HLA-B51

Further information: HLA-serotype tutorial

HLA-B51 (B51) is an HLA-B serotype. The serotype identifies the more common HLA-B*51 gene products.^[1]

B*5101-β2M with bound peptide 1e28​
major histocompatibility complex (human), class I, B51
Alleles	B*5101, 5102, 5103, . . .
Structure (See HLA-B)		Available 3D structures
EBI-HLA	B*5101	1e28​, 1e27​

B51 is a split antigen of the broad antigen B5, and is a sister serotype of B52.^[2] There are many alleles within the B*51 allele group. B51 is associated with several diseases, including Behçet's disease.

Serotype

Serotypes B51, B5, B52, and B53 recognition of some HLA B*51 allele-group gene products^[3]

B*51	B51	B5	B52	B53	Sample
allele	%	%	%	%	size (N)
*5101	96	2	1		1899
*5102	73	3	6	11	218
*5104	83	17			6
*5105	48		16	24	25
*5106	64		7	12	42
*5107	78		9		68
*5108	77			3	154
*5109	86				43
B**5102 also reacts to B5102 - 3%, **5103 with B5103
Alleles link-out to IMGT/HLA Databease at EBI

Alleles

There are 71 alleles, 57 amino acid sequence variants in B51 of which 4 are nulls. Of these only 9 are frequent enough to have been reliably serotyped. B*5101 is the most common, but others have a large regional abundance.

HLA B*5101 frequencies

		freq
ref.	Population	(%)
[4]	Bulgaria	20.9
[4]	Georgia Tbilisi Georgians	15.7
[4]	India Tamil Nadu Nadar	15.6
[4]	China North Han	14.8
[4]	Georgia Tbilisi Kurds	12.1
[4]	India Andhra Pradesh Golla	12.0
[4]	China Qinghai Hui	11.4
[4]	India New Delhi	9.8
[4]	Madeira	9.7
[4]	South Africa Natal Tamil	9.2
[4]	USA Hawaii Okinawa	8.7
[4]	Cape Verde Northwestern Islands	8.1
[4]	Cape Verde Southeastern Islands	7.3
[4]	India Mumbai Marathas	6.8
[4]	Russia Tuva pop 2	6.1
[4]	Israel Arab Druse	6.0
[4]	China Inner Mongolia	5.9
[4]	Czech Republic	5.7
[4]	Finland	5.6
[4]	Iran Baloch	8.1
[4]	Brazil	5.1
[4]	Mexico Guadalajara Mestizos	4.9
[4]	New Mexico Canoncito Navajo	4.9
[4]	China South Han	4.6
[4]	India North Hindus	3.8
[4]	Thailand	3.1
[4]	Ivory Coast Akan Adiopodoume	2.3
[4]	Singapore Chinese Han	2.3
[4]	Singapore Javanese Indonesians	2.0
[4]	Taiwan Saisiat	2.0
[4]	Kenya	1.7
[4]	Cameroon Yaounde	1.6
[4]	Senegal Niokholo Mandenka	1.6
[4]	Guinea Bissau	1.5
[4]	USA Arizona Pima	1.1
[4]	Venezuela Perja Mountain Bari	1.1
[4]	Taiwan Pazeh	0.9
[4]	China Guangdong Meizhou Han	0.5
[4]	Israel Ashk. & Non Ashk. Jews	0.5
[4]	Singapore Thai	3.0
[4]	Iran Baloch	1.0
[4]	USA Asian	1.0

Disease associations

By serotype

Bw51 was associated with Behçet's disease,^[5] in endemic (versus epidemic) mucocutaneous lymph node syndrome,^[6] susceptibility to the virus that causes German measles infection.^[7]

HLA B*5102 frequencies

		freq
ref.	Population	(%)
[4]	Mexico Sonora Seri	1.5
[4]	Thailand	1.4
[4]	Singapore Chinese	1.3
[4]	Hong Kong Chinese	1.0
[4]	USA Natives	0.8
[4]	Mexico Zaptotec Oaxaca	0.7
[4]	South Korea pop 3	0.6
[4]	Shijiazhuang Tianjian Han	0.5
[4]	China Guangxi Maonan	0.5
[4]	Japan (5)	0.4
[4]	USA Asian	0.4
[4]	USA Hispanic	0.4
[4]	USA African America	0.2

In Behçet's disease

Behçet's disease is an inflammation of the wall of blood vessels that can involve the eyes, skin, and the rest of the body.^[8] Several alleles of B51 (B*5101, B*5108, B*5105, and B*5104) are found in disease, and linkage to markers, D6S285, in the HLA locus was strong (P<0.005).^[9] Homozygotes of B51 showed considerably high risk for disease indicating a possible gene-dose effect. B51 is capable of distinguishing several varieties of disease. HLA-B51 is found more frequently in disease that has an eye involvement.^[10] However it is less common in some regions when there is increased neurological involvement.^[11] The MICA*009 allele has been found to also associated with ABD when B51 is also present,^[12] IL-8 and other cytokines may also be involved.^[13][14] Sister chromatid exchange has also been observed more frequently in B51(+) ABD.^[15]

However, B51 tends not to be found in ABD when a certain SUMO4 gene variant is involved,^[16] and symptoms appear to be milder when HLA-B27 is present.^[17]