Novel diagnostic assays for heparin-induced thrombocytopenia.

Published

Journal Article

Laboratory testing for heparin-induced thrombocytopenia (HIT) has important shortcomings. Immunoassays fail to discriminate platelet-activating from nonpathogenic antibodies. Specific functional assays are impracticable due to the need for platelets and radioisotope. We describe 2 assays that may overcome these limitations. The KKO-inhibition test (KKO-I) measures the effect of plasma on binding of the HIT-like monoclonal antibody KKO to platelet factor 4 (PF4)/heparin. DT40-luciferase (DT40-luc) is a functional test comprised of a B-cell line expressing FcγRIIa coupled to a luciferase reporter. We compared these assays to polyspecific and immunoglobulin (Ig)G-specific PF4/heparin enzyme-linked immunosorbent assays (ELISAs) in samples from 58 patients with suspected HIT and circulating anti-PF4/heparin antibodies. HIT was defined as a 4Ts score ≥ 4 and positive (14)C-serotonin release assay. HIT-positive plasma demonstrated greater mean inhibition of KKO binding than HIT-negative plasma (78.9% vs 26.0%; P < .0001) and induced greater luciferase activity (3.14-fold basal vs 0.96-fold basal; P < .0001). The area under the receiver-operating characteristic curve was greater for KKO-I (0.93) than for the polyspecific (0.82; P = .020) and IgG-specific ELISA (0.76; P = .0044) and for DT40-luc (0.89) than for the IgG-specific ELISA (P = .046). KKO-I and DT40-luc showed better discrimination than 2 commercially available immunoassays, are simple to perform, and hold promise for improving the specificity and feasibility of HIT laboratory testing.

Full Text

Duke Authors

Cited Authors

  • Cuker, A; Rux, AH; Hinds, JL; Dela Cruz, M; Yarovoi, SV; Brown, IAM; Yang, W; Konkle, BA; Arepally, GM; Watson, SP; Cines, DB; Sachais, BS

Published Date

  • May 2, 2013

Published In

Volume / Issue

  • 121 / 18

Start / End Page

  • 3727 - 3732

PubMed ID

  • 23446735

Pubmed Central ID

  • 23446735

Electronic International Standard Serial Number (EISSN)

  • 1528-0020

Digital Object Identifier (DOI)

  • 10.1182/blood-2013-01-479576

Language

  • eng

Conference Location

  • United States