Pre-transplant platelet-to- lymphocyte ratio predicts outcome after allogeneic hematopoietic stem cell transplantation.

For many patients with hematological malignancies such as acute leukemia or myelodysplastic syndrome allogeneic hematopoietic stem cell transplantation (allogeneic HSCT) is the only curative treatment option. Despite the curative potential of this treatment many patients experience relapse of their underlying disease or die due to multiple complications e.g. infections. Risk scores could help to assess the individual prognosis and guide patients and treating physicians to choose between different treatment options. Parameters reflecting the inflammatory status, such as neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR), have been demonstrated to be associated with prognosis and treatment complications in patients with various cancers. In this study, we evaluate pre-HSCT NLR, MLR and PLR as predictive markers in patients undergoing allogeneic HSCT. We demonstrate that a high (> 133) PLR level is associated with better clinical outcome. Patients with high pre-HSCT PLR show a significant better overall survival (p = 0.001), less relapses (p = 0.016), lower non-relapse-mortality (p = 0.022), less transfusions of red blood cells, platelets and fresh frozen plasma (p = 0.000), fewer episodes of fever (p = 0.002), considerably less different antibiotics (p = 0.005), fewer intensive care unit treatment (p = 0.017) and a lower in-hospital mortality (p = 0.024). Pre-HSCT PLR is easy to calculate by daily routine and could help to predict patient outcome after allogeneic HSCT.