Summary: A new study reveals a link between food allergies and relapses in Multiple Sclerosis.
Source: Brigham and Women’s Hospital.
Like many other medical conditions, the mechanism of multiple sclerosis remains an enigma–a puzzle composed of complex genetic and environmental factors. A key piece to this puzzle is the immune system, which is also responsible for regulating many other physiological (and pathological) phenomena–including allergies. Although previous studies investigating the association between MS and allergies have yielded mixed results, a research team at Brigham and Women’s Hospital sought to uncover the putative link in a new way. Investigating the correlation between allergy and inflammatory disease activity, the team found new evidence connecting food allergies and relapses of multiple sclerosis. The results are published in the Journal of Neurology, Neurosurgery & Psychiatry.
“Some multiple sclerosis patients with significant allergies would complain of frequent relapses associated with their allergic episodes,” said Tanuja Chitnis, MD, senior author and a neurologist at the Partners MS Center at the Brigham. “We felt that the most likely mechanism associated with allergy and its influence on MS would be related to inflammatory activity.”
Accordingly, Chitnis and colleagues set out to investigate the association between inflammatory disease activity and allergy history in a subset of patients enrolled in a large study known as the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB). A total of 1,349 study participants completed a self-administered questionnaire outlining food, environmental and/or drug allergies. Disease activity was assessed through evaluating the cumulative number of attacks over disease course, and new gadolinium (Gad)-enhancing lesions, as detected by MRI.
Interestingly, only participants in the food allergy group demonstrated a significantly higher rate of cumulative attacks and increased likelihood of new Gad-lesions compared to participants with no reported food allergies. This effect remained significant even when adjusted for potential confounders such as sex, age at symptom onset, and disease category. No significant effects were observed for the environmental and drug allergy groups after adjusted analyses.
This association between food allergy and MS disease activity highlights an important role for a potential player in immunity and inflammation–the gut. “It is interesting that this association was only found with food allergies and not other types of allergies, which might have been expected had this solely been an immune deviation issue,” said Chitnis. “The presence of food allergies and mechanisms related to food allergies may increase relapse rate and inflammatory activity in MS patients. There may be a common mechanism here, or other mechanisms which may induce MS relapses in a predisposed host.”
Currently, Chitnis and colleagues are working to further uncover these mechanisms of immune dysregulation in allergy and delineate how such dysregulation impacts MS inflammatory activity. Given the correlative nature of this study, the researchers are careful to highlight the limited clinical actionability of their findings. However, Chitnis is optimistic about the potential translational significance of the work and highlights the importance of addressing food allergies in MS patient care.
“There has long been a hypothesis of the gut being related to the immune system, and this really points to a stronger association than previously understood,” Chitnis said. “This research opens up a new way of thinking about the immune mechanisms in MS.”
Funding: Funding for this work was provided by Merck Serono and the National MS Society Nancy Davis Center Without Walls.
Source: Haley Bridger – Brigham and Women’s Hospital
Publisher: Organized by NeuroscienceNews.com.
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Original Research: Abstract for “Food allergies are associated with increased disease activity in multiple sclerosis” by Rami Fakih, Camilo Diaz-Cruz, Alicia S Chua, Cindy Gonzalez, Brian C Healy, Neda Sattarnezhad, Bonnie I Glanz, Howard L Weiner, and Tanuja Chitnis in Journal of Neurology Neurosurgery & Psychiatry. Published February 2019.
Food allergies are associated with increased disease activity in multiple sclerosis
The association between allergy and multiple sclerosis (MS) is still unclear. In our study, we assessed the association between a self-reported history of allergic conditions with MS clinical and MRI disease activity.
A subset of 1349 patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women’s Hospital (CLIMB) study completed a self-administered questionnaire on environmental, food and drug allergies. Patients were distributed among four allergy groups: (1) environmental, (2) food, (3) drug, (4) no known allergies (NKA). Clinical (number of attacks, expanded disability status scale (EDSS), MS severity score (MSSS)) and radiological variables (presence of gadolinium-enhancing lesions and lesion count), and their associations with the different allergy groups or those with NKA, were assessed.
The food allergy group had a 1.38 times higher rate for cumulative number of attacks compared with the NKA group (P=0.0062); this difference remained significant in the adjusted analysis (relapse rate ratio 1.27, P=0.0305). The food allergy group showed more than twice the likelihood (OR 2.53, P=0.0096) of having gadolinium-enhancing lesions on MRI. The environmental and drug allergy groups did not show significant differences when compared with the NKA group. The EDSS and MSSS were not affected by any type of allergy.
MS patients with food allergy had more relapses and a higher likelihood of gadolinium-enhancing lesions compared with patients with no known allergy. Future prospective studies are needed to confirm our findings and investigate underlying biological mechanisms, which may unveil new therapeutic and preventative strategies for MS.