Muscle-specific carbonic anhydrase III is a more sensitive marker of muscle damage than creatine kinase in neuromuscular disorders.

Serum concentration of carbonic anhydrase III (S-CA III), a novel marker of type I skeletal muscle cells was measured in 37 patients with neuromuscular diseases (polymyositis, muscular dystrophies, amyotrophic lateral sclerosis, and other neurogenic diseases) and in 24 control patients. Significant elevation in S-CA III was observed in all patient groups. Serum concentration of carbonic anhydrase III correlated positively with serum-creatine kinase. Serum concentration of carbonic anhydrase III was observed to be a more sensitive skeletal muscle marker both in myogenic and in neurogenic muscle affecting diseases than serum creatine kinase.