Immune thrombocytopenia in adults: a prospective cohort study of clinical features and predictors of outcome

Abstract

This prospective observational cohort study aimed to explore the clinical features of incident immune thrombocytopenia in adults and predictors of outcome, while determining if a family history of autoimmune disorder is a risk factor for immune thrombocytopenia. All adults, 18 years of age or older, recently diagnosed with immune thrombocytopenia were consecutively recruited across 21 hospital centers in France. Data were collected at diagnosis and 12 months after. Predictors of chronicity at 12 months were explored using logistic regression models. The association between family history of autoimmune disorder and the risk of developing immune thrombocytopenia was explored using a conditional logistic regression model, after matching each case to 10 controls. One hundred and forty-three patients were included: 63% were female, mean age was 48 years old (Standard Deviation=19), and 84% presented with bleeding symptoms. The median platelet count was 10x109/L. Initial treatment was required in 82% of patients. After 12 months, only 37% of patients not subject to disease-modifying interventions achieved cure. Baseline predictors of chronicity at 12 months included higher platelet count [Odds Ratio 1.04; 95% Confidence Interval 1.01-1.08] and the absence of severe bleeding (Odds Ratio 0.27; 95% Confidence Interval 0.08-0.86). No association was evidenced between the presence of antinuclear antibodies at diagnosis and the outcome. Likewise, family history of autoimmune disorder was not associated with incident immune thrombocytopenia. Immune thrombocytopenia in adults has shown to progress to a chronic form in the majority of patients. A lower platelet count and bleeding at onset are predictive of a more favorable outcome.