Nagler M, (2016), Blood. 2016. (Link to abstract)
Heparin-induced thrombocytopenia (HIT) is in the pediatric population a rare but potentially life-threatening adverse event of heparin-treatment. Its diagnosis relies on clinical assessment and identification of specific heparin-induced PF4 antibodies. This systematic review and meta-analysis compares different PF4 immunoassays used to identify HIT. 49 publications with 128 test evaluations in >15 000 patients. The authors found significant differences in sensitivity and specificity. In summary, only 5 tests showed high sensitivity (>95%) and high specificity (>90%): polyspecific enzyme-linked immunosorbent assay (ELISA) with intermediate threshold, particle gel immunoassay, lateral flow immunoassay, polyspecific chemoluminescent immunoassay (CLIA) with high threshold, and IgG-specific CLIA with low threshold.
* According to this analysis, only 5 immunoassays exhibit high sensitivity and specificity to ascertain the diagnosis of HIT; clinicians should be aware of this limitation and talk to the lab if there is a lab test result conflicting with the clinical picture.