Pro-oxidative/antioxidative imbalance: a key indicator of adverse outcome in hematopoietic stem cell transplantation

Pretransplantation iron overload (IO) is considered as a predictor of adverse outcome in hematopoietic stem cell transplantation (HSCT). Peroxidative tissue injury caused by IO leads to progressive organ dysfunction.

This is a retro-prospective study which explores the possible relationship between IO, oxidative stress and transplant outcome. Serum samples of 149 consecutive HSCT candidates were subjected to analysis of iron parameters, including nontransferrin bound iron (NTBI) and pro-oxidant/antioxidant status.

Serum ferritin was found to be positively correlated with NTBI and negatively correlated with glutathione peroxidase (GPx) and superoxide dismutase (SOD). An inverse correlation of NTBI with SOD, total antioxidant potential (TAP) and malonyldialdehide (MDA) was also demonstrated. An adverse impact of serum ferritin level on early posttransplant complications including pulmonary toxicity, fungal infections and sinusoidal obstruction syndrome (SOS) was shown. A significant impact of NTBI on +30 day (P = 0.027) and +100 day survival (P = 0.028) was shown in auto-transplanted patients. MDA levels had a significant impact on +30 day and +100 day survival in autologous (P = 0.047; P = 0.026) and allogeneic (P = 0.053; P = 0.059) groups. GPx (P = 0.016) and MDA (P = 0.021) were identified as independent prognostic parameters for overall survival in allo-transplanted patients.

Pretransplantation IO might be a major contributor to adverse outcome in HSCT recipients through an impaired pro-oxidative/antioxidative homeostasis. The reversible nature of IO and oxidative stress suggests that early preventive strategies might have a potential to improve transplant outcome.