Prognostic analysis of Pneumocystis jirovecii pneumonia in patients with systemic vasculitides: a retrospective cohort study

Pneumocystis jirovecii pneumonia (PJP) is a serious complication of autoimmune and inflammatory diseases. This study aimed to describe the characteristics of PJP in patients with various systemic vasculitides and explore potential prognostic factors.

Data on 62 enrolled PJP patients with systemic vasculitis were analyzed. Patients were stratified based on the outcomes. Prognostic factors were investigated using Cox-regression models. Characteristics of patients with and without interstitial lung disease (ILD) were compared.

Among 62 vasculitis-PJP patients, 48 had anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), with microscopic polyangiitis (MPA) being the most common subtype (28 patients). MPA (HR 4.33, p = 0.001), concomitant aspergillosis (HR 2.68, p = 0.019), and higher D-dimer at PJP diagnosis (HR 1.07, p = 0.004) were independent adverse prognostic factors for overall survival. Stable disease activity of vasculitis was an independent favorable prognostic factor (HR 0.28, p = 0.027). Patients with MPA were older than non-MPA patients (median age: 69 vs. 58 years, p = 0.001); both ILD and fibrotic ILD were more prevalent in MPA patients (ILD: 78.6% vs. 35.3%, p = 0.001; fibrotic ILD: 57.1% vs. 11.8%, p < 0.001). At the diagnosis of PJP, patients with preexisting ILD had higher counts of white cells, lymphocytes, and neutrophils, as well as higher levels of immunoglobulin (Ig) G and IgA, than patients without preexisting ILD.

MPA was associated with a higher risk of death in patients with vasculitis-PJP, possibly due to a higher prevalence of ILD. In clinical practice, we should pay more attention to the prophylaxis and management of PJP in patients with systemic vasculitis-associated ILD and/or MPA.