HLA 1 & 2 (Patient) HLA Tissue Typing at Test Zone Diagnostic Center

HLA 1 & 2 (Patient) HLA Tissue Typing at Test Zone Diagnostic Center

Human Leukocyte Antigen (HLA) typing, commonly referred to as tissue typing, is a highly sophisticated molecular diagnostic procedure that identifies unique genetic markers on the surface of an individual’s cells. These markers, which are part of the Major Histocompatibility Complex (MHC) located on chromosome 6, play a fundamental role in the body’s immune system. The immune system utilizes these specialized proteins to distinguish ‘self’ (the body’s own cells) from ‘non-self’ (foreign invaders such as bacteria, viruses, or transplanted tissues). At Test Zone Diagnostic Center, the HLA 1 & 2 (Patient) HLA Tissue Typing test is performed using advanced molecular biology techniques to provide high-resolution genetic profiling. This test is of paramount clinical importance in several medical fields, most notably in transplantation medicine, autoimmune disease diagnosis, and pharmacogenomics.

Class I antigens (HLA-A, HLA-B, and HLA-C) are expressed on almost all nucleated cells in the body and present endogenous peptides to CD8+ cytotoxic T-lymphocytes. Class II antigens (HLA-DR, HLA-DQ, and HLA-DP) are primarily expressed on professional antigen-presenting cells, such as dendritic cells, macrophages, and B-lymphocytes, presenting exogenous peptides to CD4+ helper T-lymphocytes. Understanding the precise genetic makeup of these loci is critical. For patients undergoing solid organ transplantation (such as kidney, liver, or heart) or hematopoietic stem cell transplantation (HSCT), matching the HLA profile of the donor and the recipient is the single most critical factor determining the success of the transplant. A close match minimizes the risk of graft rejection, where the recipient’s immune system attacks the donor organ, or graft-versus-host disease (GVHD), a life-threatening condition where the donor’s immune cells attack the recipient’s tissues.

Clinical Procedure: What to Expect

Patient Preparation

• No fasting is required prior to the HLA 1 & 2 (Patient) HLA Tissue Typing test. Patients may eat and drink normally.
• Inform the clinical staff at Test Zone Diagnostic Center if you have received a blood transfusion within the last 72 hours, as foreign white blood cells can temporarily interfere with molecular testing.
• Disclose if you have previously undergone a bone marrow or stem cell transplant, as this can affect the source of DNA in your blood.
• Provide a complete list of current medications, particularly immunosuppressants or chemotherapy agents, to the laboratory staff.
• Wear a short-sleeved shirt or clothing with sleeves that can be easily rolled up to facilitate comfortable access to the venipuncture site.

During the Procedure

The HLA 1 & 2 (Patient) HLA Tissue Typing is a straightforward blood test. A trained phlebotomist at Test Zone Diagnostic Center will locate a suitable vein, typically in the antecubital fossa of the arm. The area is thoroughly cleansed with an antiseptic solution to prevent contamination. A sterile, single-use needle is inserted into the vein, and blood is drawn into a tube containing an anticoagulant, typically ethylenediaminetetraacetic acid (EDTA), which preserves the integrity of the white blood cells from which genomic DNA is extracted. The procedure takes only a few minutes and involves minimal discomfort, comparable to a mild pinch. After the blood is collected, pressure is applied to the puncture site, and a sterile bandage is applied. The sample is then promptly sent to the molecular diagnostics laboratory under controlled temperature conditions to ensure sample stability.

When is a HLA 1 & 2 (Patient) HLA Tissue Typing Performed?

Solid Organ Transplantation Matching

Before a patient can receive a kidney, liver, heart, or lung transplant, HLA typing is mandatory. The test establishes the recipient’s HLA profile, which is then compared against potential living or deceased donors. A higher degree of HLA compatibility correlates with superior graft survival rates, lower incidence of acute and chronic rejection episodes, and a reduced requirement for high-dose post-transplant immunosuppressive therapy, which carries its own risks of infection and toxicity.

Hematopoietic Stem Cell and Bone Marrow Transplantation

For hematologic malignancies like leukemia, lymphoma, and myelodysplastic syndromes, as well as severe aplastic anemia and certain genetic disorders, hematopoietic stem cell transplantation (HSCT) is often the only curative option. Unlike solid organ transplants, HSCT requires an extremely high degree of HLA matching (ideally a 10/10 match across HLA-A, -B, -C, -DRB1, and -DQB1 loci) to prevent the devastating complication of graft-versus-host disease (GVHD). HLA typing identifies whether a sibling is a perfect match or if an unrelated donor must be sought through international registries.

Diagnosis of HLA-Associated Autoimmune and Inflammatory Diseases

Certain HLA alleles are strongly linked to specific autoimmune and inflammatory conditions. For instance, the HLA-B27 allele is present in over 90% of patients with ankylosing spondylitis, a chronic inflammatory arthritis affecting the spine. Similarly, HLA-DRB1 alleles are associated with rheumatoid arthritis, and HLA-DQ2 and HLA-DQ8 are highly associated with celiac disease. When clinical symptoms are ambiguous, identifying these specific HLA markers at Test Zone Diagnostic Center helps clinicians confirm or rule out these complex diagnoses.

Pharmacogenomic Screening for Drug Hypersensitivity

Severe, life-threatening drug hypersensitivity reactions can be predicted using HLA typing. The HLA-B*5701 allele is strongly associated with a severe hypersensitivity reaction to the antiretroviral drug abacavir, used in HIV treatment. Screening patients for HLA-B*5701 before initiating therapy has virtually eliminated this reaction. Similarly, the HLA-B*1502 allele is associated with carbamazepine-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), particularly in patients of Asian descent. Testing for these alleles ensures personalized, safe prescribing practices.

Management of Platelet Transfusion Refractoriness

Patients who receive multiple platelet transfusions may develop antibodies against foreign HLA Class I antigens present on the transfused platelets. This immune response leads to the rapid destruction of transfused platelets, a condition known as platelet refractoriness. HLA typing of the patient allows blood banks to select HLA-matched platelet donors, ensuring that the transfused platelets survive in the patient’s circulation and effectively prevent or treat bleeding episodes.

What Does a HLA 1 & 2 (Patient) HLA Tissue Typing Detect?

The HLA 1 & 2 (Patient) HLA Tissue Typing test at Test Zone Diagnostic Center is designed to detect and identify specific alleles across multiple loci. The test detects:

• Specific HLA-A alleles (Class I)
• Specific HLA-B alleles (Class I)
• Specific HLA-C alleles (Class I)
• Specific HLA-DRB1 alleles (Class II)
• Specific HLA-DQB1 alleles (Class II)
• Specific HLA-DQA1 alleles (Class II)
• Specific HLA-DPB1 alleles (Class II)
• Presence or absence of the HLA-B*27 allele (ankylosing spondylitis risk)
• Presence or absence of the HLA-B*57:01 allele (abacavir hypersensitivity risk)
• Presence or absence of the HLA-B*15:02 allele (carbamazepine-induced SJS/TEN risk)
• Presence or absence of the HLA-B*58:01 allele (allopurinol hypersensitivity risk)
• Presence or absence of the HLA-A*31:01 allele (carbamazepine hypersensitivity risk in European populations)
• Presence or absence of HLA-DQ2.5 and HLA-DQ8 heterodimers (celiac disease genetic susceptibility)
• Presence of HLA-DRB1*04 alleles (associated with severe rheumatoid arthritis)
• Presence of HLA-DRB1*15:01 allele (associated with increased multiple sclerosis susceptibility)
• Presence of HLA-A*29 allele (highly specific marker for birdshot chorioretinopathy)
• Presence of HLA-B*51 allele (associated with Behçet’s disease)
• Presence of HLA-DR3 and HLA-DR4 alleles (associated with Type 1 Diabetes Mellitus)
• Resolution level of typing (low, intermediate, or high-resolution)
• Allelic homozygosity or heterozygosity at each locus
• Percent panel-reactive antibody (PRA) compatibility (when paired with antibody screening)
• Haploidentical donor matching status (5/10 match evaluation)
• Sibling donor compatibility index (full match, haploidentical, or mismatch)
• Unrelated donor compatibility index (e.g., 8/8 or 10/10 match)
• Post-transplant chimerism status (monitoring donor vs. recipient cell ratios)

Turnaround Time and Report Access at Test Zone Diagnostic Center

HLA typing is a highly complex molecular test involving DNA extraction, amplification, and sequencing or hybridization. At Test Zone Diagnostic Center, the turnaround time is optimized to balance clinical urgency with technical precision. Reports are typically available within a few working days. Patients can access their reports online through the secure Test Zone Diagnostic Center patient portal, receive SMS notifications when results are ready, or collect physical copies from the main diagnostic center or any of its collection points.

HLA 1 & 2 (Patient) HLA Tissue Typing Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
HLA-A Locus	Normal polymorphism without disease-associated alleles	Presence of specific alleles (e.g., HLA-A*29 associated with autoimmune eye disease)
HLA-B Locus	Normal polymorphism	Presence of HLA-B*27 (ankylosing spondylitis) or HLA-B*57:01 (drug hypersensitivity)
HLA-C Locus	Normal polymorphism	Presence of HLA-C*06 (associated with psoriasis vulgaris)
HLA-DRB1 Locus	Normal polymorphism	Presence of HLA-DRB1*04 or HLA-DRB1*15 (associated with rheumatoid arthritis or multiple sclerosis)
HLA-DQB1 Locus	Normal polymorphism	Presence of HLA-DQB1*02 or HLA-DQB1*03:02 (celiac disease risk alleles)
Donor-Recipient Compatibility	High-degree match (e.g., 8/8 or 10/10 allelic match)	Mismatched alleles (increased risk of graft rejection or graft-versus-host disease)
HLA-B*5801 Allele	Negative (low risk of severe cutaneous adverse reactions to allopurinol)	Positive (high risk of allopurinol-induced Stevens-Johnson syndrome)
HLA-B*1502 Allele	Negative (low risk of carbamazepine-induced SJS/TEN)	Positive (high risk of severe carbamazepine hypersensitivity)

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Test Zone Diagnostic Center for HLA 1 & 2 (Patient) HLA Tissue Typing?

• Experienced healthcare professionals and molecular pathologists overseeing all testing.
• Patient-focused care ensuring a comfortable and seamless experience.
• Quality diagnostic services utilizing advanced molecular testing methodologies.
• Professional reporting with clear, comprehensive, and clinically actionable results.
• Modern diagnostic approach incorporating state-of-the-art laboratory equipment.
• Comfortable environment at all collection centers and the main facility.
• Convenient location in Lahore, Pakistan, with accessible collection points.
• Commitment to accurate diagnosis, adhering to strict internal and external quality control protocols.