IgG4-related sclerosing cholangitis (IgG4-SC)

IgG4-related sclerosing cholangitis (IgG4-SC) is a rare, autoimmune disease that involves an inflammatory reaction of the bile duct and pancreatic duct system. It is often associated with autoimmune pancreatitis. Other organs and tissues such as the intestines, muscles and salivary glands can also be affected by an inflammatory reaction. In IgG4-SC, however, the walls of the bile ducts are primarily thickened by inflammation. The inflammation and bile stasis can lead to cirrhosis of the liver as the disease progresses.

Causes of IgG4-SC

The development of IgG4-SC is associated with long-term exposure (often occupational) to toxic substances (e.g. industrial gases and vapours, solvents, dyes, or oil products). IgG4-SC often occurs with autoimmune pancreatitis. Men are 8 times more likely to be affected by IgG4-SC than women. They are usually over 60 years old.


Typical symptoms such as jaundice and itching, but also non-specific signs such as weight loss, upper abdominal complaints, and digestive disorders due to pancreatic involvement can be observed. Fatty, soft stools floating on water and newly diagnosed diabetes mellitus may occur. The salivary and lacrimal glands are also more frequently affected by bacteria and can become swollen with inflammation. Additional complaints in the urinary and genital organs are reported. In addition to an increase in IgG4, the blood also shows signs of biliary stasis, which is characterised by an increase in alkaline phosphatase, gamma-GT and bilirubin. The liver values GOT (AST) and GPT (ALT) may also be slightly elevated. This also applies to the tumour marker CA19-9.


Diagnosis is not easy, as the symptoms are similar to primary and secondary sclerosing cholangitis, tumours of the biliary tract or pancreas. The HISORt criteria (Histology, Imaging, Serology, Organ, Response to steroid therapy) are followed to establish the diagnosis. In addition to blood samples, imaging (ultrasound, MRCP, endosonography) and, depending on the findings, tissue examination of the liver and pancreas are important measures. Tissue samples are assessed for infiltration of IgG4 cells, among other things. If the disease cannot be clearly diagnosed, immunosuppressants can be prescribed for 2-4 weeks. If the patient's condition improves significantly, this may be a sign of IgG4-SC. If not, other biliary tract diseases or malignant tumours should be ruled out.


IgG4-SC is always initially treated with immunosuppressive therapy with steroids (prednisone, prednisolone) for up to 3 months. In most cases, this therapy is successful. Otherwise, drugs such as azathioprine, mycophenolate mofetil or, rarely, anti-CD20 antibodies (e.g. rituximab) are used.


With adequate treatment, the chances of long-term survival are very high. However, narrowing of the bile duct may make surgery necessary.