Determination Of Serum Myoglobin Research Articles

The value of determination of serum myoglobin in estimation of degree of illness and prognosis of patients with sepsis in Xining area

To investigate the value of determination of serum myoglobin (MYO) in estimation of the degree of illness and prognosis of patients with sepsis in Xining area. Serum MYO was measured and acute physiological and chronic health estimationII (APACHEII) score was evaluated in 30 cases with sepsis within 24 hours of admission to emergency intensive care unit (EICU), and their correlation was analyzed. The patients were divided into two groups, survival group and death group according to the result within 28 days. The MYO and APACHEII score were analyzed in both groups. All cases were divided into three groups: namely <500 (n=10), 500-1 000 (n=14), >1 000 μg/L (n=6) groups, according to serum MYO value, and APACHEII score and dead case were compared among three groups. Sixteen patients survived, and 14 patients died. The level of serum MYO and APACHEII score were significantly lower in survival group than death group [MYO (μg/L): 607.85±499.40 vs. 976.21±370.10, APACHEII score: 15.50±4.43 vs. 18.93±3.63, t(1)=2.28, t(2)=2.29, both P<0.05]. With the elevation of serum MYO, the dead case was increased in sepsis patients (the dead case in MYO<500, 500-1 000, >1 000 μg/L groups was 2, 7, 5 cases, respectively,χ(2)=5.94, P<0.05), but there was no difference in APACHEII score among three groups. There was significant positive correlation between serum MYO and APACHEII score (r=0.407, P<0.05). Determination of serum MYO can reflect degree of illness and prognosis of sepsis patients in Xining area.

Fast determination of myoglobin in serum using a new radial partition immunoassay

Fast determination of myoglobin in serum using a new radial partition immunoassay

Rapid determination of serum myoglobin with a routine chemistry analyzer

A turbidimetric immunoassay system (Turbitime system, Behringwerke AG) allows rapid determination of myoglobin in serum. We adapted the reagents for this myoglobin assay (Turbiquant myoglobin) for use with a Hitachi 717 analyzer. No high-dose hook effect was observed up to 15,000 micrograms/L. Interassay CVs were 4.6% (mean = 72.0 micrograms/L; n = 9) and 2.5% (mean = 365.6 micrograms/L; n = 11). The calibration curve was stable for at least 1 month. Hemolysis did not interfere, and turbidity from lipemia interfered only when absorbance exceeded 2.0 A. Results of this method (y) correlated well with those by the Turbitime method (y = 1.256x - 44.1 micrograms/L; n = 91; r = 0.991) and by a commercially available radioimmunoassay (Byk-Sangtec; y = 0.739x - 42.2 micrograms/L; n = 94; r = 0.991). The upper limit (95th percentile) of the reference interval for myoglobin was estimated at 57.9 micrograms/L. The positive predictive value for results of myoglobin at admission was 89% with this upper reference limit and 99% with 100 micrograms/L, whereas the negative predictive value was about 60% for both limits.

A new rapid and sensitive immunofluorescence assay for the determination of myoglobin in serum

Article A new rapid and sensitive immunofluorescence assay for the determination of myoglobin in serum was published on January 1, 1993 in the journal Journal of Laboratory Medicine (volume 17, issue 4).

The early diagnosis of acute myocardial infarction

Latex agglutination for serum myoglobin (Rapitex) was compared with the initial ECG for the early diagnosis of acute myocardial infarction. Forty patients suspected of myocardial infarction were prospectively evaluated by initial electrocardiogram and Rapitex serum myoglobin. The initial ECG was categorised into one of three groups: Group 1 had ST segment elevation of at least 1 mm in a limb lead or 2 mm in a precordial lead (with or without Q waves); Group 2 had abnormalities other than those seen in Group 1; and Group 3 had no particular abnormalities present that is, a normal ECG. Myocardial infarction was confirmed by a rise in creatine kinase to greater than or equal to twice the upper limit of normal for our laboratory range and with a CKMB fraction of greater than 6%. Nineteen of 40 patients sustained myocardial infarction; nine ECG group 1, six ECG group 2, and four ECG group 3. Eleven of the 19 patients with myocardial infarction had positive serum myoglobin agglutination. The initial ECG was the most predictive of a subsequent rise in CK (p = 0.003), while Rapitex serum myoglobin determination was the least predictive (p = 0.8517). We conclude that the Rapitex serum myoglobin test offers little diagnostic or economic advantage over the initial electrocardiogram.

Clinical features, pathogenesis and management of drug-induced rhabdomyolysis.

Striated musculature is considered unusually tolerant to all kinds of injuries, and rhabdomyolysis associated with drug overdose or chronic drug intake is a rare event. This may be because striated musculature, in contrast to other tissues such as liver and kidney, shows little affinity for most drugs. Several different types of drug-induced rhabdomyolysis may be distinguished, and the clinical features of the condition may vary widely, from moderate myalgia to involvement of groups of muscles to involvement of the total skeletal musculature. In clinically asymptomatic rhabdomyolysis, early diagnosis is only made if routine laboratory tests include determination of serum creatine kinase. Determination of myoglobin in serum and urine is more sensitive and allows earlier diagnosis of muscle necrosis. Myoglobinaemia may lead to toxin-induced tubular necrosis, and impairment of renal function or even acute renal failure. About 10% of all cases of acute renal failure are due to rhabdomyolysis. Fulminant rhabdomyolysis may be associated with excessive hyperkalaemia and hypocalcaemia which may induce further life-threatening complications. Therefore, early diagnosis of rhabdomyolysis is most important for prevention of its potentially life-threatening sequelae. Therapy of rhabdomyolysis consists of supportive and specific measures. Early diagnosis may help to prevent life-threatening sequelae like acute renal failure, electrolyte imbalance and shock. Withdrawal of the incriminated drug or detoxification in drug overdose should be followed by supportive measures including infusion therapy and correction of dehydration and electrolyte imbalances. Forced diuresis with sodium bicarbonate may protect the kidney function from acidosis and precipitation of myoglobin in tubules. Elimination of myoglobin from plasma may be enhanced by plasmapheresis. In patients with acute renal failure, haemodialysis is necessary. In malignant hyperthermia, immediate infusion of dantrolene sodium is required. This drug also seems to have a beneficial effect in neuroleptic malignant syndrome. The repair mechanisms of striated musculature function extremely well. The prognosis of muscular atrophy after the acute stage of rhabdomyolysis is excellent. The same is true for the prognosis of acute renal failure. However, the extent of complications or survival of the acute stage of rhabdomyolysis strongly depend on early diagnosis and start of adequate therapy.

Determination of myoglobin in human serum by high-performance liquid chromatography with chemiluminescence detection

A highly sensitive method for the determination of myoglobin in serum in described, based on high-performance size-exclusion chromatography with chemiluminescence detection. Serum proteins are separated according to their molecular masses on columns packed with TSK-SW gel and those containing haem are detected selectively by post-column chemiluminescence reaction with luminol using a conventional fluorimetric detector. The method is rapid (30 min) and sufficiently sensitive for the diagnosis of myocardial infarction. The minimum detectable myoglobin concentration is 10 ng/ml.

Muscle cell leakage of myoglobin after long-term exercise and relation to the individual performances.

Muscle protein release was studied during and after prolonged exercise by means of serum myoglobin determinations. Increased serum myoglobin levels were regularly found after performance of long-term exercise. The correlations (P less than 0.001) to muscle enzymes indicated nonselective release from muscle cells. Myoglobin measured after completed exercise was correlated to the finishing time in a ski race, i.e., the fast skiers showed lower myoglobin levels than slow skiers. Inexperienced skiers and also skiers older than 49 years of age were found to have higher myoglobin levels than the others although the mean finishing times were similar. Myoglobin measured during and after 5 h of bicycle exercise showed large differences even though the relative work load was identical. Myoglobin started to rise 1.2 h (median) after the commencement of the bicycle exercise. The time at which myoglobin started to rise correlated (P less than 0.01) with the myoglobin levels after completed exercise and was not related to the physical fitness of the individuals. The results indicated considerable individual differences with regard to muscle protein leakage during exercise. The leakage is not simply related to the individual's apparent physical fitness but probably also to constitutional factors, such as age and metabolic capacity of the muscle cells.

SERIAL MYOGLOBIN DETERMINATIONS IN NEONATES

Rhabdomyolysis resulting in myoglobinemia is associated with renal failure in adults. We examined the hypothesis that birth asphyxia in neonates results in rhabdomyolysis with subsequent release of myoglobin. Serial serum samples were obtained on a population of 20 neonates (9 asphyxiated and 11 non-asphyxiated) during the first four days of life. Serum samples were analyzed by radioimmunoassay for myoglobin (NMS Pharmaceuticals, Inc., Newport Beach, CA). Asphyxia (5 minute Apgar ≤ 5) predicted an elevation of myoglobin (> 200 ng/ml) at 12 and 24 hours (Chi square, p < .005). Serum values comparable to those reported in adults with myoglobinemic renal failure were seen in some neonates. High serum myoglobin values (> 1000 ng/ml) at 12 hours were associated with severe oliguria at 24 and 48 hours (24 hrs= 0.27 ± .28 cc/kg/hr, 48 hrs = 0.70 ± .46 cc/kg/hr, n = 3). Myoglobinemia may be associated with poor urine output during the neonatal period and serum myoglobin determination may have a value as a marker for birth asphyxia. This preliminary study suggests that birth asphyxia results in rhabdomyolysis with the subsequent release of myoglobin in some neonates.

Chemiluminescent immunosorbent assay of serum myoglobin based on the luminol reaction

A simple and sensitive method for the determination of serum myoglobin is described. Myoglobin was determined in the range of 10–500 μg/1 by the chemiluminescent luminol reaction after adsorption to anti-myoglobin IgG onto a solid phase. Only 50 μl of serum has to be used and the luminescent immunoassay (LIA) has a better sensitivity and a wider linear range than the conventional radioimmunoassay (RIA). However, in its present form LIA has a higher imprecision than RIA. In clinical specimens the correlation between the two methods was excellent.

The value of serum myoglobin determinations in the early diagnosis of acute myocardial infarction.

Myoglobin has been measured in sera from 305 consecutive patients with suspected acute myocardial infarction (AMI) to study the clinical value in relation to other diagnostic methods. On admission the frequency of false negative (i.e. the diagnostic sensitivity) myoglobin values was 28% in the AMI group as compared with 60% for serum creatine kinase (CK) and 46% for serum aspartate aminotransferase (ASAT). Four hours after admission the corresponding figures were 2, 31 and 29%. This makes the diagnostic sensitivity of the myoglobin test 0.98, which is significantly higher (p less than 0.001) than that of the two enzyme tests. The predictive value of a negative myoglobin test was 0.97 and also significantly higher (p less than 0.001 and p less than 0.01) than for CK and ASAT. S-myoglobin was further related to the number of complications and the prognosis of the patients, and high levels appeared to be an unfavourable sign, particularly in combination with an anterior wall infarct. This study has demonstrated and confirmed the superior diagnostic sensitivity of myoglobin determination in early AMI. The inclusion of S-myoglobin in the routine diagnosis of AMI warrants serious consideration.

The roles of serum myoglobin, total CPK, and CK-MB isoenzyme in the acute phase of myocardial infarction

Frequent blood samples were drawn for determination of serum myoglobin, creatine phosphokinase (CPK), and the MB isoenzyme of CPK (CPK-MB) in patients with acute myocardial infarction (AMI). Significantly elevated levels of myoglobin were present 1.5 hours following onset of chest pain and predated elevations of CPK and CPK-MB by 3 hours. No evidence of the previously described “staccato” phenomenon was found. Due to very frequent blood sampling, a detailed picture of the evolution over time of the above indices was obtained. Significant differences were found in the biochemical profile of anterior wall infarction and diaphragmatic wall MI. A time-sensitivity curve (showing sensitivity of the assay at each time following onset of symptoms) was obtained for myoglobin, CPK, and CPK-MB. It appears that myoglobin is the most sensitive biochemical indicator of AMI in its early phase and since it decreases rapidly back to normal values, it can serve as an invaluable aid in the diagnosis of reinfarction and infarct extension. CPK-MB is a less sensitive indicator of MI but has the advantage of greater specificity.

Serum myoglobin determinations in the assessment of acute myocardial infarction.

Serum myoglobin (SMb) changes following acute myocardial infarction were studied in 67 patients admitted to the coronary care unit soon after the onset of symptoms (mean delay 2.8 ± 2.2 h; CK on admission < 150 iu/l). A typical rise and fall of SMb concentrations was seen in all cases. The maximum SMb level (718 ± 301 ng/ml) was reached 7.2 ± 3.7 h after admission. Return to values lower than 80 ng/ml was observed after a mean time of 36.2 ± 20.9 h. SMb peak concentration correlated significantly with both serum enzyme peak level and cumulated CK activity (r=0.64, P < 0.0001). The myoglobin release patterns were recorded in 121 patients. The twenty-four patients whose SMb levels remained higher than 100 ng/ml 48 h following admission demonstrated a higher incidence of left ventricular failure (Killip classes III and IV) and a mortality rate of 33%. Patients who died within three months following hospitalization (n=10) showed significantly more elevated myoglobin concentrations throughout the investigation period as compared to survivors (n=111). Myoglobin determined 4 h following admission correlated with serum lactate dehydrogenase activity, and high SMb levels were associated with an increased mortality rate. Our results suggest that SMb measurements might allow a stratification of patient risk as early as 9 to 12 h following the onset of myocardial infarction.

Creatine kinase and myoglobin determination in myocardial infarction (determination of infant size).

In order to evaluate the diagnostic and prognostic importance of serum myoglobin (Mb) determination during acute myocardial infarction (AMI) we determined the time of first rise of both CK and Mb, that is the time in hours between the onset of pain and the last normal myoglobin and enzyme determination (TFR for Mb = 2.2 +/- 1.5 h; TFR for CK = 4.0 +/- 2.5 h). We also attempted to evaluate infarct size by mathematical analysis of the serum concentrations of Mb. The average percentage difference between the infarct size calculated from the CK concentrations and Mb concentrations was 35.8 +/- 35.2%. The results show that the determination of serum myoglobin is a useful and sensitive test for the early diagnosis of AML. On the other hand, the serum myoglobin cannot be utilized to evaluate infarct size. The main limitation in the determination of infarct size from the serum Mb concentrations lies in the extreme variability of the disappearance rate (Kd), mainly resulting from the renal elimination of the substance.

The role of serum myoglobin in the detection and measurement of myocardial infarction

The use of serum myoglobin determinations in the diagnosis and quantitation of acute myocardial infarction was studied in 53 patients. Serial blood samples collected for the first 72 h after pain were analysed for serum myoglobin using a radioimmunoassay procedure. Samples were also assayed for serum creatine kinase (CK) and its myocardial isoenzyme CK-MB, aspartate aminotransferase (AST) and α-hydroxybutyrate dehydrogenase (αHBDH). Analysis of first and second samples obtained at mean times of 7.6 and 10.7 h respectively after pain produced the following detection rate: serum myoglobin 85% and 98%; serum CK 71% and 85%; serum AST 58% and 81%; serum CK-MB 29% and 60%; serum αHBDH 23% and 33% respectively. Total CK-MB and myoglobin release from damaged myocardium were calculated using the method of Norris et al. [16]. A significant correlation was obtained between infarct size calculated from CK-MB and myoglobin in the whole group ( n = 29, r = 0.71, p < 0.001). The correlation was even more significant for smaller infarcts with CK-MB release < 220 U/l ( n = 13, r = 0.92, p < 0.001).

Etude de la myoglobinemie et de son evolution au cours de l'infarctus du myocarde

Thirty six patients suffering from myocardial infarction were investigated by assay of their serum myoglobin, total creatine kinase and creatine kinase isoenzyme MB activities. Determination of serum myoglobin presents, with regard to creatine kinase MB, two major advantages: a very early increase after the onset of the pain (about three hours later) and a very quick clearance, allowing the diagnosis of a second episode of necrosis after about one day.

Serum myoglobin in muscular dystrophy.

Elevated levels of serum myoglobin (MGB) were found in patients with several types of myopathic disorders, namely, Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), facioscapulohumeral dystrophy, and limb-girdle dystrophy. The frequency of hypermyoglobinemia was greatest in patients with DMD and BMD (91.7% and 100%, respectively). There was no precise direct relationship between serum creatine kinase (CK) and MGB levels, although the disorders with the highest CK levels tended to be the ones with the highest MGB levels. Among the patients with DMD, hypermyoglobinemia was slightly less marked in older children with restricted ability to walk than in the younger ones. Hypermyoglobinemia las noted among 43.8% of the mothers and 41.7% of the sisters of patients with DMD, slightly greater frequencies than for abnormal CK determinations in this group. Multiple serum samples were analyzed from 10 of these women, and the overall frequency of abnormal MGB levels was the same as that of abnormal CK levels; however, levels of CK and MGB were discrepant in some individual serum samples. For this reason, serum MGB determination may be a useful adjunct in the study of possible DMD carriers.

Myoglobinemia in duchenne muscular

We have carried out serum assays for myoglobin in parallel with the determination of serum CPK activity to assess its usefulness in raising the detectability rate of Duchenne muscular dystrophy carriers. Of the 14 carriers, ten (71.4%) had high serum levels of myoglobin and nine (64.3%) showed increased serum CPK levels. Either parameter revealed elevation in 11 (78.6%) of the 14 cases studied. Serum myoglobin determination is of noticeable value in the detection of Duchenne muscular dystrophy carriers.

The significance of the estimation of serum myoglobin in neuromuscular diseases

The serum myoglobin concentration was determined and compared with the serum creatine kinase activity in 230 patients suffering from various neuromuscular diseases. No correlation was found between the two levels. In general serum creatine kinase activity estimation seemed more sensitive for the detection of neuromuscular disease than serum myoglobin estimation. In myotonic dystrophy, however, determination of serum myoglobin was distinctly the more sensitive method.

Myoglobin in Myocardial Infarction:Results in a Coronary-care-unit Population

The purpose of this study was to define the performance characteristics of serum myoglobin determinations in the diagnosis of acute myocardial infarction (MI). Subjects of the study were 118 patients admitted consecutively to the coronary care unit. Daily measurements of serum myoglobin (by radioimmunoassay) were performed. For patients admitted within 24 hours of the onset of symptoms, a serum myoglobin level of 75 ng/ml had a diagnostic sensitivity of 91% and a specificity of 85%. In the same group of patients, the presence of the myocardial isoenzyme of creatine phosphokinase (CK-MB) showed a sensitivity of 94% and a specificity of 89%. Among the 32 patients with MI, the elevation of myoglobin preceded the appearance of CK-MB in 12 (38%), was concomitant with CK-MB appearance in 15 (47%), and followed CK-MB in none. Given the spectrum of patients in this coronary care unit, the addition of the myoglobin assay to the heart profile has increased its sensitivity for the diagnosis of MI. The assay materials are available in kit form, and the test can be performed in the routine radioimmunoassay laboratory. The results are available for reporting four to five hours after venipuncture.