Association of Immune Thrombocytopenia and Interstitial Pneumonia

OBJECTIVE: Chest physicians often encounter patients with interstitial pneumonia with autoimmune features. However, there have so far been few reports of patients presenting with concurrent immune thrombocytopenia (ITP) and interstitial pneumonia. The prevalence of interstitial pneumonia in patients with ITP is less well known. METHODS: We surveyed patients diagnosed with ITP and interstitial pneumonia at the departments of Hematology and Respiratory Medicine to evaluate the association between these diseases. RESULTS: Among 73 patients with ITP, 7 patients (9.6%) presented with interstitial pneumonia, including 4 patients (2%) who developed ITP in the course of 204 patients with interstitial pneumonia. All 7 patients were men. Four patients were positive for some autoantibodies. Two patients had autoimmune diseases other than ITP. There were significant differences in age and gender between the ITP patients with and without interstitial pneumonia. CONCLUSION: The present study suggests the possibility that the development of ITP, other autoimmune diseases, and interstitial pneumonia may be mutually associated. Advanced age and male sex in ITP may be significant predisposing factors for interstitial pneumonia. Clinicians should be aware of the potential for the coexistence of these diseases.