Reddy S, Bolen E, Abdelmalek M, et al. - In this largest cohort study of oxalate nephropathy (ON) not attributable to primary hyperoxaluria, there were differences in histologic features between patients with enteric vs nonenteric risks. The sole most significant predictor of adverse renal outcome was acute kidney injury necessitating dialysis at the time of diagnosis.

• Using a clinical data repository of native kidney pathology reports from 2009 to 2020 at all Mayo Clinic sites, 64 cases of ON were analyzed; enteric risk factors were present in 30 and nonenteric in 34.

• In the enteric hyperoxaluria group, Roux-en-Y gastric bypass (17) and pancreatic insufficiency (6) were most common, whereas vitamin C (7) and dietary oxalate (7) were common in the nonenteric group.

• More interstitial inflammation and a greater number of tubules containing intratubular calcium oxalate crystals were found in patients in the nonenteric group.

• A greater probability of having baseline chronic kidney disease and moderate-to-severe tubulointerstitial fibrosis and atrophy (OR 3.49) was noted in patients in the enteric group.

• Post- median follow-up of 10 months, dialysis dependent patients were 39%, a kidney transplant was received by 11%, and death occurred in 32%.