The use fluoroquinolones or macrolides reduced immunogenicity risk in inflammatory bowel disease (IBD) patients on anti–tumor necrosis factor (anti-TNF) therapy, according to data from nearly 2,000 individuals.
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Anti-TNF therapy with monoclonal antibodies is an established treatment for Crohn’s disease and ulcerative colitis, but approximately 40% of patients fail to respond initially and even more fail to achieve complete remission, wrote Yuri Gorelik, MD, of Rambam Health Care Campus, Haifa, Israel, and colleagues.
“Immunogenicity, which refers to the development of antidrug antibodies [ADA] is considered as the main factor driving secondary loss of response and is likely involved in primary nonresponse as well,” but data on how to predict the risk for ADA formation are limited, they said.
In a study published in Gut, the researchers identified data from 1,946 IBD patients using the epi-IIRN (epidemiology group of the Israeli IBD research nucleus), a nationwide registry of all IBD patients in Israel.
A total of 363 patients had positive ADA after a median follow-up period of 651 days after starting therapy. Overall, the risk of ADA development was significantly higher in patients on cephalosporins (adjusted hazard ratio, 1.97; 95% confidence interval, 1.58-2.44) or penicillin with beta-lactamase inhibitors (BLIs) (aHR, 1.38; 95% CI, 1.13-1.74) during anti-TNF therapy, and it was higher still for patients using both. By contrast, the risk was lower in patients on macrolides (aHR, 0.36; 95% CI, 0.16-0.82) or fluoroquinolones (aHR, 0.20; 95% CI; 95% CI, 0.12-0.35). All P values were less than .05 when compared with nontreated groups.
In the same study, the researchers reported data on mice treated with antibiotics and challenged with infliximab to evaluate the causative effect of antibiotics and the associated disruption to the gut microbiome on the formation of ADA. After 14 days, the researchers found significantly increased ADA production in mice treated with cephalosporins, compared with those treated with macrolides, but germ-free mice produced no ADA, which supports the role of microbial composition on ADA production.
The investigators cited previous research into the microbiome as a biomarker for prediction response to anti-TNF therapy; past results have also suggested that the effect of cephalosporins and penicillin-BLIs could be explained by the particular dysbiosis induced by those agents.
The study findings were limited by several factors including the retrospective design and potential for selection bias, as well as the inability to adjust antibiotic exposure according to type and severity of infection, they noted. However, “this is the first large scale study that extensively evaluated the effect of different antibiotic classes on immunogenicity of anti-TNF therapy,” and the results suggest that ADA development during anti-TNF therapy may to reduced by the use of fluoroquinolones and macrolides.
“Specific microbial manipulation may serve as a tool to modify immunogenicity which is preferably turned on for protective immunizations and off for biological therapy,” they noted. “Further studies involving detailed analysis of the antibiotic effects on the human microbiome and immune milieu are needed, as well as comparative experiments with other medications used to reduce immunogenicity.”