Abstract

Background:Unexplained azotaemia in a renal donor needs urgent evaluation. Renal biopsy is required when the urine examination shows proteinuria and when there is an unexplained worsening of renal functions. Granulomatous interstitial nephritis of solitary kidney in a renal donor has not been reported so far in the literature.
Case summary: We would like to report on the benefits of performing a renal biopsy of a solitary kidney in establishing a diagnosis. A 51-year old woman, who donated her kidney 15 years ago, developed azotaemia with mild proteinuria in the setting of significant weight loss of 10 kilograms in 3 months. Kidney biopsy revealed granulomatous interstitial nephritis with areas of caseating necrosis, suggestive of tuberculosis. She received first-line anti-tuberculous treatment for 9 months and her serum creatinine improved from baseline, which remained stable after 1 year.
Conclusion: Unusual causes of renal impairment needs to be considered in a patient without any obvious precipitating conditions. A kidney biopsy would help in identifying the exact cause in particular, a kidney donor, especially when a kidney biopsy is considered a relative contraindication.

Key words: Tuberculosis, Renal donor, renal biopsy, solitary kidney