A positive anti-nuclear antibody result does not contraindicate living kidney donation

Autoantibodies may precede the clinical onset of disease in up to two-thirds of patients with systemic lupus erythematosus (SLE). There is thus concern that antinuclear antibody (ANA) positivity in living kidney donors may eventuate in development of lupus nephritis post-uninephrectomy. Post-uninephrectomy, we routinely examine living kidney donors at 6 weeks, 6 months, 12 months, and annually thereafter. We performed a retrospective review of living kidney donors who had undergone uninephrectomy between July 1, 1999, and December 1, 2008. Data were collected for pre- and post-uninephrectomy renal function, proteinuria, hematuria, ANA, and anti-double stranded deoxyribonucleic acid (anti-dsDNA) antibodies. Among 68 living donor uninephrectomies performed during the study period, we excluded patients with no pre- uninephrectomy ANA or defaulted postoperative follow-up (n = 2). Twelve (18.2%) living donors were ANA-positive (M:F = 4:8) with a median titer of 1:100 (range, 1:100-1:800); 1 was transiently anti-dsDNA-positive. There were no significant differences between ANA-positive and ANA-negative donors in baseline demographics or pre-uninephrectomy creatinine clearance (median 108.0, range 79-179 mL/min vs. 106, range 58-172 mL/min, P = NS). Only 1 ANA-positive patient displayed transient microscopic hematuria (8 red blood cells); none had proteinuria pre-nephrectomy. Median follow-up was 63.5 (range, 21.2-139.3) months. At last clinic review, none of the ANA-positive donors had developed clinical symptoms or signs of SLE. Comparing ANA-positive and ANA-negative live donors at 5 years post-uninephrectomy, there were no significant differences in creatinine clearance (median 86.5, range 67-112 mL/min vs. 85.0, range 35-154 mL/min, P = NS), total urine protein (median 0, range 0-0.196 g/24 h vs 0, range 0-0.190 g/24 h, P = NS), or presence of hematuria (16.7% vs 33.3%, P = NS). Isolated ANA positivity does not contraindicate living kidney donation. Up to 5 years post- uninephrectomy, the risk of developing clinical lupus among low-titer ANA-positive individuals remains low.