Name of the Procedure:

Lymphocytotoxicity Assay, Visual Crossmatch with Titration

Summary

The lymphocytotoxicity assay, also known as a visual crossmatch, is a lab test that measures how a patient's immune system will react to a donor's tissue. This involves mixing the patient's blood with donor white blood cells and using a titration technique to determine the compatibility.

Purpose

The procedure is mainly used to assess compatibility for organ transplants, especially kidney transplants. It's designed to minimize the risk of organ rejection by ensuring that the recipient's immune system is unlikely to attack the transplanted tissue.

Indications

• Candidates for organ transplantation, particularly kidney transplants.
• Previous transplants or blood transfusions that may have sensitized the patient's immune system.
• A history of immune-related conditions that might affect organ transplant compatibility.

Preparation

• No specific fasting required.
• Patients may need to stop certain medications that affect the immune system, as recommended by their healthcare provider.
• Preliminary blood tests to determine the patient's and donor's tissue types and antibody levels.

Procedure Description

1. Blood samples are collected from both the patient and the potential donor.
2. The blood samples are processed to isolate white blood cells.
3. In the lab, the patient's serum is mixed with the donor's white blood cells in varying concentrations (titrations).
4. A dye that marks cell death is added to identify any immune reaction.
5. The reaction is observed under a microscope (visual crossmatch) to detect any cell damage indicating an incompatible match.

Tools/Equipment: Microscope, blood collection tubes, centrifuge, staining dyes.

Anesthesia/Sedation: Not applicable; it is a laboratory test.

Duration

Typically, the entire process can take a few hours to a day, depending on the lab's efficiency and workload.

Setting

Performed in a specialized lab within a hospital or medical center.

Personnel

Medical laboratory technicians and clinical pathologists.

Risks and Complications

• Rare allergic reaction to blood collection or processing materials.
• False positive or negative results, which could impact transplant decisions.
• Inaccuracies due to technical errors or sample contamination.

Benefits

• Helps ensure a higher success rate for organ transplants.
• Reduces the risk of organ rejection.
• Provides critical information for appropriate donor-recipient matching.

Recovery

• No recovery time required as this is a lab-based test.
• Follow-up appointments to discuss results and next steps if a transplant is planned.

Alternatives

• Flow cytometry crossmatch: A more sensitive but also more complex and expensive method compared to the traditional visual crossmatch.
• Virtual crossmatch: Uses previously collected data and computer algorithms, though it may lack the nuances detected in a physical test.

Patient Experience

• The patient will experience a standard blood draw, which involves minor discomfort at the needle site.
• No significant pain or extensive discomfort expected.
• Normal activities can be resumed immediately after the blood draw.