[1] Hosp Santa Creu & Sant Pau, Clin Hematol Div, Barcelona, Spain
[2] Osped Riuniti Bergamo, USC Hematol, I-24100 Bergamo, Italy
[3] Policlin San Matteo, Fdn IRCCS, Lab Epidemiol Clin, I-27100 Pavia, Italy
[4] Univ Florence, Florence, Italy
[5] Ist Policlin San Matteo, Clin Epidemiol Unit, Ctr Study Myelofibrosis, Pavia, Italy