Ex vivo lung perfusion increases the pool of lung grafts: analysis of its potential and real impact on a lung transplant program.

BACKGROUND: Among the strategies to increase the number of lung transplants, ex vivo lung perfusion (EVLP) represents a novel technique to expand the donor pool. METHODS: Data from donors referred to our center were retrospectively analyzed to identify grafts that could potentially be potentially reconditioned by EVLP and for comparison with those obtained by clinical application of EVLP program in our center. RESULTS: Among 75 rejected lungs, 23 organs have been identified as potentially treatable with EVLP with a hypothetic increase of lung transplant activity of 53%. After the introduction of the EVLP program in our center, lung transplantation with reconditioned grafts was performed in 7 (23%) patients with a 30% increase in transplant procedures. CONCLUSION: Although less than expected, EVLP increased the number of lungs suitable for transplantation.

C4d analysis in endomyocardial biopsies of heart transplant patients: is there a correlation with hemodynamic data?

BACKGROUND: Endomyocardial biopsy (EMB) is the gold standard for immunologic follow-up to detect acute cellular rejection after cardiac transplantation. Conversely, protocols for the diagnosis and treatment of antibody-mediated rejection (AMR) are not well defined. Histologically, AMR is diagnosed by the presence of capillary damage associated with complement activation. The aim of this study was to correlate C4d expression of activated complement in EMB with hemodynamic compromise upon right heart catheterization. METHODS: Heart transplant patients underwent hemodynamic and histologic follow-up with EMB and right heart catheterization between January 2008 and December 2009 for a total of 491 procedures. The cardiac biopsy was evaluated for acute cellular and AMR by means of the presence of the C4d complement fraction. The histologic results were compared with hemodynamic data registered during right heart catheterization. RESULTS: Comparison of the hemodynamic data of subjects with versus without C4d positivity showed no significant difference. Furthermore, there was no significant difference comparing patients with versus without C4d positivity in the absence of significant acute cellular rejection episodes. (C4d-/ACR- vs C4d+/ACR-). The variation of each single hemodynamic parameter from its basal value (defined as the mean value in case of C4d-/ACR-) seemed to not be influenced by the presence of C4d+. CONCLUSIONS: In our experience, C4d has been routinely evaluated in the majority of EMBs. We could not demonstrate a significant correlation of C4d positivity with hemodynamic compromise. These findings suggest that significant allograft dysfunction is not related to C4d positivity. Therefore, the diagnosis of AMR is difficult to establish, because allograft dysfunction is 1 of the 3 fundamental criteria.