Association of Birthdays with Late Relapses of Immune Thrombocytopenia

Abstract 4685

Adult immune thrombocytopenia (ITP) typically takes a chronic or relapsing course. Etiologies of initial presentations and/or late relapses have not been identified. Emotional stress has been associated with adult ITP, but it is not known if there is a causal relationship.^1,2  Birthdays have been described as psychosocial stressors that have been linked with vascular events including stroke and myocardial infarction.³ Based on our observation that a disproportionately high number of late relapses were occurring within 3 weeks of patients’ birthdays, we conducted a retrospective cohort study to determine if birthdays are associated with the onset and/or late relapses of ITP.

Thirty-five consecutive patients with ITP followed between July 1, 2003 through August 11, 2011 were included in the study. Median age at presentation was 48 years (range 22 to 83 yrs). The female:male ratio was 1.9:1. One patient had human immunodeficiency virus. The median duration of follow-up was 28.3 months (range 1.25 to 72 mos). Dates of initial presentation were available for 22 patients. Only 3 (13.6%) presented within 3 weeks of their birthdays. Eleven of 35 patients had a relapse (defined as a platelet count < 30,000/μL or a 50–70% decrease in platelet count from baseline) after an unmaintained remission exceeding 1 year. Four (36%) of these 11 patients had relapses within 3 weeks of their birthdays (binomial test for significance = 0.002). Two of these 4 patients presented 3 weeks following their birthdays, but had noted fatigue 1 week before presenting. Fatigue has been associated with thrombocytopenic exacerbations of ITP;⁴ these patients therefore were likely relapsing at the onset of fatigue, closer to their birthdays. The other two patients relapsed 3 – 10 days following their birthdays. One was pregnant; pregnancy may have contributed to her relapse. None of the 4 patients had concurrent infections, autoimmune disease, or malignancies.

This study is the first to show that birthdays are associated with relapses of ITP after long unmaintained remissions. Birthdays may be accompanied by stress of anticipation, indulgence, and overexertion. Stress is associated with ITP, and may have a causative role in relapsing ITP.