Extensive clinical, serologic and molecular studies lead to the first reported Rh phenotype in Argentina.

Background: A highly reduced expression of Rh antigens in the erythrocyte membrane is the main feature of Rh , an extremely rare phenotype. Mutations within RHAG gene, which encodes RhAG glycoprotein and modulates Rh antigen expression and Rh complex formation, are the molecular events responsible for the Rh phenotype. Here we report a clinical, serologic, and molecular study of an Argentinean proband with Rh-deficiency syndrome.

Characterization of RHD locus polymorphism in D negative and D variant donors from Northwestern Argentina.

Background: A notable RHD variability has been observed in Central Argentina's current population attributed to the intermixing of different ethnic groups. The Northwestern region of the country is characterized by a markedly Amerindian genetic contribution. In this sense, the definition of the RHD polymorphism in individuals from this area was lacking.

Clinical Significance of an Alloantibody against the Kell Blood Group Glycoprotein.

Background: Kell null (K) individuals can produce anti-Ku, an antibody against many epitopes in the Kell glycoprotein, after transfusion and/or pregnancy. Since sensitized K patients are rare, little is known about anti-Ku clinical relevance and in particular about its association to hemolytic disease of the fetus and newborn.

Case Report: This work describes a case of neonatal hyperbilirubinemia due to immune-mediated erythrocyte destruction by an alloantibody directed against the Kell glycoprotein.

Genotyping approach for non-invasive foetal RHD detection in an admixed population.

Background: Non-invasive foetal RHD genotyping can predict haemolytic disease of the foetus and the newborn in pregnancies with anti-D alloantibodies and also avoid antenatal anti-D prophylaxis in pregnant women carrying an RHD negative foetus. Considering that the Argentine genetic background is the result of generations of intermixing between several ethnic groups, we evaluated the diagnostic performance of a non-invasive foetal RHD determination strategy to guide targeted antenatal RhD immunoprophylaxis. This algorithm is based on the analysis of four regions of the RHD gene in cell-free foetal DNA in maternal plasma and maternal and paternal RHD genotyping.

Molecular structures identified in serologically D- samples of an admixed population.

Background: The D- phenotype is mainly caused by the complete deletion of the RHD gene in Caucasians. However, a plethora of allelic variants have been described among D- individuals from different ethnic groups.

Study Design And Methods: A cohort of 1314 routine serologically D- samples from white Argentineans was studied by molecular methods.

Expression of the gene encoding secretor type galactoside 2 α fucosyltransferase (FUT2) and ABH antigens in patients with oral lesions.

Objective: The aim of this work was to evaluate the expression of FUT2 gene in saliva and histo ABH antigens of patients with oral lesions.

Study Design: In total 178 subjects were examined, half of whom suffered from oral pre-cancerous and cancerous lesions, while the other half were the healthy control group We analyzed the FUT 2 polymorphism by ASO-PCR (allele specific oligonucleotid - polymerase chain reaction) with specific primers for G428 allele and the wild type allele of FUT2 gene. To reveal A, B and H antigens in tissue sections of the patients (n= 89) we used a modified specific red cell adherence technique.

Comprehensive analysis of RHD alleles in Argentineans with variant D phenotypes.

Background: The serologic assignment of the RhD status may be hindered in patients with weak D expression. A comprehensive study of RHD alleles occurring in the mixed population of Argentina is necessary to evaluate the most suitable DNA typing strategy.

Study Design And Methods: A total of 18,379 patients from two stratified groups, Group 1 (G1; public hospital) and Group 2 (G2; private laboratory), were RhD phenotyped, and 88 samples with reduced D expression underwent molecular characterization.

Modifications of band 3 and oxidation level of membrane proteins in senescent erythrocytes.

Objectives: To study membrane proteins modifications in Senescent Red Blood Cells (SeRBC). DESIGN ANDMETHODS: SeRBC were obtained on Percoll gradients. Membrane proteins were analyzed by SDS-PAGE, band 3 by immunoblotting, and protein oxidation by measuring the carbonyl groups.

Distribution of HLA-DRB1 alleles in Argentinean patients with Chagas' disease cardiomyopathy.

Chronic Chagas' disease occurs in a variable number of infected individuals and mainly manifests as an inflammatory cardiomyopathy that may lead to a fatal course. The factors underlying the establishment of chronic myocardial lesions are not fully understood. The study included 71 unrelated individuals serologically positive for T.

Effects of aging on antioxidant response and phagocytosis in senescent erythrocytes.

Red blood cell (RBC) aging is a complex process affected by immunological and biochemical parameters. In this work we studied the antioxidant response in RBC of different ages. We also investigated their interaction with peripheral blood monocytes.

Duffy genotyping facilitates transfusion therapy.

The Duffy (FY) blood group system is clinically significant in transfusion medicine because FY antibodies are involved in hemolytic transfusion reactions and hemolytic disease of the newborn. The Fy(a) and Fy(b) antigens are encoded by the FY*A and FY*B alleles which are responsible for the Fy(a+b+), Fy(a+b-) and Fy(a-b+) phenotypes. The Fy(a-b-) phenotype is found in individuals homozygous for a silent FY*B allele, named FY*B ( ES ), which is caused by a mutation in the promoter region of FY*B that result in the loss of FY expression in the erythroid linage.

Distribution of the FYBES and RHCE*ce(733C>G) alleles in an Argentinean population: implications for transfusion medicine.

Background: The understanding of the molecular bases of blood groups makes possible the identification of red cell antigens and antibodies using molecular approaches, especially when haemagglutination is of limited value. The practical application of DNA typing requires the analysis of the polymorphism and allele distribution of the blood group genes under study since genetic variability was observed among different ethnic groups. Urban populations of Argentina are assumed to have a white Caucasian European genetic component.

Association of leprosy with HLA-DRB1 in an Argentinean population.

Background: Previous studies have suggested an influence of HLA molecules on the regulation of the anti Mycobacterium leprae immune response.

Methods: DNA typing of HLA-DRB1 alleles in 71 leprosy patients and 81 healthy controls was performed. Genomic DNA was extracted from peripheral blood and used as a template to amplify the polymorphic second exon of the HLA-DRB1 by the polymerase chain reaction (PCR).

Secretor status and ABH antigens expression in patients with oral lesions.

Objectives: The aim of this work was to investigate the secretor status of patients with oral pre-cancerous and cancerous lesions and ABH antigens expression in fixed tissue sections of these patients.

Study Design: To reveal A, B and H antigens in tissue sections of patients with precancerous and cancerous oral lesions (n= 54) we used a modified specific red cell adherence technique (SRCA-test). Normal endothelial cells expressed ABH antigens, the presence of indicator erythrocytes at the lumen of the blood vessels served as a built in positive control.

The Dc(G48)e(s) haplotype is frequent among the Dce haplotypes within a white population.

Background: The absence of hybrid Rhesus boxes denotes an RHD homozygous status and helps to detect the presence of Dce haplotypes instead of dce. RHCE exon 1 C48, characteristic of RHC alleles, and RHCE exon 5 G733, responsible for VS antigenicity, have been noted in many RHce alleles but it was not clearly established whether they occurred in the same allele and/or cosegregate together with RHD.

Study Design And Methods: Samples from 148 white trios (father, mother, and child) were studied.

HLA class II DRB1 polymorphism in Argentinians undergoing chronic Trypanosoma cruzi infection.

DNA typing of human lymphocyte antigen (HLA)-dicloro-1-[beta]-D-ribofuranosyl-benzimidazole 1 (DRB1) alleles in 35 individuals serologically positive for T. cruzi and in 41 healthy controls was performed. DRB1*0409 allele was significantly more prevalent in seropositive individuals, with a trend being also observed for the DRB1*0701 and DRB1*1503 alleles.

[Alloimmunization to a high frequency Rh antigen].

We report the case of a pregnant woman sensitized with a panreactive anti-Rh17 alloantibody. Patient's red blood cells showed a partial deletion of Rh antigens, which was responsible for the alloimmunization. An autotransfusion program was instrumented so as to cover possible demands.

Use of the erythrophagocytosis assay for predicting the clinical consequences of immune blood cell destruction.

The erythrophagocytosis assay is a useful parameter to evaluate the immune erythrocyte destruction occurring in vivo. The aim of this work was to use this assay in: a) the diagnostic and therapeutic assessment of autoimmune haemolytic anaemia (AIHA), b) the selection of blood for immunized patients requiring transfusion and c) the prediction of the severity of haemolytic disease of the newborn (HDN). This assay was also used to study the physiological removal of senescent erythrocytes from the circulation.

Clinical aspects of Rh genotyping.

The Rh antigens are encoded by the RHD and RHCE genes. In RhD negative individuals the RHD gene is absent or grossly deleted. Routinely, Rh typing is performed by haemagglutination.