Immune microenvironment associated with the severity of Langerhans cell histiocytosis in children

The aim of this study is to investigate the clinical potential of immune microenvironment in peripheral blood for the severity and therapeutic efficacy of Langerhans cell histiocytosis (LCH). A total of 200 newly diagnosed children with LCH during 10 years was enrolled for analysis in this study. Peripheral blood samples were acquired from patients before treatment in our hospital and immune indicators were detected by a four-color flow cytometer. The levels of CD3 + CD8 + T cell, CD3 + CD4 + HLA-DR + T cell, CD3 + CD8 + HLA-DR + T cell, IL-4, IL-6, IL-10 and IFN-γ in peripheral blood were markedly elevated in LCH patients vs. healthy controls. Patients with multiple system with risk organ involvement (MS-RO + ) exhibited higher levels in IL-6, IL-10 and IFN-γ, CD3 + CD4 + HLA-DR + T cell and CD3 + CD8 + HLA-DR + T cell, compared to those in patients without risk organ involvement (RO-). Patients who responded effectively to initial chemotherapy showed significantly lower levels of IL-4, IL-10, IFN-γ, CD3 + CD4 + HLA-DR + T cell and CD3 + CD8 + HLA-DR + T cell in peripheral blood, compared to those in patients who did not respond to initial chemotherapy. Furthermore, univariate analyses were performed that the higher levels of CD3 + CD4 + HLA-DR + T cells, CD3 + CD8 + HLA-DR + T cells and IL-10 in peripheral blood were related to non-response in LCH after initial chemotherapy. Immune microenvironment in peripheral blood may be associated with the severity and treatment response of LCH. The levels of CD3 + CD4 + HLA-DR + T cells, CD3 + CD8 + HLA-DR + T cells and IL-10 may be biomarkers to predict treatment response of LCH patients.