HLA-DR5

DR Illustration

HLA-DR5 is a serotype within the HLA-DR (Human Leukocyte Antigen - DR) antigen system, which is part of the major histocompatibility complex (MHC) class II molecules. The HLA-DR5 serotype recognizes the DRB1*11 and DRB1*12 gene products.

Structure and Function

HLA-DR5 is a heterodimer consisting of an alpha (α) chain and a beta (β) chain. These chains are encoded by the HLA-DRA and HLA-DRB1 genes, respectively. The primary role of HLA-DR5, like other HLA-DR molecules, is to present peptides derived from extracellular proteins to CD4+ T cells, which are crucial for initiating the immune response.

Genetics

The HLA-DR5 serotype is associated with the DRB1*11 and DRB1*12 alleles. These alleles are part of the HLA-DRB1 gene locus on chromosome 6. The DRB1*11 allele can be further subdivided into several subtypes, including DRB1*1101, DRB1*1102, and others. Similarly, the DRB1*12 allele includes subtypes such as DRB1*1201 and DRB1*1202.

Disease Associations

HLA-DR5 has been implicated in various autoimmune diseases and other medical conditions. Some of the notable associations include:

• Rheumatoid arthritis
• Systemic lupus erythematosus
• Graves' disease
• Hashimoto's thyroiditis
• Primary biliary cirrhosis

Population Distribution

The frequency of HLA-DR5 varies among different populations. It is more commonly found in certain ethnic groups, which can be attributed to the genetic diversity and evolutionary history of human populations.

Clinical Relevance

Understanding the distribution and function of HLA-DR5 is important for organ transplantation, as matching donor and recipient HLA types can reduce the risk of graft rejection. Additionally, identifying HLA-DR5 can aid in the diagnosis and management of autoimmune diseases.

See Also

• HLA-DR
• HLA-DQ
• HLA-DP
• Major histocompatibility complex
• Autoimmune disease