Increased plasma soluble adhesion molecules in thrombotic thrombocytopenic purpura and disseminated intravascular coagulation

We measured plasma-soluble adhesion molecules (granule membrane protein [GMP]-140, endothelial leukocyte adhesion molecule [ELAM]-1. intracellular adhesion molecule [ICAM]-1, and vascular adhesion molecule [VCAM]-1) in 21 patients with thrombotic thrombocytopenic purpura (TTP), 10 with mitomycin C-induced hemolytic uremic syndrome (MMC-HUS) and 59 with disseminated intravascular coagulation (DIC) or pre-DIC. The plasma levels of soluble GMP-140 in the three groups were significantly higher than the levels in healthy volunteers, suggesting that platelets and vascular endothelial cells are activated in these diseases. The plasma-soluble GMP-140 level of the DIC patients with nonhematopoietic malignancy was significantly higher than in the DIC patients with hematopoietic malignancy, perhaps due to the release of GMP-140 mainly from platelets. The plasma levels of soluble VCAM-1 in the TTP and DIC patients were significantly higher than the levels in healthy volunteers. The plasma levels of ICAM-1 in DIC patients were significantly higher than those in healthy volunteers, but the levels in the TTP and MMC-HUS groups were not significantly high. The plasma ELAM-1 levels in the TTP and MMC-HUS groups were significantly lower than those in healthy volunteers and DIC patients. Since elevated plasma cytokine levels have been observed in TTP and DIC patients, the adhesion molecules might be upregulated in these diseases. However, plasma ELAM-1 is thought to be reduced in severe vascular endothelial cell diseases such as TTP.