Flow cytometry-based characterization of underlying clonal B and plasma cells in patients with light chain amyloidosis.
Systemic amyloid light chain (AL) amyloidosis is a life-threatening protein deposition disorder; however, effective therapy can dramatically improve the prognosis of AL patients. Therefore, accurate diagnosis of the underlying hematologic disease is important. Multi-parameter flow cytometry (MFC) is a reliable method to analyze lymphatic neoplasias and to detect even a small lymphatic clone. We analyzed the presence of clonal plasma cell (PC) and B cells in the bone marrow of 63 patients with newly diagnosed AL amyloidosis by MFC. We compared the results with the levels of monoclonal protein, the histopathology and cytogenetic results. As reference of light chain restriction, we used the immunohistochemical results of κ or λ positive amyloid deposits in various tissues. MFC identified underlying clonal lymphatic cells in all but two patients (61 of 63, 97%). Sixty-one patients harbored malignant PCs, whereas B-cell lymphomas were identified in two patients. Furthermore, MFC indicated at least one putative immunotherapeutical target (CD20, CD38, CD52, or SLAMF7) on malignant PCs in all but one patient. These results demonstrate that MFC is a reliable tool for an accurate diagnosis of the underlying hematologic disease and the detection of potential immunotherapeutical targets in patients with AL amyloidosis.
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.
Katharina
K
Lisenko
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.
Stefan O
SO
Schönland
Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany.
Anna
A
Jauch
Department of Pathology, University of Heidelberg, Heidelberg, Germany.
Mindaugas
M
Andrulis
Department of Pathology, University Medical Center Schleswig-Holstein, Kiel, Germany.
Christoph
C
Röcken
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.
Anthony D
AD
Ho
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.|National Center for Tumor Diseases, University of Heidelberg, Heidelberg, Germany.
Hartmut
H
Goldschmidt
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.
Ute
U
Hegenbart
Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany.
Michael
M
Hundemer
D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000175:diagnosis* / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism*; D015415:Biomarkers; D001854:Bone Marrow Cells / Q000378:metabolism; D002869:Chromosome Aberrations; D060965:Clonal Evolution; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000378:metabolism*; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000378:metabolism*; D015203:Reproducibility of Results; D012189:Retrospective Studies
D015415:Biomarkers; D007147:Immunoglobulin Light Chains
AL-amyloidosis; immunotherapeutical targets; lymphatic neoplasia; multi-parameter flow cytometry