Carbonic anhydrase III in neuromuscular disorders.

Plasma carbonic anhydrase III (CAIII) and creatine kinase (CK) were measured in 44 patients with a variety of neuromuscular disorders. Markedly elevated CK levels were associated with similarly increased levels of CAIII. In 9 patients, only the CAIII was elevated, but in 2 patients only the CK was raised. The determination of plasma CAIII is thus an important index of muscle disorder and is probably more sensitive than CK.