Detection of angiotensin ii type i-receptor antibodies in transplant glomerulopathy.

Background Transplant glomerulopathy (TG) is an important cause of late graft loss. The role of angiotensin type 1-receptor antibodies (AT(1)R-Ab) in TG is not known. Methods Results All the TG cases (N = 137) between January 2007 and December 2014 (N = 1410) were analyzed. Donor-specific anti-HLA antibodies (DSA) at the time of biopsy and AT(1)R-Ab IgG (positive, >17 UI/mL; "at risk," 10-17 UI/mL; negative, <10 UI/mL) in pre-transplant sera (PT-Ab) and at biopsy time (BT-Ab) were studied. AT(1)R-PT-Ab(+) and AT(1)R-BT-Ab(+) patients were 16.5% (51.5% "at risk") and 11.5% (27.4% "at risk"), respectively. Clinical correlations were found between AT(1)R-Ab and HCV infection, number of transplants, and age. Considering Banff scores, ptc was higher in DSA(+) patients vs AT(1)R-PT-Ab(+) (P = 0.002) or AT(1)R-BT-Ab(+) (P = 0.001) without differences in g and chronicity score (ci + ct); cg showed lower scores in DSA(+) patients vs AT(1)R-BT-Ab(+) (P = 0.001). Graft survival was not influenced by the presence of AT(1)R-Ab, AT1-R-Ab titer or MFI, but we observed a longer graft survival in patients with both AT(1)R-BT-Ab(+) or "at risk" and DSA(+) vs patients positive only for DSA (P = 0.02), for AT(1)R-BT-Ab (P = 0.019) or AT(1)R-BT-Ab "at risk" (P = 0.039). Conclusion AT(1)R-Ab showed no independent prognostic role in TG in this pilot analysis.