Mycobacterium tuberculosis infection may protect against allergy in a tuberculosis endemic area

Abstract

These results of inverse association of strong TST reaction and allergic disease symptoms in children from a TB endemic area are in support of the hypotheses that allergic inflammation may be inhibited by chronic infections, such as MTB.

Pediatric Asthma in Southern Africa

“…There was a significant inverse linear trend in the relation of TST size in millimetre and the frequency of allergic disease symptoms. These results of inverse association of strong TST reaction and allergic disease symptoms in children from a TB endemic area are in support of the hypotheses that allergic inflammation may be inhibited by chronic infections, such as MTB [24].…”

“…Children with positive Tine Skin Test (TST) (> or =10 mm) were significantly less likely to have allergic disease symptoms, in particular allergic rhinitis (adjusted OR 0.43; 95% CI 0.24-0.79) than those with negative TST [24]. There was a significant inverse linear trend in the relation of TST size in millimetre and the frequency of allergic disease symptoms.…”

Mycobacteria and allergies

“…In this community, TST-positive children were significantly less likely to have recent atopic rhinitis than were TST-negative children (Obihara et al, 2005). There was also a significant inverse relationship between the size of the TST response and the frequency of allergic disease symptoms, in particular allergic rhinitis (Po0.001) (Obihara et al, 2006). There is no way of determining at present whether this association is because LTBI protects from allergic disorders, or because people who encounter M. tuberculosis and control it without developing progressive TB have an inherently lower tendency to develop inappropriate Th2 responses ( Fig.…”

“…Thus TB patients have increased correlates of allergy (Adams et al, 1999;Ellertsen et al, 2005;Suzuki et al, 2001), but in individuals with non-progressing latent TB (LTBI) the reverse might be true. In populations where most TST positivity is due to LTBI, there is an inverse correlation between allergic manifestations and TST reactions (Obihara et al, 2005(Obihara et al, , 2006Shirakawa et al, 1996).…”

Immune Adjuvants in Early Life: Targeting the Innate Immune System to Overcome Impaired Adaptive Response

“…A reasonable explanation for allergy epidemics is the so-called hygiene hypothesis, which suggests that reduced family size, improvement in household amenities and personal cleanliness have decreased the opportunity of infection in children resulting in an altered immunoregulation [124]. Several clinical and experimental studies have reported that exposure to microbes or to their products leads to regulatory mechanisms that suppress allergy development [125][126][127][128][129]. However, the mechanisms underlying this suppression are still controversial.…”