Type 2 polarized immune response holds a major position in Epstein–Barr virus‐related idiopathic thrombocytopenic purpura (EBV‐ITP)

Summary Introduction: Dysfunctional cellular immunity is considered to be essential to the pathophysiology of Epstein–Barr virus‐related idiopathic thrombocytopenic purpura (EBV‐ITP). Cytokines in peripheral blood and the gene expression of transcription factors in T lymphocytes of patients with were investigated to correlate the polarization of T helper cell type 1 (Th1)/T helper cell type 2 (Th2) with the degree of thrombocytopenia. Methods: The expression of type 1 (T‐bet) and type 2 (GATA‐3) in T lymphocytes was detected by semiquantitative reverse‐transcription–polymerase chain reaction, and plasma cytokine levels were measured by enzyme‐linked immunoassay in 35 patients and 30 control subjects. Results: Th1/Th2 [(interleukin‐2 + γ‐interferon)/(interleukin‐10 + interleukin‐13)] cytokine ratios and transcription factor (T‐bet/GATA‐3) mRNA ratios were significantly decreased in patients with EBV‐ITP, and the Th1/Th2 ratio was directly correlated with platelet counts. Conclusion: Our findings clearly show that type 2 polarization of the autoimmune response accounts for the expression of cytokines and transcription factors in EBV‐ITP.