Myeloid-derived suppressor cells anticipate sustained treatment response in newly-diagnosed and persistent primary immune thrombocytopenia

Background: Myeloid-Derived Suppressor Cells (MDSCs) are used as markers for short-term immune thrombocytopenia (ITP) course. This study aimed to assess their reliability to predict the sustained treatment response within 6 months. Methods: We tested the sensitivity and specificity of MDSCs and proposed cut-off MDSCs values to predict the prognosis in newly diagnosed ITP. We enrolled 80 adults with primary ITP; 50 newly diagnosed (group I), 30 chronic (group II), and 20 controls (group III). Flow cytometry was used for peripheral blood MDSCs estimation with correlation, sensitivity, and specificity of MDSCs to predict sustained treatment response. Results: After 6 days and 6 months of treatment, MDSCs were significantly higher than pre-treatment in group I, (P < 0.001, P < 0.001). MDSCs were significantly higher in group I compared to groups II and III, (P 0.001 for both). Cut-off values were 15.75% and 5.9% at 6 days and 6 months respectively. MDSCs sensitivity was 85.7% and 100% and specificity was 94.44% and 100% at 6 days and 6 months. Conclusions: MDSCs may constitute a reliable predictor for ITP initial and prolonged treatment response with good sensitivity and specificity. This may guide the use of a specific therapeutic agent as maintenance therapy or its replacement in practice.