Method variation in lactate dehydrogenase isoenzyme determination.

1981 ◽  
Vol 27 (4) ◽  
pp. 624-625 ◽  
Author(s):  
N M Papadopoulos
Keyword(s):  
Myocardial Infarction ◽  
Lactate Dehydrogenase ◽  
Test Results ◽  
Dehydrogenase Isoenzyme ◽  
Lactate Dehydrogenase Isoenzymes

Abstract Differences between methods for determining lactate dehydrogenase isoenzymes are illustrated, which can account for discrepant results. They should be taken into consideration in the interpretation of test results for the diagnosis of myocardial infarction.

Time-related changes in the diagnostic utility of total lactate dehydrogenase, lactate dehydrogenase isoenzyme-1, and two lactate dehydrogenase isoenzyme-1 ratios in serum after myocardial infarction

1990 ◽  
Vol 36 (7) ◽  
pp. 1317-1322 ◽  
Author(s):  
L V Galbraith ◽  
F Y Leung ◽  
G Jablonsky ◽  
A R Henderson
Keyword(s):  
Myocardial Infarction ◽  
Lactate Dehydrogenase ◽  
Likelihood Ratio ◽  
Roc Curve ◽  
Operating Characteristic ◽  
Negative Likelihood Ratio ◽  
Diagnostic Utility ◽  
Time Intervals ◽  
Dehydrogenase Isoenzyme ◽  
Cardiac Care Unit

Abstract Using receiver-operating characteristic (ROC) curve and likelihood ratio analysis, we examined the diagnostic utility of total lactate dehydrogenase (LD; EC 1.1.1.27) activity (I). LD isoenzyme-1 activity (II), and the LD-1 percentage of total LD activity (III), LD-1 LD-2 (IV), and LD-1/LD-4 (V) in 347 persons admitted to the Cardiac Care Unit (of whom 173 were subsequently proven to have had myocardial infarction). Blood was sampled from these subjects at about 6-h intervals for up to 96 h from the onset of chest pain. Defining an "effective" test as one having an area under the ROC curve of greater than or equal to 0.9, we determined the ranked utility (greatest to least) of these tests as V = IV greater than III greater than II greater than I. Tests III, IV, and V had by this criterion, diagnostic effectiveness equivalent to measurements of creatine kinase-2 in serum but in samples obtained at later time intervals. The decision thresholds for both high (constant) test sensitivity and specificity varied with time, to differing extents, over the entire 96-h period, a finding with important diagnostic implications. We document positive and negative likelihood ratio values for each of these tests throughout the entire period of study.

Improved column method for separating lactate dehydrogenase isoenzymes 1 and 2.

1978 ◽  
Vol 24 (3) ◽  
pp. 480-482 ◽  
Author(s):  
D W Mercer
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Creatine Kinase ◽  
Heart Disease ◽  
Lactate Dehydrogenase ◽  
Sodium Chloride ◽  
Lactate Dehydrogenase Activity ◽  
Column Method ◽  
Creatine Kinase Mb ◽  
Lactate Dehydrogenase Isoenzymes

Abstract Lactate dehydrogenase (LD) isoenzymes 1 and 2 in human serum were separated on a column of diethylaminoethyl-Sephadex. Samples layered on mini-columns were eluted with buffered sodium chloride (100, 150, and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and their isoenzyme content was evaluated by electrophoresis on polyacrylamide gel. Results for column-fractionated LD-1 and LD-2 were expressed in two ways: LD-1/LD-2 ratios and total LD-1 + LD-2 activities. The former is a more specific indicator of myocardial infarction than the latter. Sera from 10 patients with acute myocardial infarction (increased creatine kinease isoenzyme MB activity) exhibited ratios in the range of 0.92 to 1.56, ratios for 10 patients without heart disease (normal creatine kinase MB) ranged from 0.33 to 0.69.

Lactate dehydrogenase isoenzyme-1 in serum for detection of peri-operative myocardial infarction after cardiac surgery.

1988 ◽  
Vol 34 (12) ◽  
pp. 2469-2474 ◽  
Author(s):  
Z Rotenberg ◽  
J E Squires ◽  
M T Johnston ◽  
J Hoyt ◽  
R S Gibson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Surgery ◽  
Lactate Dehydrogenase ◽  
Valve Replacement ◽  
Artery Bypass ◽  
Reference Intervals ◽  
Serum Lactate ◽  
Serum Lactate Dehydrogenase ◽  
Present Measurement ◽  
Dehydrogenase Isoenzyme

Abstract We prospectively studied changes in serum lactate dehydrogenase isoenzyme-1 (LD-1, EC 1.1.1.27) in 99 consecutive patients after either coronary artery bypass grafting (CABG, n = 61), isolated cardiac-valve replacement (n = 24), or the two procedures combined (n = 14); 86 of these had no clinical evidence of peri-operative myocardial infarction (MI). Blood was sampled immediately after surgery and at 6-h intervals for up to 42 h thereafter. LD-1 was isolated by using the LD M-subunit antiserum. Samples from the non-MI patients were used to establish the reference intervals for LD-1. By 24 h after surgery, mean serum LD-1 values were higher (P less than 0.001) in non-MI patients who underwent isolated valve replacement (222 +/- 74 U/L) or combined CABG and valve replacement (266 +/- 58 U/L) than in 50 non-MI patients who underwent CABG alone (134 +/- 42 U/L). Separate reference intervals were determined for CABG and other patients at each sampling time. By 24 h after operation, LD-1 exceeded these reference intervals in the 10 CABG and two combined-procedure patients in whom other evidence of MI was present. Measurement of LD-1 24 to 42 h after cardiac surgery appears to be a useful test for the diagnosis of perioperative MI.

Clinical evaluation of immunochemical assay of lactate dehydrogenase isoenzyme 1 in early detection of acute myocardial infarction.

1982 ◽  
Vol 28 (10) ◽  
pp. 2152-2154 ◽  
Author(s):  
T Y Wang ◽  
J H Godfrey ◽  
L G Graham ◽  
M N Haddad ◽  
T C Hamilton
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Lactate Dehydrogenase ◽  
Myocardial Ischemia ◽  
Clinical Presentation ◽  
Myocardial Infarct ◽  
Acute Myocardial Infarct ◽  
Group Iii ◽  
Dehydrogenase Isoenzyme ◽  
Group I

Abstract We immunochemically measured lactate dehydrogenase isoenzyme 1 (LD-1), calculated LD-1/LD ratios (% LD-1) for 122 specimens from 60 patients, and compared the results with those for the conventional cardiac profile and other findings such as clinical presentation and electrocardiogram. Results for LD-1 and % LD-1 could be classified into three groups: group I, with LD-1 less than 64 U/L; group II, with LD-1 greater than 64 U/L and % LD-1 between 17 and 37%; and group III, with LD-1 greater than 64 U/L and 5 LD-1 greater than 38%. These three groups correlated closely and consistently with three patients of cardiac profile, i.e., those of no acute myocardial infarct, myocardial ischemia, and acute myocardial infarct, respectively.

Information induction for predicting acute myocardial infarction.

1988 ◽  
Vol 34 (10) ◽  
pp. 2031-2038 ◽  
Author(s):  
R A Rudolph ◽  
L H Bernstein ◽  
J Babb
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Information Theory ◽  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Noisy Channel ◽  
Information Uncertainty ◽  
Test Results ◽  
Creatine Kinase Mb

Abstract We show how to make an unsupervised discrimination of disease and nondisease states by measuring information and using newer notions of inductive reason. We also present a new theory of group-based reference values that is based on measuring information uncertainty. We use data on the isoenzymes creatine kinase-MB (CK-MB) and lactate dehydrogenase-1 (LD1) and on the percentage of LD1 from 101 patients with acute myocardial infarction (AMI) and from 41 patients with suspected, but unfounded, infarction (non-AMI). Calculating the Shannon entropy, a concept from information theory, of the data base allows determination of a difference in entropy values ("effective information"), which determines decision cutoff values that produce binary-base patterns yielding the fewest classification errors. Redundancy in testing is important because it provides the information to approach a goal of errorless discrimination by coding the test results and meeting the conditions of the "Noisy Channel Theorem" of information theory. This redundancy improves the predictive value of diagnosis by isolating the area of equivocation to evident patterns. Results for CK-MB and LD1 are 99% correct in assigning cases to AMI and non-AMI categories; adding %LD1 increases the proportion of errorless binary patterns from 25% to 90%.

Accuracy of lactate dehydrogenase isoenzyme estimations by a thin-layer agarose fluorescent technique: experience with ternary and quaternary mixtures of purified human lactate dehydrogenase isoenzymes.

1983 ◽  
Vol 29 (12) ◽  
pp. 2096-2099
Author(s):  
E M Pridgar ◽  
F Y Leung ◽  
A R Henderson
Keyword(s):  
Lactate Dehydrogenase ◽  
Thin Layer ◽  
Binary Mixtures ◽  
Peak Height ◽  
Clin Pathol ◽  
Dehydrogenase Isoenzyme ◽  
Fluorescent Technique ◽  
Lactate Dehydrogenase Isoenzymes

Abstract We have further assessed the accuracy of the thin-layer agarose fluorescent technique of Elevitch et al. [Am J Clin Pathol 46, 692 (1966)]. Previously, we used semi-purified human lactate dehydrogenase isoenzyme-1 and -5 [Clin Chem 22, 1995 (1976)] and isoenzyme-1 and -2 [Clin Chem 27, 1708 (1981)] to show that this assay accurately measures the proportions of these binary mixtures. In the present study, using ternary and quaternary mixtures of isoenzyme- 1, -2, -3, and -5, we show that the assay gives accurate estimations of all of these isoenzymes, within the errors of the techniques used. We also show that peak area (integration) is more nearly accurate, but less precise, than peak height (amplitude) measurements.

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