[1] Walsgrave Gen Hosp, Dept Haematol, Coventry, W Midlands, England
[2] New Cross Hosp, Dept Haematol, Wolverhampton, W Midlands, England
[3] Princess Royal Hosp, Dept Haematol, Telford TF6 6TF, Shrops, England
[4] Royal Worcester Hosp, Dept Haematol, Worcester, England
[5] Birmingham Heartlands Hosp, Dept Haematol, Birmingham B9 5ST, W Midlands, England