{{Short description|Serotype}}{{Further2|HLA-serotype tutorial}} {| id="drugInfoBox" style="float: right; clear: right; margin: 0 0 0.5em 1em; background: #ffffff;" class="toccolours" border=0 cellpadding=0 align="right" width="240px" |- align="center" | colspan="3" | 240px|3D representation of HLA-B*5101 (blue) displaying HIV immunodominant epitope KM2 (green) PDB: 1e28 |- style="text-align: center; line-height: 0.75;background:#eeeeee" | colspan="3" color="white" | <small>B*5101-β2M with bound peptide {{PDB2|1e28}}</small> |- style="text-align: center; line-height: 1.00;background:#eeeeee" | colspan="3" color="white" | |- | align="center" colspan="3" | |- style="text-align: center; line-height: 1.00;background:#eeeeee" | colspan="3" color="white" | |- | align="center" colspan="3" | |- | align="center" colspan="3" | <div style="font-size:medium; line-height:120%;">major histocompatibility complex (human), class I, B51</div> |- | bgcolor="#e7dcc3" | Alleles | colspan = 2 bgcolor="#eeeeee" | B*5101, 5102, 5103, . . . <br> |- align="center" | colspan="2" bgcolor="#dddddd" | '''Structure''' (See HLA-B) || bgcolor="#f4f4f4" |Available<br>3D structures |- align="center" | rowspan=1 bgcolor="#e7dcc3" | EBI-HLA | bgcolor="#eeeeee" | [http://www.ebi.ac.uk/cgi-bin/imgt/hla/get_allele.cgi?B*5101 B*5101] |<small>{{PDB2|1e28}}, {{PDB2|1e27}}</small> |}

'''HLA-B51''' ('''B51''') is an HLA-B serotype. The serotype identifies the more common HLA-B*51 gene products.<ref name="pmid15787720">{{cite journal |pmc=2848993 |year=2010 |last1=Marsh |first1=S. G. |title=Nomenclature for factors of the HLA system, 2010 |journal=Tissue Antigens |volume=75 |issue=4 |pages=291–455 |last2=Albert |first2=E. D. |last3=Bodmer |first3=W. F. |last4=Bontrop |first4=R. E. |last5=Dupont |first5=B. |last6=Erlich |first6=H. A. |last7=Fernández-Viña |first7=M. |last8=Geraghty |first8=D. E. |last9=Holdsworth |first9=R. |last10=Hurley |first10=C. K. |last11=Lau |first11=M. |last12=Lee |first12=K. W. |last13=Mach |first13=B. |last14=Maiers |first14=M. |last15=Mayr |first15=W. R. |last16=Müller |first16=C. R. |last17=Parham |first17=P. |last18=Petersdorf |first18=E. W. |last19=Sasazuki |first19=T. |last20=Strominger |first20=J. L. |last21=Svejgaard |first21=A. |last22=Terasaki |first22=P. I. |last23=Tiercy |first23=J. M. |last24=Trowsdale |first24=J. |pmid=20356336 |doi=10.1111/j.1399-0039.2010.01466.x }}</ref>

B51 is a split antigen of the broad antigen B5, and is a sister serotype of B52.<ref name="pmid12622774">{{cite journal |vauthors=Cox ST, McWhinnie AJ, Robinson J, etal |title=Cloning and sequencing full-length HLA-B and -C genes |journal=Tissue Antigens |volume=61 |issue=1 |pages=20–48 |date=January 2003 |pmid=12622774 |doi=10.1034/j.1399-0039.2003.610103.x |url=http://www.ebi.ac.uk/~sp/intern/projects/pdf_archive/pdfpumped/4/12622774.pdf |archive-url=https://wayback.archive-it.org/all/20081028235823/http://www.ebi.ac.uk/~sp/intern/projects/pdf_archive/pdfpumped/4/12622774.pdf |url-status=dead |archive-date=2008-10-28 |access-date=2008-08-03 }}</ref> There are many alleles within the B*51 allele group. B51 is associated with several diseases, including Behçet's disease.

==Serotype== {| border="0" cellspacing="0" cellpadding="0" align="left" style="text-align:center; background:#ffffff; margin-right: 1em; border:2px #e0e0ff solid;" |+ Serotypes B51, B5, B52, and B53 recognition of some HLA B*51 allele-group gene products<ref>[http://www.ebi.ac.uk/imgt/hla/allele.html derived from IMGT/HLA]</ref> |- style="background:#f0f0ff" | style="width:60px" | B*51 || style="width:60px" | '''B51''' | style="width:60px" | B5 | style="width:60px" | B52 | style="width:60px" | B53 || style="width:60px" | Sample |- style="background:#f0f0ff" | allele || % || % || % || % || size (N) |- | style = "background:#e8e8f8" | {{Asterisk}}5101 || 96 || 2 || 1 || || 1899 |- | style = "background:#e8e8f8" | {{Asterisk}}5102 || 73 || 3 || 6 || 11 ||218 |- | style = "background:#e8e8f8" | {{Asterisk}}5104 || 83 || 17 || || ||6 |- | style = "background:#e8e8f8" | {{Asterisk}}5105 || 48 || || 16 || 24 || 25 |- | style = "background:#e8e8f8" | {{Asterisk}}5106 || 64 || || 7 || 12 || 42 |- | style = "background:#e8e8f8" | {{Asterisk}}5107 || 78 || || 9 || || 68 |- | style = "background:#e8e8f8" | {{Asterisk}}5108 || 77 || || || 3 || 154 |- | style = "background:#e8e8f8" | {{Asterisk}}5109 || 86 || || || || 43 |- | colspan = 6 | B*{{Asterisk}}5102 also reacts to B5102 - 3%, *{{Asterisk}}5103 with B5103 |- | colspan = 6 | Alleles link-out to IMGT/HLA Databease at EBI |} {{Clear}}

==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. {|border="0" cellspacing="0" cellpadding="1" align="left" style="text-align:center; margin-right: 3em; border:1px #ffeebb solid; background:#f8f6f8; " |+ '''HLA B*5101 frequencies''' |- style="background:#efe5ef" | || || freq |- style="background:#eee5ef" | ref. || align="left" |Population || style="width:50px" | (%) |- | <ref name = "pmid12753660">{{cite journal |vauthors=Middleton D, Menchaca L, Rood H, Komerofsky R | title = New allele frequency database: <nowiki>http://www.allelefrequencies.net</nowiki> | journal = Tissue Antigens | volume = 61 | issue = 5 | pages = 403–7 | year = 2003 | pmid = 12753660 | doi =10.1034/j.1399-0039.2003.00062.x | doi-access = free }}</ref> || align="left"|Bulgaria||20.9 |- | <ref name = "pmid12753660"/> || align="left"|Georgia Tbilisi Georgians||15.7 |- | <ref name = "pmid12753660"/> || align="left"|India Tamil Nadu Nadar||15.6 |- | <ref name = "pmid12753660"/> || align="left"|China North Han||14.8 |- | <ref name = "pmid12753660"/> || align="left"|Georgia Tbilisi Kurds||12.1 |- | <ref name = "pmid12753660"/> || align="left"|India Andhra Pradesh Golla||12.0 |- | <ref name = "pmid12753660"/> || align="left"|China Qinghai Hui||11.4 |- | <ref name = "pmid12753660"/> || align="left"|India New Delhi||9.8 |- | <ref name = "pmid12753660"/> || align="left"|Madeira||9.7 |- | <ref name = "pmid12753660"/> || align="left"|South Africa Natal Tamil||9.2 |- | <ref name = "pmid12753660"/> || align="left"|USA Hawaii Okinawa||8.7 |- | <ref name = "pmid12753660"/> || align="left"|Cape Verde Northwestern Islands||8.1 |- | <ref name = "pmid12753660"/> || align="left"|Cape Verde Southeastern Islands||7.3 |- | <ref name = "pmid12753660"/> || align="left"|India Mumbai Marathas||6.8 |- | <ref name = "pmid12753660"/> || align="left"|Russia Tuva pop 2||6.1 |- | <ref name = "pmid12753660"/> || align="left"|Israel Arab Druse||6.0 |- | <ref name = "pmid12753660"/> || align="left"|China Inner Mongolia||5.9 |- | <ref name = "pmid12753660"/> || align="left"|Czech Republic||5.7 |- | <ref name = "pmid12753660"/> || align="left"|Finland||5.6 |- | <ref name = "pmid12753660"/> || align="left"|Iran Baloch||8.1 |- | <ref name = "pmid12753660"/> || align="left"|Brazil||5.1 |- | <ref name = "pmid12753660"/> || align="left"|Mexico Guadalajara Mestizos||4.9 |- | <ref name = "pmid12753660"/> || align="left"|New Mexico Canoncito Navajo||4.9 |- | <ref name = "pmid12753660"/> || align="left"|China South Han||4.6 |- | <ref name = "pmid12753660"/> || align="left"|India North Hindus||3.8 |- | <ref name = "pmid12753660"/> || align="left"|Thailand ||3.1 |- | <ref name = "pmid12753660"/> || align="left"|Ivory Coast Akan Adiopodoume||2.3 |- | <ref name = "pmid12753660"/> || align="left"|Singapore Chinese Han||2.3 |- | <ref name = "pmid12753660"/> || align="left"|Singapore Javanese Indonesians||2.0 |- | <ref name = "pmid12753660"/> || align="left"|Taiwan Saisiat||2.0 |- | <ref name = "pmid12753660"/> || align="left"|Kenya ||1.7 |- | <ref name = "pmid12753660"/> || align="left"|Cameroon Yaounde||1.6 |- | <ref name = "pmid12753660"/> || align="left"|Senegal Niokholo Mandenka||1.6 |- | <ref name = "pmid12753660"/> || align="left"|Guinea Bissau||1.5 |- | <ref name = "pmid12753660"/> || align="left"|USA Arizona Pima||1.1 |- | <ref name = "pmid12753660"/> || align="left"|Venezuela Perja Mountain Bari||1.1 |- | <ref name = "pmid12753660"/> || align="left"|Taiwan Pazeh||0.9 |- | <ref name = "pmid12753660"/> || align="left"|China Guangdong Meizhou Han||0.5 |- | <ref name = "pmid12753660"/> || align="left"|Israel Ashk. & Non Ashk. Jews||0.5 |- | <ref name = "pmid12753660"/> || align="left"|Singapore Thai||3.0 |- | <ref name = "pmid12753660"/> || align="left"|Iran Baloch||1.0 |- | <ref name = "pmid12753660"/> || align="left"|USA Asian||1.0 |}

==Disease associations==

===By serotype=== Bw51 was associated with Behçet's disease,<ref>{{cite journal |vauthors=Ohno S, Ohguchi M, Hirose S, Matsuda H, Wakisaka A, Aizawa M |title=Close association of HLA-Bw51 with Behçet's disease |journal=Arch. Ophthalmol. |volume=100 |issue=9 |pages=1455–8 |date=September 1982 |pmid=6956266 |doi= 10.1001/archopht.1982.01030040433013}}</ref> in endemic (versus epidemic) mucocutaneous lymph node syndrome,<ref name="pmid6958087">{{cite journal |vauthors=Keren G, Danon YL, Orgad S, Kalt R, Gazit E |title=HLA Bw51 is increased in mucocutaneous lymph node syndrome in Israeli patients |journal=Tissue Antigens |volume=20 |issue=2 |pages=144–6 |date=August 1982 |pmid=6958087 |doi= 10.1111/j.1399-0039.1982.tb00337.x}}</ref> susceptibility to the virus that causes German measles infection.<ref name="pmid6950026">{{cite journal |vauthors=Ishii K, Nakazono N, Sawada H, etal |title=Host factors and susceptibility to rubella virus infection: the association of HLA antigens |journal=J. Med. Virol. |volume=7 |issue=4 |pages=287–97 |year=1981 |pmid=6950026 |doi= 10.1002/jmv.1890070405|title-link=rubella virus }}</ref>

{|border="0" cellspacing="0" cellpadding="1" align="right" style="text-align:center; margin-left: 1em; border:1px #ffeebb solid; background:#f8f6f8; " |+ '''HLA B*5102 frequencies''' |- style="background:#efe5ef" | || || freq |- style="background:#eee5ef" | ref. || align="left" |Population || style="width:50px" | (%) |- | <ref name = "pmid12753660"/> || align="left"|Mexico Sonora Seri||1.5 |- | <ref name = "pmid12753660"/> || align="left"|Thailand||1.4 |- | <ref name = "pmid12753660"/> || align="left"|Singapore Chinese||1.3 |- | <ref name = "pmid12753660"/> || align="left"|Hong Kong Chinese||1.0 |- | <ref name = "pmid12753660"/> || align="left"|USA Natives||0.8 |- | <ref name = "pmid12753660"/> || align="left"|Mexico Zaptotec Oaxaca||0.7 |- | <ref name = "pmid12753660"/> || align="left"|South Korea pop 3||0.6 |- | <ref name = "pmid12753660"/> || align="left"|Shijiazhuang Tianjian Han||0.5 |- | <ref name = "pmid12753660"/> || align="left"|China Guangxi Maonan||0.5 |- | <ref name = "pmid12753660"/> || align="left"|Japan (5)||0.4 |- | <ref name = "pmid12753660"/> || align="left"|USA Asian||0.4 |- | <ref name = "pmid12753660"/> || align="left"|USA Hispanic||0.4 |- | <ref name = "pmid12753660"/> || align="left"|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.<ref name="pmid18214795">{{cite journal |vauthors=Durrani K, Papaliodis GN |title=The genetics of Adamantiades-Behcet's disease |journal=Semin Ophthalmol |volume=23 |issue=1 |pages=73–9 |year=2008 |pmid=18214795 |doi=10.1080/08820530701745264 }}</ref> 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).<ref name="pmid15934084">{{cite journal |vauthors=Karasneh J, Gül A, Ollier WE, Silman AJ, Worthington J |title=Whole-genome screening for susceptibility genes in multicase families with Behçet's disease |journal=Arthritis Rheum. |volume=52 |issue=6 |pages=1836–42 |date=June 2005 |pmid=15934084 |doi=10.1002/art.21060 }}</ref> 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.<ref name="pmid18551141">{{cite journal |vauthors=Krause L, Köhler AK, Altenburg A, Papoutsis N, Zouboulis CC, Pleyer U, Stroux A, Foerster MH |title=Ocular involvement is associated with HLA-B51 in Adamantiades-Behçet's disease |journal=Eye |volume= 23|issue= 5|pages= 1182–6|date=June 2008 |pmid=18551141 |doi=10.1038/eye.2008.177 |doi-access=free }}</ref> However it is less common in some regions when there is increased neurological involvement.<ref name="pmid17949553">{{cite journal |vauthors=Houman MH, Neffati H, Braham A, etal |title=Behçet's disease in Tunisia. Demographic, clinical and genetic aspects in 260 patients |journal=Clin. Exp. Rheumatol. |volume=25 |issue=4 Suppl 45 |pages=S58–64 |year=2007 |pmid=17949553 |url=http://www.clinexprheumatol.org/pubmed/find-pii.asp?pii=17949553}}</ref> The MICA*009 allele has been found to also associated with ABD when B51 is also present,<ref name="pmid18158593">{{cite journal |vauthors=Mizuki N, Meguro A, Tohnai I, Gül A, Ohno S, Mizuki N |title=Association of Major Histocompatibility Complex Class I Chain-Related Gene A and HLA-B Alleles with Behçet's Disease in Turkey |journal=Jpn. J. Ophthalmol. |volume=51 |issue=6 |pages=431–6 |year=2007 |pmid=18158593 |doi=10.1007/s10384-007-0473-y }}</ref> IL-8 and other cytokines may also be involved.<ref name="pmid17257314">{{cite journal |vauthors=Lee EB, Kim JY, Zhao J, Park MH, Song YW |title=Haplotype association of IL-8 gene with Behcet's disease |journal=Tissue Antigens |volume=69 |issue=2 |pages=128–32 |date=February 2007 |pmid=17257314 |doi=10.1111/j.1399-0039.2006.00736.x }}</ref><ref name="pmid17171346">{{cite journal |vauthors=Pay S, Simşek I, Erdem H, Dinç A |title=Immunopathogenesis of Behçet's disease with special emphasize on the possible role of antigen presenting cells |journal=Rheumatol. Int. |volume=27 |issue=5 |pages=417–24 |date=March 2007 |pmid=17171346 |doi=10.1007/s00296-006-0281-6 }}</ref> Sister chromatid exchange has also been observed more frequently in B51(+) ABD.<ref name="pmid16441621">{{cite journal |vauthors=Ikbal M, Atasoy M, Pirim I, Aliagaoglu C, Karatay S, Erdem T |title=The alteration of sister chromatid exchange frequencies in Behçet's disease with and without HLA-B51 |journal=J Eur Acad Dermatol Venereol |volume=20 |issue=2 |pages=149–52 |date=February 2006 |pmid=16441621 |doi=10.1111/j.1468-3083.2006.01386.x }}</ref>

However, B51 tends not to be found in ABD when a certain SUMO4 gene variant is involved,<ref name="pmid18657476">{{cite journal |vauthors=Hou S, Yang P, Du L, etal |title=SUMO4 gene polymorphisms in Chinese Han patients with Behcet's disease |journal=Clin. Immunol. |volume= 129|issue= 1|pages= 170–5|date=July 2008 |pmid=18657476 |doi=10.1016/j.clim.2008.06.006 }}</ref> and symptoms appear to be milder when HLA-B27 is present.<ref name="pmid17923546">{{cite journal |vauthors=Ahn JK, Park YG |title=Human leukocyte antigen B27 and B51 double-positive Behçet uveitis |journal=Arch. Ophthalmol. |volume=125 |issue=10 |pages=1375–80 |date=October 2007 |pmid=17923546 |doi=10.1001/archopht.125.10.1375 |doi-access=free }}</ref>

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==References== {{reflist|2}}

{{HLA-B serotypes}}

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