Bilirubin analysis—The state of the art and future prospects

Enzymatic assay for conjugated bilirubin (Bc) in serum using bilirubin oxidase (BOD)

“…Recently, the fractional assay of bilirubins has been widely used as a clinical assay test using the HPLC method or the Ektachem (now called Vitros) system, because the significance of clinical findings with β-, γ-and δ-fractions has been reported by several groups (1,(5)(6)(7)(8).…”

“…Bδ, expressed as a percentage for T-Bil, always fails to rise above 30 to 40% during unresolved hepatic failure (6). In such cases, Bc often remains above 50% of T-Bil until or near the death of the patient (1). The correlations between Bδ/T-Bil and/or Bc/T-Bil and state of disease are more apparent when the bilirubin fractions are plotted as percentages for T-Bil than as absolute concentrations (1,5,6).…”

“…Indirect bilirubin is obtained by subtracting the value of D-Bil from that of T-Bil. Previously, it has been found that indirect bilirubin (I-Bil) corresponds to unconjugated bilirubin (Bu), and D-Bil, to conjugated bilirubin (Bc) (1). However, Bu and Bδ react in small amounts with diazo reagent in direct assay, and some observations have been also reported with other methods such as the BOD and vanadate methods (1)(2)(3)(4).…”

“…Previously, it has been found that indirect bilirubin (I-Bil) corresponds to unconjugated bilirubin (Bu), and D-Bil, to conjugated bilirubin (Bc) (1). However, Bu and Bδ react in small amounts with diazo reagent in direct assay, and some observations have been also reported with other methods such as the BOD and vanadate methods (1)(2)(3)(4). In terms of clinical significance, values of Bc and Bδ are better indicators of liver function than are the values of D-Bil, T-Bil, and hepatic enzymes such as AST and ALP (1,(5)(6)(7)(8).…”

Long-Term Extracorporeal Bilirubin Elimination: A Case Report on Cascade Resin Plasmaperfusion

“…The inability to lower bilirubin further may be due to the relative balance between bilirubin synthesis, redistribution and extracorporeal elimination. Another explanation for this incomplete elimination may be that only negatively charged, hydrophilic ß-and Á-bilirubin fractions are quantitatively bound by BR-350 resin filters [37]. The lipophilic ‰-bilirubin fraction remains covalently bound to albumin [16] and demonstrates only low affinity resin binding.…”