The effect of pre-conditioning immunoglobulin and absolute lymphocyte count on the outcomes of allogeneic hematopoietic cell transplantation

Introduction: The prevention of mortality and morbidity related to the increasingly used allogeneic hematopoietic cell transplantation (allo-HCT), along with the effects of pre- and post-transplant immune status on transplant outcomes, have become the focus of the studies conducted on this subject in recent years. In parallel, this study was designed to investigate the effects of pre-conditioning immunoglobulin (pre-conditioning-Ig) and pre-conditioning absolute lymphocyte count (pre-conditioning-ALC) levels on transplant outcomes. Methods: This study was designed as a retrospective, observational and cross-sectional study. The objective of the study is to investigate the effects of pre-conditioning-Ig and ALC levels primarily on the rate of patients with febrile neutropenia (FEN) and the duration of FEN and length of hospital stay (LoS), and secondarily on acute graft-versus-host disease (aGVHD), cytomegalovirus (CMV) viremia, and mortality in the acute leukemia patients who underwent allo-HCT. Results: A total of 104 acute leukemia patients, of whom 55 had acute lymphoblastic leukemia (ALL) and 49 had acute myeloid leukemia (AML), were included in the study. Compared to the AML group, the median pre-conditioning-IgG, IgA, and IgM levels were found to be significantly lower in the ALL group (11.3 vs. 6.6, p < 0.001; 1.8 vs. 0.9, p < 0.001; and 0.7 vs. 0.4, p < 0.001; respectively). But, there was no significant difference between the groups in pre-conditioning-Ig and ALC levels and transplant outcomes. However, subgroup analysis revealed that high pre-conditioning-ALC levels were significantly correlated with aGVHD levels (Odds Ratio: 1.02; p = 0.034) and low pre-conditioning-IgM levels were significantly correlated with increased mortality rate (Hazard Ratio: 0.08; p = 0.042) in AML patients. Conclusion: The significant difference determined between the ALL and AML groups in pre-conditioning-Ig levels was not reflected on the effects of pre-conditioning-Ig and ALC levels on transplant outcomes. However, we observed that pre-conditioning-IgM and ALC levels have an impact on transplant outcomes in AML patients