Patients with multiple sclerosis (MS) and food allergies had more relapses and gadolinium-enhancing lesions than patients with MS but no food allergies, according to a recent analysis of a longitudinal study.
Dr. Tanuja Chitnis
Patients with food allergies had a 1.3-times higher rate for cumulative number of attacks and a 2.5-times higher likelihood of enhancing lesions on brain MRI in the analysis of patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women’s Hospital (CLIMB).
By contrast, there were no significant differences in relapse or lesion rates for patients with environmental or drug allergies when compared with those without allergies, reported Tanuja Chitnis, MD, of Partners Multiple Sclerosis Center at Brigham and Women’s Hospital, Boston, and her coinvestigators.
“Our findings suggest that MS patients with allergies have more active disease than those without allergies, and that this effect is driven by food allergies,” Dr. Tanuja and her coauthors wrote in their report, which appeared in the Journal of Neurology, Neurosurgery and Psychiatry.
Previous investigations have looked at whether allergy history increases risk of developing MS, with conflicting results, they added, noting a meta-analysis of 10 observational studies suggesting no such link.
By contrast, whether allergies lead to more or less intense MS activity has not been addressed, according to investigators, who said this is the first study tying allergy history to MS disease course using clinical and MRI variables.
Their study was based on a subset of 1,349 patients with a diagnosis of MS who were enrolled in CLIMB and completed a self-administered questionnaire on food, environmental, and drug allergies. Of those patients, 922 reported allergies, while 427 reported no known allergies.
Patients with food allergies had a significantly increased rate of cumulative number of attacks, compared with those with no allergies, according to investigators, even after adjusting the analysis for gender, age at symptom onset, disease category, and time on treatment (relapse rate ratio, 1.274; 95% confidence interval, 1.023-1.587; P = .0305).
Food allergy patients were more than twice as likely as no-allergy patients were to have gadolinium-enhancing lesions on brain MRI after adjusting for other covariates (odds ratio, 2.53; 95% CI, 1.25-5.11; P = .0096), they added.
Patients with environmental and drug allergies also appeared to have more relapses, compared with patients with no allergies, in univariate analysis, but the differences were not significant in the adjusted analysis, investigators said. Likewise, there were trends toward a link between number of lesions and presence of environmental or drug allergies that did not hold up on multivariate analysis.
It is unknown what underlying biological mechanisms might potentially link food allergies to MS disease severity; however, findings of experimental studies support the hypothesis that gut microbiota might affect the risk and course of MS, Dr. Chitnis and her coauthors wrote in their report.
The CLIMB study was supported by Merck Serono and the National MS Society Nancy Davis Center Without Walls. Dr. Chitnis reported consulting fees from Biogen Idec, Novartis, Sanofi, Bayer, and Celgene outside the submitted work. Coauthors provided additional disclosures related to Merck Serono, Genentech, Verily Life Sciences, EMD Serono, Biogen, Teva, Sanofi, and Novartis, among others.
SOURCE: Fakih R et al. J Neurol Neurosurg Psychiatry. 2018 Dec 18. doi: 10.1136/jnnp-2018-319301.