There is limited evidence regarding the utility of circulating DSA in surveillance for AMR of pediatric heart recipients. Our hypothesis is that quantitation of DSA improves their power for predicting a C4d+, an integral component in the current diagnostic criteria of AMR. All pediatric recipients transplanted between 10/2005 and 1/2011 were retrospectively reviewed for DSA determined within 48 h of EMB. C4d+ was defined as >25% endothelial cell staining by immunohistochemical methods. A total of 183 paired DSA-EMB determinations were identified in 60 patients, a median of three paired studies per patient (range: 1-9). DSA were detected in 60 of these determinations. A receiver-operating characteristic plot identified a threshold single-antibody MFI of >6000 that strongly correlated with C4d+ (p < 0.0001) with a high negative predictive value (0.97) and specificity (0.95). The sensitivity and positive predictive values were 0.71 and 0.60, respectively. The predictive power of single-antigen DSA for C4d deposition was improved in pediatric heart recipients using an institution-specific MFI threshold value. In post-transplant care, quantitative DSA should be an essential component in the surveillance for AMR.
Keywords: anti-HLA antibody; antibody mediated rejection; biopsy; heart transplantation; pediatric heart transplant.
© 2013 John Wiley & Sons A/S.