Interference studies: focus on blood cell lysates preparation and testing

Hemolyzed specimens are the most frequent preanalytical problem and a serious challenge for clinical laboratories, inasmuch as the presence of intracellular components, cellular debris, and stroma in the test sample might influence the reliability of clinical chemistry, coagulation, and immunochemistry testing. The identification of reliable limits for establishing whether a certain degree of hemolysis in the specimen would produce a clinically significant bias in the test system is thereby crucial.

The aim of this article is to provide an overview of the current scientific literature about the available methods to lysate blood cells and their use in interference studies.

Several approaches have been proposed for producing the hemolysate (e.g., freezing and thawing the sample, lysis of whole blood by distilled water with or without detergents, sonication, passing the blood through a fine collection needle, stirring the blood with a metallic bar or applying the blade of a tissue homogenizer to the sample), and testing its interference.

A major standardization in the approaches for generating the hemolysate is needed in order to increase the comparability across interference studies and provide the laboratory community with transferable and thereby "usable" information. The methods able to produce a lysis of leukocytes and platelets other than erythrocytes should however be preferred, since they more reliably mirror the spurious hemolysis that is typically found in the specimens received in clinical laboratories.