Laboratory diagnostics of asthma: accuracy that helps you breathe freely
Asthma: not one disease, but several variants of the course
Bronchial asthma is not just shortness of breath and an inhaler. It is chronic inflammation of the respiratory tract, which can be allergic, non-allergic, mixed, eosinophilic, infection-dependent, aspirin-induced. Laboratory studies are the key to understanding, What type does the patient have? and what treatment will be effective.
Why are laboratory tests prescribed for asthma?
That confirm the allergic nature symptoms
Reveal inflammation level — systemic and local
To spend differential diagnosis with COPD, pneumonia, parasitic infections
Determine whether Will the patient respond to inhaled steroids?
Control effectiveness of therapy (in particular biological)
Explain frequent exacerbations or "nighttime" symptoms
Analyses that form the basis of diagnostics
Complete blood count (CBC)
Growth eosinophils over 300 cells/μl indicates eosinophilic inflammation, characteristic of atopic or severe late-onset asthma.
Leukocytosis and elevated ESR are markers inflammatory exacerbation, in particular infectious.
IgE: general and specific
Total IgE: its increase indicates allergic sensitization. The higher the level, the more the body is prone to hyperreaction.
Specific IgE: determine antibodies to specific allergens (pollen, mites, wool, mold).
High-precision method — ImmunoCAP, which allows you to create a patient's allergy profile.
These indicators are particularly important for making decisions about specific immunotherapy (SIT).
NO in exhaled air (FeNO)
Non-invasive marker eosinophilic bronchial inflammation.
– Norm: up to 25 ppb (parts per billion)
– The increase indicates inadequate control of inflammation or the need for inhaled glucocorticosteroids
FeNO is convenient to use for monitoring — can be repeated monthly.
Eosinophils in sputum
Important for verification local inflammation in the respiratory tract, especially when other markers do not provide a clear answer.
– >2–3% eosinophils — confirmation of the eosinophilic component
This test is more difficult to perform, but highly informative in difficult cases.
C-reactive protein (CRP)
Increases with acute bacterial infections. If asthma symptoms are accompanied by high CRP, you should consider: mixed or infectious exacerbation.
Additional laboratory tests
| Analysis | Value |
|---|---|
| Ferritin, iron, transferrin | Anemia worsens hypoxia in asthma |
| 25(OH)D – vitamin D | Low levels are associated with an increased risk of exacerbations |
| IgG to parasites (toxocara, Giardia) | Parasitic infestations can mimic asthma |
| Test for alpha-1-antitrypsin | If hereditary obstructive pathology is suspected |
When analyses are crucial
Undetermined etiology shortness of breath
Ineffectiveness of basic therapy
Suspicion of an infectious-allergic component
Biological treatment planning (anti-IL-5, anti-IgE drugs)
Specific immunotherapy (SIT)
The role of the laboratory in patient management
Asthma is not just the obstruction seen on spirometry. It is inflammation that begins at the molecular level. And only laboratory diagnostics is capable of:
to determine, what kind of inflammatory profile the patient has
to indicate, Will hormone therapy be effective?
allow personalize treatment, including biological drugs
explain why some patients' symptoms are not controlled despite proper treatment
Laboratory diagnostics is not just an auxiliary stage. It precision approach tool to asthma: from drug selection to controlling the risk of exacerbations. And the earlier the pathophysiological mechanisms are identified, the better the patient's prognosis and quality of life will be.
Director of Medi Lab Plus LLC, a doctor of the highest category. Has over 45 years of practical experience in medicine and laboratory diagnostics. Founder and head of the laboratory since 2007. More details…