Elevated serum levels of creatine kinase BB in autosomal dominant osteopetrosis type II

Serum levels of creatine kinase isoenzyme BB (CK-BB) were measured spectrophotometrically and by electrophoresis in 17 patients with autosomal dominant osteopetrosis (ADO) and compared with those of age- and sex-matched controls. Eight patients had ADO type 1 and nine patients had ADO type II. CK-BB was significantly increased (p less than 0.002) in type II but normal in type I compared with controls. This finding supports heterogeneity of ADO, and it may indicate a potential role for CK-BB as a marker of immature osteoclasts.