Quantitation of Muscle Mass and Muscle Protein Synthesis Rate: Documenting a Response to Myoblast Transfer

Abstract

The goal of treatment in muscular dystrophy is to provide a favorable effect on the natural history of muscle strength. Such an effect can be produced by improvement in strength, by arrest of progression, or by slowing in the rate of progression. All laboratory measurements which assess muscle histology or electrophysiology, muscle mass, or measure muscle components in serum (e.g. creatine kinase) are indirect and of value in a therapeutic trial only to the extent that they either predict or substantiate a clinical response. If myoblast transfer treatment is to be used, it will be studied initially in one muscle or at most, a small number of individual muscles. There is currently no documented way of establishing a change in the natural history of strength for individual muscles in Duchenne dystrophy. Indirect, laboratory measures of “success” of myoblast transfer treatment applied to individual muscles are therefore of potential importance since they may: (1) predict the ultimate clinical success of the treatment; (2) establish a mechanism of action for myoblast transfer; (3) provide clues as to other approaches which could be combined with myoblast transfer to improve results.