CASE 22: Renal Oxalosis

45-year-old male with history of obesity and gastric bypass at age 37. Underwent deceased donor kidney transplantation after having been on dialysis for 4 years. Post-operative course complicated by delayed graft function. An allograft biopsy was obtained on post-transplant day 20.

Biopsy (Figures 112-83 and 112-84) revealed numerous polarizable oxalate crystals. Renal oxalosis is a known complication of gastric bypass surgery, as well as other conditions inclusive of short bowel syndrome, chronic diarrhea, chronic antibiotic use due to intestinal flora alterations, increased intake of oxalate rich foods, megadoses of vitamin C, and ethylene glycol poisoning.