CREATINE-KINASE MB MEASURED BY FLUOROMETRIC ENZYME-IMMUNOASSAY AND IMMUNOCHEMILUMINESCENCE
ANNALS OF CLINICAL AND LABORATORY SCIENCE
Authors: MCBRIDE, JH; RODGERSON, DO; OTA, MK; MARUYA, M; MCEVENEY, S
Abstract
Creatine kinase MB (CK-MB) was measured in serum by a fluorometric enzyme immunoassay on the Stratus analyzer and by an immunochemiluminometric assay using the Ciba Corning Magic Lite System. Both methods were standardized against purified CK-MB, with Stratus underestimating by 20 percent and Magic Lite overestimating by 28 percent. The assays proved sensitive and linear; however, at a CK-MB concentration of 7.0-mu-g per L, Stratus gave unacceptable inter-assay precision. No cross-reactivity was observed with CK-MM or CK-BB and elevated triglycerides, bilirubin, and hemoglobin did not interfere. Correlations with an immunoradiometric assay (Embria), using 522 samples, gave: Stratus = 0.999 (Embria) -3.3; r = 0.969, and Magic Lite = 1.225 (Embria) -3.03; r = 0.971. When using Magic Lite, results from 40 acute myocardial infarction (AMI) patients gave a mean CK-MB value of 93.8-mu-g per L (range: 9.2 to 428-mu-g per L) at the peak of enzyme release and a mean value of 69.6-mu-g per L (range: 6.7 to 319-mu-g per L) when using Stratus. Both methods proved to be highly sensitive and specific in the diagnosis of AMI; however, the need for standardization of CK-MB assays is stressed.
SERUM LEVELS OF CREATINE-KINASE AND ITS ISOENZYMES DURING THE 1ST POSTPARTUM DAY IN HEALTHY NEWBORNS DELIVERED VAGINALLY OR BY CESAREAN-SECTION
GYNECOLOGIC AND OBSTETRIC INVESTIGATION
Authors: MALAMITSIPUCHNER, A; MINARETZIS, D; MARTZELI, L; PAPAS, C
Abstract
The purpose of this study is to investigate the relationship of creatine kinase (CK) and its isoenzyme levels in the newborn to the mode of delivery, time interval from birth (divided in four 6-hour time periods), parity and sex of the neonates. During the 1st postpartum day, serum levels of CK and its isoenzymes (CK-MM, CK-MB, CK-BB) were determined from 115 healthy full-term neonates born consecutively either by spontaneous vaginal delivery (VD, n = 85) or by elective cesarean section (CS, n = 30). The multiple regression analysis was applied. Total CK levels were positively correlated with VD (p < 0.0003). This was mainly attributed to a rise in the CK-MM activity which presented a similar pattern to CK. CK-MB activity was also positively correlated with VD. In contrast, CK-BB was negatively correlated to the postpartum time period. Neonatal sex and parity did not influence CK and its isoenzyme levels significantly. In conclusion, VD contributes significantly to an increase in CK levels during the 1st day of extrauterine life.