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==Function==
== Function ==
 
In [[skin]] infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells.   
In [[skin]] infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells.   


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=== HIV ===
=== HIV ===
====Former hypothesis====
==== Former hypothesis ====


Kawamura et al. (2005) suggested Langerhans cells may be initial cellular targets in the sexual transmission of [[HIV]],<ref>{{REFjournal
Kawamura et al. (2005) suggested Langerhans cells may be initial cellular targets in the sexual transmission of [[HIV]],<ref>{{REFjournal
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====Present view====
==== Present view ====


On 4 March 2007 the online ''Nature Medicine'' magazine published the letter "Langerin is a natural barrier to HIV-1 transmission by Langerhans cells."<ref>{{REFjournal
On 4 March 2007 the online ''Nature Medicine'' magazine published the letter "Langerin is a natural barrier to HIV-1 transmission by Langerhans cells."<ref>{{DeWitte etal 2007}}</ref> One of the authors of the study, Teunis Geijtenbeek, said that "Langerin is able to scavenge viruses from the surrounding environment, thereby preventing infection" and "since generally all tissues on the outside of our bodies have Langerhans cells, we think that the human body is equipped with an antiviral defense mechanism, destroying incoming viruses."<ref>{{REFnews
|last=De Witte
|first=Lot
|init=L
|last2=Nabatov
|first2=Alexey
|init2=A
|last3=Pion
|first3=Marjorie
|init3=M
|last4=Fluitsma
|first4=Donna
|init4=D
|last5=De Jong
|first5=Marein A.W.P.
|init5=MAWP
|last6=De Gruijl
|first6=Tanja
|init6=T
|last7=Piguet
|first7=Vincent
|init7=V
|last8=Van Kooyk
|first8=Yvette
|init8=Y
|last9=Geijtenbeek
|first9=Teunis B.H.
|init9=TBH
|title=Langerin is a natural barrier to HIV-1 transmission by Langerhans cells
|journal=Nature Medicine
|volume=13
|issue=3
|pages=367-371
|url=https://www.nature.com/articles/nm1541
|quote=
|pubmedID=17334373
|pubmedCID=
|DOI=10.1038/nm1541
|date=2007-03-04
|accessdate=2019-10-19
}}</ref> One of the authors of the study, Teunis Geijtenbeek, said that "Langerin is able to scavenge viruses from the surrounding environment, thereby preventing infection" and "since generally all tissues on the outside of our bodies have Langerhans cells, we think that the human body is equipped with an antiviral defense mechanism, destroying incoming viruses."<ref>{{REFnews
  |last=Mundell
  |last=Mundell
  |first=E. J.
  |first=E. J.
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==Population-based studies==
== Population-based studies ==
There is now substantial evidence that male circumcision does NOT in fact, protect against HIV infection.
{{Population-based studies}}
==Two African surveys==
The previously reported studies were from developed Western nations. Now we have information from Sub_Saharan Africa.


September 2021 saw the publication of two huge population studies on the relationship of [[circumcision]] and HIV infection:
French scientist [[Michel Garenne]], Ph.D. has published two reports in 2022 comparing the incidence of HIV infection in [[circumcised]] and [[intact]] men.
 
In his first report, Garenne presented the findings from a study in Lesotho, the enclave in South Africa. He reported:
<blockquote>
In couple studies, the effect of circumcision and VMMC on HIV was not significant, with similar transmission from female to male and male to female. The study questions the amount of effort and money spent on VMMC in Lesotho.<ref name="garenne2022A">{{REFjournal
|last=Garenne
|first=Michel
|init=M
|author-link=Michel Garenne
|title=Changing relationships between HIV prevalence and circumcision in Lesotho
|url=https://pubmed.ncbi.nlm.nih.gov/35373731/
|date=2022-04-04
|journal=J Biosoc Sci
|volume=online ahead of print
|pages=1-16
|DOI=10.1017/S0021932022000153
|pubmedID=35373731
|accessdate=2022-10-28
}}</ref>
</blockquote>


# Mayan et al. (2021) carried out a massive empirical study of the male population of the province of Ontario, [[Canada]] (569,950 males), of whom 203,588 (35.7%) were [[circumcised]] between 1991 and 2017. The study concluded that circumcision status is not related to risk of HIV infection.<ref name="mayan2021">{{REFjournal
In his second report, Garenne (2022) presented information from six Sub-Saharan African nations (Eswatini, Lesotho, Malawi, Namibia, Zambia, Zimbabwe). He reported:
  |last=Mayan
<blockquote>
  |first=Madhur
"Results matched earlier observations made in South Africa that [[circumcised]] and [[intact]] men had similar levels of HIV infection."<ref name="garenne2022B">{{REFjournal
  |last=Garenne
  |first=Michael
  |init=M
  |init=M
  |author-link=
  |author-link=
|last2=Hamilton
|first2=Robert J.
|init2=RJ
|author2-link=
|last3=Juurlink
|first3=David N.
|init3=DN
|author3-link=
|last4=Austin
|first4=Peter C.
|init4=PC
|author4-link=
|last5=Jarvi
|first5=Keith A.
|init5=KA
|author5-link=
  |etal=no
  |etal=no
  |title=Circumcision and Risk of HIV Among Males From Ontario, Canada
  |title=Age-incidence and prevalence of HIV among intact and circumcised men: an analysis of PHIA surveys in Southern Africa
  |journal=J Urol
|trans-title=
  |date=2021-09-23
|language=
  |url=https://www.auajournals.org/doi/pdf/10.1097/JU.0000000000002234
  |journal=J Biosoc Sci
  |quote=We found that circumcision was not independently associated with the risk of acquiring HIV among men from Ontario, Canada.
|location=
  |pubmedID=34551593
  |date=2022-10-26
  |DOI=10.1097/JU.0000000000002234
|season=
  |accessdate=2021-10-02
|volume=
}}</ref>
|issue=
# [[Morten Frisch]] & Jacob Simonsen (2021) carried out a large scale empirical population study in [[Denmark]] of 855,654 males regarding the alleged value of male circumcision in preventing HIV and other sexually transmitted infections in men. They found that [[circumcised]] men have a higher rate of STI and HIV infection overall than [[intact]] men.<ref name="frisch2021">{{FrischM SimonsenJ 2021}}</ref>
|article=
 
|page=
No association between lack of circumcision and risk of HIV infection was found by either study.
|pages=1-13
 
  |url=https://www.cambridge.org/core/journals/journal-of-biosocial-science/article/abs/ageincidence-and-prevalence-of-hiv-among-intact-and-circumcised-men-an-analysis-of-phia-surveys-in-southern-africa/CAA7E7BD5A9844F41C6B7CC3573B9E50
 
|archived=
  |quote=
  |pubmedID=36286328
|pubmedCID=
  |DOI=10.1017/S0021932022000414
  |accessdate=2022-10-27
}}</ref></blockquote>  
{{SEEALSO}}
{{SEEALSO}}
* [[Foreskin]]
* [[Foreskin]]
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