Background. Chronic kidney disease (CKD) is a common complication of nonrenal transplantation, influencing recipients’ morbidity and mortality. The incidence of CKD varies depending on the transplanted organ. Recipients of vascularized composite allotransplantation (VCA) need lifelong immunosuppression similar to that of solid organ transplantation. This study investigated renal function in VCA recipients. Methods. We studied 70 recipients from 17 centers (median follow-up: 8 y): 59 upper extremity, 10 face, and 1 penis transplant. Pretransplant and posttransplant clinical data and sera were collected to calculate the estimated glomerular filtration rate (eGFR) using the CKD Epidemiology collaboration 2021 formula. Results. Pretransplantation, the median eGFR was 105.36 mL/min (range, 71.39–155.39 mL/min). By 3 mo posttransplant, the eGFR had significantly decreased to 78.42 mL/min (range, 32.49–130.74 mL/min; P = 0.001) before stabilizing. Despite higher tacrolimus levels at 3 mo, no correlation with eGFR was found. During follow-up, 17.1% of patients experienced a ≥50% eGFR decline, 10.9% progressed to CKD, and 4.7% developed end-stage kidney disease. Some risk factors were identified, but their responsibility could not be established with certainty because of the low number of severe renal outcomes. Conclusions. Renal function declines in the majority of VCA recipients, but the function loss is lower compared with nonrenal solid organ transplantation recipients. Although no statistically significant correlation could be established between tacrolimus exposure and renal function decline, strategies aiming at minimizing calcineurin inhibitor exposure and avoiding other nephrotoxic causes are recommended to preserve long-term kidney function.
3. Chronic Kidney Disease after Vascularized Composite Allotransplantation
Cellular senescence is an essentially irreversible growth arrest that occurs in response to various cellular stressors and may contribute to development of type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD). In this article, we investigated whether chronically elevated insulin levels are associated with cellular senescence in the human liver. In 107 individuals undergoing bariatric surgery, hepatic senescence markers were assessed by immunohistochemistry as well as transcriptomics. A subset of 180 participants from the ongoing Finnish Kuopio OBesity Surgery (KOBS) study was used as validation cohort. We found plasma insulin to be highly associated with various markers of cellular senescence in liver tissue. The liver transcriptome of individuals with high insulin revealed significant upregulation of several genes associated with senescence: p21, TGFβ, PI3K, HLA-G, IL8, p38, Ras, and E2F. Insulin associated with hepatic senescence independently of NAFLD and plasma glucose. By using transcriptomic data from the KOBS study, we could validate the association of insulin with p21 in the liver. Our results support a potential role for hyperinsulinemia in induction of cellular senescence in the liver. These findings suggest possible benefits of lowering insulin levels in obese individuals with insulin resistance.