Familial aggregation of lupus and autoimmunity in an unusual multiplex pedigree.

Abstract

To evaluate an unusual pedigree with 8 members diagnosed with systemic lupus erythematosus (SLE) METHODS: Pedigree members were evaluated through questionnaires, interviews, and medical records. Sixty members contributed serum samples for autoantibody analysis. The 8 affected females shared several disease features, including arthritis (8/8), antinuclear antibodies (ANA) (8/8), pleuritis (6/8), malar rash (6/8), photosensitivity (5/8), and nephritis (4/8). A total of 15 of 51 (29%) blood relatives had autoantibodies; 9 had autoimmune disease, including 7 with SLE, one with psoriasis, and one with Sjögren's syndrome. Five of 11 (45%) nonconsanguineous spouses also had autoantibodies; one spouse had SLE, and 2 others had thyroid disease. Among 68 spouses of patients with SLE in other pedigrees, only 9 (13%) had autoantibodies, and none were symptomatic (p = 0.02). The high rate of autoimmunity among both blood relatives and nonconsanguineous mates in this unusual pedigree suggests a complex interaction of genetic and environmental factors contributing to disease.