Decreased efficacy of inhaled pentamidine in the prevention of Pneumocystis carinii pneumonia among HIV-infected patients with severe immunodeficiency.

Abstract

STUDY OBJECTIVE: To determine the relationship between the degree of immune deficiency and the risk of Pneumocystis carinii pneumonia (PCP) among HIV-infected patients receiving inhaled pentamidine prophylaxis. DESIGN: Retrospective chart review. SETTING: AIDS clinic of inner-city hospital. PATIENTS: Patients attending inhaled pentamidine clinic between 1989 and 1991. INTERVENTION: Review of medical records of patients receiving inhaled pentamidine, 300 mg/month, via nebulizer (Respirgard II) as primary or secondary prophylaxis of PCP. Statistical analysis of lymphocyte subset results and selected clinical data. RESULTS: Ten of 57 patients developed PCP during the period of analysis. Patients with CD4 counts less than 60/mm3 were significantly more likely to develop PCP (p = 0.01; Fisher's exact test) with a relative risk of 7.55 compared to patients with CD4 lymphocyte counts greater than 60/mm3. CONCLUSION: Failure of inhaled pentamidine prophylaxis is seen almost exclusively among patients with CD4 lymphocyte counts below 60/mm3.