Clinical and laboratory predictors of chronic immune thrombocytopenia in children: a systematic review and meta-analysis

Childhood immune thrombocytopenia (ITP) is a rare autoimmune bleeding disorder. Most children recover within 6 to 12 months, but individual course is difficult to predict. We performed a systematic review and meta-analysis to identify predictors of chronic ITP. We found 1399 articles; after critical appraisal, 54 studies were included. The following predictors of chronic ITP in children, assessed in at least 3 studies, have been identified: female gender (odds ratio [OR] 1.17, 95% confidence interval [Cl] 1.04-1.31), older age at presentation (age >= 11 years; OR 2.47, 95% Cl 1.94-3.15), no preceding infection or vaccination (OR 3.08, 95 Cl 2.19-4.32), insidious onset (OR 11.27, 95% Cl 6.27-20.27), higher platelet counts at presentation (>= 20 x 10(9)/L: OR 2.15,95% C11.63-2.83), presence of antinuclear antibodies (OR 2.87, 95% 1.57-5.24), and treatment with a combination of methylprednisolone and intravenous immunoglobulin (OR 2.67, 95% Cl 1.44-4.96). Children with mucosal bleeding at diagnosis or treatment with intravenous immunoglobulin alone developed chronic ITP less often (OR 0.39,95% C10.28-0.54 and OR 0.71,95% Cl 0.52-0.97, respectively). The protective effect of intravenous immunoglobulin is remarkable and needs confirmation in prospective randomized trials as well as future laboratory studies to elucidate the mechanism of this effect.