Higher CD56+ or CD2+ lymphocyte percentage predicts poor steroid response in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is known as an immune-mediated disease and often evolves to chronic type in adult. Corticosteroids only work in around 60% of patients. This study evaluated the roles of subgroup lymphocytes from peripheral blood in ITP adults with different treatment response.

Between October 2009 and March 2017, 37 adults were newly diagnosed as ITP requiring treatment. The patients were separated into two groups: 23 patients with platelet count <50,000/μL with corticosteroid dependence or second-line treatment (Poor-responder Group), and 14 patients with platelet counts <50,000/μL with standard steroid treatment, which stopped within three months (Good-responder Group). Subgroup lymphocyte percentages of peripheral blood were determined through flow cytometry before treatment. Data analysis with Mann-Whitney test and receiver operating characteristic curves were performed using GraphPad Prism (Version 7). A p-value of <0.05 was considered significant.

Lymphocyte percentage was significantly lower in Poor-responder Group than in Good-responder Group (p = 0.008). In subgroup lymphocytes, higher percentages of CD19+ B lymphocytes were found in Good-responder Group (p = 0.03). In Poor-responder Group, a higher CD2+ and CD56+ lymphocytes were observed (p = 0.02 and 0.03). By the cut-off value of percentage of CD56+ lymphocytes with 24.5% or CD2+ lymphocytes with 85.7%, the specificity showed 92.86%.

This study found that newly diagnosed ITP patients with increased percentages of CD56+ or CD2+ lymphocytes in peripheral blood associated with a poorer response to steroid treatment.