TUBULOINTERSTITIAL NEPHRITIS INDUCED BY THE LEUKOTRIENE RECEPTOR ANTAGONIST PRANLUKAST

A 7-year-old boy with asthma was receiving the leukotriene receptor an tagonist pranlukast (Ultair; SmithKline Beecham; Pittsburgh) as part o f an open-label clinical trial. The patient's asthma improved, and he remained asymptomatic; but routine study evaluations 9 to 12 months in to therapy showed microhematuria, proteinuria, glucosuria, anemia, and renal insufficiency. Renal biopsy demonstrated changes classic for ac ute allergic tubulointerstitial nephritis (ATIN), with mixed interstit ial inflammatory infiltrate including eosinophils. Within 6 months of pranlukast withdrawal, anemia resolved and urinary sediment and renal function normalized. The case demonstrates that hypersensitivity react ion to pranlukast and resultant ATIN is possible, and that periodic ur ine testing in patients receiving pranlukast should be considered.