Antibody responses could explain why some patients fail botulinum toxin type A (BoNT/A) treatment of hyperactive detrusor or sphincter dysfunction, according to German investigators.
Heinrich Schulte-Baukloh, MD, of Charité Medical School of Humboldt University in Berlin, and his colleagues studied 25 patients (mean age, 28.3 years; range, 11-75 years) who had received at least one previous detrusor and/or sphincter injection with BoNT/A. They looked at the presence of BoNT antibodies (BoNT/A-AB) and correlated this with clinical findings.
BoNT/A-AB titers were clearly positive in four patients, of whom three experienced complete therapy failure, the researchers reported in the International Journal of Urology (2008;15:405-415). In two patients, antibodies developed after just one treatment session.
“In patients with clinically complete therapy failure in whom no obvious other causes can be determined (such as progressive disease in a patient with multiple sclerosis), screening for BoNT/A-AB should be carried out,” they concluded.