Decreased Tim-3 and its correlation with Th1 cells in patients with immune thrombocytopenia

Here we evaluate the expression of Tim-3 in CD4 + T cells from patients with immune thrombocytopenia (ITP). We also counted platelets and evaluated plasma IFN-γ, IL-18 and IL-4 levels in patients with active ITP (n = 26), patients with ITP in remission (n = 23) and in healthy subjects (n = 34) by enzyme linked immunosorbent assay (ELISA). Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression of IL-18, IFN-γ, IL-4, T-box (T-bet) and Tim-3 was studied in the blood. The CD4 + Tim-3 + cells in blood were evaluated by flow cytometry and are expressed as a percentage of the total number of CD4 + cells. The Tim-3 positive cells within the circulating CD4 + population of newly diagnosed patients were significantly decreased compared to controls. However, T-bet, IL-18 and IFN-γ levels were significantly elevated in patients. Tim-3 mRNA expression was significantly lower in the peripheral mononuclear cells (PBMCs) of ITP patients compared to controls. The decreased levels of Tim-3 during active stages of disease suggest a possible role in the pathogenesis and course of ITP and restoration of Tim-3 may be a reasonable therapeutic strategy for ITP.