Free Airway C4d after Lung Transplantation - A Quantitative Analysis of Bronchoalveolar Lavage Fluid

In recent years, the utility of vascular complement factor 4d (C4d) deposition as diagnostic tool for antibody mediated rejection (AMR) after lung transplantation, has become a controversial issue. We aimed to pinpoint problematic nature C4d biomarker with simple experiment. quantified in broncho-alveolar lavage (BAL) transplant patients diverse post-transplant complications 3 different settings clinically clear cases of: 1/ chronic allograft dysfunction (CLAD); 2/ acute (AR), lymphocytic bronchiolitis (LB), antibody-mediated and respiratory infection (INF); 3/ parallel immunostaining Anti-HLA. All groups were compared BAL stable patients. was measured via standard ELISA. increased CLAD, predominantly RAS (p = 0.0026) but not BOS 0.89). all events, AR 0.0025), LB < 0.0001), AMR 0.0034), infections 0.0001). serum HLA antibodies, C4d-/HLA- 0.0011); C4d-/HLA+ 0.013); HLA+/C4d + 0.0081). A correlation systemic C-reactive protein (CRP) found (r 0.49; p hypothesize that free may only be representative general immune response transplanted lung.