Ulrich Abildgaard

Antithrombin-III concentration and ABO blood-groups.

An association between blood-group A and an increased risk of thromboembolic disease has been suggested. During blood coagulation antithrombin III (At-III) is partly consumed and the At-III level is higher in the plasma than in the serum. Pulmonary embolism diffuse intravascular coagulation and the use of oral contraceptives are associated with lowered levels of At-III. Normalization of the At-III in response to anticoagulant therapy suggests that the low levels in thromboembolic disease may be due to increased consumption of At-III by complex formation of the thrombin and activated factor x. If individuals of blood group A more often have thrombosis caused by activation of larger amounts of coagulation factors (and/or higher frequency of events) than those of type 0 this might be reflected in lower At-III levels. Such a correlation was found with ABO groups. The mean At-III concentration in blood group A-1 donors was significantly lower than in the other blood groups including A-2 donors. Even when blood groups A-1 and A-2 are pooled the mean value is lower than in group 0. It was concluded that At-III determination is a sensitive method for estimation of intravascular coagulation.

ORAL CONTRACEPTIVES AND LOW ANTITHROMBIN-III CONCENTRATION

In response to concern over the legitimacy of laboratory techniques for estimating progressive antithrombin activity as predicted in thrombotic and prethrombotic conditions it is contended that present immunochemical methods using an electrophoretic technique are well suited for estimation of antithrombin-III in large numbers of samples and the results can be obtained within 3 hours. Cyclical changes in antithrombin-III were found in women using combined estrogen-progestagen oral contraceptives and abnormal antithrombin-III concentrations were found in pregnant (prethrombotic) and pulmonary embolotic (thrombotic) women.

Comparison of Low Molecular Weight Heparin vs. Unfractionated Heparin in Gynecological Surgery

Abstract. In a double‐blind, randomized trial, the antithrombotic effect and haemorrhagic complications of low molecular weight heparin (LMWH) (Heparin fragment 2165, KabiVitrum) and unfractionated heparin (UH) were compared. LMWH (5000 anti‐XaU) was injected every 24 h, UH (5000 IU) every 12 h; both drugs by subcutaneous injection. During 1984–85, 215 patients were examined clinically and by plethysmography. Venography was performed whenever DVT was suspected. None of the patients proved to have DVT. Bleeding complications were found in 54% of the cases. The LMWH group had a statisticaly significant predominance of bleeding complications as reflected by wound haematomas (p = 0.02) and the number of blood transfusions (p = 0.02). The heparin concentration was higher in the LMWH group (mean 0.13 IU/ml) than in the UH group (mean 0.13 IU/ml) measured 2 h after the injection. In the doses administered, LMWH and UH seem effective in the prevention of thrombosis. The increased bleeding tendency in the LMWH group probably was a concequence of the to high dosage.

Comparison of low molecular weight heparin vs. unfractionated heparin in gynecological surgery: II: Reduced dose of low molecular weight heparin

In a double blind, randomized trial the hemorrhagic complications of a reduced dose of low molecular weight heparin (LMWH) (Fragmin, KabiPharmacia) were compared to those of the conventional dose of unfractionated heparin (UH). 2500 anti‐XaU of LMWH was given once daily and UH in a dose of 5000 anti‐XaU twice daily. During a one year period 141 patients undergoing gynecological surgery were included in this study. The patients were examined clinically for hematomas and for deep venous thrombosis (DVT) on the third and fifth day. Venography was performed when DVT was suspected. No patients developed clinical DVT. One woman in the LMWH group had pulmonary embolism 3 days after the prophylaxis was stopped. Two women in the LMWH group died, one from a stroke on day 2, one from cancer on day 39. There was no significant difference in serious bleeding complications between the two regimens, 20% in the LMWH group and 14% in the UH group. Even with the reduced dose of LMWH the mean plasma concentration of heparin in the LMWH group was higher (mean 0.14 anti‐XaU/ml) than in the UH group (0.029 anti‐XaUlml) 3 hours after injection on the 2nd postoperative day. A reduced dose of LMWH (2500 anti XaU once daily) does not cause more bleeding complications than the conventional heparin rcgimen to prevent thrombosis, as was the case in our previous study with 5000 anti Xa17 of LMWH once daily.

Antithrombin III concentration in women using low-dosage progestogen for contraception

n To determine antithrombin III levels in women using chlormadinone acetate, 59 women took 0.5 mg daily, while a control group (53) took no oral contraceptive. The single radial immuno diffusion method was used to determine amounts of antithrombin III in the serum and plasma. Results showed that the treated women had significantly higher levels of antithrombin III than the others, both in serum (7.64%) and plasma (10.63%). If age differences (mean of 2.57 years) had been corrected for the groups, the level of difference would have been even greater. The greater concentration of antithrombin III, as the result of chlormadinone acetate usage, may mean more protection against thromboembolic disease.n

Concentration of Antithrombin III during combined and progestogen-only oral contraceptive treatment.

Oral contraceptive treatment with a low daily dose of Norethindrone did not lower the Antithrombin‐III level in serum. This was in contrast to what was found in subjects taking estrogen‐progestogen agents.

Comparison of Low Molecular Weight Heparin Versus Unfractionated Heparin in Gynecological Surgery. II: Reduced Dose of Low Molecular Weight Heparin

In a double blind, randomized trial the hemorrhagic complications of a reduced dose of low molecular weight heparin (LMWH) (Fragmin, KabiPharmacia) were compared to those of the conventional dose of unfractionated heparin (UH). 2500 anti-XaU of LMWH was given once daily and UH in a dose of 5000 anti-XaU twice daily. During a one year period 141 patients undergoing gynecological surgery were included in this study. The patients were examined clinically for hematomas and for deep venous thrombosis (DVT) on the third and fifth day. Venography was performed when DVT was suspected. No patients developed clinical DVT. One woman in the LMWH group had pulmonary embolism 3 days after the prophylaxis was stopped. Two women in the LMWH group died, one from a stroke on day 2, one from cancer on day 39. There was no significant difference in serious bleeding complications between the two regimens, 20% in the LMWH group and 14% in the UH group. Even with the reduced dose of LMWH the mean plasma concentration of heparin in the LMWH group was higher (mean 0.14 anti-XaU/ml) than in the UH group (0.029 anti-XaU/ml) 3 hours after injection on the 2nd postoperative day. A reduced dose of LMWH (2500 anti XaU once daily) does not cause more bleeding complications than the conventional heparin regimen to prevent thrombosis, as was the case in our previous study with 5000 anti XaU of LMWH once daily.