Khan N, et al. - This nationwide cohort study was performed to quantify the risk of herpes zoster in patients with inflammatory bowel disease (IBD) and to assess the effects of IBD and IBD medications on the risk of herpes zoster. The researchers associated IBD and treatment with thiopurines, alone or in combination with tumor necrosis factor (TNF) antagonists, with an increased risk of herpes zoster. The effects of immunization of patients with IBD ought to be investigated, with the approval of a new and potentially safer vaccine for herpes zoster.

Methods

• From January 2000 through June 2016, the researchers conducted 2 retrospective studies of populations of Veterans.
• They compared the incidence of herpes zoster among patients with IBD receiving 5-ASA alone vs matched patients without IBD (Study 1).
• The incidence of herpes zoster was compared among patients with IBD treated with only 5-ASA, with thiopurines, with antagonists of TNF, with a combination of thiopurines and TNF antagonists, and with vedolizumab (Study 2).
• Multivariable Cox regression was used to estimate the hazard ratios and 95% CIs for herpes zoster associated with IBD in study 1 and with different treatments in study 2.
• Moreover, they estimated the incidence rate of herpes zoster based on age and IBD medication subgroups.

Results

• Ulcerative colitis (UC) and Crohn’s disease (CD) were each associated with significantly increased risk of herpes zoster infection, compared to no IBD.
• UC, CD, or IBD treated with 5-ASA treatment alone was correlated with significantly increased risk of herpes zoster, with adjusted HRs (AHR) of 1.81 for UC (95% CI, 1.56-2.11), 1.56 for CD (95% CI, 1.28-1.91), and 1.72 for treated IBD (95% CI, 1.51-1.96), in multivariable Cox regression (compared to no IBD).
• In multivariable Cox regression analysis, exposure to thiopurines (AHR, 1.47; 95% CI, 1.31-1.65) or a combination of thiopurines and TNF antagonists (AHR, 1.65; 95% CI, 1.22-2.23) was associated with increased risk of herpes zoster, compared to exposure to 5-ASA alone.
• On the other hand, exposure to TNF antagonists alone (AHR, 1.15; 95% CI, 0.96-1.38) was not correlated with increased risk of herpes zoster.
• In all age groups and all IBD medication subgroups, the incidence rates of herpes zoster were substantially higher than that in the oldest group of patients without IBD (older than 60 years).