Analysis index

1 ml serum

< 0.4 negative

0.4 – 1.0 borderline

> 1.0 positive

Suspicion of heparin-induced thrombocytopenia type II (HIT type II) in case of thrombocyte decrease to < 100.000 /µl or by more than 50 % of the initial value or indication of thromboembolism under heparin or PPSB and ATII products (which may contain heparin)

A HIT type II is a potentially life-threatening complication of heparin therapy. Thus, a thrombocyte count is recommended 2 – 3 times per week, in case of heparin treatment. In case of HIT type II, which is characterized by thrombocytopenia, paradoxically there is a markedly increased venous and arterial thrombosis risk. HIT type II is caused by antibodies, which activate thrombocytes in the presence of heparin. In approximately 20 % of patients, there is no thrombocytopenia. The detection of antibodies against the heparin platelet factor 4 complex I a criterion fpr the presence of heparin-induced thrombocytopenia type II (HIT II). Diagnosis HIT II should only be made if there are further clinical signs. In case of clear clinical signs for HIT II, heparin (also low molecular heparin) has to be discontinued and replaced with Argatroban (Argatra) or danaparoid sodium (Orgaran). In case of a prophylactic dose, Arixtra (Pentasaccharide) or the new anti-Xa inhibitors (Xarelto) or anti-IIa inhibitors (Pradaxa) can be used alternatively. The use of the new anticoagulants in most cases is an off-label-use.

The test is an EIA for the demonstration of antibodies against heparin platelet factor 4 complexes.

Labor Zentrum Weser Prof. Dr. med. Schmitz Minden