Introduction: The diagnosis of humoral rejection in lung transplant recipients is sometimes elusive, involving histopathologic (capillaritis), immunopathologic (C4d staining), and serologic (donor-specific anti-HLA antibodies, DSA) parameters. These criteria are not always present in cases and, moreover, the involvement of non-HLA antibodies in lung-allograft humoral rejection remains largely unclear. The aim of the study was to assess the involvement of HLA and non-HLA antibodies in humoral rejection diagnosis after lung transplantation.
Materials and Methods: A total of 60 consecutive lung transplant recipients were followed in our Institution from 2015. Protocol biopsy at day 21 post transplantation and screening for serum HLA and non-HLA antibodies by Luminex, LABScreen Autoantibody (One Lambda), before lung transplant and at the moment of the biopsy, were performed.
Results and Discussion: A total of 5 lung transplant recipients (8.33%) were C4d+ on biopsy but only one of them developed de novo DSA without evidence of non-HLA antibodies. The remaining 4 patients C4d+, were serum positive for non-HLA antibodies (2 against LG3 and other 2 against myosin) prior lung transplantation (6.67%) but negative at the moment of the biopsy. The incidence observed of preformed non-HLA antibodies in patients awaiting for lung transplantation was significant and potentially could drive C4d deposition on lung tissue with subsequent humoral rejection.
Conclusion: The screening of non-HLA and HLA antibodies could help to identify patient at risk of lung-allograft rejection.