To observe the efficacy and safety of atorvastatin on xanthoma in Alagille syndrome through a prospective study.

Alagille syndrome (ALGS, OMIM 118450) is an important cause of chronic cholestasis in children, and the incidence rate is about 1:30000~1:50000. Most patients with ALGS have hypercholesterolemia. In severe cases, multiple xanthomas can be seen, and some patients are accompanied by severe itching and pain. Disfigured xanthomas affect the normal social interaction of patients, thereby causing physical and mental damage to children. At present, xanthoma caused by hypercholesterolemia can be cured by treating the primary disease, taking lipid-lowering drugs (such as bile acid chelators, ezetimibe, statins, etc.), or lipoprotein apheresis. If it affects the beauty or function, local treatment such as 33% trichloroacetic acid dot coating, carbon dioxide laser, liquid nitrogen freezing or surgical resection is feasible, and even surgical operation( such as portal vena cava anastomosis, liver transplantation). Compared with expensive lipoprotein apheresis and other invasive therapies, taking lipid-lowering drug has the advantages of higher acceptance, lower cost and higher safety. However, at present, there are no guidelines for application of oral lipid-lowering drugs in children under 6 years old with hypercholesterolemia. Therefore, the purpose of this study is to clarify the safety and efficacy of atorvastatin on xanthoma in ALGS , so as to provide reference for the treatment of ALGS patients' xanthomas.

Risk prevention and treatment: The patients began to take atorvastatin from a small dose, followed up closely in the early stage (2-4 weeks) to see if the patients had obvious discomfort such as myalgia, and monitored the changes of Biochemistry (CK, ALT, AST, etc.). If moderate or more serious adverse reactions occurred during the trial or the following laboratory abnormalities occurred (CK exceeded 10 times the upper limit of normal; ALT or AST had been continued to rise, exceeding 2 times the baseline value), atorvastatin was temporarily stopped, and patients should be rechecked within 2 weeks. It is necessary to reevaluate and decide whether to restart atorvastatin treatment.

Inclusion Criteria:

• Meet the ALGS diagnostic criteria;
• Xanthoma of skin;
• Before treatment with atorvastatin,non-HDL-C≥5.76mmol/L（223 mg/dL）;
• Informed consent;
• Age 0-17 years old, male or female;
• Taking bile acid chelator (colenemide) has no obvious effect or intolerance.

Exclusion Criteria:

• Liver transplantation has been performed;
• In the recovery period of cholestasis, xanthoma is obviously subsiding;
• Patients with serious systemic diseases and unstable vital signs;
• Progressive active liver injury, such as continuous increase of transaminase;
• Serious myopathy;
• Known to be allergic to any component of atorvastatin;
• The weight is less than 5kg.