The most common opportunistic infection in patients with human immunodeficiency-1 (HIV-1) is Pneumocystis carinii pneumonia (PCP). Prophylaxis has been recommended since 1989; the current criteria for administration of primary PCP prophylaxis are a CD4 cell count of less than 200 per mm3 (200 × 106 per L), oral candidiasis, or unexplained fever that lasts more than two weeks. The introduction of highly active antiretroviral therapy (HAART) has resulted in many patients having fewer opportunistic infections and achieving increased CD4 counts—but it has not been known if these patients could safely discontinue PCP prophylaxis. Schneider and colleagues studied the withdrawal of PCP prophylactic therapy in selected patients whose CD4 counts had increased to above 200 cells per mm3 as a result of HAART.
Seventy-eight patients were recruited from a Dutch university clinic. All study patients were receiving PCP prophylaxis for documented HIV-1 infection and had achieved CD4 counts of 200 cells per mm3 on at least two occasions (with measurements taken at least one month apart) since beginning HAART protocols. After informed consent had been obtained, prophylaxis was withdrawn, and patients were assessed every three months. The mean time between start of HAART and discontinuation of PCP prophylaxis was 9.8 months. Prophylaxis was restarted if CD4 counts fell below 200 cells per mm3 during the study. If PCP was suspected, bronchoscopy was performed within 72 hours.
No patients developed PCP during the mean follow-up period of 12.7 months. Two patients underwent bronchoscopy for suspected PCP infection, but none was documented. In all but two patients, CD4 cell counts remained above 200 cells per mm3. Although the CD4 cell counts of these two patients fell as low as 14 and 27 per mm3 (14 and 27 × 106 per L), respectively, these two patients did not develop PCP.
The authors conclude that the reduction in viral load and the increase in CD4 cell counts induced by HAART enables PCP prophylaxis to be discontinued in certain patients; however, the safest criteria for discontinuation remain to be defined. In particular, it is not clear if the duration of HAART is critical or if the key issue is the magnitude and diversity of the CD4 cell count.
editor's note: Most family physicians are now treating HIV-infected patients. Even when these patients receive most of their care from specialized HIV clinics, family physicians need to be aware of developments in the field and are frequently called on by these patients for advice and support. This study illustrates the movement toward cautious reduction in prophylactic therapy. It must be stressed that these advances were only achieved in highly structured situations and in patients who successfully maintained HAART. One danger in publishing this study and others like it is that they are reported by the news media, with the result that HIV-infected patients may inappropriately stop prophylactic therapy, thereby possibly diminishing the public's impression of the seriousness of HIV infection. Family physicians play a key role in their patients' understanding of HIV infection and its consequences. We must ensure that good news is conveyed accurately and does not lead to either false hope or a reduction in vigilance against this terrible disease.—a.d.w.