The Study of Different Dose Rituximab in the Treatment of ITP

Inclusion Criteria: 1. Meet the diagnostic criteria for immune thrombocytopenia. 2. Male or female, between the ages of 10 \~ 70 years. 3. Normal glucocorticoid therapy is ineffective or effective but the maintenance dose is large, without immunosuppressive therapy or immunosuppressive treatment ineffective 4. To show a platelet count \< 30×10\^9/L, or with bleeding manifestations. 5. Eastern Cooperative Oncology Group（ECOG）performance status ≤ 2 Exclusion Criteria: 1. Current HIV infection or hepatitis B virus or hepatitis C virus infections. 2. Severe medical condition (lung, hepatic or renal disorder) other than ITP. Unstable or uncontrolled disease or condition related to or impacting cardiac function (e.g., unstable angina, congestive heart failure, uncontrolled hypertension or cardiac arrhythmia) 3. Female patients who are nursing or pregnant, who may be pregnant, or who contemplate pregnancy during the study period. 4. Have a known diagnosis of other autoimmune diseases, established in the medical history and laboratory findings with positive results for the determination of antinuclear antibodies, anti-cardiolipin antibodies, lupus anticoagulant or direct Coombs test. 5. Patients who are deemed unsuitable for the study by the investigator.