Measurement and clinical usefulness of bilirubin in liver disease

Abstract

Elevated plasma bilirubin levels are a frequent clinical finding. It can be secondary to alterations in any stage of its metabolism: (a) excess bilirubin production (i.e., pathologic hemolysis); (b) impaired liver uptake, with elevation of indirect bilirubin; (c) impaired conjugation, prompted by a defect in the UDP-glucuronosyltransferase; and (d) bile clearance defect, with elevation of direct bilirubin secondary to defects in clearance proteins, or inability of the bile to reach the small bowel through bile ducts. A liver lesion of any cause reduces hepatocyte cell number and may impair the uptake of indirect bilirubin from plasma and diminish direct bilirubin transport and clearance through the bile ducts. Various analytical methods are currently available for measuring bilirubin and its metabolites in serum, urine and feces. Serum bilirubin is determined by (1) diazo transfer reaction, currently, the gold-standard; (2) high-performance liquid chromatography (HPLC); (3) oxidative, enzymatic, and chemical methods; (4) direct spectrophotometry; and (5) transcutaneous methods. Although bilirubin is a well-established marker of liver function, it does not always identify a lesion in this organ. Therefore, for accurate diagnosis, alterations in bilirubin concentrations should be assessed in relation to patient anamnesis, the degree of the alteration, and the pattern of concurrent biochemical alterations.

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“…More stable ALP activity and concentrations of bilirubin fractions when using Xymedon and its conjugate with L-ascorbic acid, especially on day 10 of the experiment, testify to the fact that under the influence of these compounds, either the activity of undamaged hepatocytes increased or the necrotic damage to the organ in general decreased, so the metabolism of bilirubin passes in the liver 18 . The decrease in the concentrations of total protein and albumin noted in our experiment against the background of exposure to a toxicant looks quite logical since a decrease in synthetic liver function is observed in liver parenchyma damage 19 . As follows from the data obtained, when using Xymedon and its conjugate with L-ascorbic acid, the preservation of synthetic liver function or intensification of such processes in undamaged hepatocytes is observed.…”

Association of per- and polyfluoroalkyl substance exposure with fatty liver disease risk in US adults

“… [44] , [45] , [46] These paradoxical observations require further studies into the interplay of PFAS, inflammation, immunity, oxidative stress, and steatosis. 47 In vitro data may provide useful and complementary insights in this regard.…”

Association between congenital heart disease and parenteral nutrition–associated liver disease in neonates: A retrospective cohort study

“…Second, we assessed the impact of requiring more than one laboratory test at a given threshold. A single spurious laboratory value could introduce bias, and bilirubin testing is known to be subject to measurement variance 28 . We evaluated thresholds of two or more and three or more values at or above a particular bilirubin threshold to be classified as having PNALD; in these cases, the “event” date used by the Cox model represented the second or third date the threshold was met, resulting in 12 total combinations.…”