[1] UCL Hosp, Dept Haematol, London, England
[2] UCL Hosp, Dept Virol, London, England
[3] Birmingham Heartlands Hosp, Dept Haematol, Birmingham B9 5ST, W Midlands, England
[4] Birmingham Heartlands Hosp, Dept Virol, Birmingham B9 5ST, W Midlands, England
[5] Univ Birmingham, Canc Res UK Inst Canc Studies, Birmingham B15 2TT, W Midlands, England
[6] Univ Oxford, Sir William Dunn Sch Pathol, Oxford OX1 3RE, England