scholarly journals High protein S activity due to C4b-binding protein deficiency in a 34-year-old Surinamese female with ischemic retinopathy

2018 ◽  
Vol 6 (5) ◽  
pp. 935-938
Author(s):  
René Mulder ◽  
Jeroen K. de Vries ◽  
Rogier P.H.M. Müskens ◽  
André B. Mulder ◽  
Michaël V. Lukens
Keyword(s):  
Binding Protein ◽  
Protein S ◽  
Protein Deficiency ◽  
High Protein ◽  
Ischemic Retinopathy ◽  
Protein S Activity

scholarly journals Functional and immunologic protein S levels are decreased during pregnancy

Blood ◽  
1986 ◽  
Vol 68 (4) ◽  
pp. 881-885 ◽  
Author(s):  
PC Comp ◽  
GR Thurnau ◽  
J Welsh ◽  
CT Esmon
Keyword(s):  
Pregnant Women ◽  
Total Protein ◽  
Postpartum Period ◽  
Protein C ◽  
Binding Protein ◽  
Activated Protein C ◽  
Protein S ◽  
Functional Protein ◽  
Protein Levels ◽  
Protein S Activity

Abstract Protein S, is a natural anticoagulant protein which serves as a cofactor for activated protein C. During pregnancy and in the postpartum period, functional protein S levels are significantly reduced (38% +/- 17.3%, mean +/- 1 SD) when compared to nonpregnant females (97% +/- 31.6%) (P less than 0.001). In plasma an equilibrium exists between functionally active free protein S and protein S complexed with C4b-binding protein, which is functionally inactive. As a result of this equilibrium either a decreased level of total protein S antigen or an elevation of C4b-binding protein could lead to reduced protein S activity. C4b-binding protein levels measured by enzyme- linked immunoassay are not significantly different in pregnant women versus nonpregnant controls (103.5% +/- 21.2% v 100% +/- 16.9%). However, during pregnancy and in the postpartum period, total protein S levels are reduced (68% +/- 10.7%) compared to nonpregnant controls (100% +/- 17.0%). This difference is significant at P less than 0.001. These data demonstrated that the reduction in protein S activity observed during pregnancy is a result of reduced total protein S antigen.

scholarly journals Free protein S levels are elevated in familial C4b-binding protein deficiency

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2527-2529 ◽  
Author(s):  
PC Comp ◽  
J Forristall ◽  
CD West ◽  
RG Trapp
Keyword(s):  
Total Protein ◽  
Protein C ◽  
Binding Protein ◽  
Activated Protein C ◽  
Protein S ◽  
Protein Deficiency ◽  
Normal Range ◽  
Free Protein ◽  
Protein Levels

Abstract In plasma, 40% of the protein S is free and functions as a cofactor for the anticoagulant effects of activated protein C. The remaining 60% of protein S is complexed to C4b-binding protein and is functionally inactive. A family with hereditary C4b binding protein deficiency has been identified with C4b-binding protein levels in an affected father and daughter of 37 micrograms/mL and 23 micrograms/mL, respectively; these values are significantly below the normal range for this protein of 180 micrograms/mL +/- 44 micrograms/mL (mean +/- 2 SD). The total protein S (free + bound) is normal in these individuals (23.2 micrograms/mL and 17.8 micrograms/mL, respectively; normal 19.1 micrograms/mL +/- 6.0 micrograms/mL). The free protein S levels are markedly increased at 22.5 micrograms/mL and 17.4 micrograms/mL, respectively (normal 5.9 micrograms/mL +/- 2.4 micrograms/mL). This experiment of nature shows that total protein S levels in plasma are not affected by the absence of C4b-binding protein and that chronic elevation of free protein S is not associated with increased hemorrhagic tendencies.

scholarly journals Functional and immunologic protein S levels are decreased during pregnancy

Blood ◽  
1986 ◽  
Vol 68 (4) ◽  
pp. 881-885 ◽  
Author(s):  
PC Comp ◽  
GR Thurnau ◽  
J Welsh ◽  
CT Esmon
Keyword(s):  
Pregnant Women ◽  
Total Protein ◽  
Postpartum Period ◽  
Protein C ◽  
Binding Protein ◽  
Activated Protein C ◽  
Protein S ◽  
Functional Protein ◽  
Protein Levels ◽  
Protein S Activity

Protein S, is a natural anticoagulant protein which serves as a cofactor for activated protein C. During pregnancy and in the postpartum period, functional protein S levels are significantly reduced (38% +/- 17.3%, mean +/- 1 SD) when compared to nonpregnant females (97% +/- 31.6%) (P less than 0.001). In plasma an equilibrium exists between functionally active free protein S and protein S complexed with C4b-binding protein, which is functionally inactive. As a result of this equilibrium either a decreased level of total protein S antigen or an elevation of C4b-binding protein could lead to reduced protein S activity. C4b-binding protein levels measured by enzyme- linked immunoassay are not significantly different in pregnant women versus nonpregnant controls (103.5% +/- 21.2% v 100% +/- 16.9%). However, during pregnancy and in the postpartum period, total protein S levels are reduced (68% +/- 10.7%) compared to nonpregnant controls (100% +/- 17.0%). This difference is significant at P less than 0.001. These data demonstrated that the reduction in protein S activity observed during pregnancy is a result of reduced total protein S antigen.

Free protein S levels are elevated in familial C4b-binding protein deficiency

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2527-2529
Author(s):  
PC Comp ◽  
J Forristall ◽  
CD West ◽  
RG Trapp
Keyword(s):  
Total Protein ◽  
Protein C ◽  
Binding Protein ◽  
Activated Protein C ◽  
Protein S ◽  
Protein Deficiency ◽  
Normal Range ◽  
Free Protein ◽  
Protein Levels

In plasma, 40% of the protein S is free and functions as a cofactor for the anticoagulant effects of activated protein C. The remaining 60% of protein S is complexed to C4b-binding protein and is functionally inactive. A family with hereditary C4b binding protein deficiency has been identified with C4b-binding protein levels in an affected father and daughter of 37 micrograms/mL and 23 micrograms/mL, respectively; these values are significantly below the normal range for this protein of 180 micrograms/mL +/- 44 micrograms/mL (mean +/- 2 SD). The total protein S (free + bound) is normal in these individuals (23.2 micrograms/mL and 17.8 micrograms/mL, respectively; normal 19.1 micrograms/mL +/- 6.0 micrograms/mL). The free protein S levels are markedly increased at 22.5 micrograms/mL and 17.4 micrograms/mL, respectively (normal 5.9 micrograms/mL +/- 2.4 micrograms/mL). This experiment of nature shows that total protein S levels in plasma are not affected by the absence of C4b-binding protein and that chronic elevation of free protein S is not associated with increased hemorrhagic tendencies.

A Functional Protein S and Microlatex Immunoassay for Protein S and C4b-Binding Protein on the Automated Coagulation Laboratory (ACL) 300 Plus

1996 ◽  
Vol 2 (4) ◽  
pp. 268-275 ◽  
Author(s):  
Shinichiro Hirokawa ◽  
Eberhard F. Mammen
Keyword(s):  
Light Scattering ◽  
Functional Activity ◽  
Binding Protein ◽  
Protein S ◽  
Enzyme Linked Immunosorbent Assay ◽  
Functional Assay ◽  
Functional Protein ◽  
Time Saving ◽  
Normal Ranges ◽  
Protein S Activity

Protein S can be determined by functional or immunological assays. Electroimmunodiffusion (EID) or enzyme immunoassays (enzyme-linked immunosorbent assay; ELISA) are the commonly employed techniques for measuring protein S and C4b-binding protein (C4b- BP) immunologically. Procedures for these assays are time-consuming and labor-intensive. The introduction of microlatex immunoassays (LIATEST system; Diagnos tica Stago, Asnieres-Sur-Seine, France) has provided an alternative for rapid and reliable immunological determi nation. We have placed the microlatex immunoassay for total and free protein S (TPS, FPS) and C4b-BP, using the light-scattering mode, on the Automated Coagulation Laboratory (ACL) 300 Plus (Instrumentation Laboratory, Lexington, MA, U.S.A.). We also placed a functional activity assay of protein S (STACLOT protein S; Amer ican Bioproducts, Parsippany, NJ, U.S.A.) on the ACL 300 Plus. The performance characteristics for the assays yielded a within-run coefficient of variance (CV) of 2.5- 4.6% ( n = 13) for TPS, 4.0-4.8% ( n = 13) for FPS, 1.9- 3.0% ( n = 11) for C4b-BP, and 2.3-5.9% for protein S activity. The interrun CV was 2.1-5.7% ( n = 24), 3.7- 7.0% ( n = 12), 2.6-7.0% ( n = 16), and 4.0-8.4% ( n = 27), respectively. Analytical recovery was 94-109, 97-100, 91-103, and 99-103%, respectively. The normal ranges determined on plasmas from 30 healthy individuals were 113 ± 37 (mean ± 2 SD) for TPS, 106 ± 35 for FSP, 111 ± 22 for C4b-BP, and 107 ± 34 for protein S activity. The results for the microlatex immunoassay and either the EID or the ELISA methods showed excellent correla tions for FPS and C4b-BP; the correlations between LIATEST and either EID or ELISA for TPS were also relatively high. The functional activity of protein S cor related well with FPS. Microlatex immunoassays, using the light-scattering mode for TPS, FPS, or C4b-BP, and the functional assay of protein S can be adapted on the ACL 300 Plus system with a high accuracy and reproduc ibility and with considerable time saving.

Plasma Components which Interfere with Ristocetin-induced Platelet Aggregation

1975 ◽  
Vol 33 (03) ◽  
pp. 540-546 ◽  
Author(s):  
Robert F Baugh ◽  
James E Brown ◽  
Cecil Hougie
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Plasma Proteins ◽  
Binding Protein ◽  
Plasma Heating ◽  
Protein S ◽  
Fold Increase ◽  
Normal Human Plasma ◽  
Preliminary Examination ◽  
Normal Human

SummaryNormal human plasma contains a component or components which interfere with ristocetin-induced platelet aggregation. Preliminary examination suggests a protein (or proteins) which binds ristocetin and competes more effectively for ristocetin than do the proteins involved in ristocetin-induced platelet aggregation. The presence of this protein in normal human plasma also prevents ristocetin-induced precipitation of plasma proteins at levels of ristocetin necessary to produce platelet aggregation (0.5–2.0 mg/ml). Serum contains an apparent two-fold increase of this component when compared with plasma. Heating serum at 56° for one hour results in an additional 2 to 4 fold increase. The presence of a ristocetin-binding protein in normal human plasma requires that this protein be saturated with ristocetin before ristocetin-induced platelet aggregation will occur. Variations in the ristocetin-binding protein(s) will cause apparent discrepancies in ristocetin-induced platelet aggregation in normal human plasmas.

A New Functional Assay for Human Protein S Activity Using Activated Factor Vas Substrate

1989 ◽  
Vol 62 (04) ◽  
pp. 1144-1145 ◽  
Author(s):  
Martine Wolf ◽  
Catherine Boyer-Neumann ◽  
Jean-Luc Martinoli ◽  
Catherine Leroy-Matheron ◽  
Amiral Jean ◽  
...  
Keyword(s):  
Protein S ◽  
Human Protein ◽  
Functional Assay ◽  
Protein S Activity

Comparative evaluation of reagents for measuring protein S activity: possibility of harmonization

2021 ◽  
Author(s):  
Masahiro Ieko ◽  
Taeko Hotta ◽  
Kumiko Watanabe ◽  
Tomoko Adachi ◽  
Sawako Takeuchi ◽  
...  
Keyword(s):  
Comparative Evaluation ◽  
Protein S ◽  
Protein S Activity
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