TOPLINE:

The risk for infection in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis on immunosuppressive therapy is linked to having chronic lung disease as well as having a previous infection during the induction of remission, according to findings from a post hoc analysis of infections that occurred in a randomized controlled trial.

METHODOLOGY:

• The randomized controlled RITAZAREM trial compared the effectiveness of rituximab and azathioprine in achieving and maintaining remission in 187 patients with relapsing ANCA-associated vasculitis.
• Given the high rate of infections seen in the induction phase of the trial — 62 patients (33.2%) experienced at least one infection — researchers conducted a post hoc analysis of infections in the induction and maintenance phases.
• Patients were followed through the 24-month treatment period and for a further 24 months of post-treatment follow-up, to determine whether any factors predicted infection.

TAKEAWAY:

• Patients with chronic lung disease at baseline had a significant 79% greater risk of developing an infection during the induction phase of treatment, whereas those with lung nodules or cavities had a twofold greater risk for infection.
• The strongest predictor of infection during the maintenance phase of treatment was infection during the induction phase, with patients showing a 2.3 fold greater risk for infection.
• Pulmonary fibrosis and large airway obstruction were also associated with a greater than twofold increase in the risk for infection during the maintenance phase of immunosuppressive treatment.
• The analysis saw no difference in the risk for infection between patients on rituximab and those on azathioprine.

IN PRACTICE:

“The strongest predictor of having an infection during the maintenance or follow-up phase was having an infection during the induction phase,” said senior author of the study Rona Smith, MD, of the University of Cambridge and the Cambridge University Hospitals NHS Foundation Trust in Cambridge, England. 

SOURCE:

Smith presented the findings at the 22nd International Vasculitis Workshop (IVW) 2026 in Melbourne, Australia. 

LIMITATIONS:

Infection prophylaxis was at the investigator’s discretion throughout the trial. Glucocorticoid dosing was not standardized across all patients, which meant investigators may have chosen to use lower glucocorticoid doses in patients they perceived to be at greater risk for infection.

DISCLOSURES:

The RITAZAREM trial was funded by Versus Arthritis and Roche and sponsored by the Cambridge University Hospitals NHS Foundation Trust and the University of Pennsylvania. Smith reported receiving speaker fees and holding an advisory board position with CSL Vifor (formerly Vifor Pharma), receiving research grants from GSK and Union Therapeutics, and receiving speaker fees from AstraZeneca.