Synthetic Hormones and Clot Formation

Mechanical and Physical Behavior of Fibrin Clot Formation and Lysis in Combined Oral Contraceptive Users

Combined oral contraceptives (COCs) are commonly prescribed and increase the risk of venous thromboembolism (VTE). We have previously found that two COCs, both containing drospirenone (DRSP) and ethinyl estradiol (EE), cause spontaneous fibrin formation in whole blood. The aim of this study was, therefore, to use platelet-poor plasma (PPP) from the same cohort of DRSP/EE users to determine the impact of these COCs on the fibrin component, specifically the fibrin clot viscoelasticity, turbidimetry, and biophysical traits. PPP from 25 females per test group and a control group (n = 25) were analyzed using thromboelastography (TEG), turbidimetry, and scanning electron microscopy. The results highlight abnormal fibrin clot formation, lysis, and architecture; DRSP/20EE showed the greatest effect. DRSP/EE use increased the fibrin fiber diameter and showed dense matted clots. Only when the influence of COCs on the structural properties and behavior of fibrin fibers during thrombus formation and lysis is better understood are we able to predict and prevent coagulopathies associated with these synthetic hormones. Clinical practitioners should take this into consideration for female patients that either have comorbidities, which could burden the coagulation system, or may be exposed to external factors that could increase their risk for VTE.

The Impact of Two Combined Oral Contraceptives Containing Ethinyl Estradiol and Drospirenone on Whole Blood Clot Viscoelasticity and the Biophysical and Biochemical Characteristics of Erythrocytes

Venous thrombosis is associated with combined oral contraceptive (COC) use. We investigated the impact of two ethinyl estradiol (EE) and drospirenone (DRSP) containing COCs (3 mg DRSP/20 µg EE and 3 µg DRSP/30 µg EE) on the viscoelasticity of whole blood clots along with the biophysical and biochemical characteristics of erythrocytes. Thromboelastography (TEG) analysis showed a tendency toward a hypercoagulable state in the COCs groups that was more pronounced with higher EE concentrations. Light microscopy and scanning electron microscopy (SEM) showed rouleaux formation of erythrocytes and alterations to the erythrocyte shape for both COC groups, which was attributed to membrane damage. SEM analysis showed spontaneous activation of fibrin and platelets in the COC groups, along with interactions between erythrocytes and platelets and/or fibrin. Confocal microscopy confirmed compromised membrane integrity in the COC groups compared to controls. Global thrombosis test analysis showed increased platelet activation and low thrombolysis in both COC groups when compared to controls. In conclusion, DRSP/EE formulations impact erythrocytes' biophysical and biochemical properties to cause a shift in hemostasis to a prothrombotic state. Although these effects are mostly subclinical the long-term effects and risks involved with the use of these hormones should be considered carefully for each individual.

Effect of Progesterone and Synthetic Progestins on Whole Blood Clot Formation and Erythrocyte Structure

Combined oral contraceptive (COC) use is a risk factor for venous thrombosis (VT) and related to the specific type of progestin used. VT is accompanied by inflammation and pathophysiological clot formation, that includes aberrant erythrocytes and fibrin(ogen) interactions. In this paper, we aim to determine the influence of progesterone and different synthetic progestins found in COCs on the viscoelasticity of whole blood clots, as well as erythrocyte morphology and membrane ultrastructure, in an in vitro laboratory study. Thromboelastography (TEG), light microscopy, and scanning electron microscopy were our chosen methods. Our results point out that progestins influence the rate of whole blood clot formation. Alterations to erythrocyte morphology and membrane ultrastructure suggest the presence of eryptosis. We also note increased rouleaux formation, erythrocyte aggregation, and spontaneous fibrin formation in whole blood which may explain the increased risk of VT associated with COC use. Although not all COC users will experience a thrombotic event, individuals with a thrombotic predisposition, due to inflammatory or hematological illness, should be closely monitored to prevent pathological thrombosis.

The Effect of Endogenous and Synthetic Estrogens on Whole Blood Clot Formation and Erythrocyte Structure

As erythrocyte and estrogens interact so closely and erythrocytes can indicate the healthiness of an individual, it is essential to investigate the effects of natural estrogens as well as synthetic estrogens on these cells. Whole blood samples were used for thromboelastography (TEG), light microscopy (LM), and scanning electron microscopy (SEM) investigation. Viscoelastic investigation with TEG revealed that estrogens affected the rate of clot formation without any significant effect on the strength or stability of the clot. Axial ratio analysis with LM showed a statistically significant increase in number of erythrocytes with decreased roundness. Morphological analysis with SEM confirmed the change in erythrocyte shape and revealed both ultrastructural membrane changes and erythrocyte interactions. As erythrocyte shape and membrane flexibility correlates to physiological functioning of these cells in circulation, these changes, indicative of possible eryptosis brought on by estrogens, when experienced by individuals with an underlying inflammatory or hematological illness, could impair erythrocyte functioning and even result in obstructions in circulation. In conclusion, we suggest that whole blood analysis with viscoelastic and morphological techniques could be used as assessment of the hematological healthiness of individuals using estrogens.