Comparison of polyspecific versus IgG specific ELISA in predominately cardiac patients with suspected heparin induced thrombocytopenia
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A diagnosis of heparin induced thrombocytopenia (HIT) must often be made based on clinical and laboratory evidence. This was a quasi-experimental study of patients admitted from June 2016 to October 2017. The primary endpoint was the incidence of false positive results in polyspecific and IgG specific enzyme-linked immunosorbent assay (ELISA); then we compared the sensitivity and specificity of each assays in predominately cardiac patients with suspected HIT. A sensitivity/specificity analysis was conducted using serotonin release assay (SRA) as the ‘gold standard’. The secondary outcome measures included length of hospital stay. We identified a total of 155 patients who met the inclusion criteria. Confirmatory tests with SRA on both groups were completed; false positive result was higher in the polyspecific group when compared to the IgG group [60% vs. 5%]. The IgG specific ELISA test yielded a sensitivity of 100% and a specificity of 95% however, the polyspecific ELISA had a low yield for specificity of 24% but maintained 100% sensitivity. In the IgG specific group with HIT-, their median length of stay was halved compared to those who were HIT + ; hospital LOS in days, IQR [30 (27–81) vs. 15 (7–33) p = 0.023] and a shorter median LOS in the ICU, IQR [24 (5–47) vs. 6 (2–14); p = 0.079]. Hospital or ICU LOS was the same in both (HIT+ and HIT−) groups managed with polyspecific ELISA. The IgG specific test had few false positive results and a high sensitivity score. Ensuring appropriate testing can bring a substantial decrease in drug expenditure, reduced length of stay and prevent unnecessary anticoagulation.
KeywordsHeparin Enzyme-linked immunosorbent assay Heparin induced thrombocytopenia Direct thrombin inhibitor
SS: study concept and design, acquisition of data, analysis and interpretation, critical revision of the manuscript for important intellectual content. MM: analysis and interpretation, critical revision of the manuscript for important intellectual content. JC: acquisition of data, analysis and interpretation, critical revision of the manuscript for important intellectual content. ME: analysis and interpretation, critical revision of the manuscript for important intellectual content. PW: analysis and interpretation, critical revision of the manuscript for important intellectual content. AN: analysis and interpretation, critical revision of the manuscript for important intellectual content.
- 3.Cuker A, Arepally G, Crowther MA et al (2010) The HIT Expert Probability (HEP) Score: a novel pre-test probability model for heparin-induced thrombocytopenia based on broad expert opinion. J Thromb Haemost 8(12):2642–2650. https://doi.org/10.1111/j.1538-7836.2010.04059.x CrossRefPubMedGoogle Scholar
- 15.Raschke RA, Curry SC, Warkentin TE, Gerkin RD (2013) Improving clinical interpretation of the anti-platelet factor 4/heparin enzyme-linked immunosorbent assay for the diagnosis of heparin-induced thrombocytopenia through the use of receiver operating characteristic analysis, stratum-specific likelihood ratios, and Bayes theorem. Chest 144(4):1269–1275. https://doi.org/10.1378/chest.12-2712 CrossRefPubMedGoogle Scholar
- 19.Pouplard C, May MA, Regina S, Marchand M, Fusciardi J, Gruel Y (2005) Changes in platelet count after cardiac surgery can effectively predict the development of pathogenic heparin-dependent antibodies. Br J Haematol 128(6):837–841. https://doi.org/10.1111/j.1365-2141.2005.05381.x CrossRefPubMedGoogle Scholar
- 24.Husseinzadeh HD, Gimotty PA, Pishko AM et al (2017) Diagnostic accuracy of IgG-specific versus polyspecific enzyme-linked immunoassays in heparin-induced thrombocytopenia: a systematic review and meta-analysis. J Thromb Haemost 15(6):1203–1212. https://doi.org/10.1111/jth.13692 CrossRefPubMedPubMedCentralGoogle Scholar