Low Levels of Natural Killer Cell in Newly Diagnosed Myelodysplastic Syndromes Patients May Confer Poor Prognosis: A Retrospective Cohort Study

Background: Immune imbalance appears to have a critical role in tumor growth according to emerging research. Peripheral lymphocyte subsets are considered to reflect the systemic immune response and clinical prognosis. The prognostic value of lymphocyte subpopulations in myelodysplastic syndrome (MDS) patients remains unclear.
Methods: A total of 94 MDS patients were enrolled for the study. X-tile software was performed to determine the prognostic significance of various lymphocyte subpopulations, CD3, CD4, CD8, CD4/CD8 ratio, natural killer cell (NK) and CD19. Among them, the appropriate threshold of NK percent could be found only. Patients were divided into the high NK percent group and the low NK percent group. The prognostic significance was determined by univariate and multivariate Cox hazard models.
Results: MDS patients with lower NK level had significantly shorter overall survival (OS). Based on univariate analysis, male gender (P = 0.030), lower HB (< 10 g/dl, P = 0.029), higher BM blast (> 5%, P < 0.0001), higher-risk IPSS-R cytogenetic (P = 0.032) and lower NK percent (P < 0.0001) were significantly associated with shorter OS. Multivariate Cox proportional hazards regression analysis indicated that low NK was also independent adverse prognostic factor for OS in MDS.
Conclusion: Decreased NK level predicts poor prognosis independent of the IPSS-R and provide a novel evaluation factor for MDS patients.