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Non-invasive detection of cardiac rejection still remains a challenge after heart transplantation. We assessed troponin-T as a new serum marker to diagnose cardiac rejection. Twenty-five heart transplant patients (Berne) were monitored prospectively for up to 2 years, and compared to 89 retrospectively assessed patients (Stanford). Blood samples (392 Berne and 320 Stanford) were analyzed (creatine kinase, isoenzymes MB activity and MB mass, troponin-T and troponin-I). Regression analysis between the results of these blood samples and cardiac rejection grading from simultaneously performed endomyocardial biopsies was carried out. Troponin-T tests done in two different laboratories showed a good correlation (r = 0.91; P < 0.0001), whereas troponin-T versus troponin-I showed a lower correlation (r = 0.53; P < 0.0001). Troponin-T and -I in contrast to other enzymes were elevated for a longer period (up to 4 weeks before returning to baseline) after transplantation than during conventional cardiac surgery. Beyond 3 months the following correlations were found between troponin-T (new or old test) and the other enzymes (creatine kinase: r = 0.26, MB activity: r = 0.4, and MB mass: r = 0.68). The correlation between the degree of rejection and the enzyme release is poor, however, the best results were obtained for troponin-T (r = 0.22; P < 0.001). We found a low correlation between troponin-T and the degree of rejection beyond 3 months after heart transplantation. Despite a troponin-T elevation in some patients with rejection, the new test is not sensitive enough to be used alone for the non-invasive diagnosis of cardiac rejection.

In a multicenter study we compared three tests for ischemic myocardial injury (IMI): a new, automated enzyme immunoassay for S-troponin T (S-TNT; Boehringer Mannheim) and two S-creatine kinase (CK) isoenzyme MB assays (mass and catalytic concentrations). For critical evaluation of clinical sensitivity, we studied 243 cases with an IMI prevalence of 43% and an 18% prevalence of cases with unstable angina. Relative peak values of S-TNT and S-CK-MB (mass) after onset of pain were four- to fivefold higher than S-CK-MB (catalytic) results. Increases of S-TNT and S-CK-MB (mass), even though still within their reference ranges, indicated minor myocardial damage in about one-third of the cases primarily classified as unstable angina. The diagnostic window for S-TNT ranged from hours to weeks after the acute episode. The time courses were frequently biphasic, with the initial S-TNT peak closely paralleling that of the mass concentrations of S-CK-MB. With a biological half-life for S-TNT of 2 h, the prolonged increases in S-TNT indicate a continuous release of S-TNT from necrotizing cells. Clinical specificities of S-TNT and S-CK-MB (mass) were greater than that of S-CK-MB (catalytic), even in the presence of 30% to 40% severe skeletal muscle injuries. The combination of S-TNT and S-CK-MB (mass) is excellent for detection of acute IMI, including minor myocardial damage.

Following a 100 km race creatine kinase (CK) creatine kinase MB (CKMB) activities were serially measured in well trained athletes and compared with enzyme activities in patients with acute myocardial infarction (AMI). The half-time of disappearance of CK (CKt1/2) was 1.75 +/- 0.70 days in runners who trained within the 1st week after the race, and was 0.81 +/- 0.18 days in patients with AMI, P less than 0.005. CKt1/2 in runners was shorter (1.17 +/- 0.28 days) when no training was performed in the first postrace week. CKt1/2 was linearly correlated with age (P less than 0.01) in the runners but not in the patients. CKMBt1/2 was 1.30 and 1.11 days in two runners and 0.56 +/- 0.10 days in patients with AMI (P less than 0.05). In line with histologic and enzymatic findings in skeletal muscle of long distance runners as reported by other workers, our kinetic data provide further evidence that CK and CKMB are released from muscular compartments in runners other than those in patients with AMI.

We evaluated the new Greiner G-400 selective multichannel analyzer. Thirty different tests can be run in combination profile and single-test mode at a rate between 150 and 300 tests per hour. The new photometer allows kinetic and equilibrium (endpoint) measurements. The G-400 analyzer demonstrated excellent precision, linearity, accuracy, ease of operation, and no carryover. Results for 16 different analytes as determined with the Hitachi 705, GSA II, and Corning 940 correlated favorably with those obtained with the G-400. The G-400 analyzer is suitable for both emergency and routine use.

1. A mercury(II)-thiocyanate method for the determination of chloride in plasma and serum was adapted for the Greiner Electronic Selective Analyzer GSA II. A sample blank value and a partial reagent blank value were determined by omitting thiocyanate from the control system. 2. The course of the reaction was investigated. For a reaction time of 350-500 s, the response was linear between 30 and 130 mmol/l. Between 90 and 110 mmol/l, the deviation between the actual and the theoretical value is less than 1%. 3. The calibration must be checked and, if necessary, restandardized; this is probably due to variable contamination of the reagents with chloride ions. 4. Haemolysis, lipaemia and bilirubin do not interfere. Protein has no effect on the course of the reaction. 5. At concentrations around 100 mmol/l, the in series precision, expressed as the variation coefficient (%), is 0.3-0.6% for aqueous solutions, 0.4-0.8% for liquid control sera, and 0.8-1.5% for lyophilized control sera. 6. No carry over was detectable from samples containing 150 to those containing 10 mmol/l.

(Eingegangen am 31. Oktober 1973/28. Februar 1974)1. Eine Methode zur Bestimmung des Gesamt-Bilirubins in Plasma und Serum wurde fur den Greiner Electronic Selective AnalyzerGSA II adaptiert. Durch Verwendung des Diazonium-Chlorids des 2,4-Dichloranuins gelang es, Reagenzien zu entwickeln, die imGSA II mindestens l Woche stabil sind. Durch Weglassen des Nitrits im Leerwert-Ansatz wird ein Proben- und partieller Reagenzien-Leerwert durchgefuhrt·2. Die Methode hat einen linearen Mes-Bereich bis zu 40 mg/dl (680 / -3. Eine Verschleppung von Proben-Material konnte bei einem Konzentrations-Gefalle von 40 mg/dl auf 0,2 mg/dl nicht nachgewiesenwerden.4. Tyrosin, Histidin und Indikan storen in physiologischen Konzentrationen nicht. Die folgenden Medikamente gaben in Konzentra-tionen von l und 10 mmol/1 keine Interferenzen: Adrenalin, p-Aminophenol, ,-Ascorbinsaure, L-Dihydroxyphenylalanin (DOPA)Methyl-DOPA) Noradrenalin, Phenelzin, Rifampicin und Phenazopyridin. Beim Vorliegen einer Hamolyse wird die Azofarbstoff-Bildung etwas unterdruckt, und zwar bei einer Hamoglobin-Konzentration von 40 mg/dl um etwa 5

A simple photometric procedure was developed for the determination of thiocyanate (SCN-) in plasma and saliva without deproteinisation or dialysis. Fe(III) ions form a red coloured complex with SCN- with a maximum absorbance at 460 nm. Mercury(II) nitrate is used to run a sample blank. A manual and an automated version (COBAS BIO) of the method is described. The method is linear up to 5000 mumol/l SCN-. The CV of the between-run precision is 2.8-8% for the manual and 2.6-6.6% for the automated method. The SCN- plasma concentration was 21-134 mumol/l in nonsmokers and 44-260 mumol/l in smokers. In mixed saliva, the concentration is much higher than in plasma: 1.57-5.5 mumol/l in smokers and 0.79-3.9 mumol/l in nonsmokers. Plasma, but not oral fluid SCN-, is a valuable parameter for studying smoking habits in population surveys. However, its use is limited. In our experience only heavy smokers can be distinguished from nonsmokers.