• Brit Ellen Rød, Øivind Torkildsen, Kjell-Morten Myhr, Lars Bø, and Stig Wergeland.
• Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
• J. Neurol. Neurosurg. Psychiatr. 2022 Jul 25; 94 (1): 384138-41.

BackgroundThere are limited data on the safety of breast feeding during rituximab therapy. Our objective is to determine exposure from breast feeding and biological effects of rituximab in breastfed infants.MethodsIn our case series of six mother-infant pairs, the nursing mothers with relapsing-remitting multiple sclerosis received rituximab during breast feeding. As part of clinical follow-up, six serial breast milk samples, and blood samples from both mothers and infants, were collected and analysed.ResultsThe median average rituximab concentration (Cavg) in breast milk was 0.04 µg/mL and the estimated relative infant dose (RID) was 0.07%. The highest measured concentration of rituximab in the breast milk samples was 0.25 µg/mL, giving an estimated RID of 0.26%.All infant serum rituximab concentrations were below 0.01 µg/mL. The CD19 +B cell count values were within the 10th- 90th percentiles of reported normal ranges in healthy infants.ConclusionsWe found minimal transfer of rituximab into breast milk and could not reliably detect levels of rituximab in infant serum. B cell counts in infants were unaffected.© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

1 keywords...

hide…