Cryoprecipitate poor plasma does not improve early response in primary adult thrombotic thrombocytopenic purpura (TTP).

Thrombotic thrombocytopenic purpura (TTP) is a potentially fatal disease that is treated with plasma exchange and typically with replacement with fresh frozen plasma (FFP). This approach results in an approximate 50% response rate following 1 week of therapy and 80% survival. Cryoprecipitate poor plasma (CPP) is plasma from which the cryoprecipitate fraction is removed. CPP has been reported to be successful as salvage therapy in refractory TTP and has been suggested to be superior to FFP in retrospective studies. The present report compares initial therapy of TTP with exchange using replacement with either FFP or CPP in a multi-institutional prospective randomized study performed by the North American TTP Group (NATG Group) from 1993 to 1995. Initial therapy also included corticosteroids. Antiplatelet drugs or vinca alkaloids were not employed. A severity score index, response score, and individual clinical parameters (platelet count, LDH x upper limit of normal, hemoglobin level, and creatinine) were compared at their nadir or peak values, baseline, and days +6 and +13 of therapy. Thirteen patients were randomized to FFP exchange and 14 to CPP exchange. Results were equivalent for all parameters. Survival was equal with three deaths in each group. These data indicate that the efficacy of FFP and CPP are the same in the initial treatment of TTP in adults.

Plasminogen activator inhibitor (PAI-1) antigen levels in primary TTP and secondary TTP post-bone marrow transplantation.

Our objectives were to measure and compare plasminogen activator inhibitor levels (PAI-1) in primary adult thrombotic thrombocytopenic purpura (TTP) and in secondary TTP associated with bone marrow transplantation (BMT)-TTP. PAI-1 antigen levels were measured by an enzyme linked immunosorbent assay on platelet poor plasma samples obtained from patients at the time of diagnosis of the TTP disorder and from a group of normal volunteers. The samples were frozen at -70 degrees C. Patients with TTP secondary to bone marrow transplantation had their grade determined by percentage fragmented cells and lactate dehydrogenase levels. The primary TTP samples were contributed by investigators in the multi-institutional North American TTP Group, and the bone marrow transplant samples were obtained from an adult bone marrow transplant program. Nineteen patients with adult TTP, and 47 patients with bone marrow transplant-TTP were evaluated. Of the latter, 14 had Grade 2, 13 had Grade 3, and 20 had Grade 4 BMT-TTP. PAI-1 levels were elevated compared to control volunteers in both primary adult TTP and BMT-TTP, P < 0.001. Levels did not differ from normal in Grade 2 BMT-TTP (median = 16 ng/ml; quartiles = 9-20). PAI-1 levels were similar in primary TTP (median = 32 ng/ml; quartiles = 25-51) and Grade 3 BMT-TTP (median = 35 ng/ml; quartiles = 19-48 ng/ml), P = 0.7. However, PAI-1 levels were significantly higher in Grade 4 BMT-TTP (median = 83 ng/ml; quartiles = 60-143) than Grade 3 BMT-TTP, and primary TTP, P < 0.001. PAI-1 levels are high in primary TTP and secondary bone marrow transplant-TTP (Grades 3-4). In contrast, normal levels are seen in Grade 2 BMT-TTP, which is a self-limited disorder. Therefore, high PAI-1 levels may contribute to hypofibrinolysis in the pathogenesis of primary TTP and of moderate to severe TTP (Grades 3-4) following bone marrow transplantation.

Plasma von Willebrand Factor Antigen (vWF:AG) and thrombomodulin (TM) levels in Adult Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndromes (TTP/HUS) and bone marrow transplant-associated thrombotic microangiopathy (BMT-TM).

Endothelial damage is thought to be a contributing factor in the pathogenesis of Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndromes (TTP/HUS). The present studies measured two markers of endothelial cell stimulation and/or activation [von Willebrand Factor (vWF:Ag) and thrombomodulin (TM)] in patients with TTP/HUS disorders and compared them to controls. The patient groups consisted of adults with TTP/HUS, with (n = 13) and without (n = 14) peak Cr levels >2.0 mg/dl. Additionally, 52 patients with Bone Marrow Transplant-associated Thrombotic Microangiopathy (BMT-TM) following allogeneic BMT were evaluated. Both vWF:Ag and TM were elevated in all patient groups compared to controls. TTP/HUS patients with peak Cr >2.0 mg/dl had higher TM levels (P < 0.001) than did those with peak Cr levels below 2 mg/dl. However, thrombomodulin/ creatinine (TM/Cr) ratios did not differ in these two groups nor did they differ from controls. BMT-TM pts had higher vWF:Ag levels and higher TM/Cr ratios than controls and TTP/ HUS, P < 0.001. The median TM/Cr ratio in BMT-TM was 91 (range = 34-229) compared to 38 (range = 29-50) in controls, P < 0.001 and 38 (range = 6 to 156) in TTP/HUS, P < 0.001. Additionally both TM (P < 0.001) and TM/Cr (P < 0.02) were higher in patients with Grades 3 and 4 BMT-TM compared to those with Grade 2 BMT-TM. These results suggest that endothelial cell activation occurs in TTP/HUS and BMT-TM. Since TM/Cr ratios were higher in BMT-TM compared to TTP/HUS, these findings suggest that the mechanism of elevated TM in BMT-TM cannot be explained solely by altered renal excretion. Taken together, these findings strongly indicate a role of endothelial cell damage in BMT-TM.