No eligible patient was enrolled.

The project was undertaking by Qilu Hospital of Shandong University in China. In order to report the efficacy and safety of All-Trans Retinoic Acid (ATRA) combining with High-dose Dexamethasone for the treatment of adults with primary immune thrombocytopenia (ITP), compared to conventional high-dose dexamethasone therapy.

The investigators are undertaking a parallel group, randomised controlled trial of 80 primary ITP adult patients from Qilu Hospital of Shandong University in China. One part of the participants are randomly selected to receive All-Trans Retinoic Acid(10mg tablet by mouth every 8 hours a day for 12 consecutive weeks, combining with dexamethasone (given orally at a dose of 40 mg per day for 4 days, the others are selected to receive high-dose of dexamethasone treatment (given orally at a dose of 40 mg daily for 4 days). Patients were monitored every 1 to 3 days at the first two weeks and every 1 to 4 weeks afterwards for platelet counts, and were monitored every 1 month for transaminitis and other side effects

Inclusion Criteria:

1. Meet the diagnostic criteria for immune thrombocytopenia.
2. Untreated hospitalized patients, may be male or female, between the ages of 18 ~ 80 years.
3. To show a platelet count < 30×10^9/L, and with bleeding manifestations.
4. Eastern Cooperative Oncology Group（ECOG）performance status ≤ 2.
5. Willing and able to sign written informed consent

Exclusion Criteria:

1. Received chemotherapy or anticoagulants or other drugs affecting the platelet counts within 3 months before the screening visit.
2. Received high-dose steroids or [2] intravenous immunoglobulin transfusion(IVIG)in the 3 weeks prior to the start of the study.
3. Current HIV infection or hepatitis B virus or hepatitis C virus infections. Severe medical condition (lung, hepatic or renal disorder) other than ITP. 4.Unstable or uncontrolled disease or condition related to or impacting cardiac function (e.g., unstable angina, congestive heart failure, uncontrolled hypertension or cardiac arrhythmia)

5.Female patients who are nursing or pregnant, who may be pregnant, or who contemplate pregnancy during the study period.

6.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.

7.Patients who are deemed unsuitable for the study by the investigator.