Long-term survival following kidney transplantation in previous lung transplant recipients-An analysis of the unos registry.

BACKGROUND: Kidney transplantation has been advocated as a therapeutic option in lung recipients who develop end-stage renal disease (ESRD). This analysis outlines patterns of allograft survival following kidney transplantation in previous lung recipients (KAL). METHODS: Data from the UNOS lung and kidney transplantation registries (1987-2013) were cross-linked to identify lung recipients who were subsequently listed for and/or underwent kidney transplantation. Time-dependent Cox models compared the survival rates in KAL patients with those waitlisted for renal transplantation who never received kidneys. Survival analyses compared outcomes between KAL patients and risk-matched recipients of primary, kidney-only transplantation with no history of lung transplantation (KTx). RESULTS: A total of 270 lung recipients subsequently underwent kidney transplantation (KAL). Regression models demonstrated a lower risk of post-listing mortality for KAL patients compared with 346 lung recipients on the kidney waitlist who never received kidneys (P<.05). Comparisons between matched KAL and KTx patients demonstrated significantly increased risk of death and graft loss (P<.05), but not death-censored graft loss, for KAL patients (P = .86). CONCLUSIONS: KAL patients enjoy a significant survival benefit compared with waitlisted lung recipients who do not receive kidneys. However, KAL patients do poorly compared with KTx patients. Decisions about KAL transplantation must be made on a case-by-case basis considering patient and donor factors.

Gene delivery followed by ex vivo lung perfusion using an adeno-associated viral vector in a rodent lung transplant model.

OBJECTIVE: Ex vivo lung perfusion has emerged as a platform for organ preservation, evaluation, and restoration. Gene delivery using a clinically relevant adeno-associated vector during ex vivo lung perfusion may be useful in optimizing donor allografts while the graft is maintained physiologically active. We evaluated the feasibility of adeno-associated vector-mediated gene delivery during ex vivo lung perfusion in a rat transplant model. Additionally, we assessed off-target effects and explored different routes of delivery. METHODS: Rat heart-lung blocks were procured and underwent 1-hour ex vivo lung perfusion. Before ex vivo lung perfusion, 4e11 viral genome luciferase encoding adeno-associated vector 9 was administered via the left bronchus (Br group, n = 4), via the left pulmonary artery (PA group, n = 3), or directly into the circuit (Circuit group, n = 3). Donor lungs in the Control group (n = 3) underwent ex vivo lung perfusion without adeno-associated vector 9. Only the left lung was transplanted. Animals underwent bioluminescence imaging weekly before being killed at 2 weeks. Tissues were collected for luciferase activity measurement. RESULTS: All recipients tolerated the transplant well. At 2 weeks post-transplant, luciferase activity in the transplanted lung was significantly higher among animals in the Br group compared with the other 3 groups (Br: 1.1 × 106 RLU/g, PA: 8.3 × 104 RLU/g, Circuit: 3.8 × 103 RLU/g, Control: 2.5 × 103 RLU/g, P = .0003). No off-target transgene expression was observed. CONCLUSIONS: In this work, we demonstrate that a clinically relevant adeno-associated vector 9 vector mediates gene transduction during ex vivo lung perfusion in rat lung grafts when administered via the airway and potentially the pulmonary artery. Our preliminary results suggest a higher transduction efficiency when adeno-associated vector 9 was delivered via the airway, and delivery during ex vivo lung perfusion reduces off-target effects after graft implant.

Point-of-Care Assessment of DCD Livers During Normothermic Machine Perfusion in a Nonhuman Primate Model.

Normothermic machine perfusion (NMP) provides clinicians an opportunity to assess marginal livers before transplantation. However, objective criteria and point-of-care (POC) biomarkers to predict risk and guide decision making are lacking. In this investigation, we characterized trends in POC biomarkers during NMP and compared primate donation after circulatory death (DCD) livers with short and prolonged warm ischemic injury. Following asystole, livers were subjected to either 5 minutes (DCD-5min, n = 4) or 45 minutes (DCD-45min, n = 4) of warm ischemia time. Livers were flushed with heparinized UW solution, and preserved in cold storage before NMP. During flow-controlled NMP, circulating perfusate and tissue biopsies were collected at 0, 2, 4, 6, and 8 hours for analysis. DCD-45min livers had greater terminal portal vein pressure (8.5 vs. 13.3 mm Hg, P = 0.027) and terminal portal vein resistance (16.3 vs. 32.4 Wood units, P = 0.005). During perfusion, DCD-45min livers had equivalent terminal lactate clearance (93% vs. 96%, P = 0.344), greater terminal alanine aminotransferase (163 vs. 883 U/L, P = 0.002), and greater terminal perfusate gamma glutamyltransferase (GGT) (5.0 vs. 31.7 U/L, P = 0.002). DCD-45min livers had higher circulating levels of flavin mononucleotide (FMN) at hours 2 and 4 of perfusion (136 vs. 250 ng/mL, P = 0.029; and 158 vs. 293 ng/mL, P = 0.003; respectively). DCD-5min livers produced more bile and demonstrated progressive decline in bile lactate dehydrogenase, whereas DCD-45min livers did not. On blinded histologic evaluation, DCD-45min livers demonstrated greater injury and necrosis at late stages of perfusion, indicative of nonviability. Conclusion: Objective criteria are needed to define graft viability during NMP. Perfusate lactate clearance does not discriminate between viable and nonviable livers during NMP. Perfusate GGT and FMN may represent POC biomarkers predictive of liver injury during NMP.

Extracorporeal membrane oxygenation in the pre and post lung transplant period.

Evolution in technology has resulted in rapid increase in utilization of extracorporeal membrane oxygenation (ECMO) as a bridge to recovery and/or transplantation. Although there is limited evidence for the use of ECMO, recent improvements in ECMO technology, personnel training, ambulatory practices on ECMO and lung protective strategies have resulted in improved outcomes in patients bridged to lung transplantation. This review provides an insight into the current outcomes and best practices for utilization of ECMO in the pre- and post-lung transplantation period.