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Monneret D, Moreau A, Chirica C, Guergour D, Richet C, Desmurs L, Colognac S, Frugier A, Chévrier M, Marmontel O, Bonnefont-Rousselot D, Gonzalo P, Rodriguez-Lafrasse C, Cartier R. Non-linearity in lipase assays: A multicentric comparison on different analysers. Clin Biochem 2023; 114:63-66. [PMID: 36773631 DOI: 10.1016/j.clinbiochem.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/21/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
OBJECTIVES Non-linearity in lipase assays and the ensuing gaps in results distribution have been described on Roche analysers, but have yet to be studied on other analysers. DESIGN AND METHODS Eighteen lithium-heparinized plasma pools of lipase activities decreasing from 1700 to <4 U/L were prepared for multicentric evaluation on several analysers. Non-linearity was modelled as the difference between the polynomial regression of lipase activities depending on relative dilutions over the primary measuring range, and the linear regression of the same variables above the manufacturer's limit of linearity (MLL). Gaps in lipase distribution resulting from non-linearity were graphically evidenced through histograms. Upper limits of gaps were calculated, which are lipase activities where non-linearity biases no longer impact the diluted lipase results. RESULTS MLLs and lipase (U/L) calculated at MLL (%biases versus MLL) were respectively: 1200 and 1124 (-6.3%) on the Architect C16000 (Abbott); 300 and 248 (-17.3%) on the Cobas c503 (Roche); 1500 and 1458 (-2.8%) on the Dimension Vista (Siemens); and 700 and 659 (-5.9%) on the Atellica CH930 (Siemens). Using Sentinel Lipase reagents on Abbott analysers, these measurements were respectively: 300 and 294 (-2.0%) on the Architect C16000, and 300 and 298 (-0.7%) on the Alinity. Setting Randox Lipase reagents on the Alinity, MLL and lipase at MLL were 953 and 776 (-18.6%), respectively. CONCLUSIONS Considering the desirable (±14.2 %) and optimal (±7.1 %) allowable total error for lipase (EFLM/EuBIVAS), biases at manufacturer's limit of linearity were acceptable, except for Roche Cobas c503 method and Randox method on Abbott Alinity.
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Affiliation(s)
- Denis Monneret
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France.
| | - Amélie Moreau
- Service de Biochimie, CHU Saint-Etienne, F-42000 Saint-Etienne, France
| | - Carole Chirica
- Unité de Biochimie Immunoanalyse, Service de Biochimie Biologie Moléculaire et Toxicologie Environnementale, Institut de Biologie et Pathologie, CHU Grenoble, Université Grenoble Alpes, F-38000 Grenoble, France
| | - Dorra Guergour
- Unité de Biochimie Immunoanalyse, Service de Biochimie Biologie Moléculaire et Toxicologie Environnementale, Institut de Biologie et Pathologie, CHU Grenoble, Université Grenoble Alpes, F-38000 Grenoble, France
| | - Caroline Richet
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Laurent Desmurs
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Sylvie Colognac
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Audrey Frugier
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Marc Chévrier
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Oriane Marmontel
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Dominique Bonnefont-Rousselot
- Service de Biochimie Métabolique, AP-HP, Sorbonne Université, Hôpitaux Universitaires Pitié-Salpêtrière-Charles Foix, F-75000 Paris, France; Université Paris Cité, CNRS, INSERM, UTCBS, F-75006 Paris, France
| | - Philippe Gonzalo
- Service de Biochimie, CHU Saint-Etienne, F-42000 Saint-Etienne, France
| | - Claire Rodriguez-Lafrasse
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
| | - Régine Cartier
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), F-69000 Lyon, France
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Aydemir D, Gecili F, Özdemir N, Nuray Ulusu N. Synthesis and characterization of a triple enzyme-inorganic hybrid nanoflower (TrpE@ihNF) as a combination of three pancreatic digestive enzymes amylase, protease and lipase. J Biosci Bioeng 2020; 129:679-686. [DOI: 10.1016/j.jbiosc.2020.01.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/21/2020] [Accepted: 01/30/2020] [Indexed: 01/08/2023]
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Tjora E, Erchinger F, Engjom T, Aksnes L, Dimcevski G, Gudbrandsen OA. Analysis of lipase activity in duodenal juice. Comparison of an automated spectrophotometric assay to a fluorometric microplate assay, and factors affecting sample stability. Scand J Gastroenterol 2019; 53:1206-1211. [PMID: 30353747 DOI: 10.1080/00365521.2018.1518481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Direct pancreas function testing (DPFT) has been regarded as gold standard for assessment of exocrine pancreas function. One of the outcomes from DPFT is pancreatic lipase activity in duodenal juice, but no standard assay for measuring pancreas lipase activity in duodenal juice exists. AIMS To optimize and evaluate an autoanalyzer assay for measuring lipase activity in duodenal juice. METHODS We used samples of duodenal juice from our biobank, collected through a short endoscopic secretin test in patients with suspected exocrine pancreas insufficiency. Samples were analyzed on a Cobas autoanalyzer (Roche Diagnostics), using a colorimetric, kinetic enzyme activity assay. We compared stability of samples diluted in saline to samples diluted in 3-(N-morpholino) propane sulfonic acid (MOPS) buffer added bovine serum albumin (BSA). Results from the Cobas assay were compared to Confluolip method, a fluorometric, kinetic enzyme assay, modified to fit into a microplate setting. RESULTS We tested the stability of 54 samples from 21 patients. Diluting samples with MOPS buffer added BSA gave stable results, and was superior to diluting samples in saline. We compared the two assays in 50 samples from 20 patients and found a good correlation between the two assays (r = 0.91, p < .001). There was a significant proportional bias between the two assays, but no significant systematic bias. CONCLUSION Pancreatic lipase activity in duodenal juice samples diluted in MOPS buffer added BSA is stable for one hour at room temperature. Quantification of lipase activity in duodenal juice using a standard automated activity assay has comparable accuracy to a manual fluorometric method.
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Affiliation(s)
- Erling Tjora
- a Department of Paediatrics , Haukeland University Hospital , Bergen , Norway.,b Center for Diabetes Research , University of Bergen , Bergen , Norway
| | - Friedemann Erchinger
- c Department of Clinical Medicine , University of Bergen , Bergen , Norway.,d Medical Department , Voss Hospital , Voss , Norway
| | - Trond Engjom
- c Department of Clinical Medicine , University of Bergen , Bergen , Norway.,e Medical Department , Haukeland University Hospital , Bergen , Norway
| | - Lage Aksnes
- f Department of Clinical Science , University of Bergen , Bergen , Norway
| | - Georg Dimcevski
- c Department of Clinical Medicine , University of Bergen , Bergen , Norway.,e Medical Department , Haukeland University Hospital , Bergen , Norway
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Iizuka Y, Yamashita K, Sakasegawa SI, Hanada T, Tani W, Adachi H, Haga R, Yamaguchi M, Kurotani W, Sekiguchi M, Osawa S, Hosogaya S, Kang D, Ueda S. Improvement and evaluation of a 1,2-dioleoylglycerol method for measuring pancreatic lipase catalytic activity in serum. Clin Chem Lab Med 2014; 52:e171-3. [DOI: 10.1515/cclm-2014-0316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 03/24/2014] [Indexed: 11/15/2022]
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Iizuka Y, Ueda S, Hanada T, Tani W, Adachi H, Haga R, Yamaguchi M, Kurotani W, Sekiguchi M, Kang D, Sakasegawa SI. 1,2-Dioleoylglycerol method for pancreatic lipase catalytic activity in serum. Clin Chem Lab Med 2011; 50:475-81. [PMID: 22126376 DOI: 10.1515/cclm.2011.811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 11/11/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND There is a need for a pancreatic lipase (LIP) reference assay to provide an accurate base to which routine methods can be traceable. METHODS This study developed a novel LIP assay method in which 1,2-dioleoylglycerol (DODG) is the substrate and LIP activity is measured in a coupled enzymatic reaction from the increase in absorbance at 340 nm with production of NADPH. RESULTS With this method, LIP activity was linear up to 440 U/L (8-times expected upper limit of physiological concentration). When assayed manually, the between-laboratory variation for six samples surveyed at five laboratories was 3.80-26.4% (CV) for samples containing about 20-290 U/L LIP activity; when assayed using an automated analyzer, the range was 1.86-4.86% (four laboratories). Interference by >5 mmol/L glycerol and low specificity with post-heparin samples were noted, but in practice these are avoidable. Precision analyzed by automated assay of 49 samples twice in random order produced a covariance of 2.27 U/L, which is comparable to routine methods, and good correlations were obtained with five routine methods. CONCLUSIONS Although further studies are required, the DODG method may be likely applicable as one candidate reference method.
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Lessinger JM, Parashou S, Arzoglou P, Ramos P, Chapus C, Dufaux J, Junge W, Profilis C, Férard G. Determination of lipase catalytic activity in two reference materials: BCR 693 and BCR 694 by titrimetry at constant pH. ACTA ACUST UNITED AC 2004; 42:62-6. [PMID: 15061382 DOI: 10.1515/cclm.2004.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractBecause routine assays for pancreatic lipase catalytic activity are not yet standardized, between-method comparability is very poor. This is mainly due to the lack of reference materials (RMs). The aim of this study was to assign values of catalytic concentration to two human pancreatic lipase RMs, one prepared from human pancreatic juice (BCR 693), the other obtained by recombinant technology (BCR 694). Lipase catalytic activity was assayed in five experienced laboratories, using aliquots from the same lot of triolein emulsion and a standardized titrimetric procedure, optimized with regard to substrate, cofactors and pH. The accepted sets of data (n=4) gave a mean ± the corresponding uncertainty expressed as the 0.95 confidence interval of 1732±72 U/l and 1043±60 U/l for BCR 693 and 694, respectively. Transferability of the whole operating procedure proved to be quite satisfactory. The authors conclude that both RMs can be used to verify the correct implementation of the standardized measurement procedure and to assign values to secondary lipase materials (commercial calibrators, control products) which, in turn, ensures traceability to the standardized procedure in this study, and contributes to the harmonization of laboratory results according to the Directive for in vitro Diagnostic Medical Devices.
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Affiliation(s)
- Jean-Marc Lessinger
- Laboratoire de Biochimie appliquée, Faculté de Pharmacie, Université Louis Pasteur, Illkirch, France.
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Lessinger JM, Arzoglou P, Ramos P, Visvikis A, Parashou S, Calam D, Profilis C, Férard G. Preparation and characterization of reference materials for human pancreatic lipase: BCR 693 (from human pancreatic juice) and BCR 694 (recombinant). Clin Chem Lab Med 2003; 41:169-76. [PMID: 12667003 DOI: 10.1515/cclm.2003.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is a lack of certified reference material (CRM) for lipase catalytic activity. Consequently between-method comparability is very poor. The aim of this study was to produce two lipase CRMs, one from human pancreatic juice (BCR 693), and another using recombinant technologies (BCR 694). Lipase was purified from pancreatic juice, using column chromatography and isoelectric focusing. Recombinant lipase was produced with a transfected cell line and purified with column chromatography. Adding buffered bovine serum albumin and subsequent freeze-drying were used to stabilize both materials. A standardized titrimetric method was employed to compare their catalytic properties to those of two plasma pools of patients suffering from acute pancreatitis. About 5 kU (titrimetry, 37 degrees C) of each material were obtained. They were lyophilized without apparent modifications of their catalytic properties, which stayed identical to those exhibited by the enzyme present in patient's pools. Stability of both materials was estimated at several years when stored in a dry form at -20 degrees C. Both materials appear to have similar catalytic properties and stability and were found commutable as regards a reference method and a routine measurement procedure. An international certification campaign will be carried out to assign values to BCR 693 and BCR 694.
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Affiliation(s)
- Jean-Marc Lessinger
- Laboratoire de Biochimie appliquée, UFR de Sciences Pharmaceutiques, Université Louis Pasteur, Illkirch, France.
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Cattozzo G, Franzini C, Melzi d’Eril G. Commutability of Calibration and Control Materials for Serum Lipase. Clin Chem 2001. [DOI: 10.1093/clinchem/47.12.2108] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Background: To effectively assess and correct for intermethod variability, calibration and control materials (CCMs) must show the same intermethod behavior as patient sera, i.e., they must be commutable. We describe the commutability of selected CCMs for lipase assays, the impact of noncommutability of CCMs in normalizing patient results, and characteristics of reagents that affect assay specificity and commutability.
Methods: Lipase was measured in 98 patient sera and in 29 commercial CCMs, with 2 commercial methods using different substrates and with 4 experimental methods using 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6′-methylresorufin) ester as substrate and colipase as cofactor, but differing in the stabilizing proteins used and in the size of the substrate micelles.
Results: The noncommutability rate, i.e., the frequency of aberrant intermethod behavior of CCMs in comparison with patient sera, was 27% for liquid CCMs and 47% for lyophilized CCMs. The normalized residuals, measuring the degree of noncommutability, were −2.3 to 2.4 for CCMs with “normal” lipase activity, and −3.5 to 21.7 for CCMs with higher lipase activity. Recalculation of patient results with CCMs as calibrators decreased or increased the original bias according to whether the CCMs were commutable.
Conclusions: For the lipase methods in this study, the frequency of noncommutability of CCMs is affected by assay-specific characteristics, including size of substrate micelles and the presence or absence of added proteins.
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Affiliation(s)
| | | | - Gianvico Melzi d’Eril
- Ospedale F. Del Ponte-A. O. Fondazione Macchi, 21100 Varese, Italy
- Universitèa dell’Insubria, 21100 Varese, Italy
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Abstract
Standardisation in clinical enzymology needs not only reference methods but also reference materials. While single-enzyme reference enzymes have been developed, a multienzyme certified reference material (MECRM) available in high amount remains to be produced. To transfer trueness from the value of the reference system to patients' results, validated enzyme calibrators (EC) are also needed. Both the MECRM and the ECs must exhibit the same catalytic properties as the corresponding enzymes in human plasma. Moreover, commutability of these materials with patients' samples must be experimentally tested for one or a set of methods defined by an analytical specificity equal to that of the reference method. Various experimental studies have shown that the commutability of an enzyme material depends on the source of enzyme and its purification process, the matrix (including cofactors, effectors, additives, stabilisers... ) and the mode of processing of the final material. To promote intermethod calibration in clinical enzymology, a collaborative programme between the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), Institute for Reference Materials and Measurements (IRMM, Geel, Belgium) and IFCC corporate members is in progress for the development of a MECRM containing amylase, ALT, AST, ALP, CK, GGT, LDH, and lipase and exhibiting a wide and defined commutability.
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Affiliation(s)
- G Férard
- Laboratoire de Biochimie Appliquée, UFR des Sciences Pharmaceutiques, Université Louis Pasteur de Strasbourg, Illkirch, France
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Férard G, Edwards J, Kanno T, Lessinger JM, Moss DW, Schiele F, Tietz NW, Vassault A. Interassay calibration as a major contribution to the comparability of results in clinical enzymology. Clin Biochem 1998; 31:489-94. [PMID: 9740971 DOI: 10.1016/s0009-9120(98)00038-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Factors contributing to the applicability of interassay calibration of methods measuring enzyme catalytic activities are described. Also discussed are the properties essential for such a material. Similarity of specificity for the methods to be calibrated as well as commutability between the material(s) intended to be used as calibrator are the main criteria to be satisfied. RESULT Several examples demonstrated that interassay calibration is feasible but a multi-enzyme calibrator with a wide commutability for the most popular methods remains to be developed. This is the project of the IFCC Working Group on Calibrators in Clinical Enzymology (WG-CCE). Several experimental data are also presented that indicate that the temperature at which the reaction is carried out is not a limiting factor in the implementation of interassay calibration in clinical enzymology.
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Affiliation(s)
- G Férard
- Laboratoire de Biochimie Appliquée, Faculté de Pharmacie, Université Louis Pasteur, Illkirch, France
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Férard G, Edwards J, Kanno T, Lessinger JM, Moss DW, Schiele F, Tietz NW, Vassault A. Validation of an enzyme calibrator--an IFCC guideline. International Federation of Clinical Chemistry. Clin Biochem 1998; 31:495-500. [PMID: 9740972 DOI: 10.1016/s0009-9120(98)00039-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The objective of this guideline is to improve standardization in clinical enzymology in order to improve intermethod comparability of patients' results. DESIGN AND METHODS The reference system, combination of the reference method and the reference material, is used to produce a reference value for a given catalytic activity. Sets of methods are formed of methods exhibiting the same analytical specificity. Materials intended to be used as enzyme calibrators are experimentally checked for their commutability. RESULTS The transfer of accuracy from the reference value to patients' results is dependent on methods (analytical specificity) and on materials (experimentally assessed commutability). The feasibility of this approach was demonstrated with materials of high level for several enzymes and for each of them for several routine methods. CONCLUSION Expected advantages of this approach in clinical enzymology are presented.
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Affiliation(s)
- G Férard
- Laboratoire de Biochimie Appliquée, Faculté de Pharmacie, Université Louis Pasteur, Illkirch, France
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Evaluations and Validations. Clin Chem Lab Med 1997. [DOI: 10.1515/cclm.1997.35.9.693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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