HLA Class II typing, low resolution (eg, antigen equivalents); one locus (eg, HLA-DRB1, -DRB3/4/5, -DQB1, -DQA1, -DPB1, or -DPA1), each
CPT4 code
Name of the Procedure:
HLA Class II Typing, Low Resolution (e.g., Antigen Equivalents); One Locus (e.g., HLA-DRB1, -DRB3/4/5, -DQB1, -DQA1, -DPB1, or -DPA1)
Summary
HLA Class II typing at low resolution is a diagnostic test used to determine the specific types of human leukocyte antigens (HLAs) present on cells at a particular locus. This test focuses on one locus, identifying various antigen equivalents that play a significant role in immune system function.
Purpose
The test helps in matching organ and bone marrow donors with recipients, diagnosing certain autoimmune diseases, and providing information for research studies. The key goals are to ensure compatibility for transplants, improve disease diagnosis, and further scientific research.
Indications
This procedure is indicated for patients requiring organ or bone marrow transplants, those suspected of having autoimmune disorders, or individuals involved in specific clinical or genetic research studies. It is particularly appropriate for patients on transplant waiting lists or those showing symptoms of immune-related conditions.
Preparation
Patients are typically advised to prepare by following standard blood draw procedures. This includes ensuring proper hydration and avoiding certain medications that may interfere with the results. No fasting is generally required, but specific instructions will be given based on individual circumstances. Pre-testing may involve a simple blood draw to assess general health.
Procedure Description
- Sample Collection: A blood sample is drawn from the patient’s arm using a sterile needle.
- DNA Extraction: The white blood cells from the sample are separated, and DNA is extracted.
- PCR Amplification: Specific segments of the DNA are amplified using Polymerase Chain Reaction (PCR) technology.
- Low-Resolution Typing: The amplified DNA is analyzed to identify HLA antigens at the targeted locus.
- Results Interpretation: The identified antigens are compared against known datasets to determine the patient's HLA type.
Advanced laboratory equipment such as PCR machines and specialized software for HLA typing analysis are used. The procedure does not require anesthesia or sedation.
Duration
The entire process, from blood draw to results, typically takes several days to a week, depending on lab processing times.
Setting
The blood sample collection can be done at a hospital, outpatient clinic, or dedicated laboratory. The analysis is performed in a specialized medical laboratory.
Personnel
- Phlebotomist/Nurse: For drawing the blood sample.
- Lab Technician: For conducting the DNA extraction and PCR.
- HLA Specialist: For interpreting the results.
Risks and Complications
- Common Risks: Minor bruising or discomfort at the injection site.
- Rare Risks: Infection at the blood draw site or allergic reaction to adhesive bandages. Mitigation includes proper aseptic techniques and patient monitoring post-procedure.
Benefits
The procedure provides critical information for matching donors and recipients, diagnosing autoimmune conditions, and advancing research. Results can enhance the success rate of transplants and guide appropriate medical treatments.
Recovery
Post-procedure care is minimal, usually involving simple aftercare for the blood draw site such as keeping it clean and covered if necessary. There are no significant restrictions, and normal activities can be resumed immediately.
Alternatives
- High-Resolution HLA Typing: Offers more detailed results but is more costly and time-consuming.
- Serological HLA Typing: An older method that is less precise. Each alternative has different levels of accuracy, cost, and application scope, with low-resolution typing being a balanced option for many clinical needs.
Patient Experience
During the blood draw, patients may feel a slight pinch or discomfort. After the draw, there can be minor bruising or soreness at the site. Pain management is typically unnecessary, but over-the-counter pain relief can be used if needed. Comfort measures include ensuring a calm environment and providing clear information about the procedure.
This markdown description provides a comprehensive overview of HLA Class II typing, low resolution, for one locus, in an easily digestible format.