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Official Description

HLA Class II typing, high resolution (ie, alleles or allele groups); one allele or allele group (eg, HLA-DQB1*06:02P), each

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The HLA Class II typing, high resolution (CPT® Code 81383) is a specialized laboratory procedure that focuses on identifying specific alleles or allele groups within the human leukocyte antigen (HLA) system. The HLA system is a critical component of the major histocompatibility complex (MHC), which plays a vital role in the immune system by facilitating self-recognition. This means that the MHC helps the body distinguish its own cells and tissues from foreign substances, including pathogens and non-self cells. The HLA molecules are located on the short arm of chromosome 6 and are essential for the normal functioning of the immune response. HLA Class II molecules are particularly important as they are involved in initiating immune responses. They consist of five loci: DR, DQ, DP, DM, and DO, with DR, DQ, and DP being the most clinically significant. Each locus can have multiple variants known as alleles, which are designated by a specific naming convention that includes the locus name followed by an asterisk and a series of digits (e.g., HLA-DQB1*06:02P). The high-resolution typing of HLA Class II is crucial for various clinical applications, including organ transplantation, where matching donor and recipient HLA types can significantly impact transplant success. The procedure typically involves molecular techniques for DNA extraction, which require cell lysis and protein digestion. Polymerase chain reaction (PCR) is commonly employed to amplify the DNA, and one specific method used for high-resolution typing is PCR sequence-specific priming (SSP). This method utilizes a panel of primer pairs to selectively amplify groups of alleles, allowing for precise identification of specific HLA alleles or allele groups. The high-resolution typing is reported for each allele or allele group identified, providing essential information for clinical decision-making.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The HLA Class II typing, high resolution (CPT® Code 81383) is indicated for various clinical scenarios where precise identification of HLA alleles is necessary. The following conditions and situations may warrant this procedure:

  • Organ Transplantation - To determine compatibility between donors and recipients, which is crucial for the success of organ transplants.
  • Bone Marrow Transplantation - To identify suitable donors for hematopoietic stem cell transplants, ensuring a match that minimizes the risk of graft-versus-host disease.
  • Autoimmune Disorders - To investigate associations between specific HLA alleles and autoimmune diseases, aiding in diagnosis and management.
  • Pharmacogenomics - To assess the risk of adverse drug reactions related to specific HLA alleles, particularly in medications such as abacavir and carbamazepine.
  • Research Purposes - In studies aimed at understanding the role of HLA alleles in various diseases and conditions.

2. Procedure

The procedure for HLA Class II typing, high resolution, involves several critical steps to ensure accurate identification of specific alleles or allele groups. 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: DNA Extraction - The collected sample undergoes cell lysis and protein digestion to extract DNA from the nucleated cells. This step is essential for obtaining high-quality DNA suitable for amplification.
  • Step 3: Polymerase Chain Reaction (PCR) - The extracted DNA is subjected to PCR, a molecular technique that amplifies specific regions of the DNA that correspond to the HLA Class II loci. This amplification is crucial for detecting the presence of specific alleles.
  • Step 4: Sequence-Specific Priming (SSP) - PCR SSP is employed, utilizing a panel of primer pairs designed to amplify groups of alleles at the HLA Class II loci. This method allows for high-resolution typing by selectively amplifying the desired alleles.
  • Step 5: Analysis and Reporting - The amplified products are analyzed to identify the specific alleles or allele groups present in the sample. The results are then reported, detailing the identified HLA alleles, such as HLA-DQB1*06:02P.

3. Post-Procedure

After the HLA Class II typing procedure is completed, the patient may not require any specific post-procedure care, as the process is primarily laboratory-based and does not involve invasive techniques. However, it is essential for healthcare providers to communicate the results to the patient and discuss the implications of the findings, especially in the context of organ transplantation or autoimmune disease management. Follow-up consultations may be necessary to interpret the results and plan further actions based on the identified HLA alleles. Additionally, any adverse reactions to the sample collection method, such as minor bruising or discomfort at the collection site, should be monitored and addressed as needed.

Short Descr HLA II TYPING 1 ALLELE HR
Medium Descr HLA II HIGH RESOLUTION 1 ALLELE/ALLELE GROUP
Long Descr HLA Class II typing, high resolution (ie, alleles or allele groups); one allele or allele group (eg, HLA-DQB1*06:02P), each
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 2
CCS Clinical Classification 234 - Pathology
90 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.
59 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.
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
GW Service not related to the hospice patient's terminal condition
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
GZ Item or service expected to be denied as not reasonable and necessary
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2012-01-01 Added Added
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