Pneumocystis jirovecii pneumonia in people living with HIV: a review

Abstract

Pneumocystis jirovecii is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of Pneumocystis jirovecii pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.

Keywords: HIV; PCP; PWH; Pneumocystis carinii; Pneumocystis jirovecii.

Fig 1

Leaf plot for the diagnosis of PCP in seriously ill patients with HIV. Pre-test probability (diagonal line) with boxes showing scores as determined by Maartens et al.’s PCP prediction rule (63) and using test characteristics from Del Corpo et al. (70). Vertical lines represent the change in probability following a positive (upward intersection with blue dashed line) or negative (downward intersection with yellow dashed line) BDG test. The yellow shaded area represents the area where a negative test establishes a post-test probability of 5% or below.

Fig 2

RCT comparison of TMP-SMX vs other agents for treatment of PCP: treatment failure.

Fig 3

RCT comparison of TMP-SMX vs other agents for treatment of PCP: change of therapy due to toxicity.