To the Editor. —I read with interest the article by Dillon et al entitled "Diagnostic Problem in Acute Myocardial Infarction: CK-MB in the Absence of Abnormally Elevated Total Creatine Kinase Levels" published in the JanuaryArchives(1982;142:33-38). I agree with the basic premise of the article; however, I would like to address their reliance on Technicon's reference values (calculated from 100 subjects) for total creatine kinase (CK) activity. If Dillon et al had used a reference range established by them for their institution rather than by someone else, I believe they would have found substantially fewer patients with increased CK and MB (its myocardial isozyme) levels with "normal" total CK levels than reported. They probably would have found that their reference range would have been substantially lower than the Technicon values. At the Methodist Medical Center of Illinois, Peoria, where I work, we have a Technicon automated multiple analysis system