Predominant tubulointerstitial lupus nephritis.

Predominant tubulointerstitial lupus nephritis is rare. Only eight cases have been described in the literature. We report the case of a 59-year-old man with systemic lupus erythematosus who presented with acute renal failure. On renal biopsy, he was found to have chronic tubulointerstitial nephritis with a mononuclear infiltrate. The immunofluorescence showed immune deposits in the tubular basement membranes, interstitium, and glomerular capsule. The glomeruli were minimally involved. He was initially treated with high-dose corticosteroids and supported with hemodialysis. Renal function improved and dialysis was discontinued after three treatments. The corticosteroid dosage was gradually tapered. Renal function after 72 months of follow-up has remained stable (serum creatinine, approximately 1.9 mg/dL) and except for one relapse, there has been no clinical or serologic evidence of lupus activity. Furthermore, 24-hour urinary protein excretion has remained within the normal range.