparable with those observed in Caucasians. The determination of HNAs frequencies among populations with distinct racial backgrounds is important not only for anthropological reasons, but also for neonatal typing in suspected cases of alloimmune neutropenia or when patients are severely neutropenic.

Cutaneous T-cell lymphoma with HTLV-I infection: clinical overlap with adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is a malignant proliferation of mature helper T lymphocytes,(1) and is caused by human T-lymphotropic virus type I (HTLV-I);(2) an HTLV-I infection endemic in the Caribbean, south-western Japan, South America and Africa.(3,4) Seroepidemiological studies suggest that it is also endemic in Brazil.(5) Although carriers of HTLV-I show polyclonal integration of virus in T lymphocytes, only patients with ATLL of various subtypes show monoclonal integration of HTLV-I in tumor cells.(6,7) Cutaneous T-cell lymphomas (CTCL) are a group of primary cutaneous lymphoproliferative diseases(8) with unknown etiology.(9) The two most common presentations of CTCL are mycosis fungoides (MF) and Sézary syndrome (SS).(10-13) However, both CTCL categories can easily resemble ATLL. Therefore, in HTLV-I endemic areas, differentiation between ATLL and CTCL must be performed, as they have different prognoses and treatment approaches.(14).

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.

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.

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.

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.

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.