Inflammatory Bowel Disease in HIV Positive Individuals

By Liz Highleyman

Chronic HIV infection and consequent immune system decline have been linked to many conditions in HIV positive people, but the association with inflammatory bowel disease (IBD) has not been extensively studied.

IBD is a general name for chronic inflammatory conditions of the gastrointestinal tract, including Crohn's disease and ulcerative colitis. The cause of IBD is not well understood, but autoimmunity (when the immune system attacks the body's own tissues) appears to play a role.

As reported at the Digestive Disease Week 2008 conference this week in San Diego, British researchers analyzed the prevalence of IBD and the relevance of CD4 count as a predictive factor in a large cohort of HIV positive patients treated at London's Chelsea and Westminster Hospital between 1999 and 2006.

Data were collected from the hospital's HIV clinic and pharmacy databases. A diagnosis of IBD was confirmed by reviewing endoscopy and histology records. Infectious colitis (bowel inflammation due to an infectious pathogen) was excluded by reviewing microbiology records.

Results

• A total of 27 patients were identified with a diagnosis of both HIV and IBD.

• All but 1 were men, and the median age was 45 years.

• 8 patients were diagnosed with IBD before their HIV diagnosis.

• Of the 19 patients subsequently diagnosed with IBD after HIV:

• 5 had left-sided or extensive ulcerative colitis;
• 5 had proctitis (rectal inflammation);
• 2 had Crohn's disease;
• 7 had indeterminate colitis.

• The mean annual incidence of ulcerative colitis and Crohn's disease was 1.9 and 0.2, respectively, per 10,000 persons (excluding 4 patients referred from other centers).

• The median CD4 cell count at the time of IBD diagnosis was 355 cells/mm3.

• There was no significant change in CD4 counts 6 months before or after IBD diagnosis.

Conclusion

This cohort, according to the investigators, is the largest yet reported with a combined diagnosis of HIV and IBD.

"The incidence of ulcerative colitis is about double that expected in a normal population, although less than that published previously," the researchers concluded.

They added that, "There is no clear association with CD4 count and the time of diagnosis of IBD."

The cited prior study*, published at the dawn of the HAART era in 1996, found that among 8 patients with both HIV and IBD, there were no acute exacerbations of IBD in individuals with a CD4 cell count below 200 cells/mm3. However, patients with chronic colon inflammation had faster than expected CD4 cell depletion, while those who underwent colectomy (colon removal) experienced a slight CD4 cell increase.

5/20/08

Reference

J Landy, B Gazzard, M Harbord. Inflammatory Bowel Disease in HIV Seropositive Individuals: Analysis of a Large Cohort. Digestive Disease Week (DDW) 2008. San Diego, CA. May 17-22, 2008. Abstract T1193.

* D Sharpstone, A Duggal, B Gazzard. Inflammatory bowel disease in individuals seropositive for the human immunodeficiency virus. Eur J Gastroenterol Hepatol. 8(6): 575-578. June 1996.