The effects of oestrogen administration on the plasma free protein S and C4b-binding protein.
This study was undertaken to evaluate the effects of oestrogen administration (low dose as an oral contraceptive or higher dose as a hormone replacement therapy) on the levels of plasma free protein S and C4b-binding protein. The participants were 59 women aged 18-49 years, divided into 2 groups: A and B. Group A was composed of 22 post-menopausal women on a hormonal replacement therapy programme (HRT) consisting of 2 mgs daily oestradiol valerate for 21 days. Group B was divided into subgroup B1: 18 women who had been on oral contraceptive for at least one year and subgroup B2 (control): 17 women who were not pregnant and not taking any oral contraceptive. In this study were also included two young women who both suffered from severe thromboembolic disease a few months after initiation of oral contraceptive. The first was 25 years old, with congenital moderately decreased prekallikrein (activity and antigen 40% and 45% respectively) and the second was a 21 year-old woman with congenital moderately decreased plasminogen activity and antigen 45%). In both cases, family members with similarly reduced levels of prekallikrein (PK) and plasminogen (PLG) respectively were free from any thromboembolic disease and had normal protein S levels. In Group A, 22 women at the end of the first cycle of treatment, had lower levels of free protein S (p less than 0.001) than before the initiation of HRT. In subgroup B1, the levels of free protein S were found to be significantly lower than in subgroup B2 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Melissari
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E
Thrombosis Research Unit, King's College School of Medicine & Dentistry, London.
Kakkar
V V
VV
D000293:Adolescent; D000328:Adult; D002352:Carrier Proteins / Q000097:blood*; D003181:Complement C4 / Q000032:analysis*; D003169:Complement Inactivator Proteins; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D004958:Estradiol / Q000009:adverse effects; D004967:Estrogens / Q000009:adverse effects*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D017293:Protein S
D002352:Carrier Proteins; D003181:Complement C4; D003169:Complement Inactivator Proteins; D003278:Contraceptives, Oral, Hormonal; D004967:Estrogens; D006023:Glycoproteins; D017293:Protein S; D004958:Estradiol