The Effect of Anti-Nuclear Antibody Positivity on Immune Thrombocytopenic Purpura and its Clinical Course
Hematology Blood Transfusion & Disorders
Objective Immune Thrombocytopenic Purpura (ITP) is an autoimmune-mediated disease. Patients with primary ITP are occasionally found to have an Antinuclear Antibody (ANA) titer ≥1:160. Our objective was to study the effect of ANA on ITP and its clinical course. Methods This was a retrospective chart review of 765 adult patients with ITP, followed regularly at St. Paul's Hospital, Vancouver, Canada; 120 patients who had an ITP diagnosis and had ANA testing during their initial work-up were
... work-up were included. An ANA titer ≥1:160 was correlated with clinical presentation including steroid responsiveness, platelet count at presentation, and autoimmune disease development. This study took place in St. Paul's Hospital, Vancouver, British Columbia, Canada between the months of Results Of 24 patients with ANA titers ≥1:160, 10(58.8%) were steroid-resistant, compared to 9(29.0%) of 31 patients with ANA titers <1:160(P=0.044). Five (20.8%) patients with ANA titers ≥1:160 developed other autoimmune diseases after diagnosis with ITP, compared to only one (1%) patient with an ANA titer <1:160(P=0.001). Patients with ANA titers ≥1:160 had a lower platelet count than patients with ANA titers <1:160, (P<0.001). Conclusion We analyzed the relationship between high ANA and ITP clinical course. Compared to patients with ANA titers <1:160, those with ANA titers ≥1:160 were steroid-resistant, had a higher risk of developing other autoimmune diseases, and presented with a lower platelet count.