Anti-tumor necrosis factor (TNF) therapy for inflammatory bowel disease appears to double the relative risk of developing central demyelinating disease, though the absolute risk remains small, according to a preliminary report published online ahead of print October 5 in JAMA Internal Medicine.
Previous case reports have suggested a possible association between anti-TNF agents taken for inflammatory bowel disease and later development of demyelinating diseases, but a definitive link has been difficult to establish because of the rarity of these disorders and the suspicion that there already may be an underlying association between inflammatory bowel disease and demyelinating disease.
Researchers examined the issue by analyzing data from nationwide Danish health registries for patients with inflammatory bowel disease and medication exposure. They identified 4,504 patients treated during a 14-year period who had inflammatory bowel disease and took anti-TNF agents, and 16,429 patients with inflammatory bowel disease matched for sex, age, and disease duration who did not take the medications, according to Nynne Nyboe Andersen, MD, a doctoral student in the Department of Epidemiology Research at Statens Serum Institut in Copenhagen, and her associates.
Eleven patients in the group exposed to medication had central demyelinating events. Two patients had multiple sclerosis, five patients had optic neuritis, and four patients had other central demyelinating disease. Medication-exposed patients had 7.5 events per 10,000 person-years.
In comparison, 17 patients in the unexposed group had central demyelinating events. Five patients had multiple sclerosis, six patients had optic neuritis, one patient had transverse myelitis, and five patients had other central demyelinating disease. The unexposed group had 3.3 events per 10,000 person-years.
The hazard ratio for developing central demyelinating disease after exposure to anti-TNF agents was 2.19, according to the investigators. These preliminary findings represent the first report of this association and must be confirmed in future studies, according to the researchers. “If true, the observed association could either be attributed to the unmasking of a latent demyelinating disease or to the emergence of a de novo demyelinating disease,” said Dr. Nyboe Andersen.
—Mary Ann Moon