CPT® Code 81371

Official Description

HLA Class I and II typing, low resolution (eg, antigen equivalents); HLA-A, -B, and -DRB1 (eg, verification typing)

Common Language Description

The HLA Class I and II typing, low resolution (CPT® Code 81371) is a laboratory procedure that focuses on identifying specific human leukocyte antigens (HLAs) associated with the immune system. The HLA system is a critical component of the major histocompatibility complex (MHC), which plays a vital role in the body's ability to recognize its own cells and tissues while defending against foreign invaders, such as pathogens and non-self cells. HLAs are located on the short arm of chromosome 6 and are essential for the proper functioning of the immune response. They are categorized into two classes: Class I and Class II. Class I HLAs, which include the most significant loci A, B, and C, are crucial for presenting antigens to immune cells. Class II HLAs consist of five loci—DR, DQ, DP, DM, and DO—with DR, DQ, and DP being the most clinically relevant. Each locus can have multiple variants known as alleles, which are designated by a specific nomenclature that includes the locus name followed by an asterisk and a series of digits indicating the allele group and specific variant. The identification of these alleles is important for various medical applications, including organ transplantation, disease susceptibility assessments, and understanding immune responses to infections and autoimmune conditions. The low resolution typing performed under this code identifies antigen equivalents and is typically conducted using molecular techniques such as polymerase chain reaction (PCR) with sequence-specific priming (SSP). This method amplifies specific groups of alleles, allowing for the verification of HLA types, particularly for HLA-A, HLA-B, and DRB1 loci.

1. Indications

The HLA Class I and II typing, low resolution (CPT® Code 81371) is indicated for various clinical scenarios where understanding an individual's HLA type is essential. The following conditions and situations warrant this testing:

Organ Transplantation HLA typing is crucial for matching organ donors and recipients to minimize the risk of transplant rejection.
Autoimmune Diseases Testing may be performed to assess susceptibility to certain autoimmune conditions, aiding in diagnosis and management.
Infectious Diseases HLA typing can help evaluate the immune response to specific infections, providing insights into disease progression and treatment options.
Genetic Counseling This test may be utilized in genetic counseling to inform patients about potential risks of inherited conditions related to HLA types.
Research Purposes HLA typing is often used in clinical research to study associations between HLA types and various diseases.

2. Procedure

The procedure for HLA Class I and II typing, low resolution, involves several key steps to ensure accurate identification of the HLA alleles. The following procedural steps are typically followed:

Step 1: Sample Collection A biological sample, usually blood or buccal swab, is collected from the patient. This sample contains nucleated cells necessary for DNA extraction.
Step 2: Cell Lysis and Protein Digestion The collected sample undergoes cell lysis to break down the cell membranes, followed by protein digestion to prepare the nucleic acids for extraction. This step is critical for isolating DNA from the cells.
Step 3: DNA Extraction The DNA is extracted from the lysed cells using appropriate molecular techniques, ensuring that the DNA is of sufficient quality and quantity for subsequent analysis.
Step 4: PCR Amplification Polymerase chain reaction (PCR) is employed to amplify specific regions of the extracted DNA that correspond to the HLA loci of interest. In low resolution typing, a panel of primer pairs is used to target groups of alleles.
Step 5: Verification Typing The amplified products are analyzed to determine the presence of specific HLA alleles at the HLA-A, HLA-B, and DRB1 loci. This verification typing confirms the low resolution identification of the HLA types.

3. Post-Procedure

After the HLA Class I and II typing procedure, the patient may not require any specific post-procedure care, as the process is minimally invasive. However, it is essential to ensure that the results are accurately interpreted and communicated to the healthcare provider for further clinical decision-making. The expected recovery is immediate, as the procedure does not involve any surgical intervention. Patients should be informed about the potential implications of their HLA typing results, especially in the context of organ transplantation and autoimmune disease management. Follow-up consultations may be necessary to discuss the results and any further testing or treatment options that may be indicated based on the findings.

Short Descr	HLA I & II TYPE VERIFY LR
Medium Descr	HLA I&LI LOW RESOLUTION HLA-A -B&-DRB1
Long Descr	HLA Class I and II typing, low resolution (eg, antigen equivalents); HLA-A, -B, and -DRB1 (eg, verification typing)
Status Code	Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days	XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC)	9 - Not Applicable
Multiple Procedures (51)	9 - Concept does not apply.
Bilateral Surgery (50)	9 - Concept does not apply.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	9 - Concept does not apply.
Co-Surgeons (62)	9 - Concept does not apply.
Team Surgery (66)	9 - Concept does not apply.
Diagnostic Imaging Family	99 - Concept Does Not Apply
CLIA Waived (QW)	No
APC Status Indicator	Service Paid under Fee Schedule or Payment System other than OPPS
Type of Service (TOS)	5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS)	T1H - Lab tests - other (non-Medicare fee schedule)
MUE	1
CCS Clinical Classification	234 - Pathology

Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.

Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.