Popis: |
Oxalate nephropathy is a rare disease that can lead to acute kidney injury (AKI). In clinical practice, as renal biopsy is required for diagnosis, physicians often do not have sufficient understanding of this disease. When AKI is associated with positive blood anti-neutrophil cytoplasmic antibodies (ANCA), a diagnosis of renal injury due to ANCA-associated vasculitis is likely to be made, leading to treatment with immunosuppressive therapy. A case of AKI after eating a large quantity of Portulaca oleracea is reported. While blood P-ANCA was positive, both urine proteinuria and urine occult blood were negative. Renal biopsy was performed and identified an acute tubulointerstitial injury: disc-shaped crystals were seen in the lumen of renal tubules that demonstrated birefringence under polarized light, and an oxalate nephropathy was therefore diagnosed. Typical histological changes of an ANCA-associated vasculitis with renal injury such as cellulose-like necrosis and crescent formation were not present. After the patient stopped eating P. oleracea, and following rehydration and hemodialysis, renal function returned to normal. In patients with AKI, the secondary causes of hyperoxalemia should be sought and attention paid to excluding an oxalate nephropathy. In patients with AKI who are ANCA-positive, it is prudent to complete the renal pathological diagnostic process before assuming that the renal injury is caused by an ANCA-associated vasculitis, and before starting hormone and immunosuppressive therapy. |