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.