HLA class II associations with rheumatic heart disease among clinically homogeneous patients in children in Latvia.

Genetic control of immune reactions has a major role in the development of rheumatic heart disease (RHD) and differs between patients with rheumatic fever (RF). Some authors think the risk of acquiring RHD is associated with the HLA class II DR and DQ loci, but other views exist, due to the various HLA-typing methods and ways of grouping cases. Our goal was to determine the relations between HLA class II alleles and risk of or protection from RF in patients with relatively homogeneous clinical manifestations. A total of 70 RF patients under the age of 18 years were surveyed in Latvia. HLA genotyping of DRB101 to DRB118 and DQB10201-202, 0301-305, 0401-402, 0501-504, and 0601-608 was performed using polymerase chain reaction sequence-specific primers. Data for a control group of 100 healthy individuals typed for HLA by the same method were available from the databank of the Immunology Institute of Latvia. Of the RF patients, 47 had RHD and 8 had Sydenham's chorea. We concluded that HLA class II DRB107-DQB10401-2 and DRB107-DQB10302 could be the risk alleles and HLA class II DRB106 and DQB10602-8, the protective ones. Patients with mitral valve regurgitation more often had DRB107 and DQB10401-2, and patients with multivalvular lesions more often had DRB107 and DQB10302. In Sydenham's chorea patients, the DQB10401-2 allele was more frequent. Genotyping control showed a high risk of RF and RHD in patients with DRB101-DQB10301-DRB107-DQB10302 and DRB115-DQB10302-DRB107-DQB10303.