Repeated botulinum neurotoxin type A (BoNT/A) injections for various neurological indications can increase the development of neutralizing antibodies (NABs); however, decreasing doses can reduce the risk for NAB induction, according to a cross-sectional study published in Neurology.
Patients treated for facial hemispasm, blepharospasm, cervical dystonia, other dystonia, and spasticity with BoNT/A were tested for BoNT/A binding antibodies via enzyme-linked immunosorbent assay (ELISA) (N=596). The mouse hemidiaphragm test was used to investigate ELISA-positive samples for NABs. Study researchers evaluated samples to also identify factors that potentially contributed to NAB induction. In addition, the researchers calculated the estimated prevalence of NABs after a 10-year treatment duration.
Of the 596 patients included in the study, approximately 14% of patients had NABs considered measurable. Each single and cumulative dose of BoNT/A injections were associated with an increased probability of developing NABs. This increased probability was also driven by the treatment’s formulation (P <.01) and single dose per session (P =.023).
Limitations of the study included its small number of patients who had measurable NABs and the recruitment of patients from 1 center in Europe, which may reduce generalizability of the findings.
Because of the substantial “differences in treatment duration, this finding needs to be corroborated in larger cohorts with more homogeneous follow-up times,” the researchers concluded.
Albrecht P, Jansen A, Lee JI, et al. High prevalence of neutralizing antibodies after long-term botulinum neurotoxin therapy. Neurology. 2019;92(1):e48-e54.