No long-term effect of past Pneumocystis jirovecii pneumonia on pulmonary function in people with HIV

To assess the impact of past Pneumocystis jirovecii pneumonia (PJP) on the pulmonary diffusion capacity in people with HIV (PWH) with a history of advanced immunodeficiency. DESIGN: Prospective cross-sectional study. METHODS: Adult PWH with past PJP >1 year ago were included as the study group. The control group consisted of PWH with a nadir CD4(+) lymphocyte count <200 cells/mm(3), matched by age, sex, smoking status and time since HIV diagnosis. All PWH completed a pulmonary function test (PFT) consisting of pre-bronchodilation spirometry, body plethysmography and single-breath carbon monoxide transfer factor (TLCO) measurement. TLCO, diffusion impairment (defined as a TLCO Z-score <−1.645), total lung capacity (TLC) and forced expiratory volume in one second/forced vital capacity (FEV1/FVC) Z-scores were assessed. Multivariable regression analyses were conducted with Z-scores and odds of diffusion impairment as outcomes. RESULTS: PFTs of 102 participants were analyzed, 51 of whom had past PJP with a median of 10 years since PJP. Mean TLCO Z-score and diffusion impairment rate did not differ significantly between groups (P = 0.790; P = 0.650). Past PJP was not independently associated with TLCO Z-score [β = 0.14; 95% confidence interval (CI) −0.30–0.57], diffusion impairment (odds ratio 1.00; 95% CI 0.36–2.75) nor TLC or FEV1/FVC Z-scores, whereas current (vs. never) smoking was associated with more diffusion impairment and lower TLCO Z-scores. CONCLUSION: In our study, past PJP was not associated with long-term diffusion impairment. Our findings suggest that smoking plays a more important role in persistent pulmonary function impairment whereas PJP-related changes seem to be reversible.