A MAHER1, V HERON1, S GOVINDARAJULU1
1Renal Service, Darling Downs Hospital and Health Service, South Toowoomba, Australia
Background: The use of corticosteroids in acute interstitial nephritis is controversial, however may be utilised if patients do not have a significant improvement in creatinine within one week of cessation of the culprit medication.
Case Report: We report a case of a 77 year old male who presented with an acute kidney injury with renal biopsy findings suggestive of acute interstitial nephritis secondary to a course of penicillins for a gluteal abscess. His renal function continued to decline with his creatinine peaking at 218umol/L from a baseline of 77umol/L. He was initiated on 75mg of prednisolone (patient weight 125kg). Three weeks post commencement of prednisolone his creatinine had improved to 113umol/L. However, at this time, his treatment course was complicated by rapidly progressive dyspnoea and hypoxia requiring admission with room air saturations of 73%. A high resolution CT chest demonstrated widespread, non-specific ground glass opacifications in both lungs. A bronchoscopy and subsequent culture confirmed an opportunistic infection with Pneumocystis jiroveci pneumonia (PJP). Sulfamethoxazole Trimethoprim (1600mg/320mg) four times a day was initiated. One week later, he developed a thick, mud-like urinary sediment associated with deterioration in renal function with his creatinine incrementing from 125umol/L to 260umol/L. Urine microscopy with infrared spectroscopy demonstrated needle-shaped crystals, consistent with sulfonamide usage. The offending agent was ceased and his PJP was managed with clindamycin and primaquine with a subsequent improvement in both pulmonary and renal function. At time of discharge his creatinine was 93umol/L.
Conclusions: This case demonstrates the importance of the use of PJP prophylaxis whilst on high dose steroids and the awareness of the potential renal complications of sulphomethaxole induced crystalluria.
Vanessa Heron is an advanced trainee in nephrology working in the renal department at Toowoomba Hospital.