Name of the Procedure:

Leukocyte Histamine Release Test (LHR)

Summary

The Leukocyte Histamine Release Test (LHR) is a diagnostic procedure used to measure the amount of histamine released by white blood cells (leukocytes) when they are exposed to various allergens or other stimuli. This test helps determine allergic sensitivities and possible triggers for allergic reactions.

Purpose

The LHR test is used to identify specific allergens causing allergic reactions. It helps in the diagnosis of conditions like asthma, allergic rhinitis, and food allergies. By pinpointing exact allergens, the test aids in creating targeted treatment plans to manage symptoms and prevent future allergic reactions.

Indications

• Persistent or unexplained allergic symptoms (e.g., hives, itching, swelling).
• Suspected food allergies.
• Asthma exacerbated by unknown allergens.
• Allergic rhinitis not responsive to standard treatments.
• Eczema flare-ups suspected to be allergy-related.

Preparation

• Patients may need to avoid antihistamines and certain medications that could interfere with test results for a few days before the procedure.
• Fasting is generally not required.
• Inform the healthcare provider of any ongoing medications or underlying health conditions.

Procedure Description

1. A blood sample is drawn from the patient, typically from a vein in the arm.
2. The sample is sent to a laboratory where leukocytes are isolated.
3. The leukocytes are exposed to various allergens or compounds in a controlled setting.

4. The amount of histamine released by the leukocytes in response to each allergen is measured.

   Tools & Equipment:

   • Standard phlebotomy supplies for blood draw.
   • Laboratory equipment for isolating leukocytes and measuring histamine release (e.g., microplate readers).

Anesthesia and Sedation:

• Not applicable, as this is a minimally invasive blood test.

Duration

The blood draw takes a few minutes, but analyzing the sample may take a few hours to days in the laboratory.

Setting

The blood draw is usually performed in a laboratory, outpatient clinic, or doctor's office. The analysis is conducted in a specialized laboratory.

Personnel

• Phlebotomist or nurse for drawing blood.
• Laboratory technician or allergist for sample analysis.

Risks and Complications

• Minor discomfort or bruising at the blood draw site.
• Rare risk of infection at the puncture site.
• Possible mild allergic reactions during the testing process.

Benefits

• Precise identification of allergens.
• Tailored treatment plans to manage allergies effectively.
• Helps avoid unnecessary exposure to identified allergens.

Recovery

• Immediate return to normal activities post-blood draw.
• Follow-up appointment for discussing results and treatment plan.

Alternatives

• Skin prick test: quicker results but less specific.
• Serum-specific IgE testing: another blood test but measures different markers.
• Elimination diets: helpful for food allergies but time-consuming.

Patient Experience

• Minor discomfort during blood draw.
• No significant pain or discomfort expected afterward.
• Some anxiety may be associated with waiting for results.
• Clearer understanding of allergy triggers post-test, potentially leading to a more manageable condition.