Neutralizing Botulinum Toxin Type A Antibodies: Clinical Observations in Patients with Cervical Dystonia

Abstract

Neutralization of antibodies poses a
problem for a substantial number of cervical
dystonia (CD) patients treated with
botulinum toxin type A (BoNT/A). Presence
of these antibodies may lead to a
secondary nonresponse to BoNT/A
treatment. In this study, we compared 6
antibody-positive (Ab+) with 12 antibodynegative
(Ab–) CD patients treated with
BoNT/A (Dysport®) and matched for duration
of treatment, number of BoNT/A
injections, and severity of clinical symptoms.
The two groups differed in cumulative
BoNT/A dose (Ab+, 5984 mouse
units [MU], SD = 3151 MU; Ab–, 3143 MU,
SD = 1294 MU; P < .05). In addition, Ab+
patients were significantly younger (Ab+
mean age = 41.3 y, SD = 5.9 y; Ab– mean
age = 56.8 y, SD = 15.3 y; P < .05). In order
to avoid formation of neutralizing antibodies,
doses of BoNT/A should be
kept as low as possible. The risk of antibody
formation seems to be higher in
younger patients.