Comparability of sample results and commutability of reference materials among different measurement procedures for protein C activity assays

SummaryA simple and fast method for the quantitative determination of protein C activity in plasma is here described. The first step consists in the conversion of protein C in the test sample into activated protein C by means of an activator isolated from Southern Copperhead venom. Subsequently, the degradation of factor Va, in presence of protein C-deficient plasma, is measured by the prolongation of the prothrombin time which is proportional to the amount of protein C in the sample. The dose-response curve showed a linear relationship from 6 to 150% protein C activity and the inter- and intra-assay reproducibility was 3.5% and 5.6% respectively. In normal subjects, a mean of protein C level of 98 ± 15% of normal pooled plasma was found. Comparison with the anticoagulant assay in samples of patients with oral anticoagulant, liver cirrhosis, disseminated intravascular coagulation and severe preeclampsia revealed an excellent correlation (r = 0.94, p <0.001). Also, a similar correlation (r = 0.93, p <0.001) existed between amidolytic assay and the method here proposed for all the samples studied without including the oral anticoagulant group. These results allowed us to infer that this method evaluates the ability of protein C to interact with protein S, phospholipids, calcium ions and factor Va.

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High Levels of Plasma Protein C in Nephrotic Syndrome

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661225 ◽

1985 ◽

Vol 53 (01) ◽

pp. 005-007 ◽

Cited By ~ 16

Author(s):

I Pabinger-Fasching ◽

K Lechner ◽

H Niessner ◽

P Schmidt ◽

E Balzar ◽

...

Keyword(s):

Nephrotic Syndrome ◽

Plasma Protein ◽

Protein C ◽

Inverse Correlation ◽

Elevated Plasma ◽

Significant Inverse Correlation ◽

At Iii ◽

Thrombotic Tendency ◽

Protein C Activity

SummaryIn patients with severe nephrotic syndrome determinations of plasma protein C : Ag levels (8 patients: 5 adults, 3 children) and protein C activity (3 out of 8 patients) revealed significantly elevated plasma protein C concentrations. Furthermore we observed a significant inverse correlation of protein C : Ag to AT III : Ag levels. No protein C : Ag could be detected in the urine of two patients studied. We conclude from our data, that changes of plasma protein C do not contribute to the high thrombotic tendency in nephrotic syndrome.

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HAEMOSTATIC CHANGES INDUCED BY TWO LOW DOSE TRIPHASIC ORAL CONTRACEPTIVES

10.1055/s-0038-1643825 ◽

1987 ◽

Author(s):

S J Machin ◽

I J Mackie ◽

K Walshe ◽

M D Gillmer

Keyword(s):

Oral Contraceptives ◽

Protein C ◽

Low Dose ◽

Factor Vii ◽

Cycle Period ◽

Factor Xii ◽

Factor X ◽

Combined Oral Contraceptives ◽

First Time ◽

Protein C Activity

The haemostatic system was investigated in 26 women taking cyclically administered triphasic combined oral contraceptives for the first time during their first six cycles. Fourteen women received Logynon (mean dose 32.4μg ethinyloestradiol, 92pg progestagen) and 12 received SHD 415G (Schering) which contains a mean dosage of 32.4μg ethinyloestradiol and 78pg gestodene, a recently developed progesterone. The Logynon group showed a significant increase (p<0.005) in fibrinogen (pre-mean 284.4 g/1; after 1 cycle 347.3 g/1, after 6 cycles 318.6 g/1) , factor VII (65.8 u/1 to 73.9 u/1 to 83.2 u/1), factor XII (1.74 u/1 to 2.41 u/1, to 2.25 u/1), plasminogen (100.9 u/1 to 135.1 u/1 to 126.3 u/1); decrease in ATIII (115.9 u/1 to 103.1 u/1 to 93.4 u/1) but no significant change in factor X (98.4 u/1 to 108.9 u/1 to 102.4) or protein C (0.85 u/1 to 0.88 u/1 to 0.94 u/1) activity. The SHD 415G group showed similar changes with an increase in fibrinogen (247.9 g/1 to 330.8 g/1 to 373 .1 g/1), factor VII (63.1 u/1 to 73.1 u/1 to 90.3 u/1, factor X (98.3 u/1 to 112.0 u/1 to 124.4 u/1), factor XII (1.46 u/1, to 1.93 u/1, to 2.03 u/1), plasminogen (110.8 u/1 to 125.4 u/1 to 136.7 u/1); decrease in ATIII (113.1 u/1 to 96.3 u/1 to 89.7 u/1), but no change in protein C (0.84 u/1 to - 0.78 u/1 to 0.85 u/1) activity. These changes were apparent after the first cycle of therapy and the differences were maintained over the six cycle period. There was no increase in protein C activity despite changes in the other vitamin K dependent proteins factors VII and X. Both low oestrogen dose triphasic pills caused similar prothrombotic changes which were not modified by the new progesterone, gestodene.

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Protein C activity in dogs envenomed by Vipera palaestinae

Toxicon ◽

10.1016/j.toxicon.2014.05.010 ◽

2014 ◽

Vol 87 ◽

pp. 38-44 ◽

Cited By ~ 2

Author(s):

Gil Hadar ◽

Efrat Kelmer ◽

Gilad Segev ◽

Yaron Bruchim ◽

Itamar Aroch

Keyword(s):

Protein C ◽

Protein C Activity

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Assessment of protein C antigen, free protein S, and protein C activity in pregnancy: A cross-sectional study of pregnant Nigerian women

International Journal of Medicine and Health Development ◽

10.4103/ijmh.ijmh_21_20 ◽

2021 ◽

Vol 26 (2) ◽

pp. 118

Author(s):

TheresaUkamaka Nwagha ◽

HelenChioma Okoye ◽

AngelaOgechukwu Ugwu ◽

LisaIfenyinwa Eweputanna ◽

EmmanuelOnyebuchi Ugwu

Keyword(s):

Protein C ◽

Protein S ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Nigerian Women ◽

Free Protein ◽

Protein C Activity ◽

In Pregnancy

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Protein C activity value as a prognostic factor in sepsis-induced disseminated intravascular coagulation

Journal of the Japanese Society of Intensive Care Medicine ◽

10.3918/jsicm.21.614 ◽

2014 ◽

Vol 21 (6) ◽

pp. 614-622

Author(s):

Toshihiro Sakurai ◽

Shu Yamada ◽

Maki Kitada ◽

Satoshi Hashimoto ◽

Shoko Hashimoto ◽

...

Keyword(s):

Prognostic Factor ◽

Disseminated Intravascular Coagulation ◽

Protein C ◽

Intravascular Coagulation ◽

Protein C Activity

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Effects of dermatan sulfate derivatives on platelet surface P-selectin expression and protein C activity in blood of inflammatory bowel disease patients

World Journal of Gastroenterology ◽

10.3748/wjg.v10.i23.3485 ◽

2004 ◽

Vol 10 (23) ◽

pp. 3485 ◽

Cited By ~ 4

Author(s):

Sheng-Li Ji

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Protein C ◽

Dermatan Sulfate ◽

Platelet Surface ◽

Inflammatory Bowel ◽

Protein C Activity

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Protein C activity and antigen

Laboratory Techniques in Thrombosis - a Manual ◽

10.1007/978-94-011-4722-4_14 ◽

1999 ◽

pp. 129-139 ◽

Cited By ~ 1

Author(s):

R. M. Bertina

Keyword(s):

Protein C ◽

Protein C Activity

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Coagulation Activation in Extracorporeal Hemodialysis

The International Journal of Artificial Organs ◽

10.1177/039139889702000307 ◽

1997 ◽

Vol 20 (3) ◽

pp. 163-165 ◽

Cited By ~ 6

Author(s):

M. Camici ◽

L. Evangelisti ◽

P. Balestri ◽

L. Cioni ◽

P. Fundi ◽

...

Keyword(s):

Protein C ◽

Serum Lipoprotein ◽

Factor Vii ◽

Maintenance Hemodialysis ◽

Factor X ◽

Lipoprotein A ◽

Activity Factor ◽

Before And After ◽

Protein C Activity

The Authors evaluated the behavior of protein C activity, factor X and factor VII coagulant activity and serum lipoprotein(a) before and after dialytic treatment in patients on maintenance hemodialysis. They observed depressed protein C activity that significantly (p<0.005) increased and became normal immediately after hemodialysis while factor X and factor VII increased (p<0.01; p<0.05) despite heparinization together with amount of serum lipoprotein(a). In vitro incubation (30 'at 37°C) of uremic and healthy blood showed a decrease in serum lipoprotein(a) concentration. After heparin addition (final concentration 0.5 U/ml) lipoprotein(a) increased in the uremic blood only. The clinical and physiopathological implications of these results are discussed.

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