Misleading antigenic von Willebrand factor levels in acquired von Willebrand syndrome secondary to monoclonal gammopathy of undetermined significance.

Autor: Okamoto S; Department of Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan. okamoto.shuichi.c0@f.mail.nagoya-u.ac.jp.; Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, 466-8560, Japan. okamoto.shuichi.c0@f.mail.nagoya-u.ac.jp., Suzuki A; Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan., Tamura S; Graduate School of Health Sciences, Hokkaido University, Sapporo, Japan., Suzuki N; Department of Transfusion Medicine, Nagoya University Hospital, Nagoya, Japan., Kanematsu T; Department of Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan., Suzuki N; Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan., Kawaguchi Y; Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan., Katsumi A; Department of Hematology, National Center for Geriatrics and Gerontology, Obu, Japan., Hayakawa F; Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, 466-8560, Japan., Kiyoi H; Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan., Kojima T; Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, 466-8560, Japan.; Aichi Health Promotion Foundation, Nagoya, Japan., Matsushita T; Department of Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan.; Department of Transfusion Medicine, Nagoya University Hospital, Nagoya, Japan.
Jazyk: angličtina
Zdroj: International journal of hematology [Int J Hematol] 2024 Oct 24. Date of Electronic Publication: 2024 Oct 24.
DOI: 10.1007/s12185-024-03861-6
Abstrakt: In the diagnosis and treatment of acquired von Willebrand syndrome (AVWS), von Willebrand factor (VWF) antigen levels (VWF:Ag) are helpful for quantifying blood VWF-protein levels. Most clinical laboratories measure VWF:Ag by latex immunoassay (LIA), but underlying diseases of AVWS may influence LIA results. A 60 year-old AVWS patient with immunoglobulin G (IgG) kappa-type monoclonal gammopathy of undetermined significance (MGUS) showed reduced VWF activity but normal levels of VWF:Ag. His VWF multimers were broadly decreased, which represented a large discrepancy with VWF:Ag. To investigate the mechanism of this discrepancy, we measured the patient's plasma VWF:Ag by in-house enzyme-linked immunosorbent assay (ELISA) and LIA. We also purified the IgG fraction from the patient's serum and measured VWF:Ag in VWF-deficient plasma supplemented with this fraction. VWF:Ag measured by in-house ELISA (VWF:Ag ELISA ) was much lower than that measured by LIA (VWF:Ag LIA ), which indicated reduced VWF-protein volume in blood. Indeed, VWF:Ag was detected by LIA in VWF-deficient plasma spiked with a patient-derived IgG fraction. These results suggest that LIA detected a non-specific immunoreaction and overestimated the patient's VWF:Ag LIA . Clinicians should be aware that underlying diseases of AVWS could influence the LIA system, and interpret VWF:Ag cautiously.
(© 2024. Japanese Society of Hematology.)
Databáze: MEDLINE