Creatine kinase isoenzymes in serum of children with neurological disorders

Immobilized enzyme assay of creatine kinase with amperometric detection

Serum creatine kinase-MB isoenzyme was determined by an immunoinhibition-amperometric technique in a coupled reaction scheme in which ADP and ATP are recycled and hydrogen peroxide is a product of the reaction. Two enzymes in the scheme, glycerokinase and glycerol-3-phosphate oxidase, were co-immobilized on collagen membrane at the surface of a platinum electrode polarized at 700 mV. The rate of production of hydrogen peroxide in the reaction was measured amperometrically at the electrode and related to the activity of creatine kinase. Calibration curves prepared with human creatine kinase-MB isoenzyme standards were linear from 10 to 500 U liter-1 with a detection limit of 8 U liter-1. Total creatine kinase in serum was also determined by the present method. The precision of the method was 3.1% relative standard deviation at the 10 U liter-1 level of creatine kinase. Interference from adenylate kinase was eliminated by the addition of diadenosine-5'-pentaphosphate to samples.

Lactate dehydrogenase and creatine kinase activities in isolated edema fluid and peripheral blood in cold-induced brain edema

A study of the alterations in lactate dehydrogenase and creatine kinase isoenzyme patterns in isolated grey and white matter edema fluid and in peripheral blood is described with a view to possible clinical use in severe brain-injury. The breakdown of the blood-brain barrier, caused by the infliction of a cold injury to the cerebral cortex of cats, resulted in a shift in the LD isoenzyme distribution in favour of the faster moving fractions and the appearance of brain-type CK in the peripheral blood. Total lactate dehydrogenase activity demonstrated no statistical significant changes during the experiment and total creatine kinase showed only slight increased values in the samples collected simultaneously with the infliction of a cold lesion. This strongly suggests that measurements of these parameters in peripheral blood are of little value as indicators of brain damage. Alterations in isoenzyme patterns observed in edema fluids are reflected in peripheral blood. The presence, therefore, of brain-type creatine kinase accompanied by a relative high amount of lactate dehydrogenase H-sub unit in peripheral blood, can be considered as adequate indices of severe brain damage.

Brain-typical creatinekinase in the serum of newborn infants with perinatal brain damage

The normal values of serum-CK-activity in healthy newborns varied greatly (95% range: 4--165 U/l; 257 probands) and the borderline to pathological values was not sharp. Brain-typical CK-isoenzyme (CK-BB) could be detected in serum of 6 of 8 infants with perinatal brain damage by means of agar gel electrophoresis. The combination of neuropathological symptoms, increased total-serum-CK-activity, and significant amount of CK-BB in serum seemed to be a sure sign of severe CNS-damage in newborns.

Creatine kinase BB isoenzyme levels by radioimmunoassay in patients with neurological disease

Creatine kinase BB (CK-BB) isoenzyme was measured by radioimmunoassay in serum and in cerebrospinal fluid from 61 patients with various neurological disorders. Statistically significant elevations of CK-BB isoenzyme in the serum were observed in patients with acute cerebrovascular accidents and in those with seizures and a prolonged alteration in level of consciousness. Statistically significant elevations of CK-BB isoenzyme in the cerebrospinal fluid were also found in patients who had suffered acute cerebrovascular accidents. Some patients with central nervous system infections, acute demyelinating disease, certain drug overdoses, head trauma, and complex migraine also had elevations of serum and CSF CK-BB isoenzyme. In 2 patients with elevations of CK-BB isoenzyme, the elevations in serum occurred later than those detected in the cerebrospinal fluid. If CK-BB elevations determined by radioimmunoassay can be demonstrated to be quantitatively related to the extent of brain damage, then these determinations in conjunction with experimental animal models and newer radiological techniques should allow evaluation, in an objective and precise manner, of measures designed to decrease that damage.

Myocardial creatine kinase isoenzyme in serum after subarachnoid haemorrhage

The myocardial isoenzyme of creatine kinase (MB CK) has been demonstrated in the serum of seven of 16 patients presenting with acute subarachnoid haemorrhage. All patients with elevated MB CK levels exhibited at some stage either intracranial arterial spasm as demonstrated by cerebral angiography, or a focal reversible neurological deficit not due to direct pressure by either intracranial haematoma or aneurysm. The presence of MB CK isoenzymes in sera of patients with subarachnoid haemorrhage may be an index of cerebral ischaemia, and may thus be of value in determining optimal timing of surgery or, ultimately, the long-term prognosis. Changes in the sympathetic nervous system may be a common factor producing both MB isoenzyme release from the myocardium and intracranial arterial spasm.

Effect of incubation in human plasma on electrophoretic mobility of brain-type creatine phosphokinase

1. Electrophoretic mobility of brain-type creatine phosphokinase (CPK) from rabbit, rat and human decreased after incubation in human plasma for 3 h or 17 h but did not change after incubation in isotonic saline solution. The presence of the reducing agent mercaptoethanol during incubation in human plasma tended to reduce the rate of change of electrophoretic mobility of BB-CPK. 2. The activity of brain CPK was almost completely lost after incubation for 17 h in human plasma. The addition of mercaptoethanol after incubation of brain CPK in human plasma could only partially restore the enzyme activity. 3. The decrease in electrophoretic mobility of rat brain CPK occurred after incubation in an ultra-filtrate of human plasma which contained molecules whose molecular weight did not exceed 1000. 4. Gel chromatography indicated that incubation of brain CPK in human plasma did not markedly change the molecular size of the enzyme.

Radioimmunoassay for creatine kinase isoenzymes

Creatine kinase has three isoenzymes designated MM, MB, and BB, with BB being the grain form and MM the muscle form. Antibodies to BB creatine kinase were obtained by immunization of rabbits with human BB creatine kinase. The antibodies demonstrated specificity for BB and MB creatine kinase (myocardial isoenzyme) but no cross-reactivity with MM creatine kinase. With the use of this antibody, a highly sensitive radioimmunoassay capable of measuring picomolar amounts of MB creatine kinase has been developed. Clinical application of this method should provide a sensitive and specific test for the diagnosis of myocardial infarction.

Screening of malignant hyperthermia susceptible families by creatine phosphokinase measurement and other clinical investigations

We investigated 56 families afflicted with malignant hyperpyrexia. One hundred and twenty-four individuals within these families had had an episode of malignant hyperthermia, of whom we saw seventy-two. Serum creatine phosphokinase (CPK) was statistically higher in affected individuals and in close relatives than in normal volunteers. The magnitude of the serum CPK elevations varied significantly between families. While in some families the serum CPK was clearly elevated in affected individuals, in other families the serum CPK was normal or only moderately or inconsistently raised. In these latter families serum CPK measurement was therfore of little or no value in identifying afflicted members. The incidence of musculoskeletal abnormalities was greater in affected individuals and in close relatives than in the general population. Thus, the concomitant individual belonging to a family known to be susceptible to malignant hyperthermia was a better indicator of the MH trait than was the presence of only one of these parameters. For reasons which we do not fully understand, MHS individuals were found to require fewer anaesthetics than normal persons. The incidence of MH crises within each family fell significantly following investigation, counselling, and issuance of Medic-Alert bracelets.

Brain creatine kinase in blood after acute brain injury

Severe cold injury of the brain increased significantly both total creatine kinase and the corresponding brain isoenzyme (CKBB) activity in confluens sinuum samples. CKBB could be detected also in peripheral blood a few hours after severe brain injury in eight of 12 patients. Finding of CKBB in human plasma may prove a useful indicator of severe brain injury.

Clinical value of plasma creatine kinase and uric acid levels during first week of life

Levels of creatine kinase and uric acid in cord blood were variable but similar to those in maternal blood. During the first 24 hours of life there was a rise in the concentration of both substances, particularly of creatine kinase, to reach levels well above those normally found in later childhood. Thereafter there was a steady fall to stable levels around the fifth day. The causes of these obvious changes in concentration are not known. Uric acid levels during the first 24 hours were higher after a longer labour. Creatine kinase levels were lower, and uric acid levels higher in low birthweight babies. The plasma creatine kinase originated from non-cardiac muscle. Plasma creatine kinase and uric acid levels may help in the early diagnosis of rare specific disorders such as muscular dystrophy and the Lesch-Nyhan syndrome, but do not help in the diagnosis of other neurological disorders at this time of life, and give no indication of the child's prognosis, despite their occasional help in adult patients. Even with the specific syndromes, however, interpretation must be guarded. It is not known whether the high creatine kinase levels associated with Duchenne muscular dystrophy would be lost in the upper limits of the normal range for the first few days of life or whether they would be higher still. In the Lesch-Nyhan syndrome uric acid levels are well above the normal range defined in this investigation.