Heparin induced Thrombocytopenia (HIT)

Introduction

Heparin-induced thrombocytopenia (HIT) is an immunologic adverse response to heparin therapy. HIT usually results in a platelet count decrease of more than 50% and often a new thrombosis, typically occurring a couple of days after the start of the prophylactic or therapeutic dose of heparin. Antibodies associated with HIT are often directed to platelet factor 4 (PF4) bound to heparin. Large immune complexes of these IgG antibodies cross-link platelets and trigger platelet activation. The observed thrombocytopenia is caused by this intravascular platelet activation. The activated platelets form the catalytic surface for thrombin generation leading to thrombosis.

NODIA offers both immunological assays from Hyphen BioMed and functional assays from 5-Diagnostics:

Our partner Hyphen BioMed offers ZYMUTEST™ HIA, a standardized ELISA method, optimized for the detection of heparin-dependent antibodies in human plasma, serum or other biological fluid, allowing confirmation of the HIT diagnosis or its clinical suspicion. 

Our partner 5-Diagnostics offers the Emo-test HIT Confirm®. This innovative kit allows rapid and reliable HIT confirmation by measuring platelet activation using flow cytometry.

ZYMUTEST™ HIA

- Immunological assay -

Introduction

ELISA method for the detection of heparin dependent antibodies. A new concept for the diagnosis of Heparin Induced Thrombocytopenia.

Major Features

  • Better correlation with clinical context
  • Captures not only Ab’s against PF4, but also against NAP2 and IL8
  • Binds circulating heparin-protein-AB complexes
  • Detects both Heparin and Protamine Sulphate antibodies

Reaction principle

Microplates are coated with both functionally available Heparin and Protamine Sulphate.

  • Binds chemokines present in the sample and forms auto-antigen that captures the heparin dependent antibodies.
  • Can fix heparin-protein-antibody complexes generated in the blood circulation.
  • Enhanced sensitivity and specificity by addition of cell lysate: Brings a source of proteins like Platelet Factor 4 (PF4), Interleukin-8 (IL8) and Neutrophil-Activating Peptide-2 (NAP-2) which are known to be antigenic in complex with heparin.
  • Screening with IgGAM mixture or by specific testing with IgG-, IgM- or IgA- antibodies.

- Functional assay -

Introduction

A new way of dealing with HIT testing! Confirming HIT in minutes, not days!

The Emo-test HIT Confirm® (CE-IVD) allows for rapid and reliable Heparin-induced thrombocytopenia (HIT) confirmation by measuring platelet activation by flow cytometry.

The Emo-test HIT Confirm® has been developed by Emosis to address the need of clinicians and laboratories to get access to an HIT activity test that would be readily available, on-demand, 24/7, affordable and easy to use by non-specialists.

The HIT Confirm test can be used on any flow cytometer, which are more and more available in hospitals. The new generation of smaller, cheaper benchtop flow cytometers which are easier to use by non-specialized cytometrists supports more hospitals getting access to such a powerful technology.

The Emo-test HIT Confirm® is a flow cytometry based IVD Diagnostics kit aimed at confirming that patient’s HIT antibodies are present and lead to the formation of a heparin-antibody-PF4 complex that will bind to the platelets of a donor plasma (Platelet Rich Plasma – PRP), activating them and having potentially devastating consequences for patients.

During platelet activation, changes are induced in the platelet membranes with expression of surface markers. These platelet activation markers can be studied in flow cytometry with the use of fluorescent-labeled ligand.

The HIT Confirm test uses one step only (one incubation) with two fluorophores against a marker of platelets (CD 41) and a marker of activated platelets (CD 62). After 30 minutes incubation with 2 levels of Heparin (0,3 U/mL and 100 U/mL), the proportion of relevantly activated platelets is obtained by flow cytometry (1 laser, 2 colors) counting 10,000 events.

Based on platelets obtained from a donor (for PRP), results are interpreted using a platelet activation index called HEPLA (Emosis-developed) in order to get better standardized results.

Major Features

  • Better Quality and standardization
  • Confirmation of HIT in minutes, not days
  • Ease of use – available on demand, 24/7
  • Using micro-liters, not milli-liters
  • No need for same, selected donors –
    a challenge for all tests, less for HIT Confirm
Emo-test HIT Confirm®