Systemic Lupus Erythematosus Preceded by Distal Renal Tubular Acidosis

Distal renal tubular acidosis (RTA) is characterized by a decreased net H+ secretion in the collecting tubules, which results in a failure of urine acidification and results in metabolic acidosis, hypokalemia, and nephrocalcinosis. The acquired form of distal RTA is associated with tubulointerstitial involvement of immune-mediated disorders such as Sjogren’s syndrome and systemic lupus erythematosus (SLE). Only a few case reports have indicated that distal RTA precedes SLE by months to years. We present a 39-year-old woman who had manifestations of distal RTA for 21 years before the development of overt symptoms of SLE. (Korean J Med 2011;81:533-536)