Quantification of potency of neutralizing antibodies to botulinum toxin using compound muscle action potential (CMAP)

We evaluated a method for quantifying botulinum toxin-neutralizing antibodies which utilizes the CMAP. This method can be used just one day after administration, and the detection sensitivity was higher than that of the mouse neutralization test. The CMAP neutralization test detected neutralizing antibodies in patients who were resistant to treatment with the botulinum LL toxin. These results indicate that the CMAP neutralization test is useful for detecting low levels of antitoxin.