Previous reports suggested an association between allergy, autoimmunity, and risk of multiple sclerosis (MS), but results have been inconsistent. The present study assessed the association between history of allergy and autoimmune diseases, and the risk of MS.
We conducted a case-control study nested in the Nurses' Health Study (NHS) and NHS II cohorts. A total of 298 women with MS were matched with 1248 healthy controls and 248 women with history of breast cancer. A mailed questionnaire gathered information about history of allergic conditions and autoimmune disorders.
History of allergy was not associated with MS risk [odds ratio (OR) 1.0, 95% confidence interval (CI) 0.8-1.4]. As expected, cases were more likely to have a positive family history of MS than controls (OR 9.7, 95% CI 6.1-15.3). A modest association was found between family history of other autoimmune diseases and MS risk (OR 1.4, 95% CI 1.0-1.8). We obtained similar results when we used women with breast cancer as comparison group.
Family history of other autoimmune diseases was associated with a higher MS risk, suggesting a common genetic background or shared environmental triggers. There was no clear association between personal history of allergy and risk of MS.
"Of these, despite our best attempts to contact primary or corresponding authors, eight studies could not be located [20-27]; therefore, 67 potentially relevant full text articles were retrieved for closer examination. Of the retrieved articles, 34 were excluded for the following reasons: 18 did not examine surgery as a risk factor [28-45]; six did not have a control group [46-51]; five were review articles [52-56]; four were not specific to MS [57-60]; and one had insufficient data, and we were unable to locate study authors . A total of 33 studies were identified which met the inclusion criteria for the systematic review [62-94]. "
[Show abstract][Hide abstract] ABSTRACT: Background
Although the precise etiology of multiple sclerosis is largely unknown, there is some speculation that a prior history of surgery may be associated with the subsequent risk for developing the disease. Therefore, we aimed to examine surgery as a risk factor for the diagnosis of multiple sclerosis.
We searched for observational studies that evaluated the risk for developing multiple sclerosis after surgery that occurred in childhood (≤ 20 years of age) or “premorbid” (> 20 years of age). We specifically included surgeries classified as: tonsillectomy, appendectomy, adenoidectomy, or “surgery”. We performed a systematic review and meta-analyses and calculated odds ratios (OR) and their 95% confidence intervals (CIs) using a random effects model.
We identified 33 case–control studies, involving 27,373 multiple sclerosis cases and 211,756 controls. There was a statistically significant association between tonsillectomy (OR = 1.32, 95% CI 1.08-1.61; 12 studies, I2 = 44%) and appendectomy (OR = 1.16, 95% CI 1.01-1.34; 7 studies, I2 = 0%) in individual’s ≤ 20 years of age and the subsequent risk for developing multiple sclerosis. There was no statistically significant association between risk for multiple sclerosis and tonsillectomy occurring after age 20 (OR = 1.20, 95% CI 0.94-1.53; 9 studies, I2 = 32%), in those with appendectomy at > 20 years (OR = 1.26, 95% CI 0.92-1.72; 5 studies, I2 = 46%), and in those with adenoidectomy at ≤ 20 years of age (OR = 1.06, 95% CI 0.68-1.68; 3 studies, I2 = 35%). The combined OR of 15 studies (N = 2,380) looking at “surgery” before multiple sclerosis diagnosis was not statistically significant (OR = 1.19, 95% CI 0.83-1.70; I2 = 71%).
We found a small but statistically significant and clinically important increased risk for developing multiple sclerosis, in those with tonsillectomy and appendectomy at ≤ 20 years of age. There was no convincing evidence to support the association of other surgeries and the risk for multiple sclerosis. Well-designed prospective etiological studies, pertaining to the risk for developing multiple sclerosis, ought to be conducted and should include the examination of various surgeries as risk factors.
"Although Annunziata et al.  found an association between MS and other ADs in first and second degree relatives, the results were not significant when compared to non-AD controls. Conversely, Alonso et al.  and Magaña et al.  found a significant association between MS and other ADs in relatives of any degree. "
[Show abstract][Hide abstract] ABSTRACT: Background
A primary characteristic of complex genetic diseases is that affected individuals tend to cluster in families (that is, familial aggregation). Aggregation of the same autoimmune condition, also referred to as familial autoimmune disease, has been extensively evaluated. However, aggregation of diverse autoimmune diseases, also known as familial autoimmunity, has been overlooked. Therefore, a systematic review and meta-analysis were performed aimed at gathering evidence about this topic.
Familial autoimmunity was investigated in five major autoimmune diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid disease, multiple sclerosis and type 1 diabetes mellitus. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Articles were searched in Pubmed and Embase databases.
Out of a total of 61 articles, 44 were selected for final analysis. Familial autoimmunity was found in all the autoimmune diseases investigated. Aggregation of autoimmune thyroid disease, followed by systemic lupus erythematosus and rheumatoid arthritis, was the most encountered.
Familial autoimmunity is a frequently seen condition. Further study of familial autoimmunity will help to decipher the common mechanisms of autoimmunity.
BMC Medicine 03/2013; 11(1):73. DOI:10.1186/1741-7015-11-73 · 7.25 Impact Factor
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