Hyperbilirubinemia in Born (Pigmented Hepatosis)

Hyperbilirubinemia in newborns (pigmentary hepatosis)

Hyperbilirubinemia is a group of hereditary diseases characterized by impaired bilirubin metabolism in the liver. As a result of this disorder, patients experience persistent or intermittent jaundice, while the liver does not have pronounced changes in structure and function, and there are no signs of hemolysis and cholestasis.

All forms of hyperbilirubinemia appear from early childhood, their symptoms can be intermittent and intensify under the influence of various factors, such as nutrition, alcohol intake, intercurrent illnesses and physical fatigue. Dyspeptic symptoms, mild asthenia, weakness and fatigue are common.

Hyperbilirubinemia is caused by a violation of the processes of capture of free bilirubin from the blood by hepatocytes, binding it with glucuronic acid to form bilirubin glucuronide (bound bilirubin) and its subsequent release into bile.

There are several forms of hyperbilirubinemia, each of which has its own characteristics in the manifestation of symptoms and type of inheritance.

Gilbert's syndrome (juvenile intermittent jaundice, Meulengracht's syndrome) develops due to a decrease in the ability of liver cells to capture and bind bilirubin. It is characterized by a moderate intermittent increase in the content of unconjugated (indirect) bilirubin in the blood, the absence of other functional or morphological changes in the liver, and an autosomal dominant type of inheritance. The main manifestation of the disease is yellowness of the sclera, and less commonly of the skin, which appears at the age of 20 years and older.

Crigler-Najjar syndrome type I is characterized by an extremely high level of free (indirect) bilirubin in the blood due to the absence of glucuronyl transferase in hepatocytes, which converts free bilirubin into bound bilirubin. This causes a toxic effect of bilirubin on the basal and brain stem nuclei, which can lead to the development of encephalopathy and often leads to death in childhood. This form has an autosomal recessive mode of inheritance. Neurological manifestations include increased muscle tone, nystagmus, opisthotonus, athetosis, tonic and clonic seizures; respiratory and cardiac arrest are also typical.

Crigler-Nayjar syndrome type II is caused by a deficiency of the membrane transporter responsible for the removal of conjugated bilirubin from hepatocytes into the bile ducts. This leads to the accumulation of conjugated bilirubin in the liver and its insufficient excretion in bile, which causes permanent jaundice of the skin and sclera. This form also has an autosomal recessive mode of inheritance.

Dabin-Johnson and Rotor syndrome are characterized by the presence of congenital defects that lead to impaired excretion of conjugated bilirubin from the liver and its retention in hepatocyte cells. These forms are inherited in an autosomal recessive manner and manifest as icterus, which may become permanent.

Treatment of hyperbilirubinemia involves following a diet that excludes foods that increase bilirubin levels, as well as taking medications that can bind bilirubin and help remove it from the body. In some cases, a liver transplant may be required.