Analysis of clinical features and risk factors for patients with idiopathic inflammatory myopathy complicated by Pneumocystis jirovecii pneumonia.

OBJECTIVES

To analyse the clinical characteristics and risk factors for Pneumocystis jirovecii pneumonia (PJP) in idiopathic inflammatory myopathy patients (IIM).

METHODS

Retrospective analysis was conducted in 432 patients with idiopathic inflammatory myopathy by evaluation of demographic information, clinical characteristics, and treatment data. Receiver operating characteristic curves were used to evaluate the predictive value of (1-3)-β-DG-glucan for diagnosis of PJP. Multiple logistic regression analysis was used to identify independent risk factors for PJP occurrence.

RESULTS

Of the enrolled patients, 34 had PJP and were defined as the PJP+IIM group. The other patients that did not have PJP were defined as the PJP-IIM group. By univariate analysis, dermatomyositis, anti-MDA5 antibodies, rash, concomitant respiratory symptoms, decreased absolute lymphocyte count, increased erythrocyte sedimentation rate, increased ferritin levels and concurrent bacterial or viral infections were found to be risk factors for PJP in these patients. Among these, dermatomyositis, rash, decreased absolute lymphocyte count, and concurrent viral infection were the most important independent risk factors for PJP.

CONCLUSIONS

Dermatomyositis, rash, decreased absolute lymphocyte count, and concurrent viral infection are independent risk factors for the occurrence of PJP in idiopathic inflammatory myopathy patients.