Measuring creatine kinase MB isoenzyme in a maintenance hemodialysis population: chemiluminometric immunoassay and electrophoresis compared

In an effort to clarify the issue of potentially false increases in creatine kinase (EC 2.7.3.2) MB isoenzyme (CK-MB) in uremia, we evaluated the CK profile of 84 persons undergoing chronic maintenance hemodialysis. We compared the performance of a new commercial two-site chemiluminometric immunoassay of CK-MB (Magic Lite; Ciba Corning Diagnostics) with that of electrophoresis on agarose gel (Cardio Trak-CK; Corning Medical). Results of the new chemiluminometric immunoassay for samples from hemodialysis patients correlated well with those of the electrophoretic method (r = 0.86, P less than 0.001), showing that neither substances in the serum of uremic patients nor CK-MM isoenzyme give false-positive increases in CK-MB isoenzyme. Our evidence suggests that the chemiluminometric method may be more specific than is electrophoresis in establishing absolute CK-MB values in the diagnosis of suspected myocardial injury in this population.