Circulating Low Absolute CD4(+) T Cell Counts May Predict Poor Prognosis in Extranodal NK/T-Cell Lymphoma Patients Treating with Pegaspargase-Based Chemotherapy

PURPOSE: Extranodal natural killer/T-cell lymphoma, nasal type (ENKTL) is a rare subtype of non-Hodgkin lymphoma, and asparaginase-based regimens are the best first-line treatments. Data on the role of specific circulating lymphocyte subsets in the progression of ENKTL are limited. The aim of this study was to investigate the clinical correlation and distribution of circulating absolute CD4(+) T-cell counts (ACD4Cs) in ENKTL. MATERIALS AND METHODS: We retrospectively searched medical records for 70 newly diagnosed ENKTL patients treated with pegaspargase-based regimens. Comparison of ACD4Cs as a continuous parameter in different groups was calculated. Univariate and multivariate analyses were used to assess prognostic factors for overall survival (OS) and progression-free survival (PFS). RESULTS: Stage III/IV, B symptoms, elevated lactate dehydrogenase, monocytopenia, high-intermediate and high risk International Prognostic Index (IPI) and Korean Prognostic Index (KPI), high risk Prognostic Index of Natural Killer Lymphoma (PINK), and lower lymphocytes were significantly associated with low ACD4C at diagnosis. With a median follow-up time of 32 months, patients who had an ACD4C < 0.30×10(9)/L had a worse OS. Median OS was 11 months and median PFS was 5 months in the low ACD4C cohort. There were significant differences in both OS and PFS between the two cohorts. Moreover, multivariate Cox analysis identified ACD4Cs as an independent predictor for OS and PFS. CONCLUSION: Low ACD4Cs were associated with poorer survival and could act as a negative predictor for ENKTL patients treated with asparaginase-based regimens.