Objective: To characterize a monoclonal IgG(kappa) (MAb) from a patient with planar xanthoma that precipitated with serum lipids at reduced temperature.
Methods: The molecular weight (Mr), sensitivity to proteases, and glycosylation of the purified MAb were analyzed. The specificity of the MAb was tested by measuring cryoprecipitation with pure high- (HDL) and low-density (LDL) lipoproteins. The effect of choline, phosphocholine, and glycerol 3-phosphate on the precipitation temperature of LDL by the MAb was studied.
Results: The MAb was larger than normal IgG due to hyperglycosylation of the MAb light chain. It formed cryoprecipitates with pure HDL and LDL as well as the lipids extracted from these lipoproteins. Fab fragments of the MAb lowered the temperature of its precipitation with LDL. Choline, phosphocholine, and glycerol 3-phosphate also lower the precipitation temperature.
Conclusion: This is the first human IgG reported with apparent specificity for phosphocholine antigens. Its precipitation with lipids at reduced temperature suggests that it recognizes conformations of phospholipid head groups that develop below core body temperature.
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http://dx.doi.org/10.1111/j.1600-0609.2008.01072.x | DOI Listing |
Eur J Neurol
January 2025
Groupe Hospitalier Pitié-Salpêtrière, Institut de Myologie, AP-HP, Sorbonne Université, Paris, France.
Background: Monoclonal gammopathy (MG) has been reported in association with numerous neurological disorders but the spectrum of MG-associated myopathies remains poorly described.
Objective: To report a newly acquired myopathy associated with MG.
Methods: Three adult patients with the same phenotype from two French referral centers were prospectively analyzed.
J Appl Lab Med
December 2024
The Binding Site, part of Thermo Fisher Scientific, Rochester, MN, United States.
Background: Therapeutic monoclonal antibodies (t-mAbs) may interfere with electrophoresis-based methods used to monitor multiple myeloma (MM), which can create inaccurate results. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry is an alternative to gels distinguishing between endogenous M-proteins and t-mAbs based on molecular mass.
Methods: Serum samples (n = 109) from 34 MM patients receiving Dara-KRd were collected 14 or 28 days postdaratumumab administration.
J Int Med Res
November 2024
Department of Hematology, the First Hospital of China Medical University, Shenyang, Liaoning, P. R. China.
Type II cryoglobulinemia is a rare disorder characterized by abnormal immunoglobulins (Igs) precipitating in the blood at low temperatures and redissolving upon warming. Sjogren's disease (SjD) is an autoimmune disorder involving secretory gland malfunction that leads to persistent dryness of the mouth and eyes. Here, we report the case of a 61-year-old woman with a 7-year history of SjD who was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL).
View Article and Find Full Text PDFBackground: The incidence of monoclonal gammopathy of undetermined significance (MGUS) in the population of over 50-year-olds is approximately 3% and increases with age. The association between MG and neuropathy has been of interest for several years, but the causal relationship has not yet been clarified.
Methods: For 682 patients who visited the Department of Neurology and requested tests for MG work-up, we retrospectively collected demographic and clinical information, such as age, gender, diagnosis, and neurologic and laboratory test results, from their medical records.
Cancer Med
August 2024
Department of Hematology Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
Background: Immunofixation electrophoresis (IFE) is the standard method for confirming the presence of a monoclonal protein (M-protein) at multiple myeloma (MM) diagnosis. IFE is also essential at assessment of complete response (CR) and stringent CR during treatment. As the CR assessment is influenced by daratumumab and isatuximab, HYDRASHIFT assays were developed.
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