In multivariate analysis, newly diagnosed ITP and anti-GPIIb/IIIa antibodies were the two variables independently associated with a better response to IVIg (OR = 5.4 (1.2–24.7), p = 0.03 and OR = 4.82 (1.08–21.5), p = 0.04, respectively). This evidence concerns the gene ITGA2B and autoimmune thrombocytopenic purpura.