The project was undertaking by Qilu Hospital of Shandong University in China. In order to compare the efficacy, safety and response duration of different dose of rituximab in patients primary immune thrombocytopenia(pITP).

62 patients with pITP who had failed to respond to glucocorticosteroids were randomly divided into 2 groups: group A(n = 32) and group B(n = 30). In group A, Rituximab was given with a fixed dose of 100 mg administered as an intravenous infusion weekly (on day 1, 8, 15 and 22). In group B, Rituximab was given with a single dose of 375mg/m2. The clinical effect, onset time, duration of efficacy and adverse reactions were observed to compare the efficacy and safety of two different plans.

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.