185例原发免疫性血小板减少症患者特异性自身抗体种类及类型与地塞米松疗效的相关性

OBJECTIVE: To investigate the different outcomes by dexamethasone in adults immune thrombocytopenia purpura (ITP) with different types of platelet specific-autoantibodies. METHODS: A total of 185 ITP were enrolled, 61 males and 124 females, with a median age of 42 (18–83) years, including 117 newly diagnosed, 35 persistent, and 33 chronic cases. All the patients received the dexamethasone at an initial dose of 40 mg per day for 4 days and a low dose of 5–10 mg for 3–4 weeks. The platelet specific-autoantibodies were identified by the modified monoclonal antibody-specific immobilization of platelet antigen (MAIPA) assay. RESULTS: Among the IgG positive patients, the response rates in anti-GPⅡb/Ⅲa antibody, anti-GPⅠbα antibody, both antibody positive, and both antibody negative were 87.5%, 50.0%, 68.0%, and 72.3% (χ(2)=11.489,P<0.05), respectively. Among the IgM positive patients, the response rates in the four groups were 82.1%, 71.4%, 61.9%, and 68.9% (χ(2)=2.719,P=0.437), respectively. Among the GP Ⅰ bα antibody positive patients, the response rates in IgG alone, IgM alone, both positive, and both negative were 52.4%, 59.1%, 76.5%, and 77.9% (χ(2)=10.811,P<0.05), respectively. Among the GPⅡb/Ⅲa antibody positive patients, the response rates in the four groups were 73.3%, 71.0%, 78.6%, and 66.3% (χ(2)=1.374,P=0.719), respectively. CONCLUSION: ITP patients with GP I bα-IgG antibody have worse response to dexamethasone treatment.