Prognostic Value of C‐Reactive Protein/Platelet Ratio as a Biomarker Prior to Allogeneic Hematopoietic Stem Cell Transplantation in Malignant Lymphoma

ABSTRACT Previous studies have shown that the pre‐transplant C‐reactive protein (CRP)/platelet ratio (CP ratio) is a predictor of survival. The aim of this multicenter retrospective study was to evaluate the clinical significance of CP ratio in patients with malignant lymphoma (ML) who underwent allogeneic hematopoietic stem cell transplantation (alloHCT). The cohort included patients with ML who underwent first alloHCT from 2007 to 2021. CP ratio was defined as CRP [mg/dL]/platelet [10 4/ μL] and evaluated prior to alloHCT. The cutoff value for CP ratio was set at 0.05 based on previous studies. A total of 311 cases were analyzed, of which 134 were mature B cell lymphoma, 177 were T/NK cell lymphoma (including 70 cases of adult T‐cell leukemia/lymphoma), and 17 were Hodgkin's lymphoma. The median age was 53 years (range: 17–69 years). High CP ratio was associated with status of disease, presence of infections, poor performance status at alloHCT, and high transfusion volume received prior to alloHCT. Overall survival (OS) at 2 years according to CP ratio (low vs. high) was 61.1% versus 30.1% ( p < 0.001), non‐relapse mortality (NRM) was 21.4% versus 40.7% ( p = 0.001), and the relapse rate was 23.7% versus 32.6% ( p = 0.061), respectively. In multivariate analysis, the high CP ratio group was associated with poor OS (HR = 2.20, 95% CI: 1.61–3.02, p < 0.001) and higher NRM (HR = 1.90, 95% CI: 1.28–2.81, p = 0.0014). High CP ratio was found to be associated with poor post‐transplant OS and NRM, and was a suitable prognostic biomarker for stratifying the risk of patients with ML who are candidates for alloHCT.