Prevalence and Distribution of Autoimmune Diseases in 368 Rheumatoid Arthritis Families

LAËTITIA MICHOU, ANNE-CHRISTINE RAT, SANDRA LASBLEIZ, THOMAS BARDIN, and FRANÇOIS CORNÉLIS

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 second-degree 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.

Results. Probands of the ASP families were characterized by older age at RA onset, longer disease duration, and larger family size versus trio families. In the trio families, the prevalence of AI diseases was 6.05% (4.76%-7.57%) in FDR and 2.40% (1.85%-3.06%) in SDR. In ASP families, the prevalence of AI diseases was, respectively, 10.24% (8.68%-11.97%) and 1.79% (1.41%-2.25%). The most frequent AI diseases among relatives were RA, thyroid AI diseases, and vitiligo. In trio families, a proband with a mean age of RA onset < 30 years was associated with AI disease prevalence in the relatives, and male gender was associated with prevalence of RA among the FDR.

Conclusion. The prevalence of AI diseases is increased, particularly among FDR, in French RA families, and some characteristics of the RA proband seem to be associated with prevalence of AI diseases in families. (J Rheumatol First Release Mar 15 2008)

Key Indexing Terms:

RHEUMATOID ARTHRITIS
FAMILIAL AGGREGATION
AUTOIMMUNE DISEASES
PREVALENCE

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From GenHotel-EA 3886, University Evry-Paris 7 Medical School, Member of the AutoCure European Consortium, Evry-Genopole;

EA 4003, Centre d'Epidémiologie Clinique, CEC-Inserm CIE6, Service d'épidémiologie et évaluation cliniques, CHU Nancy, Nancy; and Unité de Génétique Clinique, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.

L. Michou, MD, PhD, GenHotel-EA 3886, University Evry-Paris 7 Medical School and Unité de Génétique Clinique, Hôpital Lariboisière; A-C. Rat, MD, EA 4003, Centre d'Epidémiologie Clinique, CEC-Inserm CIE6, Service d'épidémiologie et évaluation cliniques; S. Lasbleiz, MD; T. Bardin, MD; F. Cornélis, MD, PhD, GenHotel-EA 3886, University Evry-Paris 7 Medical School and Unité de Génétique Clinique, Hôpital Lariboisière.

Address reprint requests to Dr. L. Michou, Unité de génétique clinique, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris, cedex 10, France. E-mail: laetitia.michou@lrb.aphp.fr

Accepted for publication December 25, 2007.