DECREASED IN-VITRO MEGAKARYOCYTE COLONY FORMATION IN CHRONIC IDIOPATHIC THROMBOCYTOPENIC PURPURA

In vitro megakaryocyte colony formation was studied in 25 patients wit h chronic idiopathic thrombocytopenic purpura (ITP), and compared to 1 6 controls. A significantly lower number of megakaryocyte progenitors (CFU-MK) was observed in patients (10.8 +/- 12.0 CFU-MK per 10(5) bone -marrow non-adherent mononuclear cells (NAMC). compared to controls (2 2.5 +/- 15.4 CFU-MK); P<0.002. Only six patients had a normal number o f CFU-MK. The number of CFU-MK was not correlated to initial platelet count (P = 0.35). These findings indicate that in vitro CFU-MK could b e of interest in the diagnosis of chronic ITP, and also could be predi ctive for chronicity in patients with acute ITP.