Thomas Neumann, Nadette Peters, Laila Schneidewind, William Krüger

• Background: Our aim is to investigate cardiovascular risk factors, chronic graft-versus-host disease (CGvHD), and vitamin D metabolism in very long-term survivors of adult allogeneic stem cell transplantation (alloSCT). Methods: This study is a prospective unicentric, non-interventional trial. The detailed study protocol is available via the WHO Clinical Trial Registry. Results: We were able to include 33 patients with a mean age of 60.5 years (SD 11.1). Acute myeloid leukemia (AML) was the most frequent underlying disease (n = 12; 36.4%). The median survival time was 9.0 years (IQR 8.5–13.0). Relevant cardiovascular risk factors in the study population are the body mass index, cholesterol, LDL cholesterol, and lipoprotein(a). Cardiovascular risk factors have no significant impact on HRQoL. CGvHD of the skin as a limited disease was present in six patients (18.2%), and it has no impact on HRQoL. CGvHD was significantly associated with eosinophilia in peripheral blood (p = 0.003). Three patients (9.1%) had a shortage of calcitriol, and one patient (3.0%) took calcium substitution. The shortage is significantly associated with increased infection rates (p = 0.038). Conclusions: Cardiovascular risk factors and CGvHD need to be closely monitored. Eosinophilia might be a good and convenient monitoring parameter for CGvHD.