HLA-DR CLASS-II AND ICAM-1 EXPRESSION ON TUBULAR CELLS TAKEN BY FINE-NEEDLE ASPIRATION BIOPSY IN RENAL-ALLOGRAFT DYSFUNCTION

Background. Percutaneous biopsy is the method of choice for differenti al diagnosis of renal allograft dysfunction, although it is not risk-f ree. The use of less aggressive methods for diagnosis should limit the need for percutaneous biopsy to some specific situations. Methods. We analysed 42 fine-needle aspiration biopsies from 36 kidney allograft recipients immuno-suppressed with quadruple sequential therapy who suf fered renal allograft dysfunction. Seven cases with stable renal funct ion were used as controls and included as non-rejection cases in the a nalysis. In all aspirates the Corrected Increment was calculated and a n immunocytochemical analysis of renal tubular cells with the monoclon al antibodies HLA-DR and ICAM-1 was performed. Results. The Corrected Increment was increased in 13 out of 18 acute rejection cases and in o ne out of 31 non-rejection cases. HLA-DR expression was found in more than 30% of tubular cells from the aspirates in 16 out of 18 acute rej ection cases and in eight out of 31 cases without rejection (P<0.001). ICAM-1 expression was detected in more than 30% of tubular cells in 1 4 out of 18 cases with acute rejection, and in four out of 31 cases wi thout acute rejection (P<0.001). interestingly, all acute vascular rej ection cases (n=6), and six out of 13 acute cellular rejection cases e xpressed both, HLA-DR and ICAM-1, in more than 30% of tubular cells. O n the other hand, none of the non-rejection allograft dysfunctions or control samples showed more than 30% of tubular cells immunostained wi th both HLA-DR and ICAM-1 antibodies. Conclusions. The immunocytochemi cal analysis of HLA-DR and ICAM-1 on renal tubular cells taken by fine -needle aspiration biopsy, allows the diagnosis of acute cellular reje ction and acute vascular rejection even when the Corrected Increment i s not increased. Moreover, the risk of a core renal biopsy call be avo ided when both tests are negative since an acute rejection is a remote possibility.