Abstract:
Background programmed death (PD-1) has an important role in inhibiting the immune system in immune thrombocytopenic purpura (ITP) by switching off auto-reactive T-cells. This work aims to assess the expression of (PD)-1 negative co-stimulatory molecule in patients with ITP and to detect its relation with platelet count. Patient and methods, forty patients were newly diagnosed as ITP 13 males and 27 females were included, their age ranged from 1 to 43 years and twenty-six healthy subjects 8 males and 18 females as control group their age ranged from 5 to 62 year. Expression of PD-1+ CD4+ T-cells by B.D FACS Calibur flow cytometry was performed in ITP patients and healthy subjects on peripheral blood samples, Mo Abs supplied by BD Bioscience, United States. PD-1 FITC Lot: GR 145543-6 and CD4 PE Cat: 555347, San Jose, California. Negative mouse isotypic control (PE Lot: 0279236, FITC Lot: 0273533). Results, percentages of PD-1 on CD4+T cells in peripheral blood from patients with ITP were considerably higher than that from healthy subjects (p < 0.001), it has no predictive risk for thrombocytopenia Odd's ratio ( 3.773 ) p ( 0.187), CI ( 0. 525 – 27.09). Conclusion: Increased expression of PD-1 molecule on CD-4 T-cells as inhibitory signals to the activated immune system against self-antigens an important part of ITP pathogenesis. Has no predictive role in the degree of thrombocytopenia.