How is HIT Diagnosed?
How is HIT Diagnosed?
Diagnosis Demystified
Diagnosing heparin-induced thrombocytopenia (HIT) can be tricky, but with the right tests, it becomes manageable. Learn about the key tests used to diagnose HIT.
Contents
- The 4 Ts Score
- Immunoassays
- Functional Assays
The 4 Ts Score
The 4 Ts score is a clinical tool used to assess the likelihood of HIT. It stands for Thrombocytopenia, Timing of platelet count drop, Thrombosis, and absence of other causes. Scoring guides whether further testing is necessary and helps clinicians make informed decisions about treatment.
Immunoassays
Immunoassays detect antibodies against the heparin-PF4 complex. These tests are fast and readily available, providing an initial indication of HIT presence. However, they can sometimes yield false positives, so results are often followed up with more specific testing.
Functional Assays
Functional assays, like the serotonin release assay, confirm the presence and activity of HIT antibodies. These tests are more specific but take longer and are resource-intensive. They are the gold standard when immunoassay results are unclear.
FAQs
What is the 4 Ts score?
It's a clinical tool to estimate the likelihood of HIT.
Why use immunoassays?
Immunoassays quickly detect HIT antibodies but may need confirmation.
What are functional assays?
They confirm HIT by testing the antibodies' ability to activate platelets.
Are these tests accurate?
Yes, especially when used together, they provide a clear diagnosis.
Diagnosis Insights
Accurate testing is crucial for managing and treating HIT effectively.
Additional References
- Cuker A. Does my patient have HIT? There should be an app for that. Blood 2016; 127:522.
- Lo GK, Juhl D, Warkentin TE, et al. Evaluation of pretest clinical score (4 T's) for the diagnosis of heparin-induced thrombocytopenia in two clinical settings. J Thromb Haemost 2006; 4:759.
This article has been reviewed for accuracy by one of the licensed medical doctors working for Doctronic.