Fat1 is atarget antigen in de novo allograft membranous nephropoathy associated with antibody mediated rejection.

Membranous nephropathy (MN) occurs either as recurrent or de novo MN in the kidney allograft. Recurrent MN is most often associated with antibodies to the target antigen M-type phospholipase A2 receptor (PLA2R). 1-3 Most cases of de novo MN are PLA2R-negative and the target antigen in unknown.2 We have previously used the laser microdissection and mass spectrometry (LMD/MS) to search for target antigens in PLA2R-negative MN. In this study, we used LMD/MS to search for the target antigen(s) in de novo MN. Our studies identified target antigen FAT1 in de novo MN when it is associated with concurrent antibody mediated rejection.