Enzyme and isoenzyme tests in the diagnosis of myocardial infarct during aortocoronary bypass

The authors assess the diagnostic value of several enzyme and isozymic tests used in the diagnosis of myocardial infarction in aortocoronary shunting (ACS): the diagnostic sensitivity and specificity, as well as the significance of both positive and negative results, and the diagnostic efficacy of every test have been estimated. Ninety-one patients subjected to autovenous ACS have been examined for the total creatine kinase (CK), lactate dehydrogenase (LDH), aspartate and alanine aminotransferase activities, and for the activities of CK and LDH isozymes. The results evidence a high diagnostic value of CK and LDH isozymes measurements. A comprehensive study of these isozymes is a reliable criterion of the diagnosis of myocardial infarction. If myocardial infarction in ACS is diagnosed on the basis of the total enzymic activities, measurements of the transaminases and LDH are advisable; investigation of CK total activity is of poor informative value.     

Simultaneous separation of creatine kinase and lactate dehydrogenase isoenzymes using an electrophoresis method]

A specific and sensitive rapid method for simultaneous electrophoretic separation of the blood serum creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzymes is described, fit for rapid diagnosis. A common electrophoresis scheme was used for the separation of both enzymes on the same cellulose acetate plate. Then the isoenzymes were separately detected by their enzymic activities. To detect the enzymic activities at the sites of isoenzymes' localization, the samples were incubated with substrate gel. Optimal conditions for the detection of CK and LDH activities were defined. To illustrate the diagnostic value of the method, the blood serum CK and LDH isoenzymic activities were measured in the patients with acute myocardial infarction and in those operated on for aortocoronary shunting.     

Lactate dehydrogenase isoenzyme 1: Its usefulness as a screening test in diagnosis of myocardial infarction

Immunological assay of LD-1 activity provides a quantitative measurement of the type of lactate dehydrogenase (LD, EC 1.1.1.27) activity characteristic of myocardial origin. Using this test, a laboratory diagnosis of myocardial infarction can be either ruled out or confirmed in approximately 75% of patients in whom this diagnosis is suspected, without electrophoretic separation of creatine kinase (CK, EC 2.7.3.2.) and LD isoenzymes. Normal total CK and LD activities cannot be used to rule out myocardial infarction since CK-MB and LD-1 may have increased although total activities remain within their reference ranges. LD-1 activity increases as quickly as CK-MB following the onset of pain in the majority of patients but it remains elevated longer giving a greater period of time during which the diagnosis of myocardial infarction can be confirmed.     

Troponin I concentrations of shed blood might influence monitoring of myocardial injury after coronary operations

In a prospective study we evaluated the concentration of cardiac troponin I (cTnI) and creatine kinase activities (CK) in shed mediastinal blood in the early postoperative period after coronary artery bypass grafting (CABG). Forty seven patients who underwent first time elective CABG were studied. CTnI levels and CK activities in arterial blood and shed mediastinal blood were measured after admission to the intensive care unit (ICU) and 6 h after unclamping the aorta. Mediastinal shed blood samples were drawn from 23 patients (group A) before the filter of the cardiotomy reservoir and from 24 patients (group B) behind. Additionally, both markers were measured in blood samples collected from the cell-saver. There were no significant differences between both groups (A and B) with regard to perioperative parameters. Mean loss of mediastinal shed blood in all patients was 207 +/- 127 ml within the first 6 h after operation. There was a positive correlation between CK activities and cTnI concentrations in serum and mediastinal shed blood, but shed blood contained significantly higher concentrations of cTnI as well as CK activities than the circulating blood after admission to the ICU and 6 h after unclamping the aorta. At both time points the cTnI-concentrations and CK activities in shed blood in group B were lower than those in group A but much higher than in serum. The effects of the use of a blood filter diminishes with time. Mediastinal shed blood contains extremely high cTnI concentrations and CK activities. Retransfusion of higher quantities of shed blood might lead to false-positive diagnosis of perioperative myocardial infarction.     

Differential diagnosis of patients with abnormal serum creatine kinase isoenzymes

For the diagnosis of myocardial injury, particularly AMI, CK-MB has become the gold standard. Changing CK-MB activities in serially collected blood from patients with suggestive signs and symptoms of AMI is almost pathognomonic for infarction. Nevertheless, an increased CK-MB cannot be equated with AMI owing to the many other types of inflammatory, traumatic, and miscellaneous forms of injury to the heart and the trace activities of CK-MB in skeletal muscle. Other enzyme tests for AMI are less efficient. In order of decreasing efficiency, the tests are CK-MB, CK, LD1 greater than LD2 or LD1/LD2 greater than 0.76, AST and LD; the latter two tests are not cost effective and add little or nothing when results for CK-MB, CK, and LD isoenzymes are available. The value of the isoforms of CK-MM and CK-MB remains to be established. Early evidence suggests that they could be helpful in the diagnosis of AMI; however, owing to the greater technical difficulties in performing these tests, their use is necessarily more restricted. Enzyme testing on admission and then every 12 hours for 2 days is sufficient and effective in making the initial diagnosis. In patients presenting early after an attack, CK and CK-MB are often normal. Decisions on AMI cannot be made on blood tests collected in the emergency department. Clot-lysing agents like streptokinase, urokinase, and tPA have changed the therapy of AMI dramatically. Enzyme tests clearly separate patients with and without successful therapeutic or spontaneous reperfusion. With successful reperfusion, the uniform finding has been a "washout" phenomenon with significantly earlier peaking times for CK and CK-MB. The isoforms of CK and myoglobin give the earliest peaks after successful reperfusion. With faster turnaround times for these tests, they may become important tools in patient management.     

Diagnosis of perioperative myocardial infarction by considering relationship of postoperative electrocardiogram changes and enzyme increases after coronary bypass operation

We report the results of enzyme determinations in sera from 88 patients, 65 of whom showed inconspicuous reconvalescence, 14 who had myocardial infarction within 24 h (MI 1) after bypass surgery, and nine with myocardial infarction between 24 and 48 h postoperatively (MI 2). We wanted to determine whether the consequent measurement of activities of total creatine kinase (CK), CK isoenzyme MB (CK-MB), lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, and aspartate aminotransferase, conducted as a part of routine laboratory diagnostics, provided meaningful information for diagnosing infarcts besides that obtained from the electrocardiogram. The postoperative mean values of the enzyme activities in blood were significantly different among the three groups; however, only a combined evaluation of CK and CK-MB by means of a discriminant analysis allowed the prediction of MI (sensitivity: MI 1 = 98.5%, MI 2 = 95.4%; specificity: MI 1 = 71.4%, MI 2 = 81.8%). CK greater than 600 U/L or CK-MB greater than 45 U/L supports the diagnosis of acute MI.     

Increased activities of creatine kinase and lactate dehydrogenase isoenzymes in a patient with metastatic ovarian tumor

A 50-year-old woman with metastatic rhabdomyosarcoma of the ovary had increased activities of creatine kinase (CK; EC 2.7.3.2), CK-MB isoenzyme, lactate dehydrogenase (LD; EC 1.1.1.27), and LD-2 isoenzyme in her serum. The isoenzyme activities did not show a pattern of increasing, then decreasing. Clinical findings, including electrocardiograms, did not support the diagnosis of myocardial infarction. We suggest that high activities of CK-MB and LD-2 in serum may serve as a marker of rhabdomyosarcoma.     

Ratio of creatine kinase 2 mass concentration to total creatine kinase activity not altered by heavy physical exercise.

Serum creatine kinase isoenzyme 2 concentrations (CK 2 mass) were measured in marathon runners during training and 1 and 2 days after a race and compared with values from 36 acute myocardial infarction (AMI) patients whose total CK and (or) CK 2 activities were similar to those of runners in the basal state. During training, runners had CK and CK 2 activities 53% and 43% above reference values, respectively, and 36% had CK 2 activity > 5% of total CK. Nine runners (26%) showed CK 2 mass values > 6 micrograms/L but < or = 10 micrograms/L; 35 of the AMI subjects, despite having CK activities similar to those of runners, had values > 10 micrograms/L. The ratio of CK 2 mass to total CK activity was significantly (P < 0.0002) different between sexes for runners. At 1 and 2 days after racing, 100% of CK and CK 2 activities and 71% and 57% of the percentages of CK 2 activity, respectively, were abnormally high; 57% and 43% of CK 2 mass values were > 10 micrograms/L, being comparable with those observed for the AMI group. Basal CK 2 mass values of the runners appeared only slightly higher than that for sedentary subjects, but after exercise half the subjects presented increased values similar to those observed for AMI subjects. The ratio of CK 2 mass to total CK activity appeared unaltered by exercise in all but one of the samples assayed, indicating its utility in evaluating CK 2 mass increases originating in skeletal muscle.     

Increased activity of creatine kinase isoenzyme MB in a theophylline-intoxicated patient

A 78-year-old woman had increased activities of creatine kinase (CK; EC 2.7.3.2) and CK-MB isoenzyme in her serum, associated with severe theophylline intoxication. The time course for CK-MB activity was similar to that from an acute myocardial infarction. Clinical findings, however, including electrocardiograms, did not support the diagnosis of myocardial infarction. We suggest caution in interpreting CK-MB results in severe theophylline intoxication.     

Exertional compartment syndrome of the thigh: a rare diagnosis and literature review

Exercise-induced acute compartment syndrome of the thigh is an uncommon entity. We present a rare case of bilateral exercise-induced three-compartment syndrome of the thighs that required fasciotomies. The objective of this study was to understand the history, physical examination, signs, symptoms, pathophysiology, diagnosis, and treatment of compartment syndrome and rhabdomyolysis. A 42-year-old man presented to the Emergency Department (ED) complaining of worsening pain and swelling in both thighs 45 h after performing a lower extremity exercise regimen. The patient's thighs were tender and swollen, but there was no ecchymosis or evidence of trauma. Admitting serum creatinine kinase (CK) was 106,289 U/L. Treatment for rhabdomyolysis was initiated. The next day, he complained of escalating bilateral thigh pain. Repeat serum CK was 346,580 U/L. The patient was diagnosed with bilateral thigh compartment syndrome and immediately taken to the operating room for fasciotomies. Postoperatively, the patient's symptoms improved rapidly and his serum CK quickly returned to normal. His incisions were closed and he returned to normal activities of daily living. Because exercise-induced compartment syndrome is an extremely rare diagnosis with a high risk of poor outcome, this article serves to emphasize the importance of considering this diagnosis during the work-up of patients presenting to the ED with rhabdomyolysis.     

Comparison of serum creatine kinase and creatine kinase MB activities post marathon race versus post myocardial infarction

Serial total creatine kinase (CK) and CK MB activities were determined in the serum of seven runners following a marathon race and compared to enzyme activities in the sera from five patients following acute myocardial infarction (AMI). In the runner's sera, total CK and CK MB activities were significantly elevated at 1, 24, 48 and 72 hours post marathon race when compared to the 1 hour pre-marathon samples (p < 0.01). Serum CK MB activities peaked at 24 hours in both groups of subjects. The MB activities 24 hours following the marathon were substantially higher (91 ± 30 U/l; mean ± SD) than the MB activities 24 hours following AMI (46 ± 38 U/l). However, the percentages of CK MB 24 hours following the marathon and AMI were almost identical (7.0 ± 2.4% and 7.2 ± 2.3%, respectively). Furthermore, CK and CK MB clearances were significantly prolonged (p < 0.02 and p < 0.001, respectively) following the marathon race (T $\text{1}\text{2}$ CK, 49 hours; T $\text{1}\text{2}$ CK MB, 29 hours) as compared to following AMI (T $\text{1}\text{2}$ CK, 27 hours; T $\text{1}\text{2}$ CK MB, 12 hours). These results suggest release of CK MB from the skeletal muscle of marathon runners. Therefore, we recommend that elevation of CK MB in the range indicative of myocardial damage be interpreted with caution in long-distance runners.     

心肌酶谱检测在急性心肌梗死诊断中的价值

[目的]探讨心肌酶谱测定在诊断急性心肌梗死中的应用价值。[方法]选取我院2009年1月一2010年1月住院的急性心肌梗死患者40例。测定其肌酸激酶（CK）、肌酸激酶同工酶（CK—MB）、乳酸脱氢酶（LDH）、同型半胱氨酸（HCY）含量,并与40例正常对照组比较,观察其在诊断急性心肌梗死中的应用价值。[结果]AMI组CK、CK—MB、LDH以及HCY检测结果明显高于正常对照组,具有统计学意义（P〈0．01）。CK—MB、CK、LDH以及HCY的检出敏感性分别为87．5％,82．5％,75％和57．5％。[结论]心肌酶谱测定在诊断急性心肌梗死中具有较好的临床应用价值。     

成年人脑脊液CK,AST,LDH和GPx活性检测对脑血管病的鉴别诊断价值

目的 研究脑脊液(CSF)肌酸激酶(CK)、天门冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)和谷胱甘肽过氧化物酶(GPx)四种酶的活性水平变化对脑血管病的鉴别诊断价值。方法 利用日立7600全自动生化分析仪检测脑血管病患者、疾病对照组(颅脑损伤、脑出血和颅内感染)及健康对照组CSF上述四种酶的活性水平。结果 脑血管病、颅脑损伤、脑出血、颅内感染的CK,AST和LDH酶活性均有不同程度升高,其中LDH在脑血管病患者CSF中升高最为显著(P<0.05),其诊断界值为79.37 U/L(P<0.05),约登指数为0.673; GPx仅在脑血管病患者CSF中出现显著降低(P<0.05),其诊断界值为13.56 U/L(P<0.05),约登指数为0.648; CK和AST在脑血管病患者鉴别诊断中无显著性诊断价值(P>0.05)。结论 CSF中LDH和GPx在脑血管病的诊断与鉴别诊断及评估损伤和氧化应激状态中具备潜在价值,值得进行更大标本量和更多疾病种类的研究。     

Simultaneous automated measurement of serum total CK and CK-MM lsoform ratio in serum

We automated a two-step kinetic procedure for determining serum CK-MM isoform ratio using an immunoinhibition method. By measuring the total CK activity and the residual CK activity (serum CK-MM isoform) remaining after the inhibition by tissue CK-MM isoform specific monoclonal antibody reagent (CK-M01) the CKMM isoform ratio is calculated using the difference between total CK and residual CK activities divided by the residual CK activity. Linearities of total CK and residual CK assays were?7750 U/L and 2,500 U/L, respectively; within-run CVs of isoform ratio (N = 10) were 2.8 and 7.0% (mean 0.14 and 0.60), respectively. The MM³/MM¹ isoform ratio obtained with the proposed method (X) correlated well with the results of electrophoretic method (Y) according to the equation: Y = 0.98X ?0.3, r = 0.988. The normal reference range of isoform ratios obtained by assaying 1,222 serum samples from healthy subjects was 0.09–0.75. The isoform ratio increased after onset of chest pain, peaking at 2–6 hr thereafter. A mean isoform ratio of 1.86 was obtained with serum sample from 86 patients diagnosed as having an acute myocardial infarction (AMI). This method is accurate and highly sensitive, as the detection and early diagnosis of AMI can be completed in 10 min. © 1994 Wiley-Liss, Inc.     

细胞角蛋白19基因表达及其他肿瘤标志物在乳腺癌诊断中的应用

目的探讨细胞角蛋白19(CK19)基因表达水平在乳腺癌诊断和治疗监测中的应用。方法采用荧光定量PCR(FQ-PCR)技术检测20例健康女性体检者、40例良性乳腺肿瘤和86例乳腺癌患者外周血中CK19基因表达量;用化学发光法检测其CA153、CA125和癌胚抗原(CEA)含量,并进行对比分析。结果CK19对乳腺癌诊断灵敏度显著高于CA153、CA125和CEA,特别是对早期乳腺癌的诊断灵敏度较高。4种指标在手术和化疗前后均显著下降。结论CK19基因表达水平可有效监测乳腺癌的诊断、治疗和预后。     

血尿细胞角质蛋白20的表达

目的探讨血尿患者尿脱落细胞细胞角质蛋白20(CK20)的表达及其意义。方法采用逆转录聚合酶链反应(RTPCR)对47例首发症状为血尿的尿路移行细胞癌患者、18例以血尿就诊的非泌尿系肿瘤患者以及10例健康志愿者尿脱落细胞CK20的表达进行检测。结果47例尿路移行细胞癌中有38例脱落细胞CK20阳性,对照组无CK20阳性表达。结论检测尿脱落细胞CK20表达,对诊断尿路移行细胞癌敏感性和特异性高,可作为血尿患者筛选尿路移行细胞癌的方法之一。     

Isoelectric focusing of creatine kinase MM isoforms and its application for diagnosis of acute myocardial infarction

CK MM isoforms (MM 3 having the highest isoelectric point, followed by MM 2, MM 1, and MM X) were measured in 35 patients with acute myocardial infarction (AMI) by isoelectric focusing on agarose gel. Blood samples were analysed every 2 h for the first 12 h, then every 4-8 h until 72 h after AMI. In the first sample, obtained 2.1 h after the onset of chest pain, the ratio of the isoforms MM 3:1 was 0.7 (range 0.2-1.8), equivalent to a normal value. Before the total CK exceeded normal, in 86% of the patients the ratio MM 3:1 rose to 2.2 (range 0.3-3.3). The maximal individual ratio MM 3:1 was 4 (range 0.9-12) after 7 h. It fell below 1 again after 27 h. Thus, the ratio MM 3:1 was useful in the early diagnosis of AMI by enzymatic methods and to estimate the time elapsed since the onset of infarction. Twenty patients with an open infarct vessel (angiographic data after thrombolytic therapy) showed similar peak enzyme activities as ten non-reperfused patients. They differed significantly in the time to the peak activity, mostly for CK MM 3 and CK MB (p less than 0.0005). A higher ratio CK MM 3:1 and a shorter time to the maximum CK MM 3 activity in reperfused patients helps to assess the success of thrombolytic therapy.     

皮肌炎患者血清LDH、CK及其同工酶分析

目的 探讨LDH、CK及其同工酶对皮肌炎的诊断及病程判断价值。方法 用日本HTTACHI747型全自动生化分析仪及美国REP全自动快速电泳系统检测57例皮肌炎患者血清LDH、CK同工酶。结果 57例皮肌炎患者82．21％LDH总酶升高，91．22％CK升高。在总酶升高的病例中，同工酶均有不同程度的特征性改变。结论 LDH、CK同工酶的检测对皮肌炎的诊断及其病程判断有重要价值。     

Changes in serum creatine kinase isoenzyme activities after surgical procedures and cardioversion

Serum activities of creatine kinase (CK) and its isoenzymes were monitored before and 16 to 20 hours after a variety of surgical procedures and cardioversion. Changes in total CK and CK MM activities in the surgical patients were consistent with the extent of trauma; changes in these activities in the cardioversion patients were more variable, ranging from -2 to 1829 U/l, and were unrelated to the applied electrical force. CK MB activity was unchanged after cystoscopy but rose moderately in 60% of patients after cholecystectomy, in 43% of patients requiring only implantation of a new pacemaker box, and in 87% of patients after implantation of an entire pacemaker system. No increase exceeded 6U/l. Fifty per cent of patients requiring cardioversion showed rises; the maximum value was 40.9 U/l.     

胃癌表达EpCAM和CK19临床意义的研究

目的探讨胃癌中CK19和EpCAM的表达的临床意义。方法利用组织芯片-免疫组化技术,对术后病理诊断明确的胃癌31例,良性病变7例和正常胃粘膜16例的组织标本制成一张组织芯片,用免疫组化SP法检测组织芯片中CK19和EpCAM的表达,从循证诊断角度分析两者在胃癌中的诊断价值。结果 (1)CK19、EpCAM在良性病变和胃癌组织中的表达率显著高于正常组织中,差异性显著(P0.05);(2)CK19、EpCAM在胃癌的循征医学诊断中有一定的价值,其中以EpCAM、及其与CK19并联实验的价值最高。结论 CK19和EpCAM可以帮助胃癌的早期诊断。