Frequency and Clinical Significance of Antinuclear Antibody Positivity in Immune Thrombocytopenia in Adults

Background Immune thrombocytopenia is an immune-mediated disorder with heterogenous presentation. It shows association with other autoimmune disorders with varying frequency. Objective The objective of this study was to establish the frequency of antinuclear antibody (ANA) in our population and to evaluate its association with severity of clinical presentation, disease remission and association with other autoimmune diseases. Design Cross-sectional study. Methods This was a descriptive cross-sectional study that included 160 patients with immune thrombocytopenia purpura (ITP) presented at National Institute of Blood Disease and Bone Marrow Transplantation from February 2021 to July 2022. Patients were screened for ANA and other causes of secondary ITP. ANA-positive patients were compared with ANA-negative patients in terms of bleeding manifestations and platelet counts at initial presentation, association with other autoimmune diseases and response to first-line treatment. Results In our study 43 (26.9%) patients were ANA positive and 117 (73.1%) were negative for ANA. The initial platelet counts, and bleeding symptoms were not found to be significantly different among the 2 groups. And 79.1% of the ANA-positive patients had other autoimmune markers as well compared to 20.9% ANA-negative patients, showing a significant association ( P<.001). Response to treatment with steroid ± azathioprine assessed at 3 and 6 months were similar in both the groups. Conclusion Our results demonstrate that ANA positivity is not associated with severity of presenting symptoms, initial platelet counts, or response to treatment. However, the presence of ANA is associated with increased risk of other autoimmune diseases in patients with ITP.