Papillomavirus Notes

NOTES NOTES PAPILLOMAVIRUS HUMAN PAPILLOMAVIRUS osms.it/human-papillomavirus PATHOLOGY & CAUSES ▪ Human papillomavirus (HPV): virus that causes cutaneous and mucosal infections, resulting in warts (verrucae) ▪ > 200 known types; > 40 transmitted through sexual contact ▪ Humans: only host Genetic material ▪ Small, double-stranded, circular DNA virus Taxonomy ▪ Papillomaviridae family Morphology ▪ Non-enveloped, capsid virus CAUSES ▪ Transmission ▫ Skin-to-skin contact via breaks in epithelium (autoinoculation causes local spread) ▫ Vaginal, anal, oral sexual intercourse ▫ Vertical transmission (congenital infection) ▪ Cutaneous HPV ▫ Infection of the basal stem cells of keratinized skin → viral genome replicates within proliferating cells → infected cell eventually reaches the upper epithelial layers → hyperkeratotic growth ▪ Mucosal HPV ▫ → infection of epithelium → integration into the host genome → flat, papular, or pedunculated growths → high-grade lesions and cancer may develop RISK FACTORS ▪ Epithelial trauma ▪ Walking barefoot ▪ Occupational ▫ Meat, poultry, and fish handlers ▪ Use of communal showers ▪ Smoking ▪ Early age of first sexual intercourse ▪ Multiple sexual partners ▪ Uncircumcised males ▪ Immunocompromised state; esp. HIV/AIDS COMPLICATIONS ▪ Some types have oncogenic potential SIGNS & SYMPTOMS ▪ Common warts: verruca vulgaris (HPV types 2, 4) ▫ Cauliflower-like raised surface located on hands, feet, elbows, knees, subungual/periungual (under, around fingernail/on cuticle; may be painful) ▫ Common in children, adolescents ▪ Plantar: verruca plantaris (HPV type 1) ▫ Located on soles of feet ▫ May induce pain when walking ▪ Flat: verruca plana (HPV types 3, 20, 28) ▫ Flat warts found on arms, face, forehead ▫ Common in children, adolescents ▪ Anogenital: condyloma acuminatum (HPV types 6, 11 low risk; 15 types have oncogenic potential; types 16 and 18 cause 90% of all genital warts) OSMOSIS.ORG 475

▫ Cervical cancer: types 16 and 18 70% of all cases ▫ Anal cancer: type 16 is the usual cause ▫ Other cancers; e.g. oropharyngeal, vaginal, vulvar, penile cancers usually caused by type 16 ▪ Laryngeal papillomatosis (HPV types 6, 11) ▫ Larynx, respiratory tract TREATMENT MEDICATIONS ▪ Cutaneous warts ▫ Topical salicylic acid, fluorouracil 5% ▪ Anogenital warts ▫ External warts: podofilox solution or gel, sinecatechins ointment, imiquimod cream SURGERY ▪ Anogenital warts ▫ Surgical removal OTHER INTERVENTIONS ▪ Cutaneous warts ▫ May resolve spontaneously ▫ Cryotherapy (liquid nitrogen) ▪ Anogenital warts ▫ External or internal (vaginal, cervical, intra-anal): cryotherapy, trichloroacetic acid, bichloroacetic acid Figure 86.1 A giant anal condyloma in an immunocompromised male. DIAGNOSIS LAB RESULTS ▪ Genetic testing: in situ hybridization/ polymerase chain reaction (PCR) ▫ Real-time PCR (detect HPV viral load) ▪ Immunohistochemistry: biomarker detection ▫ E6, E7 mRNA ▫ p16 cell-cycle protein ▪ Cervical lesions: cytology ▫ If positive for abnormal cells: colposcopy and biopsy 476 OSMOSIS.ORG Prevention ▪ HPV vaccines ▫ Gardasil (quadrivalent), Cervarix (bivalent), 9-valent ▫ Both vaccines protect against HPV 16, 18; Gardasil also protects against HPV 6, 11 ▫ Administered before primary infection occurs (9–13 years old) ▪ Cervical cancer screening ▫ Pap smear ▪ Effective barrier contraception ▫ Condoms (reduces risk; less protection compared to other STIs) ▪ Decrease number of sexual partners

Chapter 86 Papillomavirus Figure 86.2 The histological appearance of a condyloma. There is hyperkeratosis and parakeratosis. Numerous keratinocytes demonstrate perinuclear clearing known as koilocytosis. OSMOSIS.ORG 477