Cardiac troponin I, cardiac troponin T, and creatine kinase MB in dialysis patients without ischemic heart disease: evidence of cardiac troponin T expression in skeletal muscle.
Serum cardiac troponin T (cTnT) concentrations are frequently increased in chronic dialysis patients as measured by the first-generation ELISA immunoassay, as is creatine kinase (CK) MB mass in the absence of acute ischemic heart disease. We designed this study to compare four serum markers of myocardial injury [CK-MB mass, first-generation ELISA cTnT, second-generation Enzymun cTnT, and cardiac troponin I (cTnI)] in dialysis patients without acute ischemic heart disease. We also evaluated skeletal muscle from dialysis patients as a potential source of serum cTnT. No patients in the clinical evaluation group (n = 24) studied by history and by physical examination, electrocardiography, and two-dimensional echocardiography had evidence of ischemic heart disease. Biochemical markers were measured in serial predialysis blood samples with specific monoclonal antibody-based immunoassays. For several patients at least one sample measured above the upper reference limit: CK-MB, 7 of 24 (30%); ELISA cTnT, 17 of 24 (71%); Enzymun cTnT, 3 of 18 (17%); and cTnI, 1 of 24 (4%). In a separate group of dialysis patients (n = 5), expression of cTnT, but not cTnI, was demonstrated by Western blot analysis in 4 of 5 skeletal muscle biopsies. Chronic dialysis patients without acute ischemic heart disease frequently had increased serum CK-MB and cTnT. The specificity of the second-generation cTnT (Enzymun) assay was improved over that of the first-generation (ELISA) assay; cTnI was the most specific of the currently available biochemical markers. cTnT, but not cTnI, was expressed in the skeletal muscle of dialysis patients.
McLaurin
M D
MD
Department of Medicine, Hennepin County Medical Center, Minneapolis, MN 55415, USA.
Apple
F S
FS
Voss
E M
EM
Herzog
C A
CA
Sharkey
S W
SW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D001806:Blood Urea Nitrogen; D003402:Creatine Kinase / Q000032:analysis* / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007527:Isoenzymes; D007676:Kidney Failure, Chronic / Q000145:classification / Q000201:enzymology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000201:enzymology; D017202:Myocardial Ischemia / Q000097:blood / Q000201:enzymology / Q000378:metabolism; D009206:Myocardium / Q000737:chemistry* / Q000201:enzymology; D006435:Renal Dialysis; D014336:Troponin / Q000032:analysis* / Q000097:blood; D019210:Troponin I / Q000032:analysis* / Q000097:blood; D020107:Troponin T
D015415:Biomarkers; D007527:Isoenzymes; D014336:Troponin; D019210:Troponin I; D020107:Troponin T; D003402:Creatine Kinase