[Oxalate nephropathy due to malabsorption syndrome].

Enteric oxalate nephropathy is caused by hyperoxaluria. Factors which contribute to excessive oxalate absorption are an abundance of free fatty acids in the intestine due to malabsorption, changes in the microbiome, and bowel inflammation. We present two cases that illustrate different pathophysiological aspects of this disease. The first patient was a 70-year-old male who developed oxalate nephropathy through malabsorption caused by chronic pancreatitis. It is plausible that the oxalate nephropathy was set off by antibiotic treatment which influenced the microbiome. The second patient was a 63-year-old male who underwent a Roux-en-Y gastric bypass. The associated malabsorption resulted in oxalate nephropathy. Kidney biopsies from both patients showed typical oxalate crystals. Therapeutic regimens using calcium supplementation, steroids, and a low oxalate diet are rational treatments, which have proven to prevent deterioration of renal function in some patients.