HLA-A,B,C TYPING

HLA-A, HLA-B, and HLA-C are genes encoding MHC class I proteins expressed on nearly all nucleated cells. They present intracellular peptide fragments to CD8+ T cells, enabling recognition and killing of infected or abnormal cells. Highly polymorphic, these loci influence immune responses, transplant compatibility, and susceptibility to certain autoimmune and infectious diseases; matching them is critical in transplantation.

HLA typing identifies specific Human Leukocyte Antigen (HLA) genes or proteins on a person’s white blood cells. It assesses tissue compatibility for organ and bone marrow transplants, aids donor matching, and can indicate susceptibility to certain autoimmune conditions and some drug hypersensitivity reactions. Results guide transplant decisions and targeted clinical management.

HLA-B27 DNA typing is a genetic test that detects the HLA-B27 gene variant using blood or cheek-swab samples and molecular methods (PCR). It helps identify increased risk for ankylosing spondylitis and related spondyloarthropathies but is not diagnostic alone — many carriers are healthy and some patients lack it. Results support diagnosis, prognosis, and treatment planning with clinical correlation.

Celiac disease is strongly associated with HLA‑DQ2 and HLA‑DQ8; about 90–95% of patients carry HLA‑DQ2 and most of the remainder carry HLA‑DQ8. HLA‑DQ2 is encoded by DQA1*05 and DQB1*02; HLA‑DQ8 by DQA1*03 and DQB1*03:02. Presence indicates genetic susceptibility but not diagnosis; absence of both makes celiac disease very unlikely.

HLA‑B testing identifies specific alleles of the HLA‑B gene. It’s used for transplant compatibility and to detect alleles linked to disease risk (for example HLA‑B27 with ankylosing spondylitis) and for pharmacogenetic screening to predict severe drug reactions (for example HLA‑B*57:01 with abacavir, HLA‑B*15:02 with carbamazepine). Results guide medication choice and donor–recipient matching.

Cost varies by country and test type. In India HLA‑B (commonly HLA‑B27) tests typically cost about ₹400–2,000 at private labs. In the US they’re commonly $50–$200 through commercial labs; in the UK they’re free on the NHS when clinically indicated, or roughly £30–£100 privately. High‑resolution HLA‑B typing for transplant workups can run several hundred dollars more.