We measured creatine kinase (CK) isoforms by a new immunoinhibition method to evaluate their usefulness in detecting early coronary reperfusion. Blood samples were collected at 15-minute intervals from 50 patients with acute myocardial infarction. CK isoforms were determined by a 10-minute immunoinhibition method with an autoanalyzer. Values for inhibited isoforms (MM3, MM2/2, and MB2/2) were divided by those of noninhibited isoforms (MM1, MM2/2, MB1, MB2/2, and BB) to calculate the isoform ratio. In the reperfused group the increase in the isoform ratio was 2.69 +/- 1.80 (SD) 30 minutes after reperfusion and 2.41 +/- 2.01 at 60 minutes, which was significantly higher than the corresponding values in the nonreperfused group (0.17 +/- 0.16 and 0.32 +/- 0.26, respectively). When an increase of 0.70 or more in the isoform ratio was used as the criterion for reperfusion, the sensitivity and specificity were 92% and 100% at 30 minutes and 100% and 100% at 60 minutes after recanalization, respectively. We conclude that the isoform ratio obtained by the new 10-minute assay of CK isoforms is useful for the noninvasive detection of reperfusion 30 and 60 minutes after recanalization in acute myocardial infarction.

In order to evaluate central nervous system disorders in myotonic dystrophy (MyD), neuron-specific enolase (NSE), S-100b protein and creatine kinase BB (CK-BB) isoenzyme were measured using enzyme immunoassay in MyD. Intelligence quotient (IQ) test (WAIS, 17 cases), electro-encephalography (17 cases) and brain computed tomography (18 cases) were examined. In patients with MyD, NSE level was significantly elevated in comparison with 25 age-sex matched control subjects. In some cases of MyD levels of S-100b protein and CK-BB in CSF were elevated. IQ test disclosed intellectual impairment in 70.6% of the patients examined and EEG study demonstrated slowing of basic rhythm in the majority of the cases. On brain CT both enlarged ventricles and dilated sulci were commonly found. The results of the present study suggest that in MyD the CNS is involved not only functionally but structurally as well. Since NSE, S-100b and CK-BB are localized in neuronal and glia cells, their elevated levels in CSF indicate existence of organic lesions in the central nervous tissue in patients with MyD.

By employing a highly sensitive immunoassay method, concentration of aldolase C (Ald C) was determined in cerebrospinal fluid (CSF) of 180 patients with various neurological disorders and 46 age-and-sex matched control subjects. The results were compared with CSF levels of neuron-specific enolase (NSE), S-100b proteins (S-100b) and creatine kinase BB isoenzyme (CK-BB) in the same samples. Normal level of Ald C was 7.95 +/- 2.52 (mean +/- SD) ng/ml. CSF level of Ald C was elevated not only in patients with acute disorders, but also those of degenerative diseases. It increased significantly in purulent meningitis, encephalitis, cerebral infarction, and cervical spondylosis as compared with control subjects. The levels of Ald C were reached the peak levels later than those of NSE, S-100b and CK-BB. Concentration of Ald C in CSF correlated well with that of NSE but poorly with that of S-100b or CK-BB. These results suggested that Ald C in CSF was one of the useful marker in neurological disorders. Since these proteins have different distributions in the central nervous system and have different molecular weights, simultaneous determination of Ald C, NSE, S-100b and CK-BB levels in CSF might provide valuable information about pathologic nature of the underlying neurological disorders.

Beneficial effects of monotherapy with ACE inhibitors or beta-blockers on hemodynamic function after myocardial infarction are well known. Until now, the effects of combined treatment on cardiac function and energy metabolism have been poorly described. This study examines the effects of combined ramipril and metoprolol treatment on the creatine kinase (CK) system and hemodynamic function in rats after infarction. Wistar rats with experimental infarction were randomized for treatment with ramipril (R), metoprolol (M), combined treatment (MR), or placebo (P). Sham-operated (SO) animals served as controls. After 6 weeks, we assayed for CK isoenzymes and performed hemodynamic measurements. In P versus SO, left ventricular systolic pressures (dp/dt(max) and dp/dt(min)) diminished, whereas left ventricular end-diastolic pressure (LVEDP) increased. Decreased total CK activity and mitochondrial CK isoenzyme, increased CK-MB, and increased CK-BB isoenzymes were measured in P versus SO. With infarct size < or =45%, mitochondrial CK increased in M and R versus P. Combined treatment had an additional enhancing effect on mitochondrial CK isoenzyme level versus M and R, decreased LVEDP versus P, as well as increased dp/dt(max) and dp/dt(min) versus R. These results provide evidence of an interaction between normalization of energy metabolism and improvement in cardiac function due to a combination of ACE inhibition and beta blockade after myocardial infarction.

Creatine kinase (CK) and its BB isoenzyme (CK-BB) were measured in CSF in 65 evaluable patients suspected of CNS metastases secondary to small-cell lung cancer (SCLC). In addition, CSF and plasma levels of beta-2-microglobulin (beta-2-m) were measured in a group of 73 evaluable patients. Of the 65 patients analysed for CK-BB, 17 had meningeal carcinomatosis (MC), 26 had parenchymal metastases only, and 22 had no CNS disease. Patients with MC had a significantly higher CK-BB concentration in CSF than did patients belonging to the other two groups (P less than .01). Taking 0.4 U/L (upper limit in patients without CNS disease) as a cut-off point, 15 patients (88%) with MC had elevated CSF concentrations of CK-BB. Patients without CNS metastases had no CSF levels exceeding this value, whereas five patients with multiple CNS metastases did. Receiver operating characteristic (ROC) analysis suggests that CK-BB may be useful in distinguishing MC among patients suspected of having CNS metastases, and CK-BB appears superior to total CK, CSF protein, and CSF lactic dehydrogenase (LDH). In 12 patients with MC at autopsy, CK-BB was, with the above cut-off point, elevated in six patients with a false negative cytology. Of the 73 patients examined for beta-2-m, 18 had MC, 30 had parenchymatous metastases only, and 25 patients had no CNS metastases. The CSF concentrations in the three groups were not significantly different. The median concentrations in the groups were 133 nmol/L, 125 nmol/L, and 107 nmol/L, respectively. The ratios between beta-2-m in CSF and plasma were also not significantly different between the three groups. Thus, the data on CK-BB are promising, and further studies are warranted to see if the usefulness of CK-BB can be more firmly established. By contrast, beta-2-m has no role as a marker of CNS disease secondary to SCLC.

The assay for the MB isoenzyme of creatine kinase is widely used in the diagnosis of acute myocardial infarction. Patients with metastatic carcinoma of the prostate may have an elevated serum creatine kinase BB fraction, which by immunoinhibition method may be read mistakenly as creatine kinase MB. We report the case of a patient with a history of myocardial injury, chest pain, total CK above of reference range and CK-MB isoenzyme, determinated with an immunoinhibition technique, larger than 100% of enzymatic activity of total CK, that was carrier of a prostatic adenocarcinoma in stage D2. We comment the diseases in which the CK-BB fraction may be elevated, discuss the laboratory methods for the determination of creatine kinase isoenzymes, and revised, briefly, the properties of the new immunoassays, that measure mass concentration of creatine kinase MB, in the diagnosis of acute myocardial infarction.

A rise in serum creatine kinase-BB (CK-BB) levels has been reported previously in cases of dementia. In the present study the levels of serum CK-BB have been measured in patients clinically assessed to have senile dementia of the Alzheimer's type (SDAT) and in cognitively intact individuals, matched for age, by a specific two-site monoclonal immunoradiometric assay. No significant difference was found between the 2 groups. Total creatine kinase activity in temporal cortex (Brodmann area 21 and 22) was also found to be similar in brains from SDAT or control cases, obtained at autopsy. These results suggest no major change in the permeability of the blood-brain barrier to this enzyme in SDAT patients.

The presence of macro creatine kinase type 2 (M<em>CK</em>2) activity was noted in the serum of seven out of 32 newborn infants with perinatal asphyxia or birth trauma. M<em>CK</em>2 isoenzyme, when present, represented 15-35% of the total creatine kinase (<em>CK</em>) activity. The clinical and biochemical features of the seven M<em>CK</em>2-positive and 25 M<em>CK</em>2-negative newborns were compared. The infants with M<em>CK</em>2 activity were all males and clinically appeared to be more severely injured, requiring longer hospitalization. Total <em>CK</em> activity was similar in the two groups and <em>CK</em>-MB and <em>CK</em>-<em>BB</em> isoenzyme fractions were present in a similar proportion of infants in both groups. Two infants in each group had long-term neurological disorders. Although the presence of M<em>CK</em>2 has been noted in adult patients with end-stage metastatic solid tumors, the presence of this isoenzyme has not previously been reported in newborn infants.

Myoglobin, myosin creatine kinase MM (CK-MM), creatine kinase BB(CK-BB) in cardiac muscle and H chain of myosin in atrial and ventricular muscle were studied in specimens from 8 patients who died of sudden nocturnal death syndrome (SNDS) by avidin-biotin complex (ABC) method to investigate the possible early or very early myocardial ischemia in the syndrome. Hematoxylin-eosin staining was conducted for comparison. The results showed evident loss of CK-MM, CK-BB, myoglobin and myosin from cardiac muscle cells, indicating that occurrence of SNDS is closely associated with acute myocardial ischemia.

Creatine kinase (CK) and CK isoenzymes are known to fluctuate in labor. Reliable information about the longitudinal changes of CK and CK isoenzymes during labor is sparse. Nevertheless, they have been used to direct care in women with cardiopulmonary disease and preterm labor requiring tocolysis. This study evaluated fluctuations of CK and its isoenzymes longitudinally across labor in 49 women. Blood samples were obtained at 33 to 34 weeks' estimated gestational age, on admission in labor at 3 cm or less dilation, 8 cm to complete dilation, and postpartum in the recovery room. Specimens were analyzed for total CK, CK-MM, CK-MB, and CK-BB activity. CK levels increased for all peripartum patients (p < 0.001). CK activity at 3 cm was greater than at 34 weeks (p < 0.01). Furthermore, the early rise in CK activity was greater in those in active labor compared with those who required oxytocin stimulation (p < 0.001). CK values at 8 cm and postdelivery (mean IU/liter) were often above nonpregnant norms. The early rise of CK in spontaneously laboring patients versus those requiring oxytocin augmentation may represent a difference in uterine activity. Nonpregnant normative data for CK is not appropriate when assessing cardiovascular side effects of betamimetic therapy.

Rats show an elevated creatine kinase (CK) activity in plasma after a 20-hour exposure to hypoxia. The increase of CK activity is essentially caused by CK-BB activity attaining its maximum at the 3rd day after exposure to hypoxia. The possibility of establishing a potential brain damage by determining CK-BB activity in plasma is discussed.

In this case of mixed small cell--large cell cancer of the lung in an elderly woman, creatine kinase (EC 2.7.3.2) isoenzymes were assayed serially because of chest pain. The proportions of serum CK-BB and CK-MB isoenzyme activities were persistently above normal (CK-MB 10-18%, normal less than 5%). Electrocardiograms revealed no signs of ischemia or infarction. At autopsy no gross or microscopic infarction or inflammation of the heart was seen. There was also no infarction of smooth or skeletal muscle. The tumor was the probable source of most of the circulating CK-MB isoenzyme. Future cases may pose a similar diagnostic dilemma: differentiating creatine kinase that is present as a result of myocardial infarction from tumor-related CK-MB. Whether or not CK-MB assay could be useful in detecting tumors remains to be investigated.

A serial measurement of serum creatine kinase (CK) activity and its isoenzymes were made in elderly patients following an acute stroke. Seven out of ten patients had elevated CK levels. The maximum concentration was observed between 12-24 h and the level returned to normal within 84 h after a stroke. They all had positive skeletal (MM) muscle isoenzyme, and in only one patient heart (MB) isoenzyme was detected. None of them had positive brain (BB) isoenzyme. Measurement of serum CK activity will possibly provide guidance in the management of patients having recently suffered a stroke.

Creatine kinase (CK) isoenzymes were determined on 15 patients undergoing open heart surgery with bypass. The study was performed to examine the relationship between the hypothermia under which the surgery is conducted and the appearance of CK isoenzymes in the serum both during and after surgery. All patients showed dramatic rises in total CK activity commencing during surgery. Myocardial CK (CK-MB or CK-2) was seen in fourteen patients and brain CK (CK-BB or CK-1) was seen in ten patients. Peak activities of CK-BB did not coincide with peak activities of CK-MB. The serum elevations of CK-BB in these patients appear to arise from a mechanism different from that responsible for the elevations of CK-MB, and it is assumed that the former is due to intermittent disruptions in the perfusion and/or oxygenation of tissues rich in CK-BB. CK-MB elevations appear to be due directly to the surgical intervention. Hypothermia alone does not in itself appear to be solely responsible for elevations of CK-BB although it can not be completely excluded from playing some role in its production.

Measurement of creatine kinase MB (CK-MB) and its isoforms CK-MB2 and CK-MB1 are now applied in the diagnosis of acute myocardial infarction (AMI). The most common approach for analysis includes RIA, IRMA, and electrophoresis, all of which may be time-consuming. This study examines determination of CK-MB and CK-MB2 by a rapid immunochemical extraction method followed by an automated measurement for both analytes. The automated method was sensitive to 2 U/L, linear to 180 U/L, and gave excellent interassay precision (< 10% CV). Interference studies indicated that bilirubin, hemolysis, and lipemia caused analytical problems as did the presence of high activities of other CK isoenzymes, notably CK-MM and CK-BB, requiring dilution of samples prior to analysis. Application of immunochemical extraction gave a reference interval of CK-MB (0-2.5 U/L) and CK-MB2 (0.1-1.4 U/L) for blood donors (20-60 years), peak levels for ruled-out AMI patients of CK-MB (0.5-7.3 U/L) and CK-MB2 (0.3-4.9), peak levels for ruled-in AMI patients of CK-MB (80-174 U/L) and CK-MB2 (80-155 U/L). Coronary artery bypass patients (n = 24) and all trauma patients (n = 14) also demonstrated elevations in CK-MB and CK-MB2, whereas only five of the trauma patients demonstrated increased CK-MB by IRMA. In patients (n = 7) having increased total CK and normal CK-MB by IRMA, the extraction assay for CK-MB and CK-MB2 yielded increased values in all patients. This new approach to CK-MB and CK-MB2 analysis can be performed within 30 minutes of sample receipt.

Serum creatine kinase (CK) B subunit (CK-B) activity, as estimated by the enzymatic anti-M immunoinhibition method, and the CK isoenzyme pattern after agarose gel electrophoresis, were studied in 28 patients with advanced, untreated malignant disease. CK-B was above the decision limit, i.e. the discrimination limit used in the diagnosis of acute myocardial infarction (AMI), in 14 patients (50%). Electrophoresis demonstrated, besides CK-MM, an atypical, cathodically migrating CK band in 10 of these patients. This band may represent mitochondrial CK. The CK-BB isoenzyme was detected in 9 and CK-MB in 3 subjects. Histopathologic findings indicated that the occurrence of these isoenzymes was related to tumour burden and the overall severity of the disease. Survival among patients with CK-B elevation was shorter than among other patients. The present findings are relevant to the enzyme diagnosis of AMI and of potential significance for the evaluation of patients with known or suspected malignant tumours.

The expression of mRNAs of creatine kinase (CK)-B and CK-M has been show to be affected by insulin, and myocardial CK-MB activity is suppressed in insulin-deficient rats. We investigated the dose-related effect of insulin on CK-MB activity in cardiac and skeletal muscles. Male Wistar rats were divided into three groups: (1) control group, (2) diabetic group, injected with 65 mg/kg streptozotocin for 4 weeks, and (3) atenolol group, administered 30 mg/kg per day atenolol. Each group was further divided into three subgroups and administered either saline, or 20 (Ins 20) or 30 (Ins 30) U/kg per day insulin. After 3 weeks, the isoenzyme activity of CK and lactate dehydrogenase (LDH) in the left ventricle of the heart (LV) and the major pectoral muscle (PM) was measured. Serum insulin increased and plasma glucose decreased in Ins 20 and Ins 30, dose-dependently, in all three groups. Both CK-MB and -BB activity in LV increased dose-dependently with insulin treatment in the control, diabetes, and atenolol groups, although these changes did not occur in skeletal muscles. CK-MB in LV correlated with the serum insulin levels in all rats, while no correlation was found in the skeletal muscles. These findings suggest that insulin possibly regulates the distribution of CK isoenzymes in rat heart muscle, and that the effect of insulin is not due to the sympathetic drive induced by hypoglycemia.

OBJECTIVE

The Macro creatine kinase (Macro-CK) is a complex constituted by polymerization of isoenzymes of creatine kinase (CK-BB or CK-MM together with IgG in the type I and oligomers of CK mitochondrial in the type II). Their presence in plasma generates false elevations of the CK-MB isoenzyme, upon interfering with the techniques of imunoinhibition used in the emergency room laboratories, what it constitute a serious problem in the diagnosis of squares of myocardial ischemia. The ignorance of this clinical situation has pushed us to present this study in order to begin to consider their utility like marker of illness, giving shortly, some recommendations for the correct management of this discovery in the emergency.

METHODS

They have been studied the total of patients valued in the emergency for 16 months that they gathered this requirements (25), valuing the pathology that appeared under this analytic determination. The identification of the isoenzymes of CK was carried out by means of agarose gel electrophoresis.

RESULTS

The 13 cases with Macro-CK type I (9 women and 4 males) had a half age of 64 years (4-89). The levels means of CK were 274 mU/mL with a CK-MB of 440 U/L (166%). The 7 cases with Macro-CK type II (1 woman and 6 males) had a half age of 69 years (32-80). The levels means of CK were 314 mU/mL with a CK-MB of 569 U/L (191%). The 53.8% of the patients with Macro-CK type I presented any cardiovascular pathology, the 38.5% diabetes mellitus and the 30.8% pathology muscle-articulate with possible component autoimmune. The 100% of the patients with Macro-CK type II suffered processes malignant tumors, highlighting the presence of tumors of digestive origin and prostatic, with metastasis, being the more frequent in liver and bone (71.4%), and a high mortality of the 71.4% (5 deaths). The Macro-CK type II (form oligomer of mitochondrial) is liberated like consequence of a lesion of the mitochondrias of the affected fabrics tissues, associating to serious illnesses like cirrhosis and tumors.

CONCLUSIONS

In all the studied cases the payees of Macro-CK presented underlying pathology, being in the case of Macro-CK type I of heart prevalence, and in the case of type II of nature tumoral. A management Macro-CK algorithm is also presented for the emergency.

Creatine kinase BB isoenzyme (CK-BB) is overexpressed in many tumor tissues, including ovarian cancer. Using a highly sensitive and specific immunofluorometric method, CK-BB levels in 89 primary ovarian cancer cytosolic extracts have been measured and the associations between CK-BB and clinicopathological features of ovarian cancer have been studied. It was found that CK-BB levels are higher in endometrioid cell carcinomas. No clear association was established between CK-BB levels and patient age, menopausal status, clinical stage, histological grade or size of residual tumor. CK-BB was not associated significantly with either disease-free or overall survival of the patients. Based on these data, it was concluded that there is no prognostic value of CK-BB in ovarian cancer. Drugs that target CK-dependent energy metabolism of tumor cells may not be selective in ovarian cancer therapy.

IgA-linked creatine kinase (CK, EC 2.7.3.2) is a macro CK type 1 isoenzyme that has an identical electrophoretic mobility to CK-MB. Its presence has the potential of causing misdiagnosis of myocardial infarction. Mixing anti-CK-B antiserum with the sample prior to electrophoresis did not unequivocally distinguish between the two isoenzymes. Similarly, anti-human IgG and IgM antibodies were also ineffective. However, the IgA-linked isoenzyme band was removed by anti-human IgA antiserum. While anti-CK-M antibodies did not affect the electrophoretic mobility of IgA-linked CK-BB, the antibody eliminated both the CK-MB and CK-MM bands. Thus, specific anti-IgA and anti-CK-M antibodies may be used to establish the presence of the myocardial isoenzyme.

We report what we believe to be the first proven marked concomittant elevations in serum creatine kinase (CK) and lactic dehydrogenase (LD) in a patient with bowel necrosis. The necrosis was the result of infarction secondary to bowel strangulation. The serum from this patient showed elevation of total CK activity resulting from an abnormal amount of MM, MB, and BB isoenzymes with LD2, LD3, and LD5 yielding 18 per cent, 19 per cent, and 29 per cent, respectively, of the total LD activity.

For diagnostic purposes, creatine-kinase (CK) isoenzymes were separated on mini-columns of DEAE Sephadex A50 from the serum of 55 patients with myocardial infarction or cerebral disturbances and from 45 normal subjects. The optimum conditions of separation were determined by separation of CK isoenzymes (CK--MM, CK--MB, CK--BB) from human organ homogenates (skeletal muscle, myocardium, brain). In the patients with myocardial infarction the CK-MB isoenzyme activity amounted to more than 6% of the total enzyme value. The chromatogram in these cases was similar to that of human myocardium homogenate. The CK-BB isoenzyme was found only in patients with severe cerebral disturbances (cerebral hemorrhage). In such cases the chromatogram was similar to that of human brain homogenate. Therefore, by associating the assay of serum CK total activity with the separation of CK isoenzymes it was proved that the CK--MB and CK--BB isoenzymes can supply a useful test in differential diagnosis.

Creatine kinase-brain isoenzyme activity (CK-BB) was measured longitudinally in the serum of 31 pregnant women in the first stage of labor (early and advanced), at delivery, and 1, 6 and 24 h after delivery, in the umbilical cord and in the serum of their neonates on the first day of life. There was no increase in serum CK-BB values of mothers that delivered normally (n = 15) or had an elective cesarean section (n = 5). Pregnant women with signs of fetal distress had an increase in CK-BB levels in the first stage of labor (mean +/- SD 4.5 +/- 4.9 U/l, p < 0.03) and 6 h after delivery (12 +/- 4 U/l, p < 0.0001). Neonates with intrauterine stress also had an increase in their CK-BB to 144 +/- 116 U/l at 6 h of life, in comparison with babies born without signs of stress. It appears that CK-BB during labor and in the first hours of life may be indicative of intrauterine stress.

Peri-intraventricular bleeding (PIVH) is considered the most common cause of neurologic damage or death in low birthweight infants (less than 1000 g birth weight and 31 weeks of gestation). High-resolution real-time ultrasound scan is used for early diagnosis of PIVH in neonates. Furthermore, increase of serum creatine-kinase BB (CK-BB) values has been found to be clinically useful for diagnosis and prognosis of several perinatal cerebrovascular injuries. Eighty-eight preterm infants with different grades of PIVH (I-IV) were studied by serial measurements of CK-BB levels in serum. No statistical correlation was found between enzymatic levels and severity of PIVH (p greater than 0.5).