[HLA-DRB1 alleles and rheumatoid arthritis in northern Italy: lack of correlation with disease severity and extra-articular manifestations].

We studied HLA-DRB1 alleles in 101 patients with rheumatoid arthritis (RA) and 229 normal subjects by polymerase chain reaction and sequence-specific oligonuclotide hybridization. We observed a statistically significant association between HLA-DR4 and RA (p = 0,0088). This association was not observed for the DR1 status. No particular DR4 suballeles were preferentially expressed in patients. Allele *0102 was more frequent in RA patients (p = 0.0084), while *0103 in controls (p = 0.000047). No difference was observed for the presence of early erosions and extra-articular features in patients with no, one or two RA associated alleles and among share epitope positive and negative patients.