Sevoflurane preconditioning protects from posttransplant injury in mouse lung transplantation

Although sevoflurane (Sevo) had been shown to ameliorate posttransplant injury in various organs, data available are inconsistent, particularly in the context of lung transplantation (Tx). We here investigated if preconditioning by Sevo can protect from posttransplant injury regarding both, primary graft dysfunction (PGD) and acute rejection (AR) after experimental lung Tx, thereby focusing on two important clinical outcome parameters.

Three experimental approaches were used: (1) BALB/c mice were preconditioned for 2 h with Sevo or a fentanyl cocktail (Control; n = 10); (2) syngeneic (Syn) mouse lung Tx (C57BL/6) with a Sevo-preconditioned graft followed by 18 h storage to mimic PGD (Syn-Tx, n = 12) versus controls (fentanyl cocktail); and (3) allogeneic (Allo) Tx (BALB/c, donor; C57BL/6, recipient) to mimic AR (Allo-Tx, n = 12) versus controls (fentanyl cocktail). Syn-Tx grafts were harvested on Day 1, Allo-Tx grafts on Day 3 and analyzed for histology, immunohistochemistry, blood gas analysis, and inflammatory cytokines (enzyme-linked immunosorbent assay or reverse transcription polymerase chain reaction).

Evaluating the preconditioning effect of Sevo only showed significantly better oxygenation (P = 0.03) and a tendency toward lower levels of lung tissue messenger RNA for tumor necrosis factor-α. In Syn-Tx recipients, the Sevo group had histologically a tendency toward an attenuation of PGD and showed significantly lower levels of interleukin 6 (P = 0.01) in plasma, but higher levels of interleukin 10 (P < 0.01) in lungs. Allo-Tx grafts in Sevo Tx recipients showed attenuated AR with histologically significantly lower rejection scores (P = 0.03), fewer classical macrophages (F4/80+; P < 0.01), but more anti-inflammatory activated macrophages (M2, CD206+; P < 0.01). Functionally, the Sevo group had a tendency toward improved oxygenation.

We demonstrated that Sevo preconditioning has protective effects on lung transplants in both, PGD and AR. The observed amelioration may be attributed to suppressed inflammatory cytokines during PGD and the induction of alternatively activated macrophages during AR. These promising data could set the base for using Sevo preconditioning in donor lungs for a human trial.