1. Natalizumab in cerebrospinal fluid and breastmilk of patients with multiple sclerosis
- Author
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Ilaria Callegari, Mika Schneider, Vera Aebischer, Margarete M. Voortman, Undine Proschmann, Tjalf Ziemssen, Raija Lindberg, Bettina Fischer-Barnicol, Michael Khalil, Ludwig Kappos, Jens Kuhle, Nicholas S.R. Sanderson, and Tobias Derfuss
- Subjects
Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background: Natalizumab is a highly effective monoclonal antibody for the treatment of multiple sclerosis (MS), which can diffuse in different anatomical compartments, including cerebrospinal fluid (CSF) and milk. Objectives: Starting from incidental detection of natalizumab in the CSF of MS patients, the objective of this study was to develope a flow-cytometry-based assay and apply it to quantify natalizumab in body fluids, including milk collected from nursing patients over 180 days and in patients with neutralizing antibodies against natalizumab. Methods: CSF, milk and sera samples from patients with multiple sclerosis were tested by flow-cytometry for binding to a VLA-4 expressing cell line or to a control cell line. A standard curve was prepared by incubating the same cells with natalizumab at 50 μg/ml and serially diluted to 0.005 ng/ml. Binding specificity was confirmed using an anti-natalizumab neutralizing antibody. Results: Our assay was sensitive enough to detect natalizumab in CSF, with a lower detection limit of 1.5 ng/ml. Neutralizing antibodies against natalizumab inhibited binding to the cell line. In breastmilk, the peak concentration was observed during the first 2 weeks after infusion and the average concentration over the observation time was 173.3 ng/ml, with a trend toward increased average milk concentration over subsequent administrations. Conclusion: Routine use of such an assay would enable a better understanding of the safety of therapeutic antibody administration during pregnancy and lactation.
- Published
- 2023
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