Specific IgE to respiratory allergens and IgG antibodies to Toxoplasma gondii and Streptococcus pneumoniae in Norwegian military recruits.

Declining exposure to infections has been implicated as a cause for the rising trend of allergy. Gastrointestinal infections, in particular, have been suggested to have a protective effect against allergy development. In contrast, there are only limited data available regarding the effect of respiratory tract infections with encapsulated bacteria on allergy development. We investigated the association between IgG antibodies against the gastrointestinal parasite Toxoplasma gondii and the bacterium Streptococcus pneumoniae and specific IgE to common allergens in Norwegian military recruits. IgG antibodies to T. gondii and to a 23-valent pneumococcal polysaccharide vaccine (Pneumovax) were determined by ELISA. Specific IgE to common airborne allergens was determined by Phadiatop. Individuals with Phadiatop values from class 0-2 were classified as non-atopic (n = 419), while those with class 3-6 were classified as atopic (n = 201). No significant difference was observed in IgG antibody levels to pneumococcal polysaccharides between atopic and non-atopic recruits, whereas seropositivity to T. gondii was found to be less frequent among the atopic recruits (odds ratio, 0.37; 95% CI, 0.17-0.81; P = 0.01). Hence, in Norwegian recruits, the serological response to a gastrointestinal pathogen, but not to the respiratory encapsulated bacteria, was found to be associated with a lower probability for being sensitized according to the criteria used. The present study conforms to the hypothesis that reduced rates of infection with certain microorganisms may be associated with an increased risk of allergic sensitization.

Effect of a medicinal extract from Agaricus blazei Murill on gene expression in a human monocyte cell line as examined by microarrays and immuno assays.

Extracts from the edible mushroom Agaricus blazei Murill (AbM) are used extensively as a non-prescription remedy against cancer, infections, and immune related diseases. The presumed effect is to activate certain parts of the immune system. In order to investigate the effect, we examined the changes of gene expression caused by the extract on a human monocyte cell line (THP-1). Changes in the levels of mRNA transcripts were measured using 35 k microarrays, and the changes in select cytokine gene products by immuno assays. Lipopolysaccharide (LPS) was included for comparison. Both AbM and LPS had drastic effects on gene expression. Genes related to immune function were selectively up-regulated, particularly proinflammatoric genes such as the interleukins IL1B and IL8. Although most genes induced by AbM were also induced by LPS, AbM produced a unique profile, e.g., as to a particular increase in mRNA for the cytokines IL1A, CXCL1, CXCL2 and CXCL3, as well as PTGS2 (cyclooxygenase2).

Allergic sensitisation in tuberculosis and leprosy patients.

BACKGROUND: A negative association has been observed between infections and allergy in several studies. The aim of the present study was to examine whether tuberculosis and leprosy patients have more or fewer allergies than healthy individuals. METHOD: Sera from tuberculosis patients, leprosy patients and healthy controls were analysed by ELISA and Pharmacia Unicap for serological markers for allergy and mycobacterial infection. The serological markers for allergy were total IgE, specific IgE using Phadiatop and specific IgE to the dust mite allergen Dermatophagoides pteronyssinus 1 (Der p 1). Serological markers for mycobacterial infections included specific IgG to a mixture of bacille Calmette-Guérin culture filtrate antigens, to purified mannose-capped lipoarabinomannan (manLAM) and to purified secreted antigen 85B. RESULTS: Both tuberculosis and leprosy patients had significantly higher levels of total IgE than controls. Furthermore, a significantly higher level of specific IgE (Phadiatop) was also found in the tuberculosis patients compared with controls. A similar result, but not statistically significant, was observed for the leprosy group. Specific IgG to antigen 85B and to manLAM was found to be significantly higher in both tuberculosis and leprosy patients compared with controls. In addition, leprosy patients had significantly more IgG to the BCG culture filtrate antigen than controls. CONCLUSIONS: The results indicate that patients with mycobacterial infections have allergic sensitisation more frequently compared with healthy controls. This is seemingly in contrast with the notion that there is a negative association between allergy and infection ('hygiene hypothesis'). However, since only one in ten of those infected with Mycobacterium tuberculosis will develop the disease, patients with active mycobacterial disease represent a selected group. A similar relationship applies for leprosy. It is conceivable that those predisposed to allergy are less resistant to mycobacterial infections.