[1] Univ London Imperial Coll Sci Technol & Med, Lung Immunol Grp, MRC, Fac Med,Infect & Immun & Natl Heart & Lund Inst, London SW7 2AZ, England
[2] Royal Brompton & Natl Heart Hosp, Host Def Unit, Dept Resp Med, London SW3 6NP, England
[3] Univ London Imperial Coll Sci Technol & Med, Hammersmith Hosp, Dept Infect Dis & Immun, Human Dis Immunogenet Grp, London W12 0NN, England
[4] Univ London Imperial Coll Sci Technol & Med, Dept Occupat & Environm Med, NHLI, London SW3 6NP, England
[5] Univ Oxford, Gastroenterol Unit, Gibson Labs, Oxford OX2 6QX, England
[6] Univ Cambridge, Dept Med, Addenbrookes Hosp, Cambridge CB2 1QQ, England
[7] St Marys Hosp, Chest & Allergy Dept, London W2 1NY, England
[8] Univ London Imperial Coll Sci Technol & Med, Harefield Hosp, Heart Sci Ctr, Harefield UB9 6JH, Middx, England