title: If it is in the marrow, is it also in the blood? An analysis of 1,000 paired samples from patients with B-cell non-Hodgkin lymphoma.
abstract: BACKGROUND
  Staging of B-cell non Hodgkin's lymphoma (NHL) routinely involves bone marrow (BM) examination by trephine biopsy (BM-TB). The evidence of disease in the BM-TB results in a clinical stage IV classification affecting therapeutic strategies for NHL patients. BM immunophenotyping by flow cytometry (FC) is also used, although its clinical value is still under debate.
  
  
  METHODS
  Using FC we analyzed 1,000 paired BM aspirates and peripheral blood (PB) samples from 591 NHL patients to investigate the concordance between BM and PB. B-lymphocytes were defined monoclonal when a ratio of 0.3 < κ/l > 3 was observed. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. BM-TB was also performed in 84.1% of samples (841/1000), and concordance between BM-TB and BM-FC was evaluated. Concordance was defined as the presence of a positive (in terms of disease detection) or negative result in both BM-FC and PB-FC or BM-TB and BM-FC.
  
  
  RESULTS
  Using FC, the overall concordance between BM and PB was 95%. Among the discordant cases (ie presence of neoplastic B-lymphocyte in the BM but under the sensibility of the technique in the PB) the most frequent diagnosis was Waldenstrom's macroglobulinemia (WM, accounting for 20.8% of all discordant cases). The expression of CXCR4, a receptor involved in B-cell trafficking and homing, was found to be down regulated in WM compared to other NHL types, thus suggesting a possible role of CXCR4 in WM cell homing in the BM. WM excluded, FC investigation of BM and PB in NHL patients gives overlapping information.BM involvement was observed by FC in 38% of samples, and concordance between BM-FC and BM-TB was 85%.
  
  
  CONCLUSIONS
  The finding that FC data from BM and PB samples overlap in NHL might have major implications for the design of future clinical studies and for patients' follow-up.
authors.affiliation: Laboratory of Hematology-Oncology, European Institute of Oncology, via Ripamonti 435, 20141 Milan, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Mancuso
authors.forename: Angelica
authors.initials: A
authors.lastname: Calleri
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Antoniotti
authors.forename: Jessica
authors.initials: J
authors.lastname: Quarna
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertolini
mesh_terms: D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D016393:Lymphoma, B-Cell / Q000097:blood* / Q000175:diagnosis*; D008228:Lymphoma, Non-Hodgkin / Q000097:blood* / Q000175:diagnosis*; D016555:Matched-Pair Analysis; D019718:Receptors, CXCR4 / Q000096:biosynthesis; D012189:Retrospective Studies
chemical_list: C527276:CXCR4 protein, human; D019718:Receptors, CXCR4