PB1342 - Clinical significance of Anti-Nuclear Antibody positivity in Immune Thrombocytopenia Purpura in adults.

Background: Immune thrombocytopenia purpura (ITP) is an autoimmune disorder with increased peripheral destruction of platelets and with heterogenous presentation. This destruction of platelets in ITP may present as a primary disorder or secondary and its association with other autoimmune disorders with varying frequency.

Aims: The objective of this study is to establish the frequency of Anti-Nuclear antibody (ANA) in our population and to evaluate its association with severity of clinical presentation, disease remission and its association with other auto immune diseases.

Methods: This was a descriptive cross-sectional study that included 160 ITP patients from February 2021 to July 2022. Patients were screened for ANA antibodies 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 auto immune 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. Median (range) platelet count at baseline in the ANA positive group was 20(94) while 18 (98) in the ANA negative group. No significant association (p-value >0.05) in the median platelet counts during the study follow-ups was observed between the two groups. Similarly, bleeding symptoms were not found to be significantly different among the two groups, table 1. 79.1% of the ANA positive patients reported presence of other auto immune markers compared to 20.9% ANA negative patients, showing a significant association (p-value < 0.00). Response to treatment with steroid ± Azathioprine assessed at 3 and 6 months were similar in both the groups, table 2 .

Conclusion(s): This study 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 positivity is associated with increased risk of other autoimmune diseases in ITP patients.