Science for Health
04 September 2012
Bacterial respiratory infections remain a major global cause of death, despite the availability of antibiotics. Mortality results from infection with antibiotic-resistant organisms and the problem of pathological inflammatory responses.
Vitamin D induces innate antimicrobial responses and suppresses pro-inflammatory cytokine responses in vitro and thus has a potential role in the prevention and treatment of infection. However, the effects of in vivo vitamin D supplementation on immune responses in humans with an infectious disease have not previously been described.
Vitamin D was used to treat tuberculosis in the pre-antibiotic era, and vitamin D supplementation has been shown to enhance healthy tuberculosis contacts’ immunity to mycobacteria. These observations prompted a randomised controlled trial evaluating the influence of adjunctive high-dose vitamin D on time to bacterial clearance in patients receiving antimicrobial therapy for smear-positive pulmonary tuberculosis. Anna Coussens, working in the lab of Robert Wilkinson (pictured) in NIMR’s Division of Mycobacterial Research, measured concentrations of inflammatory markers in blood samples collected from patients taking part in the trial, which was funded by the British Lung Foundation and conducted by Adrian Martineau at NIMR and Queen Mary University of London, in collaboration with a group of London hospitals.
Their main finding was that high-dose vitamin D, given in addition to antibiotic treatment, accelerates the resolution of inflammatory responses in patients with lung tuberculosis and helps them to recover more quickly. The results indicate that vitamin D may have a role in accelerating the resolution of inflammatory responses in tuberculosis patients. This can lead to patients being infectious for a shorter period of time, and thereby suffering less lung damage.
Our study represents the most detailed characterisation of the effects of antituberculous therapy on the immune response conducted to date, and the first clinical investigation into the immunomodulatory actions of in vivo vitamin D supplementation during treatment of an infectious disease. This is the first study to look at the effects of vitamin D supplementation in patients suffering from any infectious disease. There is a growing appreciation that vitamin D might have a role both as an add-on to conventional antibiotic treatment for respiratory infections, and to prevent these infections in the first place.
Mycobacterium tuberculosis (Mtb) in a macrophage.
Blue = macrophage nucleus
Anna K. Coussens, Robert J. Wilkinson, Yasmeen Hanifa, Vladyslav Nikolayevskyy, Paul T. Elkington, Kamrul Islam, Peter M. Timms, Timothy R. Venton, Graham H. Bothamley, Geoffrey E. Packe, Mathina Darmalingam, Robert N. Davidson, Heather J. Milburn, Lucy V. Baker, Richard D. Barker, Charles A. Mein, Leena Bhaw-Rosun, Rosamond Nuamah, Douglas B. Young, Francis A. Drobniewski, Christopher J. Griffiths, Adrian R. Martineau. (2012)
Vitamin D accelerates resolution of inflammatory responses during tuberculosis treatment
Proceedings of the National Academy of Sciences of the USA. Epub ahead of print. Publisher abstract.
© MRC National Institute for Medical Research
The Ridgeway, Mill Hill, London NW7 1AA