Scripps VIVO scripps research logo

  • Index
  • Log in
  • Home
  • People
  • Organizations
  • Research
  • Events
Search form

Determination of functional and antigenic protein-C inhibitor and its complexes with activated protein-C in plasma by ELISA's

Academic Article
uri icon
  • Overview
  • Identity
  • Additional Document Info
  • View All
scroll to property group menus

Overview

authors

  • Espana, F.
  • Griffin, John

publication date

  • September 1989

journal

  • Thrombosis Research  Journal

abstract

  • Enzyme-linked immunosorbent assays (ELISA's) were developed for the measurement of protein C inhibitor (PCI) antigen and activity and for its complexes with activated protein C (APC) in plasma. For PCI activity and antigen, APC or anti-PCI, respectively, was immobilized to microtiter plates and PCI bound was detected with labelled anti-PCI antibodies. For APC:PCI complexes, two different antibodies directed against protein C and PCI were used. The assays for PCI were calibrated with pooled normal human plasma (NHP) and with purified PCI, and for APC:PCI complexes with known concentrations of purified pre-formed complexes added to buffer or to plasma. The lower limit of sensitivity of the PCI activity and antigen assays was 10 ng/ml and 0.5 ng/ml, respectively and for plasma APC:PCI complexes 12 ng/ml. Mean coefficients of variation of 1.5% to 5.8% (intra-assay) and 2.1% to 9.8% (inter-assay) were found for the assays. For PCI antigen, a range of 56% to 162% of the NHP value was obtained in samples from 70 healthy donors (mean +/- SD = 98.6% +/- 23.1%). For PCI activity, the range was 59% to 148% (94.3% +/- 20.2). A good correlation (0.92) was obtained when both assays were compared. Plasma levels of APC:PCI complexes in 30 normals were under the detection limit (less than 12 ng/ml). In plasma samples from 10 patients with disseminated intravascular coagulation (DIC) PCI antigen concentrations were decreased (55.6% +/- 20%) and 8 of the patients had APC-PCI complex levels between 32 and 240 ng/ml (median, 35 ng/ml). After addition of 20 micrograms/ml APC to NHP or to protein C depleted plasma, 6.1 micrograms/ml complexes were recovered after 90 min incubation. Incubation of 10 micrograms/ml APC with NHP in the presence of 10 U/ml heparin yielded 11 micrograms/ml complexes after 90 min, which represent more than 90% of the maximum possible value. Thus, the method should be adequate to study complexes of APC in vivo in clinical conditions in which activation of protein C pathway may occur.

subject areas

  • Blood Proteins
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Male
  • Protein C
  • Protein C Inhibitor
scroll to property group menus

Identity

International Standard Serial Number (ISSN)

  • 0049-3848

Digital Object Identifier (DOI)

  • 10.1016/0049-3848(89)90298-3

PubMed ID

  • 2551066
scroll to property group menus

Additional Document Info

start page

  • 671

end page

  • 682

volume

  • 55

issue

  • 6

©2021 The Scripps Research Institute | Terms of Use | Powered by VIVO

  • About
  • Contact Us
  • Support