Non-overt disseminated intravascular coagulation in patients during treatment with antithymocyte globulin for unrelated allogeneic hematopoietic stem cell transplantation.

We assessed the effect of rabbit antithymocyte globulin manufactured by Fresenius (ATG-F) on the hemostatic system in patients (n=12) with various hematological malignancies undergoing hematopoietic stem cell transplantation (HSCT) from HLA-matched unrelated donors. For this purpose, we monitored different parameters of coagulation before, during and after the administration of ATG-F. As a control group, we recruited patients (n=10) undergoing HSCT from their HLA-identical siblings who did not receive ATG-F as part of their preparative regimens. At 24 and 48 h after ATG-F treatment had been initiated, we found a temporary rise in D-Dimer, tissue factor, soluble thrombomodulin and thrombin-antithrombin III complex levels and a significant decrease of platelet counts in patients treated with ATG-F as compared to the control group. No differences between the two groups could be detected with regard to global coagulation tests as well as the incidence of bleeding manifestations, thromboembolic complications or the development of vascular-occlusive-disease of the liver. This temporary state of a stressed but compensated coagulation system under ATG-F therapy can be addressed as nonovert disseminated intravascular coagulation (DIC). The effect was independent from the different conditioning regimens and eased off after cessation of ATG-F. We conclude that ATG-F can induce nonovert DIC in patients receiving antithymocyte globulin as part of their conditioning regimen for HSCT.