Botulinum toxin type B de novo therapy of cervical dystonia: frequency of antibody induced therapy failure.
Botulinum toxin induced therapy failure type B antibody (BT-B, BT-B-AB) has so far only been reported after previous formation of antibodies against botulinum toxin type A (BT-A, BTA- AB). We wanted to explore the risk of BT-B-AB-induced therapy failure in patients who were exposed to botulinum toxin for the first time. For this purpose we followed nine patients with cervical dystonia receiving BT-B (NeuroBloc/Myo- Bloc, Elan Pharmaceuticals) in a dose of 11435 +/- 2977MU during 4.9 +/- 3.0 injection series. All patients showed a satisfactory initial therapeutic response as documented by a Toronto Western Spasmodic Torticollis Rating Scale score reduction from 17.7 +/- 9.4 to 5.3 +/- 4.8 and an overall subjective improvement of 56.1 +/- 28.3%. Seven patients experienced systemic anticholinergic side effects. Five patients had stable therapeutic responses over subsequent injection series. Four patients experienced complete therapy failure with BT-B-AB titres in excess of 10 mU/ml on the mouse diaphragm assay. Doubling the last effective BT-B dose produced neither therapeutic effects nor side effects. Subsequent applications of botulinum toxin type A produced a continued therapeutic response in one patient and complete therapy failure in the other.Despite the small sample size a frequency of 44 % indicates a high risk for BT-B-AB-induced complete therapy failure. The high amount of neurotoxin administered when NeuroBloc/MyoBloc is used might be a contributory factor. Further prospective comparative studies are necessary to monitor the frequency and time course of BT-B-AB formation.
Dressler
Dirk
D
Dept. of Neurology, Rostock University, Gehlsheimer Str. 20, 18147 Rostock, Germany. dirk.dressler@med.uni-rostock.de
Bigalke
Hans
H
D000328:Adult; D001905:Botulinum Toxins / Q000276:immunology / Q000627:therapeutic use*; D019274:Botulinum Toxins, Type A; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000276:immunology / Q000627:therapeutic use*; D012720:Severity of Illness Index; D014103:Torticollis / Q000188:drug therapy* / Q000276:immunology*; D017211:Treatment Failure
D009465:Neuromuscular Agents; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A