HLA and juvenile rheumatoid arthritis

HLA class II analysis in a group of 153 Czech children with juvenile rheumatoid arthritis by PCR and oligonucleotide hybridization demonstrated associations with several alleles. DRB1*0801 (RR = 5.3, p < 0.005) and DRB1 * 11 (RR = 2.2, p < 0.01) including all subtypes were shown to be increased in the rheumatoid factor-negative group (N = 137). The same results were observed in Italy, England and Norway. In patients with the pauciarticular onset with conversion to polyarticular within 3 years, a statistically significant increase in DR2 (RR = 10.1, p < 0.00005), mostly due to DRB1*1501, was found. In the iridocyclitis and antinuclear factor groups, susceptibility to DRB1*1201 was observed. There was a striking decrease in DRB1*0701 (RR = 0.3, p < 0.00005) in all groups. There was neither an increase in DRB1*1301 or DPB1*0301 nor a decrease in DRB1*04, as reported from other studies in Texas and Norway. The rheumatoid factor-positive group with polyarticular onset (N = 13) was associated with DRB1*04 (RR = 7.1, p < 0.005), as observed in adults. DPB1*0201 was increased in the persistent pauciarticular group (RR = 3.7, p < 0.0005). DPB1*0402 was decreased in all pauciarticular groups with or without conversion (RR = 0.3, p < 0.005). Taken together, there are not only genetic differences and clinical heterogeneity in juvenile rheumatoid arthritis patients but, also, common predisposing factors.