The classical and alternate pathways of complement in oral contraceptive users.
Whole complement (CH50), C3, C4, the alternate pathway activity of complement (APH50) and factor B were measured in 159 women currently taking oral contraceptives and in 186 women who were not taking the pill. The mean levels of all components of the complement, except APH50, were found to be elevated in current users compared to non-users. The elevation in serum levels was seen in the first year after initiation of oral contraceptive use. Thereafter, levels changed little with duration of use. Among women who stopped using oral contraceptives, complement levels were similar to those of women who had never used the pill. Results appeared to be similar irrespective of the type of progestagen included in the oral contraceptive. These data provide support for the view that oral contraceptives have no adverse effect on the classical and the alternate pathways of complement.
Delâge
J M
JM
Centre d'hématologie et d'immunologie clinique, Hôpital du Saint-Sacrement, Québec, Canada.
Lehner-Netsch
G
G
Brisson
J
J
D000293:Adolescent; D000328:Adult; D003167:Complement Activation / Q000187:drug effects*; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D011415:Complement Factor B / Q000032:analysis; D003170:Complement Pathway, Alternative / Q000187:drug effects*; D003171:Complement Pathway, Classical / Q000187:drug effects*; D003165:Complement System Proteins / Q000032:analysis; D003276:Contraceptives, Oral / Q000494:pharmacology*; D005260:Female; D006801:Humans; D013997:Time Factors
D003176:Complement C3; D003181:Complement C4; D003276:Contraceptives, Oral; D003165:Complement System Proteins; D011415:Complement Factor B