ABSTRACT
There are many factors that influence the pathogenesis of autoimmune disease of which host genetic factors play an important role. The aim of this study was to investigate the HLA Class I and II genes in a family with a high incidence of AID to establish whether they contribute to the development of these disease. Four of them had been diagnosed with SLE and one with AHA. The patients with SLE showed the presence of HLA-A*02 B*40 DRB1*04:07 DQB1*03:02 haplotype with a high statistical significance. This haplotype was not present in the healthy individuals and in the patient with AHA, although the DRB1*04:07 DQB1*03:02 haplotype (carried by both parents) was found in the AHA patients and one of the healthy individuals. We must consider how HLA Class I in linkage disequilibrium with HLA Class II may be involved in susceptibility or in the development of SLE. An extensive study in this population should be conducted to establish the true participation of the HLA Class I region.