A new study from Statens Serum Institut in Copenhagen, Denmark reports that Inflammatory Bowel Disease (IBD) patients present a higher risk of invasive pneumococcal disease (IPD), before and after diagnosis. The study, entitled “Inflammatory Bowel Disease Patients Are at Increased Risk of Invasive Pneumococcal Disease: A Nationwide Danish Cohort Study 1977–2013”, was published in The American Journal of Gastroenterology.

IBD is a chronic, potentially life-threatening disease, caused by an exacerbated and inappropriate immune response, leading to inflammation of the digestive tract. This response, together with immunosuppressive medication used to treat it, can lead to a higher risk of bacterial infection, as explained in a news release by the study’s first author Bjørn Kantsø, MSc, from the Department of Microbiological Diagnostics and Virology at Statens Serum Institut in Copenhagen, “The inappropriate innate immune response against infective agents observed in patients with IBD is hypothesized to increase the risk of bacterial infections. Also, treatment with immunomodulators has been suspected to increase the risk of bacterial infection in patients with IBD.”

The team of researchers studied the risk for IPD infection among IBD patients when compared to the general population, before and after diagnosis, and also how this risk was changed by IBD medication, namely azathioprine. The study included 74,156 IBD patients, from whom 29.8% had Crohn’s disease  (CD) and 70.2% ulcerative colitis (UC), and 1,482,363 non-IBD controls.

Results showed a significantly higher risk to develop IPD for IBD patients when compared to the controls. Specifically, UC patients presented a 1.5 higher risk for IPD and CD patients presented an even higher risk (3 times more likely), when compared to the control population. Regarding variation of risk before and after diagnosis, researchers concluded that up until 1 year after IBD diagnosis, CD patients presented an almost 3 times higher risk, and UC patients had twice the risk in the same time-frame, when compared to the controls. This risk decreased for both diseases 2 to 4 years after IBD diagnosis. Up to 4 years before IBD diagnosis, the risk for IPD was increased for both CD and UC patients. The use of azathioprine was also correlated to higher risk for IPD.

This research is especially important in terms of disease prevention, as highlighted by the team, “The finding in this study highlights the numerous recommendations on routine pneumococcal vaccination,” Kantsø stated “However, it is uncertain whether these recommendations are followed.”