[Expression of co-stimulatory molecules in peripheral blood of patients with idiopathic thrombocytopenic purpura in relation with platelet antibodies].

This study was aimed to detect the expression of co-stimulatory molecules CD80, CD86 and CD137 in peripheral blood of patients with idiopathic thrombocytopenic purpura (ITP), the content of platelet antibodies in serum (PAIgG), and to analyze the relationship between them and their correlation with the number of platelet in peripheral blood, so as to clarify the roles of co-stimulatory molecules in pathogenesis of idiopathic thrombocytopenic purpura and evaluation of disease status. The co-stimulatory molecules CD80, CD86 and CD137 in peripheral blood mononuclear cells (PBMNCs) of 48 ITP patients and 40 normal persons were detected by immunofluorescence and flow cytometry (FACS), PAIgG content in serum was detected by enzyme-linked immunosorbent assay (ELISA). The results showed that CD80, CD86 and CD137 expression levels in ITP patients were (4.92 +/- 2.02)%, (8.68 +/- 4.25)%, (5.32 +/- 2.67)% respectively, PAIgG content was 210 +/- 3.02 ng/10(7) PA, all these of which were significantly higher than these in normal control group (2.01 +/- 0.75)%, (4.56 +/- 2.06)%, (1.37 +/- 1.25)%, PAIgG 20 +/- 1.13 ng/10(7) PA (p < 0.01). Correlation of co-stimulatory molecule expression with PAIgG content were positive (r = 0.302, p < 0.05), but correlation of co-stimulatory molecule expression with platelet number was negative (r = -0.369, p < 0.05). It is concluded that the co-stimulatory molecules CD80, CD86 and CD137 are involved in immune response and the incidence of ITP. Their over-expression closely associates with the pathogenesis of ITP and clinical status, so that correcting the abnormal expression and regulating the immune status may be one therapeutic strategy and have important clinical significance.