Allergic sensitisation in tuberculosis patients at the time of diagnosis and following chemotherapy
1 Department of Environmental Immunology, Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway
2 Department of International Health, Institute of General Practice and Community Medicine, University of Oslo, Norway
3 Centre for Imported and Tropical Diseases, Ullevål University Hospital, Oslo, Norway
4 Aker University Hospital, The Research Center, Oslo, Norway
5 Broegelmann Research Laboratory, The Gade Institute, University of Bergen, Bergen, Norway
6 Section of Microbiology and Immunology, The Gade Institute, University of Bergen, Bergen, Norway
7 Department of Microbiology and Immunology, Haukeland University Hospital, Bergen, Norway
8 Department of Immunology and Transfusion Medicine, Ullevål University Hospital, Oslo, Norway
BMC Infectious Diseases 2009, 9:100 doi:10.1186/1471-2334-9-100Published: 26 June 2009
It is still a matter of debate whether there is an association between infection with Mycobacterium tuberculosis (M. tuberculosis) and allergy. Previously, we have shown higher levels of specific IgE to different inhalant allergens and total IgE in tuberculosis (TB) patients compared to controls. The objectives of this study were to evaluate a possible change in allergic sensitisation after successful TB treatment and to confirm the finding of our previous study of enhanced allergic sensitisation in TB patients compared to controls in a more controlled setting. Additionally, we wanted to determine the cytokine profile in the same groups and finally to evaluate the association between the presence of Bacillus Calmette-Guérin vaccination (BCG) scar and allergic sensitisation among the controls.
Sera were analysed for specific IgE to inhalant allergens (Phadiatop) and total IgE by the use of ImmunoCAP 1000 (Pharmacia Diagnostics). Thirteen different cytokines were also analysed in the sera by multiplex bead immunoassay (Luminex 100, Luminex Corporation), and clinical symptoms of allergy and BCG scar were reported in a questionnaire.
A reduction in levels of specific and total IgE were observed after successful TB treatment. TB patients also had higher levels of specific and total IgE compared to healthy controls. Both interleukin (IL)-6 and interferon (IFN)γ were higher in TB patients compared to healthy controls. The levels of IL-6 were reduced after successful TB treatment. The presence of a BCG scar was associated with a reduced risk of developing allergic sensitisation.
We observed a reduced level of allergic sensitisation after successful TB treatment. TB patients seem to be more allergically sensitised than healthy controls, confirming our previous finding. Furthermore, we observed an inverse association between allergic sensitisation and visible BCG scar, which adds additional support to the hygiene hypothesis.