HLA ANTIGENS AND HAPLOTYPES IN IGA-DEFICIENT BRAZILIAN PEDIATRIC-PATIENTS

In the present study we determined the HLA-A, B and DR antigenic and h aplotypic frequencies in unrelated Brazilian Caucasian paediatric pati ents with IgA deficiency (IgA-D). Out of 17 IgA-D subjects typed for H LA A and B specificities, 12 (71%) presented B8 and/or B14; of 15 pati ents also typed for HLA-DR specificities, 14 (93%) were positive for a t least one of the HLA markers previously reported to be associated wi th IgA-D, i.e. B8, B14, DR1, DR3 or DR7. The haplotypes B8, DR3, B14, DR1 and B13, DR7 were present in 43, 21 and 14% of the cases, respecti vely, while they have a frequency in the general population of 2, 2 an d 1%, respectively. The concomitant association with the three IgA-ass ociated haplotypes found in our study probably reflects the admixture of European genetic influences present in the Brazilian Caucasian popu lation of S (a) over tilde o Paulo.