Renal outcomes in children with lupus and a family history of autoimmune disease

Abstract

Genetic factors play an important role in systemic lupus erythematosus (SLE) susceptibility and development of lupus nephritis (LN). The significance, however, of a positive family history of autoimmune disease on renal outcome in SLE patients is unknown. This retrospective study of 64 children with LN investigates whether children with LN and a family history of AID (autoimmune disease; 34 patients) had worse renal outcomes when compared with children who did not have a family history (26 patients) of AID. In four patients the family history was unknown. The primary endpoint was doubling of serum creatinine (sCr) and the secondary endpoint was requiring dialysis or transplant (ESRD). Demographic variables for family history + versus mean age in years (range) at onset of LN were 13.5 (7.4-15.9) versus 13.2 (6.4-19.7); female 26: 34 (76%) versus 24: 26 (92%), P = 0.097; race Black 23 (68%), Caucasian 7 (21%), Asian 1 (2%), Hispanic 3(9%) versus Black 14 (54%), Caucasian 6 (23%), Asian 2 (8%), Hispanic 4 (15%). Three patients died (1.6%); sCr doubled in 6/34 (17.6%) versus 2/26 (7.7%), P = 0.45, followed for 2.8 years (0.8-5.8) and 1.8 years (1.8-1.9), respectively, P = 0.24; sCr doubled plus ESRD in 10/34 (29%) versus 6/26 (23%), P = 0.77, followed for 2.7 years (0.8-5.8) and 2.0 years (0.7-4.1) respectively, P = 0.29. In the family history + group, more Black versus non-Black patients doubled their sCr or reached ESRD, 8/23 (35%) versus 2/11 (18%), P = 0.44. More males and Black patients with LN had a positive family history for AID and were more likely to double their sCr or reach ESRD. These results suggest that a family history of AID impacts on renal outcome in children with SLE.