Accumulation of circulating myeloid-derived suppressor cell subsets: predicting poor clinical efficacy and prognosis through T cell suppression in non-Hodgkin's lymphoma.

Myeloid-derived suppressor cells (MDSC) are implicated in the regulation of immune responses closely associated with poor clinical outcomes in cancer. However, the MDSC subtypes in non-Hodgkin's Lymphoma (NHL) has not been systematically investigated. So we investigated the percentage of MDSC subsets in 78 newly diagnosed NHL patients by flow cytometry. The results showed that all MDSC subsets increased in NHL patients compared to healthy donors. Notably, MDSC, M-MDSC, and CD14+CD66b+MDSC significantly increased in NHL patients compared to those with lymphadenitis. PMN-MDSC, e-MDSC and IPI were independent risk factors for poor clinical efficacy and were involved in constructing the nomogram for predicting clinical efficacy. Progression-free survival (PFS) was significantly shorter in patients with high level of MDSC subsets, and PMN-MDSC emerged as an independent prognostic factor for PFS. PMN-MDSC, e-MDSC and IPI were involved in constructing the nomogram for predicting PFS. Patients with a higher percentage of MDSC, PMN-MDSC, e-MDSC, and CD14+CD66b+MDSC experienced a shorter OS compared to those with lower percentages. In addition, research on mechanisms found that T cell function was suppressed and mediated by the expansion of MDSC via involving Arg-1 and IL-10 in vitro and in vivo. In conclusion, our study demonstrates that the increased circulating MDSC subsets predict poor clinical efficacy and prognosis in NHL, potentially involving T cell suppression through MDSC subsets expansion. These findings indicate the potential of MDSC subsets as comprehensive diagnostic, prognostic biomarkers, and therapeutic targets for NHL.