title: Quantification of bone marrow plasma cell infiltration in multiple myeloma: usefulness of bone marrow aspirate clot with CD138 immunohistochemistry.
abstract: Accurate quantification of plasma cells (PCs) in bone marrow (BM) is critical for diagnosis and assessment of treatment response in patients with multiple myeloma (MM). We compared the % of BM PC quantified by 250 cell differential count on May-Giemsa-stained BM smears, by counting 500 - 2500 cells in 2 - 5 representative microscopy fields in CD138-immunostained BM clot and biopsy sections, and CD38/CD45/CD138 gated BM PCs on flow cytometry (FCM) in 150 sets of BM samples from 120 patients. Percentages of PC were significantly correlated between BM biopsy and clot, and between smear and FCM (r = 0.96, 0.93, respectively). However, quantification by smear and FCM significantly underestimated the PC compared to biopsy or clot, and the degree of underestimation increased with blood dilution. FCM consistently showed lower % of PC compared to aspirate smears. Fifty-nine of 103 patients with M-protein level < 3000 mg/dL in serum or 500 mg/24 h in urine and diagnosed with monoclonal gammopathy of undetermined significance (MGUS) based on smear alone were reclassified as smoldering MM when reassessed using CD138-stained biopsy/clot sections. Among the 72 patients with sMM diagnosed by BM biopsy and/clot, three patients (4.2%) had extensive BM infiltration of PC (≥ 60%) and required treatment. Our data clearly showed the necessity of CD138 immunostaining of BM biopsy/clot specimens for correct diagnosis of MM and related disorders. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Kosei
authors.initials: K
authors.lastname: Matsue
authors.affiliation: Department of Cardiology, University Medical Center Groninge, Groninge, The Netherlands.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Matsue
authors.affiliation: Department of Clinical Pathology, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kumata
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Usui
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Suehara
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Fukumoto
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Fujisawa
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Narita
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8602, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Takeuchi
mesh_terms: D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination; D002452:Cell Count; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000175:diagnosis; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000378:metabolism; D010950:Plasma Cells / Q000378:metabolism / Q000473:pathology*; D053668:Syndecan-1 / Q000378:metabolism
chemical_list: D053668:Syndecan-1
keywords: CD 138 immunostaining; aspirate smear; bone marrow biopsy; flow cytometry; multiple myeloma; plasma cell quantification