Neuropediatrics 2004; 35 - V18
DOI: 10.1055/s-2004-819362

High prevalence of antibody formation against botulinumtoxin A in the treatment of children – a long-term cohort study in the years 1993–2001

U Fietzek 1, J Herrmann 2, V Mall 3, H Bigalke 4, K Geth 1, J Schulte Mönting 5, M Linder 3, JB Kirschner 3, S Berweck 1, R Korinthenberg 3, F Heinen 1
  • 1Dr. von Hauner’s Children's Hospital, University Munich
  • 2Charité, University Berlin
  • 3University Children's Hospital Freiburg
  • 4Institute of Toxikology, University Hannover
  • 5Institute of Biomathematics and Medical Statistics, University Freiburg, Germany

Objective: The clinical impact of neutralizing antibody formation against botulinum toxin A in long-term treatment of children is unclear so far.

Patients and Methods: In a retrospective cohort study of 133 patients who were treated with botulinum toxin A due to focal spasticity in between 1993–2001, the status of antibody formation was determined using the mouse bioassay, and the therapy response status was assessed by standardised clinical examination. The results were correlated using logistical regression analysis. A Kaplan-Meier curve was calculated for the occurrence of antibodies.

Results: Neutralizing antibodies were found in 31.8% of the patients. The formation of antibodies was highly significantly correlated to the number of treatments (p<0.0001) and to the maximum single dose (p<0.001). Following 8 treatments 50% of the patients were positive for neutralizing antibodies. The formation of antibodies was highly significantly correlated to secondary non-response (p<0.0001).

Conclusions: Neutralizing antibodies are demonstrated in 50% of patients who were treated over a period of 2 or more years. The influencing variables on antibody formation are the number of treatments and the size of the treatment dose.

Keywords: botulinum toxin, antibodies, secondary non-response