Functional and immunologic protein S in normal pregnant women and in full-term newborns.
Total and free protein S antigen and C4b-binding protein (C4bp) were determined by rocket immuno-electrophoresis, and functional protein S was assayed by a coagulation method, throughout pregnancy and normal puerperium and in a group of normal full-term newborns (FTN). The functional protein S assay is based on a modification of the APTT, using a mixture of test sample, protein S deficient plasma, activated protein C, phospholipids and calcium. This protein S functional assay is specific for protein S since the APTT prolongation by normal plasma was abolished by incubation of plasma with monospecific, rabbit anti-protein S IgG. The ratios of functional protein S/free protein S antigen in healthy men (n = 13) and women (n = 14) were 1.0 +/- 0.13 (mean +/- SD) and 1.03 +/- 0.20, respectively. During pregnancy there is a decrease in functional protein S and a progressive decrease in total and free protein S antigen, with a functional/free protein S ratio of 0.75 +/- 0.28 in the third trimester of pregnancy (n = 16). In early puerperium the functional protein S level was lower than the free protein S antigen level (ratio about 0.5). In the FTN group, the free protein S level was 39% and protein S activity was about 70% that of adults, with a functional/free protein S ratio of 1.84 +/- 0.31. C4bp values were 23.5 +/- 10.3% in the FTN group, and crossed immunoelectrophoresis showed that in this group the major protein S peak corresponded to free protein S.(ABSTRACT TRUNCATED AT 250 WORDS)
Fernández
J A
JA
Research Center, Hospital La Fe, Valencia, Spain.
Estellés
A
A
Gilabert
J
J
España
F
F
Aznar
J
J
D000328:Adult; D001780:Blood Coagulation Tests; D005260:Female; D006023:Glycoproteins / Q000097:blood* / Q000502:physiology; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D007231:Infant, Newborn / Q000097:blood*; D008297:Male; D011247:Pregnancy / Q000097:blood*; D017293:Protein S; D015203:Reproducibility of Results
D006023:Glycoproteins; D017293:Protein S