TUMOR-NECROSIS-FACTOR MICROSATELLITE HAPLOTYPES ARE DIFFERENT IN MALEAND FEMALE-PATIENTS WITH RA

We investigated whether tumor necrosis factor (TNF) microsatellite pol ymorphisms are associated with sex and age at disease onset in rheumat oid arthritis (RA). A case-control study was used to compare the frequ encies of TNF microsatellite alleles in 181 Caucasian RA cases and 251 controls. TNF microsatellite genotyping was performed using fluoresce nt based polymerase chain reaction (PCR) techniques and HLA-DR typing using PCR based sequence specific oligonucleotide probing, The associa tion of TNF microsatellite alleles a6, b5, and d4 with RA was confirme d. These polymorphisms were more frequent in female patients. Male pat ients with RA with young age at onset had a different TNF microsatelli te profile, TNFa2, b1, and c2 being the most frequent, TNF microsatell ite polymorphisms are different in male and female patients with RA, T his difference was more obvious in patients stratified according to ag e at onset. Sex and age at onset should be considered in studies of ge netic factors in RA.