Detection of B-Cell Lymphoma in Bone Marrow Aspirates Using BIOMED-2 Immunoglobulin Primers
Ellen Berget, Lars Helgeland, Anders Molven, Olav Vintermyr. University of Bergen, Bergen, Norway; Haukeland University Hospital, Bergen, Norway
Background: Staging of bone marrow (BM) involvement in non-Hodgkin lymphoma is based on morphological evaluation of trephine biopsies, flow cytometry and molecular analyses. However, morphology is usually considered most important. The BIOMED-2 multiplex PCR protocols are commonly used to detect clonally rearranged immunoglobulin genes in B-cell lymphomas (Leukemia 2003, 17: 2257–2317; Leukemia 2007; 21: 207-214). However, there are few reports on their usage in terms of BM involvement (Leukemia 2004, 18: 1102-1107; Pathology 2009, 41: 214-222). The aim of our study was to correlate morphological BM findings with molecular analyses using BIOMED-2 primers.
Design: Molecular involvement was evaluated in BM aspirates from 408 patients diagnosed with B-cell lymphoma at the Department of Pathology, Haukeland University Hospital, Bergen, Norway in the period 2003-2011. All cases had a trephine biopsy obtained at the same time as the aspirate. DNA was extracted by standard methods, and BIOMED-2 PCR primer sets for immunoglobulin heavy (IGH VH-FR2-JH) and kappa light (IGK Vκ-Jκ) chains were applied. Positive clonal results were compared to the molecular profile of the initial tumors.
Results: Clonal immunoglobulin rearrangements were found in BM aspirates from 139 (34%) of the 408 patients. The IGH VH-FR2-JH primer set detected clonality in 118 patients and IGK Vκ-Jκ in 94 patients. In 77 patients both clonal IGH and IGK rearrangements were detected. Of the 139 clonal cases, trephine biopsies demonstrated involvement in only 82 (59%) cases, whereas 57 (41%) cases were without histological involvement. Of the 57 clonal cases without histological involvement, an identical clonal peak was identified in material from the primary tumor in 36 (63%) cases. In 14 (15%) of the 96 patients with reported histological BM involvement, no clonal rearrangement was detected.
Conclusions: Immunoglobulin rearrangement analysis of BM aspirates can detect a higher proportion of patients (p<0.05) with BM involvement compared to histological evaluation alone in patients diagnosed with B-cell lymphoma.
Tuesday, March 5, 2013 9:30 AM
Poster Session III # 165, Tuesday Morning