INCREASED SERUM LEVELS OF THROMBOPOIETIN IN PATIENTS WITH THROMBOTIC THROMBOCYTOPENIC PURPURA, IDIOPATHIC THROMBOCYTOPENIC PURPURA, OR DISSEMINATED INTRAVASCULAR COAGULATION

The serum levels of thrombopoietin (TPO) were measured in 16 patients with thrombotic thrombocytopenic purpura (TTP), 12 with hemolytic urem ic syndrome (HUS), 10 with aplastic anemia (AA), 10 with disseminated intravascular coagulation (DIG), and 71 with idiopathic thrombocytopen ic purpura (ITP). The serum TPO levels were measured with a sensitive sandwich enzyme-linked immunosorbent assay. The serum TPO level in the ITP group (1.68 +/- 0.85 fmol/ml) were not significantly increased co mpared with those of the normal subjects. The TPO levels in the TTP (2 .77 +/- 1.38 fmol/ml) and HUS groups (5.77 +/- 4.41 fmol/ml) were high er than those of the normal subjects. The patients with AA (12.7 +/- 8 .0 fmol/ml) and those with DIC (13.3 +/- 5.7 mol/ml) had significantly higher serum TPO levels than did the normal subjects and ITP patients . The TPO levels were well correlated with the platelet counts in the TTP patients, and were negatively correlated with the platelet counts in the ITP patients. These results suggest that the serum TPO levels i n some thrombocytopenic diseases are regulated not only by the platele t count and the megakaryocyte mass, but also by other factors.