Long‐term followup of children with neonatal lupus and their unaffected siblings

Objective To determine in a longitudinal cohort study whether children with varied manifestations of neonatal lupus or their unaffected siblings later develop autoantibodies and/or rheumatic diseases. Methods To obtain information on the health of children ages ≥8 years who had manifestations of neonatal lupus (affected group) and their unaffected siblings (unaffected group), questionnaires were sent to mothers (with anti‐SSA/Ro and/or anti‐SSB/La antibodies) who were enrolled in the National Institute of Arthritis and Musculoskeletal and Skin Diseases/Hospital for Joint Diseases Research Registry for Neonatal Lupus. Children of healthy mothers referred by the Registry enrollees comprised the control group. Further data were provided by review of medical records. Results Fifty‐five mothers enrolled in the Registry returned questionnaires on 49 children with neonatal lupus and their 45 unaffected siblings. Six children with definite rheumatic/autoimmune diseases were identified: 2 with juvenile rheumatoid arthritis, 1 with Hashimoto thyroiditis, 1 with psoriasis and iritis, 1 with diabetes mellitus and psoriasis, and 1 with congenital hypothyroidism and nephrotic syndrome. All had neonatal lupus, and their mothers had manifestations of autoimmune diseases (Sjögren's syndrome in 4, systemic lupus erythematosus/Sjögren's syndrome in 1, and undifferentiated autoimmune disease in 1). Antinuclear antibodies were present in 4 of 55 sera tested (2 of 33 affected children and 2 of 22 unaffected children). No serum contained antibodies reactive with SSA/Ro or SSB/La antigens. Conclusion These data suggest that children with neonatal lupus require continued followup, especially prior to adolescence and if the mother herself has an autoimmune disease. While there was no apparent increased risk of systemic lupus erythematosus, the development of some form of autoimmune disease (systemic or organ‐specific) in early childhood may be of concern. During adolescence and young adulthood, individuals with neonatal lupus and their unaffected siblings do not appear to have an increased risk of developing systemic rheumatic diseases.