[show abstract][hide abstract] ABSTRACT: Observational evidence suggests that infection with helminths protects against allergic disease and allergen skin sensitization. It is postulated that such effects are mediated by helminth-induced cytokine responses, in particular IL-10.
We tested this hypothesis in a rural area of central Vietnam where hookworm infection is endemic.
One thousand five hundred and sixty-six schoolchildren aged 6-17 were randomly allocated to receive either anti-helminthic therapy or a placebo at 0, 3, 6, and 9 months. We compared changes in the prevalence of exercise-induced bronchoconstriction, allergen skin sensitization, flexural eczema on skin examination, questionnaire-reported allergic disease (wheeze and rhinitis symptoms), and immunological parameters (hookworm-induced IFN-gamma, IL-5, IL-10) between 0 and 12 months.
One thousand four hundred and eighty-seven children (95% of these randomized) completed the study. The most common helminth infections were hookworm (65%) and Ascaris lumbricoides (7%). There was no effect of the therapy on the primary outcome, exercise-induced bronchoconstriction (within-participant mean percent fall in peak flow from baseline after anti-helminthic treatment 2.25 (SD 7.3) vs. placebo 2.19 (SD 7.8, P=0.9), or on the prevalence of questionnaire-reported wheeze [adjusted odds ratio (OR)=1.16, 95% confidence interval (CI) 0.35-3.82, P=0.8] and rhinitis (adjusted OR=1.39, 0.89-2.15, P=0.1), or flexural dermatitis on skin examination (adjusted OR=1.15, 0.39-3.45, P=0.8). However, anti-helminthic therapy was associated with a significantly higher allergen skin sensitization risk (adjusted OR=1.31, 1.02-1.67, P=0.03). This effect was particularly strong for children infected with A. lumbricoides at baseline (adjusted OR=4.90, 1.48-16.19, P=0.009). Allergen skin sensitization was inversely related to hookworm-specific IL-10 at baseline (adjusted OR=0.76, 0.59-0.99, P=0.04). No cytokine tested, including IL-10, changed significantly after the anti-helminthic therapy compared with the placebo.
A significant reduction in worm burden over a 12-month period in helminth-infected children increases the risk of allergen skin sensitization but not of clinical allergic disease. The effect on skin sensitization could not be fully explained by any of the immunological parameters tested.
[show abstract][hide abstract] ABSTRACT: The Cochrane collaboration aims to produce high-quality systematic reviews. It is not known whether the methods used in producing Cochrane Skin Group (CSG) reviews result in higher quality reviews than other systematic reviews in dermatology.
To determine how the methodological quality of dermatological CSG reviews published in The Cochrane Library and in peer-reviewed journals compare with non-Cochrane systematic reviews.
Two blinded investigators independently assessed review quality using the 10-item Oxman and Guyatt scale.
Thirty-eight systematic reviews (17 Cochrane reviews published in The Cochrane Library, 11 Cochrane reviews published in peer-reviewed journals and 10 non-Cochrane reviews published in peer-reviewed journals) were examined. The Cochrane Library reviews included quality of life (11/17 vs. 1/10, P = 0.014) and adverse outcomes (14/17 vs. 2/10, P = 0.003) more often than non-Cochrane reviews published in peer-reviewed journals. Cochrane reviews published in both peer-reviewed journals and The Cochrane Library were more likely to include comprehensive search strategies (11/11 and 17/17 vs. 6/10, P-values = 0.04 and 0.01), take steps to minimize selection bias (11/11 and 16/17 vs. 3/10, P-values = 0.003 and 0.001) and appropriately assess the validity of all included trials (10/11 and 16/17 vs. 4/10, P-values = 0.04 and 0.007) than non-Cochrane reviews. Overall, Cochrane reviews published both in peer-reviewed journals and in The Cochrane Library were assigned higher quality scores by reviewers than non-Cochrane reviews (median = 6.0 and 6.5 vs. 4.5, P-values = 0.01 and 0.002).
The Cochrane Library systematic review methodology leads to higher quality reviews on dermatological topics.
British Journal of Dermatology 01/2007; 155(6):1230-5. · 3.76 Impact Factor