I read with great interest the recent article by Tirosh et al. in the June 20, 2006 issue of the Annals of Internal Medicine. I would like to make some interesting points regarding the article.
The hypothesis of Th1 versus Th2 phenotypes as explanatory for autoimmune diseases and asthma is not sharply defined. This hypothesis is supported by the recent trials using parasites (human hookworm - Necator americanus) to treat asthma (1); the proposed mechanism being subversion of the immune system from a Th2 to Th1 response and improved regulatory T cell function (2). Although the authors have stated that vasculitis stems from a Th1 dependent profile, Churg-Strauss vasculitis has the distinction of having a significant Th2 cytokine profile (3).
The investigators enrolled recruits from the Israeli military. They have included various autoimmune disorders including some of the systemic vasculitides, but Behcet’s disease, which has a high incidence in this region (the Silk Road) (4), is not quoted. Interestingly, Behcet’s disease can present as asthma secondary to gastro-esophageal reflux following esophageal stricture formation (5).
Most autoimmune diseases exhibit a latent period of months to many years. The period of follow- up (maximum three years) for new-onset autoimmune disease may also account for the differences seen in the two groups and may disappear at longer follow-up.
References
1. Falcone FH, Pritchard DI. Parasite role reversal: worms
on trial. Trends Parasitol. 2005; 21:157-60.
2. Ling EM, Smith T, Nguyen XD, Pridgeon C, Dallmann M,
Arbery J, et al. Relation of CD4+CD25+ regulatory T-cell
suppression of allergen-driven T-cell activation to
atopic status and expression of allergic disease.
Lancet. 2004; 363: 608 – 15.
3. Hellmich B, Csernok E, Gross WL. Proinflammatory
cytokines and autoimmunity in Churg-Strauss syndrome.
Ann N Y Acad Sci. 2005; 1051:121-31.
4. Sakane T, Takeno M, Suzuki N, Inaba G. Current concepts:
Behcet’s disease. N Engl J Med 1999; 341:1284-1291.
5. Wooster D, Henderson RD, Lilker ES, Peress L. Further
manifestations of Behcet's syndrome. Can J Surg. 1980;
23:195-7.
None declared