Avaliação da interferência da luz na quantificação da bilirrubina: uma revisão da literatura

Abstract

The determination of bilirubin is part of a basic panel of tests that assess liver function. Hyperbilirubinemia can occur due to defects in bilirubin metabolism resulting in jaundice, which can occur at each stage of the metabolic pathway. Neonatal hyperbilirubinemia is a clinical condition found very frequently and affects approximately 60% of healthy babies and may develop severe hyperbilirubinemia. Bilirubin is a yellow photosensitive pigment that is produced by the body when red blood cells are degraded. Therefore, to avoid falsely altered results, the sample that will be used to determine bilirubin must be protected from light. Given the above, the purpose of this work was to perform a literature review on the evaluation of the interference of the direct action of ambient light in the quantification of total and direct bilirubin samples, since they can be photooxidized. For this, 13 scientific articles were analyzed, after searching the following databases: PubMed, Scielo and Sciencedirect, and the descriptors used during the research: “bilirubin test”, “bilirubin quantification”, “bilirubin determination”, and “stability” and "light protection" and "storage". After selection by title, summary and full reading of the articles, 2 papers were included, in which a decrease in concentrations in total bilirubin and direct bilirubin due to photodegradation was observed. Articles that evaluated the stability of biochemical analytes in tubes with or without barrier gel were excluded, articles dealing with the stability of biochemical tests under different conditions of temperature and centrifugation time, and a literature review on the stability of analytes in different storage temperature conditions. In summary, the results found in this review of the literature demonstrated that the samples suffered a reduction in their serum bilirubin concentrations when exposed to light. Therefore, an inappropriate pre-analytical phase can cause a false result.