[1] Univ Cologne, Fac Med, Cologne, Germany
[2] Univ Cologne, Univ Hosp Cologne, Dept Internal Med 1, Ctr Integrated Oncol Aachen Bonn Cologne Duesseld, Cologne, Germany
[3] Univ Cologne, German CLL Study Grp, Cologne, Germany
[4] St Marienhospital Cologne, Dept Geriatr Med, Oncogeriatr Unit, Cologne, Germany
[5] Univ Duisburg Essen, Univ Hosp Essen, West German Canc Ctr, Clin Hematol & Stem Cell Transplantat, Essen, Germany
[6] Stadt Klinikum Karlsruhe, Karlsruhe, Germany
[7] Ulm Univ, Div CLL, Dept Internal Med 3, Ulm, Germany
[8] Univ Ulm, Div CLL, Dept Internal Med 3, Ulm, Germany
[9] Munich Clin Schwabing, Dept Hematol Oncol Palliat Care Infect Dis & Trop, German CLL Study Grp, Munich, Germany
[10] Univ Schleswig Holstein, Dept Internal Med 2, Kiel, Germany
[11] Ludwig Maximilians Univ Hosp, Dept Med, Med Clin 3, Munich, Germany
[12] Study Centrum Unter Ems, Practice Oncol & Hematol, Leer, Germany
[13] Praxis Haematol & Oncol, Dresden, Germany
[14] Caritas Krankenhaus Bad Mergentheim, Med Klin 2, Bad Mergentheim, Germany
[15] Outpatient Clin, Landshut, Germany
[16] Multiprofile Hosp Active Treatment HristoBotev, Dept Internal Med 1, Vratsa, Bulgaria
[17] Univ Hosp, Dept Med Hematol Oncol & Palliat Care 3, Rostock, Germany
[18] Heidelberg Univ Hosp, Dept Hematol Oncol & Rheumatol, Heidelberg, Germany
[19] Cantonal Hosp Lucerne, Div Hematol, Luzern, Switzerland
[20] Med Univ Vienna, Div Hematol & Hemostaseol, Dept Med 1, Vienna, Austria
[21] Copenhagen Univ Hosp Rigshosp, Dept Hematol, Copenhagen, Denmark
[22] Acad Med Ctr, Amsterdam, Netherlands
[23] Univ Cologne, Cologne, Germany