1 North Central London Tuberculosis Service, Whittington Hospital NHS Trust, London, UK.
2 Department of Respiratory Medicine, University College London, Royal Free Campus, London, 6UCL Respiratory, University College London, London, UK.
3 Department of Infectious Diseases, Royal Free London NHS Foundation Trust, London, University College London, Royal Free Campus, London, 6UCL Respiratory, University College London, London, UK.
4 Department of Clinical Immunology, Royal Free London NHS Foundation Trust, London, UK, Institute of Immunity and Transplantation, University College London, Royal Free Campus, London, UK.
5 Department of Respiratory Medicine, University College London, Royal Free Campus, London, 6UCL Respiratory, University College London, London, UK, UCL Respiratory, University College London, London, UK.