What is Idiopathic Neonatal Hepatitis?

Idiopathic neonatal hepatitis (INH) or Idiopathic neonatal cholestasis is a general term for inflammation of the liver leading to poor bile flow and pathologic jaundice (cholestasis, or cholestatic jaundice) without an identifiable cause.  This pathologic jaundice is different than the jaundice that commonly occurs in babies and naturally goes away with time or with light therapy.  Pathologic jaundice in a baby can be due to several causes including:

• Obstructive causes, such as biliary atresia, gall stones, or abnormal cysts in the liver
• Genetic causes that can be passed on to children by their parents, such as in Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC)
• Infectious causes, such as cytomegalovirus (CMV), congenital syphilis, echovirus, and some herpes viruses
• Metabolic causes, such as alpha-1 antitrypsin deficiency, cystic fibrosis (CF), respiratory chain defects, fatty acid oxidation defects, or one of many other possible disorders

When doctors test for all of these things but still can’t find the reason for the inflammation, they diagnose the problem as INH.

What are the symptoms?

The symptoms of INH can vary greatly from one person to another.  Infants with INH may have jaundice as their only symptom. This usually occurs in the first two weeks of life and can last up to the third month of life.  Infants may also have dark urine, an enlarged liver, and pale-colored stools from the lack of bile. Other symptoms may also include poor growth, irritability, and/or itching.

How is it diagnosed?

INH is considered a “diagnosis of exclusion”, which means that it is diagnosed only because other known causes of liver disease have been excluded.  The greatest challenge in diagnosing INH is in making sure other neonatal liver diseases with known causes are not the cause of the liver disease.  Doctors will run tests to rule out obstructive, metabolic, infectious, and genetic causes of the liver problems they see.  These include blood tests, scans of the liver and bile ducts, genetic testing and, often, liver biopsy.  If biopsy results show that the liver cells are enlarged but no specific cause is found after all testing is completed, doctors might diagnose INH. 

How is it treated?

Since there is no known cause of INH, treatment is focused on managing symptoms and providing good nutritional support. This includes medications to stimulate bile flow (ursodeoxycholic acid), predigested (“elemental”) formulas with fats that can be more easily digested in babies with liver disease, and extra vitamins A, D, E, and K.

What is the outlook for infants diagnosed with INH?

Most infants diagnosed with INH recover fully from the condition. As doctors have discovered new diseases that cause liver problems in babies over the years, the number of cholestatic infants diagnosed with INH has decreased. This is because some babies that may have been diagnosed with INH in the past may now be given a diagnosis with a recently discovered disease (instead of calling their undiagnosed disease “INH”).  In the future we expect that number to continue to decrease as doctors learn more about cholestasis in babies.

Does the ChiLDReN Network have any studies that include patients with INH?

Yes.  The ChiLDReN Network currently has one study that includes patients with INH.

The PROBE study is a natural history study that includes patients with INH.  A natural history study is aimed at acquiring information and data over a period of time and will provide a better understanding of rare conditions. Participants will be asked to allow study personnel to obtain information from medical records and an interview, and to collect blood, urine, and tissue samples when they are also being taken for medical care, in order to understand the causes of these diseases and to improve the diagnosis and treatment of children with these diseases. All of the information obtained in these studies is confidential and no names or identifying information are used in the study.

PROBE: A prospective study of infants and children with cholestasis.

Eligibility: Infants up to 6 months of age that have been diagnosed with cholestasis (direct hyperbilirubinemia).

ClinicalTrials.gov Study NCT00061828

Are there any organizations or foundations that help families dealing with INH?

Yes.  The ChiLDReN Network works with numerous groups that support patients and families who are dealing with rare liver diseases.  Please click here to go to that page on our website (Information for Families).  You will see the list of groups and information about them.