title: Bone marrow angiogenesis and proliferation in B-cell chronic lymphocytic leukemia.
abstract: OBJECTIVE
  To assess angiogenesis and the proliferative activity of bone marrow in patients with chronic lymphocytic leukemia (CLL) in relation to the bone marrow infiltration pattern.
  
  
  METHODS
  Bone marrow samples were obtained by trephine biopsy from 46 patients with B-cell CLL (B-CLL). Infiltration pattern was diffuse in 20 patients and nondiffuse--i.e., nodular, interstitial or mixed--in the remaining 26 patients. Ten normal bone marrow samples were used as a control group. Studies were carried out by immunohistochemical staining of paraffin-embedded bone marrow samples. Angiogenesis was assessed in the zones of highest vascular density (hot spots), visualized by the expression of endothelial antigen CD34 and expressed as a number of microvessels per high-powerfield (hpf) (final magnification, 400x). Proliferative activity was estimated by the expression of nuclear protein Ki-67, cyclin A and mean number of nucleolar organizer regions (AgNORs).
  
  
  RESULTS
  Microvessel density was higher in B-CLL marrow than in normal marrow (30.1 and 16.44 per hpf, respectively) and was higher in the diffuse than nondiffuse pattern (33.6 and 27.5 per hpf, respectively). B-CLL bone marrow also showed higher proliferative activity, as assessed by mean number of AgNORs, than did normal marrow (1.52 and 1.25, respectively) and a higher mean percentage of cyclin A-positive cells (7.5 and 6.8, respectively). In contrast, mean Ki-67 expression was similar in B-CLL and the control group. Mean AgNORs number, Ki-67 and cyclin A-positive cell percentage were significantly higher in B-CLL marrow with a diffuse as compared to nondiffuse involvement pattern (AgNORs, 1.75 and 1.35; cyclin A, 9.27% and 3.95%; Ki-67, 34.9% and 23.3%, respectively).
  
  
  CONCLUSIONS
  Our results indicate enhancement of bone marrow angiogenesis in B-CLL and a relationship between microvessel density and the bone marrow infiltration pattern. The study points also to a possible relationship between the bone marrow infiltration pattern and proliferative activity of bone marrow cells.
authors.affiliation: Departments of Hematology and Pathology, Medical University of Wroclaw, Wroclaw, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Wolowiec
authors.forename: Zdzisław
authors.initials: Z
authors.lastname: Wozniak
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Potoczek
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Ganczarski
authors.forename: Tomasz
authors.initials: T
authors.lastname: Wrobel
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Kuliczkowski
authors.forename: Irena
authors.initials: I
authors.lastname: Frydecka
authors.forename: Michal
authors.initials: M
authors.lastname: Jeleń
mesh_terms: D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D001853:Bone Marrow / Q000098:blood supply* / Q000473:pathology; D001856:Bone Marrow Examination; D016022:Case-Control Studies; D049109:Cell Proliferation; D019925:Cyclin A / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D019394:Ki-67 Antigen / Q000032:analysis; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D017254:Leukemic Infiltration / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic
chemical_list: D018952:Antigens, CD34; D019925:Cyclin A; D019394:Ki-67 Antigen