Download PDF
Thromb Haemost 1992; 68(02): 149-154
DOI: 10.1055/s-0038-1656340
Original Article
Schattauer GmbH Stuttgart

Multicenter Evaluation of Three Commercial Methods for Measuring Protein S Antigen

Armando Tripodi
1   The A. Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milano, Milano, Italy
,
Rogier M Bertina
2   The Hemostasis and Thrombosis Research Unit, University Hospital, Leiden, The Netherlands
,
Jacqueline Conard
3   The Laboratoire Central d'Hematologie, Hôtel Dieu, Paris, France
,
Ingrid Pabinger
4   The I. Medizinische Universitätsklinik, Vienna, Austria
,
Nuria Sala
5   The Servei de Hematologia, Hospital de la Santa Creu I Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
,
Pier Mannuccio Mannucci
1   The A. Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milano, Milano, Italy
› Author Affiliations
Further Information

Publication History

Received 01 November 1991

Accepted after revision 25 March 1992

Publication Date:
03 July 2018 (online)

Also available at
  PDF Download  Permissions and Reprints

Summary

This collaborative study was designed to assess the performance of commercial methods for protein S (PS) antigen measurement. Twenty-five different samples were distributed deep-frozen (24 plasmas) or lyophilized (one plasma) to five laboratories. They were analyzed blind in each laboratory by the method used locally and by three commercial methods which included two electroimmunoassays (EIA), Asseraplate-PS (Diagnostica Stago), Rellplate-S (American Diagnostica) and an ELISA system, Asserachrom-PS (Diagnostica Stago). 1. Reproducibility. Average between-laboratory coefficients of variation were 15.4%, 17.6% and 25.3% for Asserachrom-PS, Asseraplate-PS and Rellplate-S. 2. Specificity. Results of all methods showed that PS is underestimated when C4b binding protein is high. This influence was particularly evident for the ELISA Asserachrom-PS and disappeared when the antibody-antigen incubation period was prolonged to overnight. 3. Sensitivity. In all laboratories ELISA detected even the lowest PS concentration (4 U/dl), whereas the two EIAs were less sensitive (lower detection limit 14 U/dl). All methods and laboratories correctly diagnosed a plasma sample from a PS congenitally deficient patient. Conclusions. This study shows that better standardization of PS immunoassays is necessary to improve accuracy and reduce interlaboratory variability before a candidate plasma standard can be successfully calibrated in an international collaborative study.

 

  • References

  • 1 Walker FJ. The regulation of activated protein C by a new protein: a possible function for bovine protein S. J Biol Chem 1980; 255: 5521-5524
    PubMedGoogle Scholar
  • 2 Walker FJ. Protein S and the regulation of activated protein C. Semin Thromb Hemostas 1984; 10: 131-138
    Article in Thieme ConnectPubMedGoogle Scholar
  • 3 Dahlbäck B, Stenflo J. High molecular weight complex in human plasma between vitamin-K dependent protein S and complement component C4b-binding protein. Proc Natl Acad Sci USA 1981; 78: 2512-2516
    CrossrefPubMedGoogle Scholar
  • 4 Dahlbäck B. Purification of human C4b-binding protein and formation of its complex with vitamin-K dependent protein S. Biochem J 1983; 209: 847-856
    CrossrefPubMedGoogle Scholar
  • 5 Comp PC, Nixon RR, Cooper MR, Esmon CT. Familial protein S deficiency is associated with recurrent thrombosis. J Clin Invest 1984; 74: 2082-2088
    CrossrefPubMedGoogle Scholar
  • 6 Comp PC, Esmon CT. Recurrent venous thromboembolism in patients with a partial deficiency of protein S. N Engl J Med 311: 1522-1528
    PubMedGoogle Scholar
  • 7 Schwarz HP, Fisher M, Hopmeier P, Batard MA, Griffin JH. Plasma protein S deficiency in familial thrombotic disease. Blood 1984; 64: 1297-300
    PubMedGoogle Scholar
  • 8 Broekmans AW, Bertina RM, Reinalda-Poot J, Engesser L, Muller HP, Leeuw JA, Michiels JJ, Brommer EJP, Briët E. Hereditary protein S deficiency and venous thromboembolism. A study in three Dutch families. Thromb Haemostas 1985; 53: 273-277
    PubMedGoogle Scholar
  • 9 Mannucci PM, Tripodi A. Laboratory screening of inherited thrombotic syndromes. Thromb Haemostas 1987; 57: 247-251
    PubMedGoogle Scholar
  • 10 Preda L, Tripodi A, Valsecchi C, Lombardi A, Finotto E, Mannucci PM. A prothrombin time-based functional assay of protein S. Thromb Res 1990; 60: 19-32
    CrossrefPubMedGoogle Scholar
  • 11 Bertina RM, van Wijngaarden A, Reinalda-Poot J, Poort SR, Bom VJJ. Determination of plasma protein S. The protein cofactor of activated protein C. Thromb Haemostas 1985; 53: 268-272
    PubMedGoogle Scholar
  • 12 Malm J, Laurell M, Dahlbäck B. Changes in the plasma levels of vitamin-K dependent proteins C and S and of C4b-binding protein during pregnancy and oral contraception. Br J Haematol 1988; 68: 437-443
    CrossrefPubMedGoogle Scholar
  • 13 Deutz-Terlouw PP, Ballering L, van Wijngaarden A, Bertina RM. Two ELISA’s for measurement of protein S and their use in the laboratory diagnosis of protein S deficiency. Clin Chim Acta 1989; 186: 321-334
    PubMedGoogle Scholar
  • 14 Krachmalnicoff A, Tombesi S, Valsecchi C, Albertini A, Mannucci PM. A monoclonal antibody to human protein S used as the capture antibody for measuring total protein S by enzyme immunoassay. Clin Chem 1990; 36: 43-47
    PubMedGoogle Scholar
  • 15 Fair DS, Revak DJ. Quantitation of human protein S in the plasma of normal and warfarin treated individuals by radioimmunoassay. Thromb Res 1984; 36: 527-535
    CrossrefPubMedGoogle Scholar
  • 16 Comp PC, Thurnau GR, Welsh J, Esmon CT. Functional and immunological protein S levels are decreased during pregnancy. Blood 1986; 68: 881-885
    PubMedGoogle Scholar