[Creatine kinase "NAC-activated": reference values for children (author's transl)].

Reference values for 327 children aged between 1 day and 15 years are given for the revised standard method for the determination of serum creatine kinase (CK) activity by activation with N-acetylcysteine (NAC). No sex-dependence could be observed, but CK activity was found to vary markedly with age. The following values are suggested as upper limits of the reference ranges for measurements at 25 degrees C: neonates: 1-3 days: less than or equal to 370 U/l, 4-10 days: less than or equal to 200 U/l, 11-31 days: less than or equal to 100 U/l; children (2 months-15 years): less than or equal to 90 U/l.