Serial serum determinations of the tumour associated antigens carcinoembryonic antigen, tissue polypeptide antigen, CA 19-9, CA 15-3 and CA 125 were performed on 70 patients who were undergoing, or had undergone renal transplantation. The period of observation ranged from 4 days pre-operative to 708 days post-operative, although daily monitoring was usually carried out during the first 14-35 days post-operatively. With the exception of tissue polypeptide antigen, which was analysed with an immunoluminometric assay, all analytes were measured with the Enzymun-Test System ES-300 using immunoenzymometric assays with colorimetric determination. The interassay coefficients of variation were less than 5% for the immunoenzymometric assays and 8.7% for tissue polypeptide antigen, all values being derived from 20 consecutive assays. Only 8/70 patients with no complications showed normal concentrations for all five analytes. 6/79 patients showed parallel changes of at least three markers. 7/70 patients had transient elevations of at least one marker, whereas 25/70 patients had a continual elevation of CA 125, 9/70 CA 19-9 and 1/70 CA 15-3, although no patient showed evidence of disease. Two patients, each with 2 rejection episodes, showed daily fluctuations up to 100% for all markers, with the exception of carcinoembryonic antigen. There was no correlation between elevated tumour markers and cytomegalovirus infection.

Results from a multicenter evaluation of two new enzyme-linked immunosorbent assays [Enzymun-Test for follitropin (FSH) and lutropin (LH)] are presented and compared with results from 11 other commercial immunoassays, radioactive as well as nonradioactive. Enzymun-Test FSH and LH assays are suitable for automated systems and manual applications. The tests were reproducible (CV less than 5%), highly specific, and sensitive enough (less than 0.5 int. unit/L) to measure the hormones directly in almost all patients' samples, except for LH measurements in prepubertal children. We did not find interference by heterophilic antibodies or other factors. A comparison of assays for FSH found very good agreement among all modern two-site assays; competitive immunoassays almost invariably yielded systematically lower results for FSH, probably because of the heterogeneity of the International Reference Preparation (2nd IRP FSH, 78/549). For LH also we found good agreement, with no systematic differences among the various reagents. Guidelines for reference values with the new reagents are given.

The use of a new monoclonal enzyme immunoassay (EIA) for the carcinoembryonic antigen (CEA) (Enzymun-Test CEA) was evaluated in a multi-centre study. Fifteen different laboratories [participated in the study. Data from the investigation were analysed in terms of precision, sensitivity, specificity and correlation with other test methods. The intra-assay coefficient of variation was between 1.3% at 23.0 microg/l CEA and 13.9% at 1.3 microg/l CEA. Inter-assay reproducibility ranged from 3.6% to 19.2%. The apparent sensitivity of the new EIA for CEA was approx. 0.5 microg/l CEA. The findings indicate that lipaemic and haemolytic sera and samples taken from icteric, rheumatic and dialysis patients did not have any influence on the results. There was no evidence that drugs commonly used in the treatment of carcinoma patients have any influence on the assay results. A good correlation between the new EIA for CEA and six other CEA enzyme immunoassay or radioimmunoassay methods was registered. These results seem to be of significance in particular for the monitoring of therapy for carcinoma patients. The new EIA for CEA exhibits a high degree of sensitivity, specificity and reproducibility.

Journal Article Individual variations of carcinoembryonic antigen (CEA) in serum of healthy subjects. Get access W Riesen, W Riesen Universität Bern, Institut für klinisch-experimentelle Tumorforschung, Tiefenauspital, Switzerland Search for other works by this author on: Oxford Academic Google Scholar A C Kessler, A C Kessler Universität Bern, Institut für klinisch-experimentelle Tumorforschung, Tiefenauspital, Switzerland Search for other works by this author on: Oxford Academic Google Scholar V Ehrhardt V Ehrhardt Universität Bern, Institut für klinisch-experimentelle Tumorforschung, Tiefenauspital, Switzerland Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 33, Issue 11, 1 November 1987, Page 2123, https://doi.org/10.1093/clinchem/33.11.2123 Published: 01 November 1987

A new test-combination for the enzymatic determination of lecithin in amniotic fluid for the assessment of fetal lung maturity has been developed by Boehringer Mannheim. This test was evaluated by 12 hospitals and has been compared with the L/S ratio, the foam-test or the densitometric determination of lecithin. The assay is based on the hydrolysis of lecithin by phospholipase C which starts an enzymatic chain reaction in which NADH consumption if measured photometrically. The intra- and interassay precision were characterized by CV values below 10%. Average recoveries of lecithin were 95-102%. It is recommended to centrifuge the samples (10 min, 700 g) and to start the analysis as soon as possible after receipt of the specimen. The total amount of time required is 2 hours for a single determination. Batches of up to 10 samples require little extra time. An opened test-combination can be used for a maximum of 30 single determinations. Comparison of the quantitative enzymatic lecithin determination with other methods showed that the critical value for lecithin is 5.0 mg/100 ml. Above 5.1 mg/100 ml no case respiratory distress syndrome was observed. The good precision accuracy and the simple handling make the enzymatic lecithin determination suitable for routine use.

A new test-combination for the enzymatic determination of lecithin in amniotic fluid for the assessment of fetal lung maturity has been developed by Boehringer Mannheim. This test was evaluated by 12 hospitals and has been compared with the L/S ratio, the foam-test or the densitometric determination of lecithin. The assay is based on the hydrolysis of lecithin by phospholipase C which starts an enzymatic chain reaction in which NADH consumption if measured photometrically. The intra- and interassay precision were characterized by CV values below 10%. Average recoveries of lecithin were 95-102%. It is recommended to centrifuge the samples (10 min, 700 g) and to start the analysis as soon as possible after receipt of the specimen. The total amount of time required is 2 hours for a single determination. Batches of up to 10 samples require little extra time. An opened test-combination can be used for a maximum of 30 single determinations. Comparison of the quantitative enzymatic lecithin determination with other methods showed that the critical value for lecithin is 5.0 mg/100 ml. Above 5.1 mg/100 ml no case respiratory distress syndrome was observed. The good precision accuracy and the simple handling make the enzymatic lecithin determination suitable for routine use.