The project was undertaking by Qilu Hospital of Shandong University in China. In order to report the efficacy and safety of diammonium glycyrrhizinate enteric-coated capsule plus high-dose dexamethasone for the treatment of adults with newly-diagnosed primary immune thrombocytopenia (ITP).

The investigators anticipate to undertaking a parallel group, randomised controlled trial of 106 ITP patients. One part of the participants are randomly selected to receive diammonium glycyrrhizinate enteric-coated capsule orally at a dose of 150mg tid for 1 month), combining with dexamethasone (given orally at a dose of 40 mg qd for 4 days). The others are selected to receive high-dose of dexamethasone alone. Patients who do not respond to the treatment may receive another cycle of high-dose dexamethasone therapy with an interval of 10 days. Platelet count, bleeding and other symptoms were evaluated before and after treatment. Adverse events are also recorded throughout the study. The purpose of this study is to report the efficacy and safety of diammonium glycyrrhizinate enteric-coated capsule combining with high-dose dexamethasone therapy for the treatment of ITP.

Inclusion Criteria:

• Meet the diagnostic criteria for immune thrombocytopenia;
• Untreated hospitalized patients or patients from the clinic, may be male or female, between the ages of 18~ 80 years;
• To show a platelet count <30 * 10^9/L, or with bleeding manifestations, or both;
• Willing and able to sign written informed consent
• ITP patients with hepatitis virus infection or ITP patients with abnormal liver function at the time of enrollment, i.e., ITP patients with indications for diammonium glycyrrhizinate enteric-coated capsule, should be separately stratified.

Exclusion Criteria:

• secondary thrombocytopenia;
• severe immune-deficiency;
• active or previous malignancy;
• HIV virus infection, tuberculosis, or other active infection (sepsis, pneumonia, or abscess);
• pregnancy or lactation;
• diabetes;
• hypertension;
• cardiovascular diseases;
• severe kidney function impairment;
• psychosis;
• osteoporosis;
• inflammatory bowel disease or gastric disease;
• arterial or venous thromboembolism within the 6 months before screening or patients who required anticoagulant treatment;
• an organ or haematopoietic stem-cell transplantation;
• neutrophil count of less than 1500 cells per mm³;
• glycosylated haemoglobin less than 8%;
• partial thromboplastin time 1∙5 times or less the upper limit of normal (ULN); •clinical electrocardiogram changes;
• history of primary immunodeficiency;
• neoplastic disease within the past 5 years;
• corrected QT interval greater than 450 ms for men and greater than 470 ms for women;
• substance misuse within the previous 12 months;
• people who could not adhere to the protocol or were planning to have a surgical procedure in 6 months.