HLA-DRB1*04 subtypes are associated with increased inflammatory activity in early rheumatoid arthritis

The sequence polymorphism of HLA-DRB1 molecules in 84 rheumatoid arthritis(RA) patients with early RA has been analysed to evaluate whetherparticular HLA-DR alleles influence disease progression in the early stageof the disease. Clinical data were analysed by grouping the patientsaccording to disease-associated haplotype combinations(DRB1*04,04/DRB1*04,01/DRB1*04,X/DRB1*01,X) in comparison to patients whodid not carry these haplotypes (DRB1*X,X). Our results indicate thatpatients with early RA who are homozygous for DRB1*04 exhibit an elevatedinflammatory activity and an increase of joint affections. In addition, theamino acid polymorphism (QR/KRAA) at position 70-74 seems to affect theproduction of rheumatoid factors. These results support the role ofHLA-DRB1 alleles in the pathogenesis of RA and indicate that patients withparticular HLA-DRB1*04 haplotype combinations may require intensifiedtherapeutic interventions in the early stage of the disease to preventdisease progression.