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

Background: 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.

Conclusions: Our findings clearly show that type 2 polarization of the autoimmune response accounts for the expression of cytokines and transcription factors in EBV-ITP.