HLA-DRB1*07:01 allele is primarily associated with the Diego a alloimmunization in a Brazilian population.

Background: The Diego blood group presents a major polymorphic site at Residue 854, causing a proline (Di(b) antigen) to leucine (Di(a) antigen) substitution. Di(a) alloimmunization has been observed among Asian and Native South American populations. Considering that Brazilians represent a genetically diverse population, and considering that we have observed a high incidence of Di(a) alloimmunization, we typed HLA-DRB1 alleles in these patients and performed in silico studies to investigate the possible associated mechanisms.

HNA-3 gene frequencies in Brazilians and a new polymerase chain reaction-restriction fragment length polymorphism method for HNA-3a/3b genotyping.

Background: HNA-3 antigens are the result of a rs2288904 single-nucleotide polymorphism (SNP) in the CTL2, and the HNA-3a and HNA-3b variants are encoded by a guanine and adenine at Nucleotide Position 461. Anti-HNA-3 are involved in severe transfusion-related acute lung injury reactions and in neonatal alloimmune neutropenia. Since the distribution of the HNA-3 system was unknown in South Americans, in this study we determined the frequency of the HNA-3 alleles in Brazilians.

A PCR-based strategy for Dombrock screening in Brazilian blood donors reveals a novel allele: the DO* A-WL.

Background: Determination of the molecular basis underlying the antigens in the Dombrock blood group system has shown various rearrangements between the alleles associated with DO(*) A and DO(*) B. Based on this, we employed a PCR-based strategy to screen DO alleles (DO(*) A, DO(*) B, HY(*) 1, HY(*) 2 and JO) in Brazilians.

Methods: We tested DNA of 278 Brazilian blood donors by PCR-RFLP on plates of 96 wells to determine the 793A/G (DO(*) A/DO(*) B), 323G/T (HY), 350C/T (JO) and 898C/G (HY(*) 1/HY(*) 2) single nucletide polymorphisms.

Impact of using different laboratory assays to detect human leukocyte antigen antibodies in female blood donors.

Background: HLA antibodies passively transferred to transfused recipients may cause transfusion reactions such as transfusion-related acute lung injury (TRALI), but in many of the reported TRALI incidents, no white blood cell antibodies have been identified. We investigated whether a higher number of anti-HLA would be detected in donor's plasma by using a method with potential higher sensitivity rate.

Study Design And Methods: Sera from 300 previously pregnant female blood donors were screened for anti-HLA using a solid-phase mixed-antigen assay (enzyme-linked immunosorbent assay [ELISA]).

A novel immunosuppressive pathway involving peroxynitrite-mediated [corrected] nitration of platelet antigens within antigen-presenting cells.

Background: Studies have demonstrated that immunity against platelet (PLT) transfusions is dependent on recipient antigen-presenting cells (APCs) and their ability to produce nitric oxide (NO). To further analyze this, we focused on NO's major metabolite peroxynitrite (ONOO(-)) and its ability to affect PLT immunity.

Study Design And Methods: To address how NO and its major metabolite may mediate PLT immunity, GP91(PHOX) knockout (KO) mice that lack the ability to produce the ONOO(-) were transfused weekly with allogeneic BALB/c PLTs, and donor antibody development was analyzed.

Transfusion-related acute lung injury.

Transfusion-related acute lung injury (TRALI) is a serious clinical syndrome associated with the transfusion of plasma-containing blood components. Recently, TRALI has come to be recognized as the leading cause of transfusion-related death in the United States and United Kingdom. This complication typically presents as shortness of breath, hypoxemia, hypotension, fever and noncardiogeneic pulmonary edema, all occurring during or within 6 h after transfusion.

Anti-KEL7 (anti-Js(b)) alloimmunization diagnostic supported by molecular KEL*6,7 typing in a pregnant woman with previous intrauterine deaths.

Anti-KEL7 (anti-Js(b)) is a rare antibody that has been related to haemolytic transfusion reactions and HDN. We report a case of anti-KEL7 alloimmunization detected in a pregnant woman who had an obstetric previous history of four miscarriages and one stillborn. Employing classical immunohematological techniques, we studied the propositus and her available relatives.

Dombrock gene analysis in Brazilian people reveals novel alleles.

Background And Objectives: The Doa and Dob polymorphisms are associated with three single nucleotide polymorphisms (SNPs) in exon 2 of the DO gene: 378C/T, 624T/C and 793A/G for the DOA and DOB alleles, respectively. The SNPs 350C/T (JO allele) and 323G/T (HY allele) are associated with the Jo(a-) and Hy-negative phenotypes. Recently, two new DO alleles [DOB-SH (378C, 624C, 793G) and DOA-HA (378T, 624T, 793A)] were identified using microarray technology.

Application of noninvasive phagocytic cellular assays using autologous monocytes to assess red cell alloantibodies in sickle cell patients.

We investigated red cell (RBC) alloantibodies in 125 sickle cell anemia (SCA) patients using tube indirect antiglobulin test (PEG, LISS or enzyme) and gel centrifugation test (LISS or enzyme). Prediction of clinical significance of alloantibodies was evaluated by the monocyte monolayer assay (MMA) and the chemiluminescence test (CLT) using autologous monocytes. The alloimmunization rate was 20.

A novel DI*A allele without the Band 3-Memphis mutation in Amazonian Indians.

Background And Objectives: The blood-group antigens Dia and Dib are carried on erythrocyte band 3 and are defined by a single amino acid substitution at position 854 (Leu for Dia and Pro for Dib). The Band 3-Memphis variant has a point mutation (166A>G) in the SLC4A1 gene, which encodes the amino acid substitution Lys56Glu. Two types of Band 3-Memphis, variants I and II, are distinguished by their susceptibility to covalent labelling with 4,4'-diisothiocyanato-1,2-diphenylethane-2,2'-disulphonic acid (H2DIDS).

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.

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%.

Human T-lymphotropic virus type I and type II infections and correlation with risk factors in blood donors from São Paulo, Brazil.

Background: Little is known about the prevalence of and risk factors for human T-lymphotropic virus type I and type II (HTLV-I, HTLV-II) infections in Brazil.

Study Design And Methods: Sera from 17,063 healthy Brazilian donors were screened by enzyme-linked immunosorbent assay for antibody to HTLV-I/II between August 1991 and July 1993. Repeatedly reactive samples were confirmed by Western blot, and discrimination between HTLV-I and HTLV-II was made by polymerase chain reaction or synthetic peptide enzyme-linked immunosorbent assay.