Micro RNA142-3p Is Differentially Expressed in the Peripheral Blood of Kidney Transplant Recipients With Graft Dysfunction Without Acute Rejection.

Abstract

Background and aims. The uncovering of non invasive molecular biomarkers of graft dysfunction would be an important accomplishment in the clinical management of kidney transplant recipients (KTR). We evaluated the transcriptional expression of micro RNA 142-3p (miRNA 142-3p) in urinary sediment cells and peripheral blood cells of KTR in order to evaluate it as a non-invasive biomarker for graft dysfunction. Patients and methods. Seventy-six KTR who underwent 98 graft biopsies for the evaluation of renal dysfunction were included. There were forty-nine indication biopsies obtained for evaluation of acute graft deterioration, 42 surveillance biopsies obtained during the period of delayed graft function and 7 were protocol biopsies from stable patients at the third post-transplant month. Peripheral blood and urine were obtained immediately before the biopsy for the evaluation of the miRNA 142-3p by real-time polymerase chain reaction (RT-PCR). Biopsies were classified according to the Banff squema into three groups: acute rejection (AR, n = 23), other causes of dysfunction (OD, n = 68) and normal kidney transplant biopsy (NKT, n = 7). Results. The molecular expression of miRNA 142-3p in the urinary sediment cells of NKT was [(0.7 (95%CI 0.6 - 2.0)] and no difference was found in the comparison with the AR group [(9.0 (95%CI 0.3 - 38.2)] and OD group [(8.0 (95%CI 0.5 - 80.3)], (P = 0.29). In the peripheral blood, miRNA 142-3p expression values were [(1.1 (95%CI 0.4 - 2.4)] for the NKT group and presented lower expression in the group of patients with AR [(1.3 (95%CI 0.5 - 1.8)] as compared with the OD group [(2.39 (95%IC 1.06 - 5.82)], (P = 0,01). Conclusions. Micro RNA 142-3p presented increased expression in the peripheral blood of patients with kidney graft function not due to acute graft reejction. The uncovering of the clinical situation in which this miRNA is increased may lead to the development of an accurate biomarker for such situation.