Rafael Gustavo Vargas

Activating killer cell immunoglobulin-like receptor genes' association with recurrent miscarriage.

Problem  Natural killer (NK) cells are regulated through NK cell receptors such as killer cell immunoglobulin‐like receptors (KIRs). KIRs are suspected of being involved in the causes of recurrent miscarriage (RM) as a higher proportion of activated NK cells were observed in women with RM when compared with that in controls. The aim of this study was to investigate if KIR genes coding for receptors known to have as ligands HLA class I molecules are correlated with RM.

ORIGINAL ARTICLE: Activating Killer Cell Immunoglobulin-Like Receptor Genes’ Association with Recurrent Miscarriage

Problem  Natural killer (NK) cells are regulated through NK cell receptors such as killer cell immunoglobulin‐like receptors (KIRs). KIRs are suspected of being involved in the causes of recurrent miscarriage (RM) as a higher proportion of activated NK cells were observed in women with RM when compared with that in controls. The aim of this study was to investigate if KIR genes coding for receptors known to have as ligands HLA class I molecules are correlated with RM.

HLA class II polymorphisms and recurrent spontaneous abortion in a Southern Brazilian cohort

A high proportion of human recurrent spontaneous abortions (RSA) remain unexplained. The possible association between RSA and different genetic polymorphisms within the human leucocyte antigen system (HLA system, the human major histocompatibility complex) has been investigated with conflicting results since many decades. Here, we describe a case–control study with 136 Southern Brazilian women of predominantly European ancestry (75 control and 61 cases with unexplained RSA). We investigated the relationship between unexplained RSA and alleles and genotypes from two classical loci of the HLA: HLA‐DRB1 and HLA‐DQB1, as well as three loci related to cytokine production and their serum levels: TNFA (−308G>A), IL10 (−1082G>A, −819T>C, −592A>C) and IFNG (+874A>T). Genotyping was performed by an allele‐specific PCR method. While all results concerning cytokine‐related genes turned out to be negative, we found the genotype HLA‐DQB1*02:02, 03:01 to be significantly decreased and the allele HLA‐DRB1*11:04 to be significantly increased among patients.

HLA-B*18:35, a new HLA-B*18 allele identified by sequence-based typing in a Brazilian volunteer bone marrow donor

A novel human leukocyte antigen-B allele named B*18:35 was identified in a Brazilian volunteer bone marrow donor.

A new allele, HLA-B*4212, identified in a Brazilian volunteer bone marrow donors by sequence-based typing.

Here we report the discovery of a novel HLA‐B allele, named B*4212 in a Brazilian volunteer bone marrow donor. The new sequence has nucleotide variation at position 496 (T→G) as compared with B*4201. This variation results in a conservative amino acid substitution from valine to glycine at codon 165 of exon 3.

ORIGINAL ARTICLE: Activating Killer Cell Immunoglobulin-Like Receptor Genes’ Association with Recurrent Miscarriage: ACTIVATING KIR GENES AND RECURRENT MISCARRIAGE

Problem  Natural killer (NK) cells are regulated through NK cell receptors such as killer cell immunoglobulin‐like receptors (KIRs). KIRs are suspected of being involved in the causes of recurrent miscarriage (RM) as a higher proportion of activated NK cells were observed in women with RM when compared with that in controls. The aim of this study was to investigate if KIR genes coding for receptors known to have as ligands HLA class I molecules are correlated with RM.

Identification of a novel HLA-A allele, HLA-A*0355, in a Brazilian family of eastern European descendents

The new human leukocyte antigen (HLA) class I allele, HLA-A*0355 was identified in a Brazilian family. Our sequence analysis detected a mismatch located in exon 2, codon 86, at position 258 (C-->A) that results in a nonsilent and nonconservative substitution with the replacement of asparagine by lysine. Substitutions located at this oligosaccharide attachment site of the protein were observed in only other four classic HLA class I sequences, indicating a highly conserved peptide site however its function remains unknown.