LAUSR

INTRODUCTION A lkaline-encrusted pyelitis is an infectious disease of the renal pelvicalyceal system characterized by calcific encrustation of the urothelium. Corynebacterium urealyticum (C urealyticum) has been identified as the causative organism. This slow-growing, gram-positive bacillus is a skin commensal with a tropism for uroepithelial cells. As a urease-producing organism, C urealyticum converts urea to ammonia within the urinary tract. The resultant alkalinization of urine causes precipitation of struvite and calcium phosphate along the mucosal surface of the renal pelvis. The initial presentation is often nonspecific, but commonly reported clinical features include hematuria, fever, and declining renal function. Diagnosis is based on the triad of an alkaline urine, positive cultures for C urealyticum, and urothelial calcification on noncontrast computed tomography (CT). However, diagnosis is often delayed. C urealyticum is a fastidious organism that will not grow using routine culture methods. Unless there is a specific request for prolonged culture using enriched media, the urine will be reported as sterile. A high index of clinical suspicion is therefore vital. Both renal allograft loss and patient mortality have been reported due to a delay in diagnosis. Treatment is aimed at eradicating C urealyticum with antibiotic therapy and dissolving the encrusted material by urinary acidification. The duration of treatment is ill defined, but prolonged hospital admission with i.v. antibiotic administration for 4 weeks has been reported. We present a case of alkaline-encrusted pyelitis in a kidney transplant recipient successfully managed with a predominantly home-based treatment regimen.