DECREASED EFFICACY OF INHALED PENTAMIDINE IN THE PREVENTION OF PNEUMOCYSTIS-CARINII PNEUMONIA AMONG HIV-INFECTED PATIENTS WITH SEVERE IMMUNODEFICIENCY

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.