TnI, cTnT, and CK-MB in patients with chronic renal failure

Yun, Jung E; Lee, Hyung Cheol; Lee, June Sang; Park, Kyu Yong; Park, Dae Kyun; Goo, Ja Ryong; Kim, Hyung Jik; Kim, Gheun Ho; Chun, Rho Won; Chae, Dong Wan; Noh, Jung Woo; Kim, Hyun Tae; Cho, Hyun Chan

Abstract

BACKGROUND: Nonspecific elevations of CK-MB, cTnT have been well known in patients with chronic renal failure(CRF) on maintenance hemodialysis. It has been suggested that recently developed cTnI seldom shows nonspecific elevations in these patients. Status of CRF patients can be divided into three groups: predialysis group, hemodialysis group and peritoneal dialysis group. Until now, most researchers have studied CK-MB, cTnT and cTnI only in CRF patients receiving maintenance hemodialysis. No previous studies have ever compared the differences of the nonspecific positivity of CK-MB, cTnT and cTnI according to the different status of CRF patients.
METHODS
Nonspecific positive ratios of cTnI, cTnT, & CK-MB in were evaluated 20 predialysis patients, 13 CAPD patients and 20 hemodialysis patients. No one had had any evidence of myocardial ischemia during the previous 3 months before the study entry. The predialysis group was again divided into two groups according to the cut off level of serum creatinine of 3.0 mg/dl. Authors also compared the nonspecific positive ratios of cTnI, cTnT, CK-MB between diabetic CRF group and non diabetic CRF group. The sensitivity, specificity and false positive ratios of each enzymes were examined on and 6 hours after arrival in 21 CRF patients who visited the emergency room with the complaint of chest pain.
RESULTS
1) There were no nonspecific significant elevations of cTnI in CRF patients regardless of the status of CRF. But there were significant nonspecific elevations of CK-MB, cTnT in them. It was more marked in cTnT especially with the cut-off value of 0.1 ng/ml. 2) Nonspecific positive ratios of cTnT was significantly increased in diabetic CRF patients. 3) The sensitivity and specificity of cTnI were 100% and 93.3% each, which were significantly higher than those of CK-MB(83.3%, 66.7%) & cTnT(66.7%, 53.3%).
CONCLUSION
In CRF patients, the nonspecific positive ratios of CK-MB, cTnT were higher than that of cTnI, and only cTnI did show significant specific elevations in all the CRF patients with acute myocardial infarction. It is likely that the status of CRF patients, dialysis mode, the sampling time point would not give significant changes in the nonspecific positive ratios of CK-MB, cTnT and cTnI.