The 46th Annual Meeting of the European Society for Blood and Marrow Transplantation, 29 August - 01 September 2020, vol.55, pp.422-423
Background: Vitamin D (VitD), which regulates several immun system functions including hematopoietic stem cell proliferation and differentiation, may be considered to have a potential role in hematopoietic stem cell transplantation (HSCT) setting. The aim of this study was to evaluate the possible impact of donor and recipient VitD levels on HSCT outcome.
Methods: A total of 123 donor [median age: 44 (18-70) years; M/F: 66/57] and allogeneic HSCT (allo-HSCT) recipient [median age: 46 (18-68) years; M/F: 72/51] pairs were included in this retrospective study. The association of pre-HSCT VitD levels with certain HSCT parameters were analysed statistically. Subjects were classified into two subgroups, as low- (< 20 μg/L) and high-VitD (>20 μg/L) groups. Patient and transplant characteristics are summarized in Table 1.
Results: Median pre-HSCT VitD levels were 16(3-62.6) μg/L and 12.8(3-63.3) μg/L in donor and recipient groups respectively. Neutrophil engraftment day was found to be longer in low-VitD group compared to high-VitD group in allo-HSCT recipients [14(10-26) days vs 12(10-21) days; p=0.032]. A negative correlation was demonstrated between recipient VitD levels and chronic graft versus host disease (GvHD) (p=0.011, r=-0.235). Among donor and recipient arms, no statistical difference was observed between low- and high-VitD subgroups in terms of postHSCT complications including veno occlusive disease (VOD), cytomegalovirus (CMV) reactivation, mucositis, acute and chronic GvHD. At a median follow-up of 16(1- 67) months, overall survival (OS) was better in low-VitD group compared to high-VitD group in both donor [53.1% vs 49.2%, p>0.05] and recipient [60.9% vs 29.4%, p>0.05] arms, without statistical significance. On the other hand, the probability of progression free survival (PFS) was found to be higher in high-VitD group compared to low-VitD group in donor [68.4% vs 71.7%, p>0.05] and recipient [63.5% vs 72.5%, p>0.05] arms, without statistical significance. Multivariate Cox regression analysis revealed pre-HSCT European Society for Blood and Marrow Transplantation (EBMT) score (p=< 0.001), Karnofsky score (p=0.013) and VOD (p=0.002) as significant prognostic factors for OS.
Conclusions: Prevalence of VitD deficiency was shown to be extremely high among allo-HSCT recipients like healthy individuals. Based on its effects on immunological network and hematopoietic cell compartment, several studies have demonstrated a potential association of VitD with acute/chronic GvHD, CMV reactivation, post-HSCT relapse and survival. In the current study, a significant association of pre-HSCT VitD levels with neutrophil engraftment and chronic GvHD was also observed. Donor and recipient VitD levels did not represent distinct effect profiles on post-HSCT complications. However, a discordance was indicated between the impact of pre-HSCT VitD levels on OS and PFS, which did not reach statistical significance. Eventually, we can conclude that VitD requires more evidence to be considered as a potential prognostic marker in allo-HSCT setting even if remarkable data was provided in the previous reports.