CASE REPORT: PDF OnlyMacroenzyme Creatine Kinase in the Era of Modern Laboratory MedicineLiu, Chun-Yua, e; Lai, Yi-Chunc, e, f; Wu, Yi-Chid; Tzeng, Cheng-Hwaia, e; Lee, Shou-Dongb, c, e, *Author Information aDivision of Hematology and Oncology, I-Lan, Taiwan, R.O.C. bDivision of Gastroenterology, I-Lan, Taiwan, R.O.C. cDepartment of Medicine, I-Lan, Taiwan, R.O.C. dSection of Biochemistry, Department of Laboratory Medicine and Pathology, Taipei Veterans General Hospital, I-Lan, Taiwan, R.O.C. eNational Yang-Ming University School of Medicine, I-Lan, Taiwan, R.O.C. fDepartment of Medicine, National Yang-Ming University Hospital, I-Lan, Taiwan, R.O.C. *Correspondence to: Dr Shou-Dong Lee, Department of Medicine, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan, R.O.C. E-mail: [email protected] Received: June 16, 2009; • Accepted: September 11, 2009. Journal of the Chinese Medical Association: January 2010 - Volume 73 - Issue 1 - p 35-39 doi: 10.1016/S1726-4901(10)70019-8 Metrics Abstract Among the conditions in which creatine kinase (CK)-MB activity is elevated in the absence of myocardial injury or infarction, macroenzyme (macro) CK merits special attention from clinicians. We present 2 cases, 1 with macro CK type 1 and the other with macro CK type 2, to stress the common clinical situations and diagnostic dilemma that clinicians encounter when evaluating patients with macro CK. Moreover, the rare conditions associated with macro CK, and the phenomenon of spuriously high CK-MB activity out of proportion to total CK, are discussed. The biochemical characteristics, clinical significance and potential implications of macro CK are reviewed within the scope of modern laboratory medicine. © 2010 by Lippincott Williams & Wilkins, Inc.