HIV and the Anus

Mr Pepe Mulleat, Royal Free Hospital, London

Powerpoint File

HIV - AIDS patients

42 million people are HIV + or AIDS (1 million in the US; 65,000 in the UK) by end 2003.

5 million new HIV + patients per year in the world; in the UK, 7,000 new cases diagnosed (58% were heterosexuals) in 2003. Two thirds of all heterosexual diagnoses were women.

HAART - Highly Active Antiretroviral Therapy

Since the introduction of HAART, in the mid 1990's:

Increase in survival rates. Decreased morbidity after surgery.

Decrease in opportunistic infections

No impact in the incidence of anorectal pathology

No reduction in the incidence of AIN. ? change in the incidence of anal SCC

ANORECTAL PATHOLOGY IN HIV PATIENTS

5% of HIV/AIDS patients are referred to proctologist (mean age 35 - 45). 96% of these are male. Females usually attend the Gynaecologist. 1/3 of them will require surgical intervention.

Commonest presenting symptoms: pain (55%), perianal mass (19%), PR bleeding (16%).

Common anorectal pathology in HIV patients.

HIV - related:

o Warts (42%)

o Anorectal ulcers (34%) - - HSV, CMG

o Herpes (3%)

o AIN - SCC (7%)

Non HIV - related:

o Fistula - abscess (34%)

o Fissure (32%)

o Haemorrhoids (6%)

INITIAL MANAGEMENT OF AIN + PATIENTS WITH ANAL SYMPTOMS

High resolution anoscopy. Acetic acid

Gonorrhoea and Chlamydia screening

If ulcer of fissures: HSV and syphilis tests

Understand homosexual intercourse

Reinforce safe sex

Treat pathology as in HIV - population, but close follow up. Beware of non-healing fissures and ulcers, as they could be AIN lesions.

HPV ANAL RELATED LESIONS

HPV is the commonest sexually transmitted virus. Anal SCC and its precursor lesion, AIN, are associated with HPV infection.

Over 100 different serotypes of HPV have been identified. The commonest types, causing benign anal (and genital) warts are 6 and 11. The commonest oncogenic types are HPV 16 and 18. Other oncogenic types include HPV 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68. HPV 6 and 11 have been isolated in LG AIN lesions, but these lesions don't progress to HG AIN.

Oncogenic HPV has been isolated in 100% of anal SCC lesions, and in 100% and 88% of HG AIN lesions of HIV + and HIV -, respectively.

POPULATIONS AT RISK OF ANAL HPV:

HIV +

MSM

Females with CIN or cervical SCC

Partners of HPV infected patients

Prostitutes

Transplant receptors

The incidence and progression of AIN in MSM:

Incidence of AIN Progression to HG AIN

HIV - 7% 35%

HIV + 36% 62%

The prevalence of anal SCC is: (in 1/106)

Males 7

Females 9

MSM HIV - 350

HIV + 700

IMMUNE RESPONSE IN ANAL HPV LESIONS

HPV elicits a local immune response, mostly T lymphocytes (CD3), in all patients. This immune response has been measured in the stroma and the epithelium of these lesions. In HIV + patients, the density of T lymphocytes is 6 - 8 times lower than in immunocompetent individuals, and the CD4:CD8 ratio is inversed.

The poorer prognosis in HIV + patients is likely to be due to the inherent cellular immunosupression of this group, rather than a higher presence of carcinogenic HPV types.

MANAGEMENT OF AIN

Recognise 'at risk' groups

Screening

prophylactic HPV vaccines

High resolution anoscopy

Cytology

Viral PCR

LG AIN - follow up and High resolution anoscopy. Cytology

HG AIN - directed biopsy and ablation

50% have postop pain

6/12 follow up

References:

Gonzalez-Ruiz C, et al: anorectal pathology in HIV/AIDS -infected patients has not been impacted by highly active antiretroviral therapy. Dis Colon Rectum; 47:1483-6. 2003

Chin- Hong PV, et al: Natural history and clinical management of anal human papillomavirus disease in men and women infected with human immunodeficiency virus. Clin Infect Dis 1;35 (9):1127-34, 2002.

Piketty C, et al: High prevalence of anal squamous intraepithelial lesions is HIV + men despite the use of highly active antiretroviral therapy. Sex Transm Dis 31 (2): 96-9, 2004

Palefsky JM, et al: Anal squamous intraepithelial lesions in human immunodeficiency virus- positive men and women. Semin Oncol 27: 471-479, 2000.