title: Early presence of calcium oxalate deposition in kidney graft biopsies is associated with poor long-term graft survival.
abstract: Accumulated oxalate will be excreted after renal transplantation, creating an increased risk of tubular precipitation, especially in the presence of allograft dysfunction. We evaluated calcium oxalate (CaOx) deposition in renal allograft biopsies with early dysfunction, its association with acute tubular necrosis (ATN) and graft survival. We studied 97 renal transplant patients, submitted to a graft biopsy within 3 months post-transplant, and reanalyzed them after 10 years. We analyzed renal tissue under polarized light and quantified CaOx deposits. CaOx deposits were detected in 52.6% of the patients; 26.8% were of mild and 25.8% of moderate intensity. The deposits were more frequent in biopsies performed within 3 weeks post-transplant (82.4 vs. 63.0%, p < 0.05) and in allografts with more severe renal dysfunction (creatinine 5.6 mg/dL vs. 3.4 mg/dL, p < 0.001). ATN incidence was also higher in patients with CaOx deposits (47% vs. 24%, p < 0.001). Twelve-year graft survival was strikingly worse in patients with CaOx deposits compared to those free of deposits (49.7 vs. 74.1%, p = 0.013). Our study shows a high incidence of CaOx deposits in kidney allografts with early dysfunction, implying an additional risk for acute tubular injury, with a negative impact on graft survival.
authors.affiliation: Nephrology Division, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
authors.forename: Hélady Sanders
authors.initials: HS
authors.lastname: Pinheiro
authors.forename: Niels Olsen Saraiva
authors.initials: NO
authors.lastname: Câmara
authors.forename: Kikumi Suzete
authors.initials: KS
authors.lastname: Osaki
authors.forename: Luiz Antonio Ribeiro
authors.initials: LA
authors.lastname: De Moura
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pacheco-Silva
mesh_terms: D000293:Adolescent; D000328:Adult; D002129:Calcium Oxalate / Q000378:metabolism*; D002648:Child; D005260:Female; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D013534:Survival; D013997:Time Factors
chemical_list: D002129:Calcium Oxalate