Name of the Procedure:

Lymphocyte Transformation Test (LTT), Mitogen-Induced Lymphocyte Blastogenesis, Antigen-Induced Lymphocyte Blastogenesis

Summary

The Lymphocyte Transformation Test (LTT) evaluates how well lymphocytes (a type of white blood cell) respond to certain stimulants known as mitogens or antigens. This response is measured to understand the state of the patient’s immune system.

Purpose

The test primarily diagnoses or monitors conditions related to the immune system, such as immunodeficiencies or autoimmune disorders. It assesses the lymphocytes' ability to grow and transform, indicating their functional capacity and overall immune health.

Indications

• Recurrent infections with no clear cause
• Diagnosis of primary or secondary immunodeficiency
• Monitoring of immune function in patients receiving immunosuppressive therapy
• Investigation of allergic reactions or autoimmune diseases

Preparation

• No specific fasting is required.
• Patients should inform their healthcare provider about all medications they are taking, as some drugs can interfere with test results.
• Blood is drawn, so patients should stay hydrated for easier vein access.
• No significant dietary restrictions.

Procedure Description

1. Blood Sample Collection: A healthcare provider collects a blood sample from the patient, usually from a vein in the arm.
2. Lymphocyte Isolation: The lymphocytes are isolated from the blood sample in a laboratory setting.
3. Stimulation: The isolated lymphocytes are exposed to mitogens (like phytohemagglutinin) or specific antigens in a controlled environment.
4. Incubation: The cells are incubated for a predetermined period, typically 3 to 7 days.
5. Measurement: After incubation, the rate of lymphocyte proliferation is measured, often using radioactive thymidine incorporation or a colorimetric assay (such as MTT).

Duration

The initial blood draw takes a few minutes. Laboratory analysis and incubation usually span several days.

Setting

The blood draw is performed at a hospital or outpatient clinic. The subsequent laboratory analysis is conducted in a specialized laboratory.

Personnel

• Phlebotomist or nurse (for blood draw)
• Laboratory technician or medical laboratory scientist (for analysis)
• Immunologist or physician (for result interpretation)

Risks and Complications

• Common Risks: Minor bruising or discomfort at the blood draw site.
• Rare Risks: Slight risk of infection or hematoma at the puncture site.

Benefits

• Provides critical information about the immune system’s functionality.
• Helps diagnose immunodeficiencies and guides appropriate treatment plans.
• Assesses the impact of immunosuppressive drugs and monitors immune recovery.

Recovery

• Minimal recovery time needed.
• Patients can typically resume normal activities immediately after the blood draw.
• Follow-up depends on test results and underlying conditions.

Alternatives

• Flow Cytometry: Another advanced method to measure lymphocyte subset populations.
• Complete Blood Count (CBC): Provides general white blood cell counts but lacks functional detail.
• Skin Tests: Such as tuberculin skin test, which is less precise for systemic immune function.

Patient Experience

• During the Procedure: Minimal discomfort from the blood draw; a slight prick and brief stinging sensation.
• After the Procedure: Patients may experience minor soreness at the needle site. Discomfort is usually manageable with over-the-counter pain relief if necessary.
• Overall: The procedure is minimally invasive with a quick recovery, making it a convenient option for immune function assessment.