Significantly lower antigenicity of incobotulinumtoxin than abo- or onabotulinumtoxin.

BACKGROUND: For many indications, BoNT/A is repetitively injected with the risk of developing neutralizing antibodies (NABs). Therefore, it is important to analyze whether there is a difference in antigenicity between the different licensed BoNT/A preparations. METHODS: In this cross-sectional study, the prevalence of NABs was tested by means of the sensitive mouse hemidiaphragm assay (MHDA) in 645 patients. Patients were split into those having exclusively been treated with the complex protein-free incoBoNT/A preparation (CF-MON group) and those having started BoNT/A therapy with a complex protein-containing BoNT/A preparation (CC-I group). This CC-I group was split into those patients who remained either on abo- or onaBoNT/A (CC-MON group) and those who had been treated with at least two BoNT/A preparations (CC-SWI group). To balance treatment duration, only CC-MON patients who did not start their BoNT/A therapy more than 10 years before recruitment (CC-MON-10 group) were further analyzed. The log-rank test was used to compare the prevalence of NABs in the CF-MON and CC-MON-10 group. RESULTS: In the CF-MON subgroup, no patient developed NABs. In the CC-I group, 84 patients were NAB-positive. NABs were found in 33.3% of those who switched preparations (CC-SWI) and in 5.9% of the CC-MON-10 group. Kaplan-Meier curves for remaining NAB-negative under continuous BoNT/A therapy were significantly different (p < 0.035) between the CF-MON and CC-MON-10 group. CONCLUSION: Frequent injections of a complex protein-containing BoNT/A preparation are associated with significantly higher risks of developing NABs than injections with the same frequency using the complex protein-free incoBoNT/A preparation.

Long-term adherence and response to botulinum toxin in different indications.

OBJECTIVE: The objective of the study was the analysis of adherence and self-perceived treatment response to long-term botulinum neurotoxin type A (BoNT-A) treatment in different neurological indications. METHODS: In this retrospective, monocentric, observational study, cross-sectional and longitudinal data of 1351 patients documenting 20705 injection appointments at the BoNT outpatient clinic of Heinrich Heine University Duesseldorf between 1989 and 2014 were retrospectively analyzed. Patients had been treated with BoNT for neurological conditions, including cervical dystonia (CD), blepharospasm (BSP), other dystonia (ODT), hemifacial spasm (HFS), and spasticity (SPAS). The parameters longitudinally analyzed for the entire cohort were therapy duration as well as the mean and cumulative BoNT-A dose. Cross-sectionally, for subgroups of at least 721, patients' global self-perceived quality of health and life, global self-perceived reduction of symptoms by BoNT-A treatment as well as the clinical global impression were evaluated. Furthermore, mouse hemidiaphragm assay antibodies (MHDA-ABs) were analyzed in a subgroup. RESULTS: The mean treatment duration was 4.58 years (95% CI 4.32-4.84), and 678 (50.2%) therapy dropouts of 1351 patients occurred within the first 8 years. Therapy adherence and self-perceived symptom reduction in long-term BoNT-A treatment over the years were significantly longer in BSP, HFS, and CD patients than in ODT and SPAS patients. INTERPRETATION: The treatment indication determines long-term adherence and self-perceived symptom reduction in BoNT-A therapy, which are better in BSP, HFS, and CD patients than in ODT and SPAS patients. MHDA-ABs had a significant impact on global self-perceived symptom reduction, but with only a limited degree.

High prevalence of neutralizing antibodies after long-term botulinum neurotoxin therapy.

OBJECTIVE: To investigate the prevalence of neutralizing antibodies (NAbs) against botulinum neurotoxin type A (BoNT/A) during long-term BoNT/A treatment in different neurologic indications. METHODS: In this monocentric, observational cross-sectional study, 596 outpatients treated with BoNT/A for different indications were tested for BoNT/A binding antibodies by ELISA. Positive samples were investigated for NAbs with the mouse hemidiaphragm test. The prevalence of NAbs was analyzed for different indications: facial hemispasm, blepharospasm, cervical dystonia, other dystonia, and spasticity. Besides the rate of NAb-positive patients overall and per patient subgroup, a Kaplan-Meier analysis of the probability of remaining NAb negative with duration of treatment is provided, and a stepwise binary logistic regression analysis is performed to identify factors significantly contributing to the induction of NAbs. RESULTS: Overall, 83 of 596 patients (13.9%) had measurable NAbs. The probability of developing NAbs increased with the single and cumulative dose of treatment and was influenced by the BoNT/A formulation, while all other factors analyzed, including disease entity and treatment duration, had no additional influence. CONCLUSIONS: We present the largest study to date of the prevalence of BoNT/A NAbs in a large unbiased cohort of patients including the relevant neurologic indications. Repeated injections of BoNT/A inevitably bear the risk of developing NAbs. However, in addition to avoiding booster injections and providing short intervals between injections, reducing the individual injected doses may diminish the risk of NAb induction independently of the indication for which BoNT/A is used.

Telemedicine: insulin pump controlled via the Global System for Mobile Communications (GSM).

In the future, the delivery of drugs using telemetric techniques will become more and more important. In the present investigations an experimental insulin pump has been developed which is remote-controlled via a computer program and the Global System for Mobile Communications (GSM). The commands for pump control are transferred in encrypted form via the Short Message Service (SMS). The pump can be programmed in advance for a time period of 24 h. An integrated sensor gives exact information about the number of steps executed by the stepping motor which is controlling the drug release. Model experiments show that there is almost no delay between sending the control SMS and execution of the commands by the pump.