Pentraxin‐3 expression in acute renal allograft rejection

Pentraxin-3 (PTX3) is an acute phase reactant produced by a variety of cell types at sites of local inflammation. We examined by immunohistochemistry renal biopsies from patients with acute rejection (n = 10), protocol biopsies without rejection (n = 37), and peri-operative donor biopsies of the same transplant patients (n = 94) for intra-renal expression of PTX3, and its correlation with clinical, laboratory, and histopathologic parameters. PTX3 was mainly expressed in the interstitium of renal allograft. In the non-rejection biopsies (pre- and post-reperfusion and protocol biopsies), PTX3 expression area (PTX3%) was equally maintained at a low level, whereas in the rejection biopsies, PTX3% was significantly higher (p < 0.0001). Treatment of acute rejection resulted in a significant reduction of PTX3% (p < 0.0001). PTX3% positively correlated with the degree of allograft dysfunction and acute rejection scores of Banff classification (2009). This study suggests that PTX3% may be an available histological marker of acute renal allograft rejection.