Refractory ITP definition
The variables used when defining rITP included: patient history (7
studies), complete blood count with differential and platelets (3
studies), bleeding risk (3 studies), and splenectomy outcome (1 study)
(Table 1).
Among the 11 studies, nine defined rITP as being unresponsive to medical
treatment options such as splenectomy, corticosteroids, IVIG,
cyclosporine, rituximab, and/or mycophenolate mofetil. Six studies
further defined rITP as an increased risk of bleeding necessitating
treatment, requiring frequent therapeutic intervention or therapy
(International Working Group (IWG) definition). Three studies required
specific platelet counts for rITP: two studies defined rITP platelet
counts as less than 30x109/L and one study defined
rITP platelet counts as less than 20 x109/L. One
study’s rITP definition included: “unable or disinclined to
undergo splenectomy and in whom primary objective is to improve health
related quality of life was used ”.8