Expressão de marcadores imuno-histoquímicos em biópsias renais de pacientes transplantados

Abstract

From the 60's, with the use of renal transplantation on a large scale as replacement therapy for patients with organ failure, came out the concern about the development process of graft rejection. This intercurrence, generally, evolves with clinical signs and symptoms only when the event is well established, or even when irreversible damage has already been installed. So, is essential a close monitoring, looking forward to detect subclinical cases. The present work, in order to provide new tools that help in the early diagnosis of rejection of the graft, evaluated the immunohistochemical expression of CD3, CD5, CD20, CD68, CD25, FoxP3 and C4d in renal biopsies performed between the years 2007 and 2009 in transplanted patients accompanied by the Department of Nephrology of Pedro Ernesto University Hospital, UERJ - RJ, correlating the results with the histological diagnosis. To this, the biopsies were evaluated by three pathologists who classified them, according to Banff 2007 Criteria, for the presence or absence of graft rejection and its type, acute or chronic. Thereafter, the paraffin blocks were processed by Tissue Microarray for all technique (Pires, ARC. & cols.) and submitted to immunohistochemistry. The positivity of the markers was evaluated and graded and the results were correlated, at first, with the presence or absence of rejection. Later, cases with histological diagnosis of rejection had their immunohistochemical profile considered according to the positivity for C4d, a defining marker of humoral rejection. At this point, we sought to determine whether the antibodies would be useful in detecting, in this studied group, humoral and cellular rejection. After statistical analysis, performed by Fisher's Exact Test, it could be, therefore, concluded that the behavior of the CD3 marker is able to infer the presence of rejection and that CD5 and CD25 antibodies may suggest cellular and humoral rejection, respectively. It was also observed that cases without histological diagnosis of rejection may have markings for C4d in more than 10% of their peritubular capillaries.