ABSTRACT. Objective. To investigate whether frequency of rheumatoid arthritis (RA) and/or other autoimmune (AI) disorders was increased in RA French Caucasian families among the first-(FDR) and seconddegree relatives (SDR), and to test whether the presence of AI disease family history identified a specific RA subset. Methods. We conducted telephone interviews to obtain histories of AI diseases among the FDR and SDR of 368 RA probands, belonging either to trio or affected sib-pair (ASP) families. All the AI diagnoses were confirmed by the physician of the affected relative
