Eligibility criteria
Studies where >20% of participants were pediatric (< 18 years of age) and diagnosed with “refractory” or “treatment-resistant” ITP were included in this systematic review. For inclusion, studies needed to report on diagnostic criteria, laboratory work-up, or treatments other than first- line therapy (short course prednisone, IVIG, or anti-D). Commentaries, editorials, narrative reviews, conference abstracts, reviews, case reports or case series with fewer than ten patients were excluded.