Hemoglobin-based oxygen carriers: Clinical application of HBOC-201 as an alternative to red blood cells for machine perfusion in liver transplantation

Abstract

Liver transplantation is the gold standard treatment option for end-stage liver diseases and failure. In recent years, ex vivo liver machine perfusion has been introduced to resuscitate livers before transplantation. The RBC-based solution is the main perfusate for this matter. Due to logistic and functional limitations in order to use an RBC-based solution, Hemoglobin-based oxygen carrier-201 (HBOC-201) is the new perfusion solution that is introduced to replace the RBC-based solution. A systematic literature search of the PubMed registry was performed. A three-stage independent screening method was applied. Inclusion criteria for this review were published prospective, retrospective, clinical trials, and systematic reviews studies using acellular hemoglobin as a perfusion solution. Five studies that used HBOC-201 as the perfusate solution were identified. The overall number of livers that were resuscitated with HBOC-201 perfusate in all the studies was 50 livers. These studies have demonstrated the efficacy of HBOC-201 perfusate in terms of liver post perfusion metabolic and function assessment. Two studies compared HBOC-201 and PRBC as the perfusate solution. One study found comparable outcomes when HBOC-201 was used as the perfusate solution and in the other study, not only the results were comparable, but also, the study showed livers perfusate with HBOC-201 based solution had higher ATP levels, higher bile production, and quicker lactate reduction, and significantly lower ALT level at the end of MP. Machine perfusion (MP) was introduced as an alternative preservation strategy in transplantation. The perfusion solution used in MP is a key factor in the process of organ revitalization, preventing hemolysis, and providing near-to-body physiologic hemostasis. HBOC-201 is a safe and convenient alternative to packed red blood cells in organ perfusion and recent studies showed promising results.