Investigation of novel polymorphisms within the 3 ' region of the IL-6 gene in patients with rheumatoid arthritis using Genescan analysis

A highly polymorphic AT rich repeat exists in the 3' flanking region of the IL-6 gene. Using Genescan analysis we studied this region of the IL-6 gene in 55 normals and 95 patients with rheumatoid arthritis (RA), The influenc e of alleles on need for early major joint surgery in RA patients was asses sed. We identified nine alleles of which, G8, G7 and G4 were the most commo n (37% vs 36% vs 13%), RA surgery patients had an increase in the frequency of G7 compared to non-surgery and control populations (46% vs 27% vs 34%, respectively) and a decrease in G8 (22% vs 46% vs 43%, respectively). RA pa tients homozygous for G8 had a lower ESR than those homozygous for G7 (23 m m/h vs 36 mm/h) although this was not significant. We have determined these alleles and their distribution in a normal and RA population. Initial find ings suggest G8 may be associated with lower erythrocyte sedimentation rate (ESR) and less severe RA, Although trends in allele distribution were obse rved, further studies in larger cohorts are required. (C) 2001 Academic Pre ss.