In vitro verification of antithrombotic effect of recombinant soluble nucleotide triphosphate diphosphohydrolase 1.
OBJECTIVE
Ecto-ADPase (NTPDase1 or CD39) has been identified on endothelial cells and found to be antithrombogenic, with actions resulting from degradation of adenosine diphosphate (ADP), a thrombogenic molecule secreted by activated platelets at sites of vascular injury. Reasoning that the ADPase activity of CD39 might provide clinical use as an antithrombotic agent, the authors investigate the comparative ability of the agent to inhibit platelet and fibrin deposition.


METHODS
With use of an in vitro perfusion system, fresh, heparinized human blood was passed over expanded polytetrafluoroethylene grafts at hemodynamic conditions similar to those observed in the human arterial circulation. Three different concentrations of CD39 (30 mcg/mL, 100 mcg/mL, and 300 mcg/mL) were compared with abciximab (4 mcg/mL) and heparin controls. The deposition of radiolabeled platelets and fibrinogen was measured in five perfusions for each treatment group.


RESULTS
The addition of soluble CD39 to heparinized blood inhibited platelet deposition to an extent greater than that of heparin alone (P =.04). Effects were similar to those observed with abciximab. The addition of CD39 to heparinized blood did not result in augmentation of fibrin inhibition beyond that observed with heparin alone. The fibrin inhibitory effects of CD39 appeared to be less significant than the fibrin inhibition observed with abciximab, but this difference did not attain statistical significance.


CONCLUSIONS
These results suggest that recombinant CD39 holds potential as antithrombotic agent, with the potential to achieve antiplatelet effects similar to that observed with abciximab.
Sampram
Ellis S K
ES
Department of Vascular Surgery, The Cleveland Clinic Foundation, Desk S40, 9500 Euclid Ave, Cleveland, Ohio 44195, USA.
Ouriel
Kenneth
K
D000077284:Abciximab; D000251:Adenosine Triphosphatases / Q000187:drug effects / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D015703:Antigens, CD / Q000187:drug effects / Q000378:metabolism; D001081:Apyrase / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005337:Fibrin / Q000187:drug effects / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006493:Heparin / Q000008:administration & dosage; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000008:administration & dosage; D010477:Perfusion; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011138:Polytetrafluoroethylene / Q000008:administration & dosage; D012995:Solubility; D013223:Statistics as Topic; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015415:Biomarkers; D005343:Fibrinolytic Agents; D007140:Immunoglobulin Fab Fragments; D010975:Platelet Aggregation Inhibitors; D005337:Fibrin; D011138:Polytetrafluoroethylene; D006493:Heparin; D000251:Adenosine Triphosphatases; D001081:Apyrase; C067869:CD39 antigen; D000077284:Abciximab