Invasive bilirubin measurements remain the gold standard for the diagnosis and treatment of infants with severe neonatal hyperbilirubinemia. The present paper describes different methods currently available to assess hyperbilirubinemia in newborn infants. Novel point-of-care bilirubin measurement methods, such as the BiliSpec and the Bilistick, would benefit many newborn infants, especially in low-income and middle-income countries where the access to costly multi-analyzer in vitro diagnostic instruments is limited. Total serum bilirubin test results should be accurate within permissible limits of measurement uncertainty to be fit for clinical purposes. This implies correct implementation of internationally endorsed reference measurement systems as well as participation in external quality assessment programs. Novel analytic methods may, apart from bilirubin, include the determination of bilirubin photoisomers and bilirubin oxidation products in blood and even in other biological matrices. IMPACT: Key message: Bilirubin measurements in blood remain the gold standard for diagnosis and treatment of severe neonatal hyperbilirubinemia (SNH). External quality assessment (EQA) plays an important role in revealing inaccuracies in diagnostic bilirubin measurements. What does this article add to the existing literature? We provide analytic performance data on total serum bilirubin (TSB) as measured during recent EQA surveys. We review novel diagnostic point-of-care (POC) bilirubin measurement methods and analytic methods for determining bilirubin levels in biological matrices other than blood. Impact: Manufacturers should make TSB test results traceable to the internationally endorsed total bilirubin reference measurement system and should ensure permissible limits of measurement uncertainty.

• MeSH
• bilirubin krev   MeSH
• biologické markery krev   MeSH
• lidé MeSH
• novorozenec MeSH
• novorozenecká hyperbilirubinemie krev   diagnóza   terapie   MeSH
• novorozenecká žloutenka krev   diagnóza   terapie   MeSH
• novorozenecký screening * MeSH
• point of care testing * MeSH
• prediktivní hodnota testů MeSH
• prognóza MeSH
• reprodukovatelnost výsledků MeSH
• stupeň závažnosti nemoci MeSH
• upregulace MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• bilirubin MeSH
• biologické markery MeSH

Neonatal hyperbilirubinemia or jaundice is associated with kernicterus, resulting in permanent neurological damage or even death. Conventional phototherapy does not prevent hyperbilirubinemia or eliminate the need for exchange transfusion. Here we investigated the potential of therapeutic bile acids ursodeoxycholic acid (UDCA) and obeticholic acid (OCA, 6-α-ethyl-CDCA), a farnesoid-X-receptor (FXR) agonist, as preventive treatment options for neonatal hyperbilirubinemia using the hUGT1*1 humanized mice and Ugt1a-deficient Gunn rats. Treatment of hUGT1*1 mice with UDCA or OCA at postnatal days 10-14 effectively decreased bilirubin in plasma (by 82% and 62%) and brain (by 72% and 69%), respectively. Mechanistically, our findings indicate that these effects are mediated through induction of protein levels of hUGT1A1 in the intestine, but not in liver. We further demonstrate that in Ugt1a-deficient Gunn rats, UDCA but not OCA significantly decreases plasma bilirubin, indicating that at least some of the hypobilirubinemic effects of UDCA are independent of UGT1A1. Finally, using the synthetic, non-bile acid, FXR-agonist GW4064, we show that some of these effects are mediated through direct or indirect activation of FXR. Together, our study shows that therapeutic bile acids UDCA and OCA effectively reduce both plasma and brain bilirubin, highlighting their potential in the treatment of neonatal hyperbilirubinemia.

• MeSH
• bilirubin krev   MeSH
• ileum účinky léků   metabolismus   MeSH
• isoxazoly farmakologie   MeSH
• játra účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyselina chenodeoxycholová analogy a deriváty   terapeutické užití   MeSH
• kyselina ursodeoxycholová terapeutické užití   MeSH
• myši MeSH
• novorozenecká hyperbilirubinemie krev   farmakoterapie   MeSH
• potkani Gunn MeSH
• receptory cytoplazmatické a nukleární agonisté   metabolismus   MeSH
• výsledek terapie MeSH
• žlučové kyseliny a soli terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bilirubin MeSH
• farnesoid X-activated receptor MeSH Prohlížeč
• GW 4064 MeSH Prohlížeč
• isoxazoly MeSH
• kyselina chenodeoxycholová MeSH
• kyselina ursodeoxycholová MeSH
• obeticholic acid MeSH Prohlížeč
• receptory cytoplazmatické a nukleární MeSH
• žlučové kyseliny a soli MeSH

BACKGROUND: Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced neurological damage and eventually death by kernicterus. Bilirubin neurotoxicity is characterized by a wide array of neurological deficits, including irreversible abnormalities in motor, sensitive and cognitive functions, due to bilirubin accumulation in the brain. Despite the abundant literature documenting the in vitro and in vivo toxic effects of bilirubin, it is unclear which molecular and cellular events actually characterize bilirubin-induced neurodegeneration in vivo. METHODS: We used a mouse model of neonatal hyperbilirubinemia to temporally and spatially define the response of the developing cerebellum to the bilirubin insult. RESULTS: We showed that the exposure of developing cerebellum to sustained bilirubin levels induces the activation of oxidative stress, ER stress and inflammatory markers at the early stages of the disease onset. In particular, we identified TNFα and NFKβ as key mediators of bilirubin-induced inflammatory response. Moreover, we reported that M1 type microglia is increasingly activated during disease progression. Failure to counteract this overwhelming stress condition resulted in the induction of the apoptotic pathway and the generation of the glial scar. Finally, bilirubin induced the autophagy pathway in the stages preceding death of the animals. CONCLUSIONS: This study demonstrates that inflammation is a key contributor to bilirubin damage that cooperates with ER stress in the onset of neurotoxicity. Pharmacological modulation of the inflammatory pathway may be a potential intervention target to ameliorate neonatal lethality in Ugt1 -/- mice.

• Klíčová slova
• Apoptosis, Astrocytes, Autophagy, Crigler-Najjar syndrome, ER stress, Microglia, Oxidative stress, Ugt1a1,
• MeSH
• degenerace nervu etiologie   metabolismus   patologie   MeSH
• glukuronosyltransferasa nedostatek   MeSH
• modely nemocí na zvířatech MeSH
• mozeček patologie   MeSH
• myši knockoutované MeSH
• myši MeSH
• novorozená zvířata MeSH
• novorozenecká hyperbilirubinemie komplikace   patologie   MeSH
• zánět etiologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glukuronosyltransferasa MeSH
• UGT1A1 enzyme MeSH Prohlížeč