The utility of patient characteristics in predicting severe ADAMTS13 deficiency and response to plasma exchange.

Background: Idiopathic thrombotic thrombocytopenic purpura (TTP) is a rare form of thrombotic microangiopathy (TMA) characterized by extreme deficiency of ADAMTS13, an enzyme responsible for cleavage of von Willebrand factor. Plasma exchange therapy is the cornerstone of current treatment and is ineffective for most other forms of TMA. The availability of ADAMTS13 testing has improved diagnostic accuracy and appropriate selection of patients who are most likely to respond to plasma exchange.

Change in CD34+ cell concentration during peripheral blood progenitor cell collection: effects on collection efficiency and efficacy.

Background: An understanding of factors affecting CD34+ cell collection efficacy is essential to minimize donor toxicity and cost.

Study Design And Methods: Peripheral blood CD34+ cell (CD34) measurements were determined at various intervals before, during, and after automated cell collection (Cobe Spectra 6.0).