Association of Impaired Reactive Aldehyde Metabolism with Delayed Graft Function in Human Kidney Transplantation

Utility of SIFT-MS to evaluate volatile organic compounds in nephropathic patients' breath

Several studies highlighted a correlation between exhaled air volatile organic compounds (VOCs) and some pathological conditions, such as chronic kidney disease (CKD), chronic liver disease, etc. In fact, in literature has been reported that CKD is characterized by an increased concentration of ammonia, trimethylamine (TMA) and isoprene compared to healthy subjects. Currently, there is not a validate and standardized method to detect VOCs. For this purpose, we examined the utility of selected ion flow tube-mass spectrometry (SIFT-MS) to measure VOCs in CKD patients and we evaluated the possible correlation between VOCs and the presence of CKD and its stage. We enrolled 68 CKD patients under conservative therapy and 54 healthy subjects. The analysis of the VOCs of the exhaled air of the enrolled subjects was performed by SIFT-MS. Among all the VOCs analyzed, the most relevant results by ROC curves were observed for TMA, acetone, ammonia and dimethyl sulfide. We found that a breath TMA concentration superior to 26 ppbv characterizes a 6.11 times greater risk of CKD, compared to subjects with lower levels. Moreover, we detected an increased concentration of acetone and ammonia in CKD patients compared to healthy subjects. We highlight the potential utility of SIFT-MS in CKD clinical management.

Clinical trial registry: R.S. 15.19 of 6 February 2019.

Pretransplant endotrophin predicts delayed graft function after kidney transplantation

Delayed graft function after kidney transplantation is common and increases morbidity and health care costs. There is evidence that endotrophin, a specific fragment of pro-collagen type VI, promotes the inflammatory response in kidney diseases. We tested the hypothesis that pretransplant endotrophin in kidney transplant recipients may be associated with the risk of delayed graft function. Pretransplant plasma endotrophin was assessed using an enzyme-linked immunosorbent assay in three independent cohorts with 806 kidney transplant recipients. The primary outcome was delayed graft function, i.e., the necessity of at least one dialysis session within one-week posttransplant. In the discovery cohort median pretransplant plasma endotrophin was higher in 32 recipients (12%) who showed delayed graft function when compared to 225 recipients without delayed graft function (58.4 ng/mL [IQR 33.4-69.0]; N = 32; vs. 39.5 ng/mL [IQR 30.6-54.5]; N = 225; P = 0.009). Multivariable logistic regression, fully adjusted for confounders showed, that pretransplant plasma endotrophin as a continuous variable was independently associated with delayed graft function in both validation cohorts, odds ratio 2.09 [95% CI 1.30-3.36] and 2.06 [95% CI 1.43-2.97]. Pretransplant plasma endotrophin, a potentially modifiable factor, was independently associated with increased risk of delayed graft function and may be a new avenue for therapeutic interventions.