CPT® Code 86817

1. Indications

HLA typing is indicated for several specific conditions and purposes, including:

• Celiac Disease Susceptibility Testing for HLA-DQ2 and HLA-DQ8 is performed in symptomatic patients or those with a family history of celiac disease to assess genetic predisposition.
• Narcolepsy Differentiation HLA-DR15 and HLA-DQ6 typing is utilized to help differentiate narcolepsy from other sleep disorders, aiding in accurate diagnosis and management.
• Autoimmune Disorders Class II HLA-DR and HLA-DQ DNA typing is used to identify susceptibility to various autoimmune disorders, providing valuable information for patient care.
• Tissue Compatibility HLA typing is essential for determining tissue compatibility between potential donors and recipients for stem cell, bone marrow, or solid organ transplants, which is critical for successful transplantation outcomes.

2. Procedure

The procedure for HLA typing involves several key steps, which are detailed as follows:

• Sample Collection A blood sample is collected from the patient, which serves as the source of white blood cells needed for HLA typing. This sample is typically drawn in a clinical setting by a qualified healthcare professional.
• Cell Isolation The white blood cells are isolated from the collected blood sample. This process may involve centrifugation to separate the cellular components from the plasma, ensuring that the HLA typing is performed on the appropriate cells.
• DNA Extraction Once the white blood cells are isolated, DNA is extracted from these cells. This step is crucial as the HLA typing relies on analyzing specific genetic markers present in the DNA.
• Typing Procedure The extracted DNA is then subjected to typing techniques, which may include polymerase chain reaction (PCR) amplification and sequencing or other molecular methods to identify the presence of specific HLA antigens, particularly the DR and DQ antigens.
• Result Interpretation After the typing is completed, the results are interpreted by a qualified laboratory professional. The presence or absence of specific HLA alleles is documented, providing essential information for clinical decision-making.

3. Post-Procedure

Post-procedure care for HLA typing is generally minimal, as the procedure is non-invasive and involves only a blood draw. Patients may be advised to hydrate adequately and can typically resume normal activities immediately following the sample collection. Results from the HLA typing may take several days to process, and patients should follow up with their healthcare provider to discuss the findings and any implications for treatment or further testing. It is important for healthcare professionals to ensure that patients understand the significance of the results, especially in relation to potential disease susceptibility and transplant compatibility.