RENAL IMPAIRMENT AND HYPERSENSITIVITY REACTION DUE TO EFAVIRENZ

A 55-year-old man with known HIV infection since 1994 was admitted with a 4 day history of fever, rigors and chills, loss of appetite, lethargy and mild diarrhoea. He described exertional shortness of breath, pleuritic chest pain and reduced urine volumes. His antiretroviral therapy for the preceding 5 years had been with efavirenz and Kaletra (lopinavir and ritonavir) with the addition of Truvada (tenofovir and emtracitabine) during the recent past. Renal function was previously normal. At admission there were fine crackles in the lung bases and oxygen saturation was 94% on air with no other localizing abnormalities. Admission blood tests revealed a neutrophil leukocytosis (total white cell count 22.3 ¥ 10E9/L), a creatinine of 762 umol/L, urea of 27.9 mmol/L, potassium of 4.1 mmol/L and phosphate of 1.12 mmol/L. Liver function tests were mildly deranged with a mixed picture. Further relevant investigation findings included a midstream urine that showed 70 million white cells/L and a moderate amount of protein (urine protein creatinine ratio 136 mg/mmol) and a normal renal ultrasound scan and chest X-ray. Serological screening tests for acute glomerulonephritis were negative and inflammatory markers were raised with a c-reactive protein that peaked at 337 mg/L. The patient was commenced on intravenous cefuroxime and oral roxithromycin for a possible chest infection and his anti-retroviral therapy was discontinued. On the second day of admission to hospital he commenced spiking fevers up to 38.3C and renal function continued to remain abnormal. A renal biopsy was performed and acute haemodialysis was commenced. Renal histology revealed an acute interstitial nephritis with a neutrophilic and eosinophilic infiltrate. Prednisone was commenced at a dose of 60 mg a day with rapid resolution of fever and improvement in renal function. The patient was discharged and has remained well with normalization of renal function. He has been commenced on Kaletra (lopinavir and ritonavir), nevirapine and Kivexa (abacavir and emtricitabine) with good control of his HIV infection and no significant adverse effects. DISCUSSION