Human papillomavirus infection and pathogenesis in urothelial. What is the pathogenesis of human papillomavirus hpv infection. Hepatitis b virus is dangerous because it attacks the liver, thus inhibiting the functions of this vital organ. New insights in the pathogenesis of hpv infection and the.
However, the etiological role of hpv infection in the pathogenesis of urinary tract has not been clarified. Pathogenesis of human papillomaviruses in differentiating epithelia. Anogenital or mucosal further subclassified as latent asymptomatic, subclinica. Identification of genital hpv infection as a important step in the pathogenesis of cervical cancer has focused attention on developing a vaccine against the virus. The human papillomavirus hpv is one of the most common causes of sexually transmitted disease in both men and women around the world, especially in developing countries, where the prevalence of asymptomatic infection varies from 2 to 44%, depending on the population and studied region sanjose et al. To this date, over 150 genotypes are known and are classified into two major groups, lowrisk and highrisk strains, depending on the ability of the virus to induce malignant transformation. Risk factors for the presence of hpv are high number of sexual partners, early cohabitarche, young age at first delivery, suppression and alteration of. The role of human papillomavirus in the pathogenesis of head. The most extensive and well demonstrated evidence about the association between human papillomavirus hpv oncogenic types infection and neoplasms include the cervical and the anal squamous cell carcinomas. Pathogenesis of human papillomavirusassociated mucosal. To this end, lower eukaryotic cells can produce preparative amounts of properlyfolded selfassembled viruslike particles vlp composed of the major structural viral protein l1. The virus causes persistent infection, chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, and immune complex disease.
Although host immune responses clear most infections, persistence of some hpv types causes 5% of human cancers and severe pathogenesis in immunosuppressed individuals. Pdf share checkonlearning questions display options. In the early 1980s, cervical cancer cells were demonstrated to contain hpv dna. Highrisk types are associated with mild to severe pap test abnormalities and, rarely, cancers of the cervix, vulva, vagina, anus, penis. Clinical, subclinical, and latent human papillomavirus hpv infections are distinguished from hpvassociated neoplasia. Summary human papillomaviruses hpv are the etiological agents of cervical and other anogenital malignancies.
Human papillomavirus infection hpv infection is an infection caused by the human papillomavirus hpv. Recommendations for vaccination against human papilloma virus hpv infection for the prevention of cervical cancer. The virus is transferred primarily by skintoskin contact. Autoinoculation of virus into opposed lesions is common. The impact of quadrivalent human papillomavirus hpv. About 90% of hpv infections cause no symptoms and resolve spontaneously within two years. Review of the current knowledge on the epidemiology. In the last decades, the human papillomavirus hpv emerged as an etiological cause of head and neck squamous cell carcinoma hnscc, especially in the oropharynx. Subclinical or latent cervical infections with highrisk hpv types such as hpv 16 and 18 have an increased risk for the development of hpvassociated neoplasia. Normal hpv infections are not associated with malignant transformation since the majority of hpv infections are spontaneously cleared and most patients show an effective immune response against subsequent hpv infections,21,30. Vaccination against hpv prevents the acquisition of cervical dysplastic lesions among eligible women who have not already acquired the vaccinespecific hpv types.
Feb 20, 2020 human papillomavirus hpv produces epithelial tumors of the skin and mucous membranes. However, the majority of infections are subclinical 7. Hpv infection occurs when the virus enters your body, usually through a cut, abrasion or small tear in your skin. Clinical, subclinical, and latent human papillomavirus hpv infections are distinguished from hpv associated neoplasia. Hpv infection is a sexually transmissible disease, and most breast cancers originate from mammary duct epithelia. Over 100 different types of hpvs have been identified to date, and all target epithelial tissues for infection. Human papillomavirus 175 11 human papillomavirus hpv is the most common sexually transmitted infection in the united states. Citeseerx human papillomavirus infection and cervical.
Pathogenesis of human papillomavirus immunological responses to hpv infection. The role of two intracellular dna sensors, which belong to the pyhin family interferoninducible protein 16 ifi16 and absent in melanoma 2 protein aim2, has been analyzed in relation to hpv infection and head and neck. Pathogenesis of human papillomavirus immunological responses to hpv infection chapter pdf available july 2016 with 1,293 reads how we measure reads. Pinkbook hpv epidemiology of vaccine preventable diseases. Pathogenesis of human papillomaviruses in differentiating. Pathology and epidemiology of hpv infection in females. If the both immune responses cannot clear the hpv infection in two years cervical cancer and other high risk cancers may result. The current classification system for hpv, which is based on similarities in genomic sequences, generally correlates with the 3 clinical categories applied to hpv infection.
Besides hpv additional cofactors are necessary to transform hpv infected tissue to intraepithelial or invasive neoplasia. Regression or persistence of subclinical and latent genital hpv infections as observed in longitudinal investigations show a constant comeandgo of hpv presence. Recognition of the etiologic role of human papillomavirus hpv infection in cervical cancer has led to the recommendation of adding hpv testing to the screening regimen in women 3065 years of age see workup. The adaptive immune response is thought to be responsible for viral clearance and disease pathogenesis during hepatitis b virus infection. However, women who have symptoms, abnormal screening test results, or a gross lesion of the cervix are best evaluated with colposcopy. Core concepts human papillomavirus infection pathogenbased. Some types of hpv infection cause warts, and some can cause different types of cancer.
Although the incidence of infection is high, most infections resolve spontaneously. Spread of hpv infection is usually through skinassociated virus and not bloodborne infection. Feb 12, 2019 recognition of the etiologic role of human papillomavirus hpv infection in cervical cancer has led to the recommendation of adding hpv testing to the screening regimen in women 3065 years of age see workup. Mar 29, 2011 cancer statistics report an increased incidence of oscc and opscc around the world. A simplified association between hpv type and the skin lesion it produces is presented in the table. Glandular cells do not support productive hpv infection, and hpv dna in adenocarcinomas is present in low copy numbers. Risk factors for the presence of hpv are high number of sexual partners, early cohabitarche, young age at first delivery, suppression and alteration.
The relationship of cervical cancer and sexual behavior was suspected for more than 100 years and was established by epidemiologic studies in the 1960s. Thetime course of infection has been studied on human xenografts in nude mice infected with hpv 11 usingin situhybridisation. Biology and pathogenesis 21 aneuploidy with the presence of tetraploid cells is frequently found in precancerous lesions ass ociat ed wit h hpv inf ectio n. In most women, cervical infection even with a highrisk hpv is selflimited. Human papillomavirus hpv is a common cause of cutaneous and mucosal infection.
Onethird of hpv types specifically infect the genital tract, and a subset of these are the causative agents of anogenital cancers. Infections by highrisk human papillomaviruses hpvs have been implicated as. Human papillomavirus hpv is a small doublestranded dna virus with tropism for epithelial cells. Author summary human papillomaviruses hpv are epitheliotropic tumor viruses causing mostly benign warts but that have developed strategies to establish persistent infections. Persistence of infection by highrisk hpv types is the greatest risk factor for development of genital.
Seroreactivity against genital hpv may be due to an active infection or the result of contact with hpv earlier in life. It is generally acknowledged that the humoral antibody response contributes to the clearance of circulating virus particles and the prevention of viral spread within the host while the cellular immune. Human papillomavirus infection of the skin archives of. The 9valent hpv vaccine 9vhpv is the major hpv vaccine used and this vaccine prevents infection with hpv types 6, 11, 16, 18, 31, 33, 45, 52, and 58. To date, studies on the role of hpv in breast carcinogenesis have generated considerable controversies and it is still not clear whether hpv infection is implicated in breast cancer pathogenesis. Human papillomavirus hpv produces epithelial tumors of the skin and mucous membranes. Pathogenesis of human papillomavirusassociated mucosal disease. If hpv infection becomes a prolonged persistent infection there is a higher risk of cancer development. N2 human papillomaviruses hpvs are small doublestranded dna viruses that infect the cutaneous and mucosal epithelium. You are just a few steps away from free ce credits. The role of human papillomavirus infection in the pathogenesis of penile squamous cell carcinomas. Persistent infection by human papilloma virus hpv is. Most hpv infections are asymptomatic and result in no clinical disease.
Infection by specific hpv types has been linked to the development of cervical carcinoma. Effects of urethane, ambient temperature and injection route on rat body temperature and metabolism due to endotoxins. Hpv replication cycle hpv is a nonenveloped and doublestranded dna virus with tropism for epithelial cells 9. Immunology and vaccinepreventable diseases pink book. Aetiology,pathogenesis,andpathologyofcervical neoplasia. Cin1 overlaps with hpv infection and usually resolves spontaneously within 912 months. Classification of hpv is based on the dna sequence of the viral l1 gene 2. Human papillomaviruses hpv are the etiological agents of cervical and other anogenital malignancies. Microbiology, pathogenesis, and natural history human. Cellmediated immunity cmi probably plays a significant role in wart regression. Several recent studies described that highrisk human papillomavirus hpv infection could have a potential role in the development of malignancies other than cervical cancer, such as laryngeal carcinoma, penile carcinoma, and anal carcinoma. Although hpv infection is nearly ubiquitous, the virus does not cause cancer in the large majority of cases 7.
In order to establish infection, hpv needs access to the basal cells ofthe differentiating epithelium which occurs most commonly throughmicrolacerations. Cancer statistics report an increased incidence of oscc and opscc around the world. Pathogenesis of human papillomavirus immunological responses to hpv. Hpv infection is a viral infection that commonly causes skin or mucous membrane growths warts. Human papillomavirus hpv is the most common sexually transmitted infection in the united states. Clinical manifestations of hpv infection include anogenital warts, recurrent respiratory papillomatosis, cervical cancer precursors cervical intraepithelial neoplasia, and cancers, including cervical, anal, vaginal, vulvar, penile, and oropharyngeal cancer. Genital hpv is a very common viral infection in sexually active adults. There are numerous followup studies of cin1 showing a highly variable risk of progression to cin23 and a consequent risk of invasive cancer in a small minority of patients ostor 1993. Though improvements in screening and early diagnosis have dramatically reduced the incidence of this neoplasm in recent years, the 5yeardiseasefree survival, is still poor, specially for oropharyngeal cancer, despite the great scientific and financial efforts. Pdf pathogenesis of human papillomavirus immunological. What is the pathogenesis of human papillomavirus hpv. There are more than 100 varieties of human papillomavirus hpv. However, in some cases, an hpv infection persists and results in either warts or precancerous lesions.