Pancreatic lipase assays: time for a change towards immunoassays?

What is it about?

Lipase is a unique enzyme, where standardisation approaches cannot overcome all issues related to contemporary assays. Lipase acts at the interphase area between water and the substrate, whereby the cuvette surface plays a role in kinetic lipase assays. Cuvettes show important differences in chemical composition. Serum lipase activitiy not only depends on substrate and enzyme concentrations, but also on the composition of the cuvette. Since the chemical composition of the cuvette is determined by the choice of the analytical platform, inter-laboratory comparison of serum lipase results is difficult. Even when all standardisation issues would be solved, discrepant results remain when lipase assays are applied on different chemistry analyzers equipped with different cuvettes. The methodological variation may lead to incorrect interpretation. Serum may contain three enzymes showing lipolytic activity: L1 and L2 are pancreatic isoenzymes of lipase, and L3, pancreatic carboxyl ester lipase (cholesterol esterase). The presence of non-pancreatic isoforms reduces the specificity of current lipase assays as a pancreatic test. Although immunoassays are not perfect, the ELISA assays disappeared from the market when the colorimetric lipase methods were introduced. At that time, fast immunoassays were not yet available. The isoforms L1 and L2 are immunochemically distinct from L3, which increases specificity of lipase immunoassays. As colorimetric lipase assays are facing many analytical problems, we encourage manufacturers to use modern immunochemistry technology for the development of a reliable lipase immunoassay that provide clinicians with rapid high quality results.

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Photo by Rene Böhmer on Unsplash

Photo by Rene Böhmer on Unsplash