title: A minority of concurrent monoclonal lymphocytes and plasmacytic cells sharing light chains are genetically related in putative lymphoplasmacytic lymphoma.
abstract: Flow cytometric cell sorting combined with molecular gene rearrangement analysis was used to detect and to further characterize simultaneously occurring phenotypically distinct B cell monoclonal lymphoid and monoclonal plasma cell populations from 38 individual specimens. By sorting and subsequent gene rearrangement analysis, separate or identical monoclonality genotypes could be revealed and confirmed. In only 13 of 38 specimens, the B lymphoid cells and plasma cell populations showed an identical genotypic profile, while 25 had non-identical profiles (including 4 process control specimens). The majority of the genotypically identical group had a phenotype consistent with Waldenström's/lymphoplasmacytic lymphoma (WM/LPL), while WM/LPL phenotype was present in 16/25 of the non-identical cases. Proof of an identical monoclonal genotype for plasmacytic and B-lymphoid cell populations must be used to define WM/LPL as a distinct entity in the clinical setting of monoclonal lymphoid and plasma cells expressing the same light chains. Conversely, the confirmation of genotypically distinct populations can significantly improve confidence in diagnostic and prognostic decisions in specimens with B lymphoid lymphomas and a concurrent, possibly smoldering myeloma or multiple myeloma. These techniques are requisite in future clinical studies for diagnosis and prognosis in these diseases.
authors.affiliation: HematoLogics Inc., 3161 Elliott Ave, Seattle, WA 98121, USA. barbara@hematologics.com
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Zehentner
authors.forename: Jevon A
authors.initials: JA
authors.lastname: Cutler
authors.forename: Wayne K
authors.initials: WK
authors.lastname: Fritschle
authors.forename: Richard K
authors.initials: RK
authors.lastname: Bennington
authors.forename: Collette
authors.initials: C
authors.lastname: Wentzel
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Smading
authors.forename: Eric W
authors.initials: EW
authors.lastname: Jeffery
authors.forename: Denise A
authors.initials: DA
authors.lastname: Wells
authors.forename: Michael R
authors.initials: MR
authors.lastname: Loken
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology; D015331:Cohort Studies; D020732:Cytogenetic Analysis; D005260:Female; D005787:Gene Frequency; D015322:Gene Rearrangement, B-Lymphocyte / Q000502:physiology; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000235:genetics / Q000378:metabolism*; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000378:metabolism / Q000473:pathology*; D017422:Sequence Analysis, DNA; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics* / Q000276:immunology* / Q000473:pathology
chemical_list: D007147:Immunoglobulin Light Chains