AGE-RELATED REFERENCE INTERVALS FOR CREATINE KINASE-BB IN SERUM

  • 1 January 1982
    • journal article
    • research article
    • Vol. 42  (8) , 621-625
Abstract
The mass concentration of creatine kinase BB (CK-BB) isoezyme was measured in serum of 365 healthy children and adults with a CK-BB specific radioimmunoassay. Eight separate age groups (newborns, 4 days, and 1, 8, 14, 25, 40 and 65 yr) were examined and the reference intervals for these groups were estimated. The concentration of CK-BB generally decreased with increasing age, most of the changes taking place within the first year of life. Thus, the median value at age 1 yr (9.2 .mu.g/l) was 1/15th of that observed at birth, 1/2 of that observed at age 4 days, but 4 times higher than that observed in adults. A transient increase in CK-BB concentration was observed in boys 14 yr old. At this age, in contrast to at all other ages, the values measured in boys were significantly (P < 0.005) higher than the values measured in girls. In 27 of the sera from cord blood the relationship between estimates of CK-BB mass and activity were examined, the latter being estimated by immunoinhibition technique. The 2 estimates were highly correlated (r = 0.98), 2 .mu.g of enzyme mass being roughly equivalent to 1 U of enzyme activity.