Soluble HLA-G pre-transplant levels to identify the risk for development of infection in heart transplant recipients

Infection is still a leading cause of death during the first year after heart transplantation. We evaluated the pre-transplant levels of HLA (Human Leukocyte antigen) – G molecules as a means of identifying heart recipients at risk of serious infections. We prospectively analyzed 122 adult heart transplant (HT) recipients. Serum samples were collected before transplantation and analyzed for sHLA-G levels by ELISA assay. The clinical follow-up period lasted 5 years. Clinical outcomes were bacterial infections requiring intravenous anti-microbial agents, cytomegalovirus (CMV) disease, and fungal infections requiring therapy. We found that 39 patients (32%) developed at least 1 serious bacterial infection. Higher pre-transplant sHLA-G levels were a risk factor for serious infection (above median value 5.4 ng/ml; relative risk 3.70; 95% confidence interval 1.03–12.64; p = 0.043). Patients with high levels of pre-transplant sHLA-G are also characterized by a lower overall survival at 5 years (p = 0.017), with microbial infections as major causes of death. No association was observed with the development rejection episode. Early monitoring of sHLA-G molecules proved useful for the identification of heart recipients who are at risk of serious infections.