Immune Thrombocytopenia (ITP) is a bleeding disorder characterized by immune-mediated destruction and/or impaired production of platelets, leading to clinical manifestations such as petechiae, purpura, mucosal bleeding, and in severe cases, life-threatening visceral or intracranial hemorrhage. Research on the diagnosis, treatment, and prognosis of ITP is critical for improving patient outcomes and quality of life. However, most existing hematologic cohort studies are limited to single-center or small multicenter samples, lacking comprehensive, large-scale prospective investigations.

To address this gap, our center plans to conduct a large-sample, combined retrospective and prospective longitudinal observational cohort study of ITP patients. The study will enroll patients to collect baseline demographic and diagnostic data, followed by longitudinal follow-up via questionnaires, telephone interviews, video consultations, online platforms, and in-person visits. Key variables including treatment regimens, comorbidities, and prognostic outcomes will be systematically recorded. Additionally, hospitalization and outpatient expenditure data will be extracted from electronic medical records.

This study aims to provide high-quality real-world evidence on the epidemiology, treatment patterns, clinical outcomes, and healthcare costs of ITP patients in China, ultimately informing clinical decision-making and health policy.

Immune Thrombocytopenia (ITP) is an immune-mediated acquired bleeding disorder characterized by thrombocytopenia with normal or increased megakaryocytes in the bone marrow accompanied by maturation defects. Epidemiological studies estimate its incidence at approximately 2-5 cases per 100,000 individuals in the general population.

The primary clinical manifestation of ITP is bleeding, ranging from minor cutaneous/mucosal hemorrhage to life-threatening organ bleeding. Notably, some patients also exhibit increased risk of thrombotic/embolic events. Embolic complications in critical organs (e.g., heart, brain) may significantly impair quality of life and lead to life-threatening conditions.

Currently, most ITP cohort studies in China are limited to single-center designs or small multicenter studies with insufficient sample sizes. There remains a notable lack of large-scale, longitudinal prospective cohort studies.

To address these limitations, this multicenter, retrospective-prospective longitudinal observational study will enroll diagnosed ITP patients to systematically collect:

Baseline demographic and diagnostic data Prospective follow-up data via questionnaires, telemedicine, and clinical visits Treatment regimens, comorbidities, and prognostic outcomes Healthcare utilization costs through electronic medical records

By establishing this comprehensive real-world database, the study aims to:

Elucidate the epidemiology, treatment patterns, and economic burden of ITP in China Provide evidence-based support for developing novel clinical strategies Improve long-term hemorrhage-free survival rates This investigation will serve as a foundational platform for optimizing ITP management and enhancing patient outcomes across China.

Inclusion Criteria:

1. Patients with confirmed diagnosis of ITP
2. Patients treated at Peking University People's Hospital since January 1, 2005

Exclusion Criteria:

1. Any condition that may render follow-up data unreliable, including but not limited to severe psychiatric disorders"
2. Patients deemed ineligible for the study by investigators"

Patients with confirmed immune thrombocytopenia (ITP).

Diagnostic Criteria for ITP:

1. Sustained platelet count <100×10⁹/L
2. Normal or increased megakaryocyte count in bone marrow with maturation defects
3. Exclusion of other potential causes of thrombocytopenia including: pseudothrombocytopenia, drug-induced thrombocytopenia, viral infections, helicobacter pylori infection, hematologic disorders, autoimmune diseases, hypersplenism, malignancies