[1] Royal Hallamshire Hosp, Sheffield Pulm Vasc Dis Unit, Sheffield S10 2JF, S Yorkshire, England
[2] Sheffield Teaching Hosp NHS Fdn Trust, Acad Dept Resp Med, Sheffield, S Yorkshire, England
[3] Royal Hallamshire Hosp, Sheffield Haemophilia & Thrombosis Ctr, Sheffield S10 2JF, S Yorkshire, England
[4] Univ Sheffield, Dept Infect & Immunol, Sheffield, S Yorkshire, England