The majority of patients diagnosed with rheumatic disease, such as systemic lupus erythematosus, inflammatory myositis, and vasculitis, will experience fever or infection during their course of therapy. The most common microbiologically documented infection is bacterial, virus, and fungal, which can be associated with the severity and mortality of disease. Current methods of diagnosis require a significant load of pathogen making early detection difficult. Delayed diagnosis and delayed optimal therapy of infection are associated with increased morbidity and mortality.

This study seeks to identify whether next generation sequencing (NGS) of pathogens can identify patients with infection treated with corticosteroid and immunosuppressive agents. This would enable preemptive targeted therapy to replace prophylaxis treatment which often leads to some adverse events and antibiotic resistance.

Plasma/Serum samples collected but not required for clinical care (discarded samples) will be collected and stored. Results of NGS will be compared between patients who develop definite infection immediately (within 72 hours) after sample collection, and those who remain well. Clinical data describing baseline information about the patient and rheumatic diseases, antibiotic and steroid or immunosuppressor therapy exposure, pathogen testing, immunology results, and infection-related events will be collected prospectively from the electronic medical record.

An initial exploratory phase will examine approximately 50 participants to determine whether the effectiveness of predicting infections. The study may then enroll up to 200 participants to collection additional data for analysis.

Inclusion Criteria:

• 18 years to 70 years;
• Undergoing care for rheumatic disease at Peking University People's Hospital;
• In a category of patients who are considered by the investigator to be at high risk of infection

Exclusion Criteria:

• Any condition that would, in the opinion of the investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol

Participants who are being treated at Peking University People's Hospital and who have a high risk of infection.