Acute Kidney Injury and Urinary and Histopathological Disorders in Kidney Transplant Patients with SARS-CoV-2 Infection.

BACKGROUND: Acute kidney injury (AKI) is a manifestation of SARS-CoV-2 infection. The evidence in kidney transplant (KT) is limited, as there are scarce data about the histologic features in graft biopsies of these patients. MATERIAL AND METHODS: A retrospective cohort study of KTs with SARS-CoV-2 infection from August 28, 2020, to April 23, 2021. We collected the incidence of AKI and the presence of urinary and histopathological disorders. Both groups were compared (AKI vs no AKI). Immunohistochemical and reverse transcription-polymerase chain reaction studies were performed on the anatomopathological samples. RESULTS: In our study, 72 KTs had SARS-CoV-2 infection and, among them, 27 patients (35.1%) developed AKI related to increased severity and a worse evolution of the infection, defined by a greater presence of pneumonia (P < .001), hospitalization (P < .001), admission to the intensive care unit (P < .001), the need for ventilation support (P < .001), and continuous renal replacement therapy (P < .001). In the multivariable analysis, pneumonia behaved as an independent predictor for AKI development (P = .046). No differences were observed between proteinuria a month before and after infection (P = .224). In addition, 5 patients showed microhematuria and 2 patients presented transient glycosuria without hyperglycemia. Of the 5 kidney biopsies performed, 1 biopsy (20%) showed positive reverse transcription polymerase chain reaction for SARS-CoV-2. CONCLUSIONS: AKI is a frequent and potentially serious complication in KT patients. Occasionally it could be accompanied by abnormalities in the urinary sediment. Of 5 biopsied patients, 1 patient had positive reverse transcription polymerase chain reaction in renal tissue, which suggests the systemic spread of the virus and the tropism for the renal graft.

Evaluation of Expanded Criteria Donors Using the Kidney Donor Profile Index and the Preimplantation Renal Biopsy.

The increasing comorbidity of kidney transplant (KT) donors make it necessary to develop scores to correctly assess the quality of kidney grafts. This study analyzes the usefulness of the preimplantation biopsy and the Kidney Donor Profile Index (KDPI) as indicators of KT survival from expanded criteria donors (ECD). Retrospective study of KT in our center between January 2010 to June 2019 who received a kidney from an ECD and underwent a preimplantation biopsy. 266 KT were included. Graft survival was categorized by KDPI quartiles: Q1 = 86%, Q2 = 95%, Q3 = 99% and Q4 = 100%. KT from KDPI Q1 presented better survival (p = 0.003) and Q4 donors had worse renal function (p = 0.018) and poorer glomerular filtration rate (3rd month; p = 0.017, 1st year; p = 0.010). KT survival was analyzed according to KDPI quartile and preimplantation biopsy score simultaneously: Q1 donors with biopsy score ≤3 had the best survival, especially comparing against Q3 with a biopsy score >3 and Q4 donors (p = 0.014). In multivariable analysis, hyaline arteriopathy, glomerulosclerosis, and KDPI Q4 were predictors for graft survival. High KDPI and a greater histological injury in the preimplantation biopsy, especially glomerular and vascular lesions, were related to a higher rate of KT loss from ECD.