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

Abstract

OBJECTIVES: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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. Key Points • Data from this study showed that MPA was the most common subtype of vasculitis among vasculitis-PJP patients. • Compared with non-MPA patients in this study, patients with MPA were older, had more ILD and fibrotic ILD, and had a poorer prognosis. • 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.