Primary HLH can be difficult to diagnose because many symptoms are common to other illnesses. To diagnose primary HLH, doctors must rule out other illnesses, like infections or cancers, that could be causing symptoms.
Most people see many doctors before this rare disease is identified. If you or your loved one have been diagnosed, you may be wondering how the doctor figured it out.
What do doctors check for?
If you or your loved one are experiencing physical symptoms of primary HLH, your doctor may explore these 3 factors:
LAB WORKUP
There is a list of diagnostic criteria used to diagnose primary HLH. Your doctor may run a variety of laboratory tests to identify any features within that criteria to help confirm a diagnosis. Those tests may include:
- Ferritin level testing
- Bone marrow testing
- Blood and liver function testing
Family history
Primary HLH may be inherited from parents, so your doctor may look at your family history to find out if primary HLH may have been passed down to you or your child.
Because primary HLH may be inherited from parents, it may be a good idea to have other members of your immediate family tested. Talk to your doctor or genetic counselor about potential next steps for your family.
GENETIC TESTING
Doctors use genetic tests to confirm whether someone has primary HLH. These tests can include targeted individual gene sequencing, HLH gene panel testing, and clinical whole exome sequencing.
Genetic tests can help determine if you or your loved one has certain gene mutations that cause primary HLH.
It may take several weeks to get genetic testing results. Since it’s very important to treat primary HLH quickly doctors may check for it another way using diagnostic criteria.
DIAGNOSTIC CRITERIA
If a person meets at least 5 out of the 8 criteria below, doctors may diagnose primary HLH:
- Persistent fever
- Enlarged spleen
- Lower numbers of blood cells called cytopenia (pronounced SIGH-TOE-PEA-NEE-UH)
- A higher level of triglycerides and/or lower level of fibrinogen in the bloodstream
- Higher levels of ferritin
- Evidence that blood cells might be damaging other blood cells (hemophagocytosis) in certain areas of the body
- Low levels of immune cells called “natural killer cells,” or none at all
- Higher levels of sCD25, an immune cell associated with inflammation
Your doctor is your main source of medical information. Talk with your doctor to learn more about how primary HLH is diagnosed.
