HLA-DR3 is composed of the HLA-DR17 and HLA-DR18 split 'antigens'

serotypes A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their shared reactivity between their su ...

. DR3 is a component gene-

allele An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), ...

of the AH8.1 haplotype in Northern and Western Europeans. Genes between B8 and DR3 on this haplotype are frequently associated with autoimmune disease. Type 1 diabetes mellitus is associated with HLA-DR3 or HLA-DR4. Nearly half the US population has either DR3 or DR4 (only 1–3% have both), yet only a small percentage (about 0.5%) of these individuals will develop type 1 diabetes.

Serology

Some DR3 also react with HLA-DR17 and/or HLA-DR18. The DRB1*03:04 primarily reacts with DR3. The serotypes of *03:05, *03:06, *03:08 to *03:31 are unknown.

Disease associations

By serotype

HLA-DR3 is associated with early-age onset

myasthenia gravis Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, ...

Hashimoto's thyroiditis Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, Hashimoto's disease and autoimmune thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on, symptoms may not be noticed. Over ti ...

(along with DR5),

primary sclerosing cholangitis Primary sclerosing cholangitis (PSC) is a long-term progressive disease of the liver and gallbladder characterized by inflammation and scarring of the bile ducts, which normally allow bile to drain from the gallbladder. Affected individuals may ...

, and

opportunistic infection An opportunistic infection is an infection that occurs most commonly in individuals with an immunodeficiency disorder and acts more severe on those with a weakened immune system. These types of infections are considered serious and can be caused b ...

s in

AIDS The HIV, human immunodeficiency virus (HIV) is a retrovirus that attacks the immune system. Without treatment, it can lead to a spectrum of conditions including acquired immunodeficiency syndrome (AIDS). It is a Preventive healthcare, pr ...

, but lowered risk for cancers. It is also associated with

membranous glomerulonephritis Membranous glomerulonephritis (MGN) is a slowly progressive disease of the kidney affecting mostly people between ages of 30 and 50 years, usually white people (i.e., those of European, Middle Eastern, or North African ancestry.). It is the sec ...

By allele

DRB1*03:01 (see HLA-DR17) DRB1*03:02 (See HLA-DR18) DRB1*03:04 is associated with

Graves disease Graves' disease, also known as toxic diffuse goiter or Basedow's disease, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyroid. ...

By haplotypes

DR3 and/or DQ2 is associated with Moreen's ulceration, "bout onset" multiple sclerosis,

Graves' disease Graves' disease, also known as toxic diffuse goiter or Basedow's disease, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyro ...

and

systemic lupus erythematosus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...

DR3-DQ2 linkage is associated with

coeliac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine. Patients develop intolerance to gluten, which is present in foods such as wheat, rye, spelt ...

dermatitis herpetiformis Dermatitis herpetiformis (DH) is a chronic autoimmune blistering skin condition, characterised by intensely itchy blisters filled with a watery fluid. DH is a cutaneous manifestation of coeliac disease, although the exact causal mechanism is not ...

Diabetes mellitus type 1 Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body's immune system destroys pancreatic cells (beta cells). In healthy persons, beta cells produce insulin. Insulin is a hormone required ...

. DR3-DQ2 is the serological marker for HLA-DQ2.5cis isoform. Although it cannot identify the alpha ".5" chain of HLA DQ, DQA1*05:01 gene is almost always found within the DR3-DQ2 haplotype Eurasia (however in older studies DQA1*05:05 is commonly confused with DQA1*05:01)

Genetic linkage

DR3 is genetically linked to HLA-DR52, DRB3*02:02 allele, and HLA-DQ2 (DQ2.5).

References

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