Included with every panel
Baseline labs come free with any panel you build.
Other tests
Reactive Lymphocytes test
The percentage of reactive (atypical) lymphocytes, normal lymphocytes that look enlarged while responding to infection. Included with every panel.
At a glance
In about 5 days
Most results are ready in about 5 days. Some specialty markers can take up to 21 days.
Check before your draw
This marker has no preparation tag, but it can still need preparation. Contact us before your draw if you’re not sure.
Walk in at Quest
Your lab order arrives by email. Most Quest locations take walk-ins, so bring it with a photo ID.
What it measures
Reactive lymphocytes are white blood cells that have grown larger and changed shape while fighting an infection. They may be a sign of a recent viral illness, such as mono.
Why it matters for women
The range is the same for women and men, and these cells can fade within weeks as you recover. In pregnancy, a mono-like illness is worth mentioning to your clinician, because some of the germs that cause one can pass to the baby.
You might check it if…
- you’ve had a sore throat, fever and swollen glands
- you’ve felt deeply tired since a recent illness
- you’re pregnant and recently had a flu-like illness
- you’re getting a routine blood count as part of a checkup
What your result may mean
High Reactive Lymphocytes: what it may mean
High reactive lymphocytes may mean your immune system is responding to a viral infection, classically mononucleosis (mono) from Epstein-Barr virus (EBV). Other viruses, such as cytomegalovirus (CMV) or hepatitis, can do this too, and some medicines can as well. In pregnancy, a mono-like illness can be worth mentioning to your clinician, because some of the germs behind one can pass to the baby. A sore throat, fever, swollen glands or deep tiredness may go along with it. These cells can fade within weeks as you recover, so a later count may look different.
Low Reactive Lymphocytes: what it may mean
Low or no reactive lymphocytes may be the normal state, and few or none can be the expected result in a healthy person. The range may be the same for women and men. These cells can fade within weeks of an illness, so a low count can’t rule out a recent viral infection. A low result may come with no symptoms. If you feel unwell, a clinician may turn to a specific test, such as one for mono.
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These notes provide context and do not diagnose a condition. Not yet available in NY, NJ, RI, HI, ND, SD or WV.