Avaliação da função endotelial e a sua associação com a evolução do enxerto em receptores do transplante renal

Abstract

Renal transplantation is considered the treatment of choice for patients with end-stage renal disease. The rejection process is one of the main causes of graft loss, especially in the long term and can affect the integrity and the function of endothelial cells. The association between renal transplantation and endothelial function can be evaluated using biomarkers such as cell microparticles (MPs), von Willebrand Factor (VWF) and endothelial nitric oxide synthase (eNOS) gene polymorphisms. The aim of this study was to investigate the relation of endothelial (EMP) and platelet microparticles (PMP), von Willebrand factor (vWF) and G894T, T-786C and VNTR b/a polymorphisms in the eNOS gene with allograft function, post-transplantation time and presence of previous history of rejection in renal transplant recipients. A total of 178 patients were evaluated, distributed into groups according to creatinine plasma levels, estimated glomerular filtration rate eRFG, post-transplantation time and presence of previous history of allograft rejection. Regarding the total number of MPs, higher levels of PMPs were observed among patients with better renal filtration function and in the assessment according to diameter, levels of PMPs and EMPs of smaller size ( 0.7m) were also increased in recipients with better renal filtration function. Recipients with shorter posttransplantation time had a predominance of PMPs and EMPs of larger size (>0.7m) compared to patients with longer post-transplant time. Higher levels of vWF were observed among the recipients with intermediate creatinine levels and those with a previous history of rejection. The analysis of allelic carriers revealed lower frequency of carrier b of the VNTR b/a polymorphism in receptors with the worst renal filtration function and a higher frequency of the T-C-b haplotype was observed among patients with better renal filtration function. The results found for allelic and genotypic frequencies, allelic carrier models and haplotype analysis of the studied polymorphisms according to rejection history showed no differences between groups. Negative correlations were observed between post-transplantation time and PMPs and EMPs; between creatinine levels and platelet counts, and with total MPs; between the eRFG and the FvW. On the other hand, platelet counts positively correlated with eRFG, PMPs and EMPs levels. Thus, according to the analyses performed, it is concluded that the decline of renal allograft function may be characterized by varying profiles of PMPs and EMPs and by increased levels of vWF. In contrast, the presence of the b allele of the VNTR b/a polymorphism was related to better creatinine levels, being considered a potential biomarker in renal transplantation.