Appendicitis in HIV-Infected Patients

Date of Report: 11/06/2002
Author:  Laurence Peiperl, MD, Medical Director, AETC NRC
Source: National Resource Center
Description: Coverage of the 42nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC)

Effects of HAART

Appendicitis in HIV Patients Before and After HAART

This retrospective, case-control study in a large HMO in northern California examined hospitalizations for pathology-confirmed appendicitis in HIV-positive men (age 20-74 years) and in controls not known to be HIV-positive. Between January 1991 and December 1995, prior to the advent of potent antiretroviral therapy in this population, the rate of hospitalization for appendicitis was approximately 3-fold higher in the HIV-infected group: 2.9 versus 0.92 events/1,000 patient-years in cases and controls, respectively. The study also included over 18,000 person-years of follow-up among HIV-infected men in an era of effective antiretroviral therapy (January 1996-February 2001). Among these patients, the rate of hospitalization for appendicitis was 3.1 per 1,000 patient-years, compared with 0.73 per 1,000 patient-years among patients not known to be HIV positive (p < .01). Interestingly, during the same time period (1996-2001) the percentage of appendicitis admissions with initial white blood cell count >12,500 /mm³ was 70% among HIV-negative controls but only 26% among HIV-infected patients (p < .0001). CD4-cell count was not predictive of risk for perforation, which was not statistically different between HIV-infected and -uninfected patients (although a trend towards increased frequency of perforation in HIV-positive patients was noted).

The risk of appendicitis remains increased in HIV-positive patients in the era of potent antiretroviral therapy. The absence of an elevated white blood cell count does not rule out a diagnosis of appendicitis, especially in the setting of HIV infection.

Klein DB, Hurley LB, and Horberg MA. Appendicitis in HIV Patients Before and After HAART. 42nd Interscience Conference on Antimicrobial Agents and Chemotherapy, September 27 - 30, 2002, San Diego, California, Abstract H-1154.