Extended Platelet Parameters as a Means to Differentiate Immune Thrombocytopenia From Hypo-proliferative Thrombocytopenias.

Patient to be registered at the Haematology-Oncology department Mount Sinai Roosevelt Hospital. Inclusion criteria are as follows: All individuals age 18yrs and above capable of rendering consent Known ITP confirmed by response to IVIG, glucocorticoids, or WinRho and exclusion of all other possible causes of thrombocytopenia Confirmed aplastic anemia \[as assessed through bone marrow trephine biopsy\]. Chemotherapy-induced thrombocytopenia assessed at time of predicted nadir.