Delayed Liver Function Impairment Secondary to Interferon β-1a Use in Multiple Sclerosis
A 43-year-old Taiwanese woman had right optic neuritis in 2001. Her second attack, with brain stem encephalitis, developed in April 2007. Cranial MRI studies at that time showed multiple periventricular and right paramedian pontine white matter lesions which fitted the criteria of dissemination in space according to the McDonald criteria []. Her IgG index was 0.65; oligoclonal bands were not found in the cerebrospinal fluid. Autoimmune factors such as anti-SSA/SSB antibody, antinuclear antibody, and rheumatoid factor were within the normal ranges. Since she did not have acute myelitis, which is one of the absolute diagnostic criteria of NMO [], she did not receive an anti-AQP4 antibody test. She received interferon β-1a (Rebif 44 μg subcutaneous injection 3 times a week) under the diagnosis of multiple sclerosis starting in January 2007. Results of liver function tests in November 2007 were within the normal ranges: ALT 33 U/l and AST 22 U/l. Concomitant medications during this period were baclofen 10 mg twice a day and zolpidem 10 mg before sleep. However, follow-up liver function tests in July 2012 showed impaired liver function: AST 93 U/l (6.8 × ULM); ALT 251 U/l (7.4 × ULM); amylase 636 [6.4 × ULM (<100 U/l)]; r-GT 73 U/l, and total bilirubin 0.8 mg/dl. She did not have any clinical symptoms like malaise or jaundice. She also denied any alcoholic intake and taking any other medication during this period. Rebif was reduced to 22 μg 3 times a week. Detailed hepatological evaluation was also started. Results of hepatitis markers (HBsAg and anti-HCV antibody) and autoimmune titers (antinuclear antibody and anti-mitochondrial antibody) were within normal ranges. She only had mild elevated anti-smooth muscle antibody tilter (1:80). Further abdominal computed tomography scan studies only showed a slight predominance of periportal fat raising suspicion of inflammatory change. Her liver function improved a little after reducing the interferon dose [November 2012: AST 84 U/l (2.5 × ULM); ALT 92 U/l (2.6 × ULM)]. Interferon was discontinued in January 2013 due to the persistently elevated liver function tests. The results of her liver function test then returned into normal ranges (February 2013: AST 35 U/l; ALT 36 U/l), and interferon treatment was not resumed this time. The RUCAM scale for this patient after receiving interferon treatment is 7.