Unexpected severe reversible cyclosporine A-induced nephrotoxicity in a patient with systemic lupus erythematosus and tubulointerstitial renal disease.

We describe a patient with systemic lupus erythematosus and impaired renal function probably mainly due to tubulointerstitial disease. After a six-week course of low-dose cyclosporine A, she developed a severe but reversible loss of glomerular filtration rate and effective renal plasma flow despite of low cyclosporine A plasma levels. Based upon the observed fall of the filtration fraction, the rise in the relative clearance of 99Tc-dimercaptosuccinic acid and the increase in proteinuria, we suggest that in this case the tubules and/or interstitium are the main targets for cyclosporine A nephrotoxicity. Neither our patient's clinical symptoms nor her serologic parameters improved possibly because of the low dosage and/or short duration of cyclosporine A treatment. We conclude that one should be cautious when treating patients with systemic lupus erythematosus and pre-existing renal disease with cyclosporine A especially when tubulointerstitial abnormalities are present and/or other nephrotoxic drugs are used.