Secondary oxalosis induced acute kidney injury in allograft kidneys

Secondary oxalosis causing acute kidney injury (AKI) has been widely reported in native kidneys but its occurrence in allograft kidneys is relatively uncommon. We present three patients with acute kidney allograft dysfunction secondary to tubular oxalate microcrystal deposits confirmed on allograft biopsy in the setting of acute gastrointestinal dysfunction. These three patients presented with AKI that was preceded by episodes of ongoing diarrhea ranging from 10 to 90 days. All patients were on vitamin C and/or multivitamin supplementation. Two of the three patients needed long-term renal replacement therapy with the third patient recovering his kidney function after 2 months. The risks versus benefits of vitamin C supplementation in renal transplant patients should be carefully evaluated especially in the setting of gastrointestinal dysfunction.