Related Experiment Videos
Asthma and multiple sclerosis: an inverse association in a case-control general practice population
H L Tremlett1, J Evans, C M Wiles
1Department of Medicine (Neurology), University of Wales College of Medicine, Cardiff, Wales, UK. tremlett@interchange.ubc.ca
Background:
Th1/Th2 imbalance is hypothesized to up-regulate some diseases and down-regulate others. Compared to controls, multiple sclerosis (MS) (Th1-mediated) has been linked to a reduced risk of allergy and asthma (Th2-mediated), based on patient questionnaire studies and a review of asthma medication.
Aim:
To investigate whether MS is associated with a reduced risk of Th2-associated diseases and an increased risk of Th1-associated diseases.
Design:
Retrospective matched case-control study.
Methods:
Three hundred and twenty MS patients and controls matched for age, gender, location and smoking were selected from the Welsh General Practice Morbidity Database from 1995-99. Case and control records were assessed for Th1-mediated and Th2-mediated diseases.
Results:
Overall, 346 MS patients were identified, giving a prevalence of 127 per 100 000. There was an inverse relationship between multiple sclerosis (MS) and asthma (OR 0.33; 95%CI 0.15-0.77). No statistically significant relationships emerged between other Th2-associated (eczema, dermatitis) or any Th1-associated (rheumatoid arthritis, thyroid disorders, inflammatory bowel disease [IBD], type 1 diabetes) diseases and MS, although no patient in either group had treated type 1 diabetes. A trend existed for IBD, with 5/320 of cases affected and no controls; OR infinity; 95%CI 1.30-infinity; p=0.063.
Discussion:
This inverse association between MS and asthma is compatible with a Th1/Th2 imbalance. Although the Th1/Th2 theory is probably an over-simplification in MS, a shift from Th1 cytokine dominance towards Th2 may provide drug-targeting routes for MS.