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Determination of heparin–platelet factor 4–IgG antibodies improves diagnosis of heparin‐induced thrombocytopenia

2001; Wiley; Volume: 113; Issue: 4 Linguagem: Inglês

10.1046/j.1365-2141.2001.02869.x

1365-2141

Edelgard Lindhoff‐Last, Frank Gerdsen, Hanns Ackermann, Rupert Bauersachs,

Intramuscular injections and effects

Only a few patients with heparin-induced antibodies develop heparin-induced thrombocytopenia (HIT). In this study, we investigated whether different immunglobulin classes can be used to differentiate between antibody-positive patients with and without HIT. Four different patient populations were investigated: 32 patients with the immune type of HIT with thromboembolic complications, 13 patients with HIT without thromboembolism, 24 patients with heparin-platelet factor 4 (PF4) antibodies without clinical symptoms of HIT, and 20 heparin-treated patients with thrombocytopenia caused by other reasons. In all patients the immunglobulin mixture of IgG, IgM and IgA, and the single immunglobulin classes of heparin-PF4 antibodies, were investigated. No significant differences between HIT patients with thromboembolic complications and patients with isolated HIT were found concerning the different immunglobulin classes. Antibody-positive patients with HIT had significantly higher levels of IgG antibodies than those without HIT (P < 0.05), while they did not differ concerning IgM and IgA antibodies. By determining IgG antibodies, the specificity of the enzyme-linked immunosorbent assay (ELISA) system was increased without loss of sensitivity. Heparin-PF4-IgG antibodies can identify patients at risk of developing life-threatening HIT. Future ELISAs should only include this immunglobulin class, as the determination of the antibody mixture may lead to overestimation of HIT.