The Burden of Viral Respiratory Infections in Immunosuppressed Inflammatory Bowel Disease Patients

Due to the increasing immunosuppressant use in inflammatory bowel disease (IBD) and the risk of serious infections, this study investigates the prevalence and risk factors of respiratory pathogen detection in this population to improve patient care.

A retrospective study conducted at Mater Hospital Brisbane examined viral respiratory swab results from patients with IBD who presented with respiratory symptoms between February 2020 and September 2023. Relevant clinical data-including patient characteristics, IBD treatments, and respiratory outcomes-were extracted from electronic medical records. Statistical analyses were performed using SPSS version 30, employing chi-square tests and logistic regression for univariate and multivariate analyses, with a significance threshold set at p < 0.05.

Total of 184 IBD patients with 288 episodes of respiratory symptoms underwent respiratory swabs and PCR. Overall detectable pathogens on respiratory swab were 14% (n = 40), including 60% (n = 24) COVID, 5% (n = 2) RSV, 8% (n = 3) Influenza and 28% (n = 11) other viruses. Of the total IBD patients, the median age was 37.5 [IQR 27-55], median disease duration 7 years [IQR 3-14] and the majority diagnosed with ulcerative colitis (n = 97, 52.7%) or Crohn's disease (n = 80, 43.5%). The median age was 37.5 years (interquartile range [IQR] 28-55.5) in the pathogen positive detection group and 38 years (IQR 27-56.25) in the undetectable pathogen group. Most of the patients with a positive detectable respiratory pathogen had ulcerative colitis (n = 22, 57.9%) or Crohn's disease (n = 18, 45%). We found no significant effect of conventional or advanced IBD therapy on respiratory pathogen detection including infliximab (p = 0.856), adalimumab (p = 0.148), vedolizumab (p = 0.957), ustekinumab (p = 0.976), immunomodulator(s) (p = 0.560, 0.573) or 5-ASA (p = 0.758). However, concurrent prednisolone use significantly increased the risk of detectable pathogens (OR 2.78 [95% CI 1.07-7.19], p = 0.035).

This study found no increase in respiratory pathogen detection in IBD patients taking advanced therapies or immunomodulators, but concurrent prednisolone use was a significant risk factor. This suggests the importance of reducing steroid exposure via early introduction of steroid-sparing agents.