Prophylaxis for Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients

Pneumocystis pneumonia (PCP) is a disease affecting immunocompromised patients. PCP among these patients is associated with significant morbidity and mortality.

To assess the effectiveness of PCP prophylaxis among non-HIV immunocompromised patients. To define the type of immunocompromised patients for whom evidence suggests a benefit for PCP prophylaxis.

Electronic searches of The Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 1, 2007), PubMed (March 2007), LILACS (March 2007), relevant conference proceedings; references of identified trials; the first author of each included trial was contacted.

RCTs or quasi- RCTs comparing prophylaxis with an antibiotic effective against Pneumocystis versus placebo, no intervention, an antibiotic/s with no activity against Pneumocystis or another antibiotic effective against Pneumocystis for immune-compromised non-HIV patients. Only trials pre-defining Pneumocystis infections as an outcome were included.

Two authors independently appraised the quality of each trial and extracted data from included trials. Relative risks (RR), with 95% confidence intervals (CI) were estimated and pooled using the random effects model.

Eleven trials including 1155 patients (520 children), performed between the years 1974 and 1997, were included. Compared to no treatment or treatment with fluoroquinolones (inactive against Pneumocystis), there was a 91% reduction in the occurrence of PCP in patients receiving prophylaxis with trimethoprim/sulfamethoxazole, RR 0.09 (95% CI 0.02 to 0.32), eight trials, 821 patients. No significant difference was encountered in all cause mortality, RR 0.81 (95% CI 0.27 to 2.37), five trials, 509 patients, while PCP-related mortality was significantly reduced, RR 0.17 (95% CI 0.03 to 0.94), seven trials, 701 patients. Occurrence of leukopenia, neutropenia and their duration were not reported consistently. No significant difference in any adverse event was seen comparing trimethoprim/sulfamethoxazole to no treatment/ placebo (four trials, 470 patients). No differences between once daily versus thrice weekly trimethoprim/sulfamethoxazole were seen (two trials, 207 patients).

Given an event rate of 7.5% as in included trials' control group, prophylaxis for PCP using TMP/SMX is highly effective among non-HIV patients, with a number needed to treat of 15 patients (95% CI 13 to 20). Prophylaxis should be considered for the types of patients with hematological malignancies, bone marrow transplantation and solid organ transplantation included in these trials.