title: The natural history of interferon-α induced thyroiditis in chronic hepatitis c patients: a long term study.
abstract: BACKGROUND
  Autoimmune thyroid disease is a common complication of patients with chronic hepatitis C undergoing combination pegylated interferon-α and ribavirin treatment. A small proportion develops interferon-induced thyroiditis of which the long term natural history is unknown and how it compares with de novo thyroiditis. The aim of the study is to determine the natural history of thyroid disease including antibody profile in this particular setting 36 months from the completion of therapy.
  
  
  METHODS
  A cohort of 18 hepatitis C patients (mean age 45 ± 8 years (standard deviation)) who developed exclusively thyroiditis in this setting was followed every 12 months after the completion of therapy for 36 months. Investigations included thyrotropin, free tetra-iodothyronine, free tri-iodothyronine levels and thyroid autoantibodies.
  
  
  RESULTS
  None of the patients developed any long term thyroid disease. Two patients had a prolonged hypothyroid phase of the thyroiditis early after the completion of treatment but recovered fully. The remaining 16 patients remained euthyroid. Similarly, thyroid autoantibodies all declined and returned to reference range.
  
  
  CONCLUSIONS
  The long term natural history in this small series of interferon induced thyroiditis was benign. If a larger series confirms a similar outcome then there is no long term residual effect on thyroid function and follow-up testing would not be warranted.
authors.affiliation: Hunter Area Pathology Service and University of Newcastle, Locked Bag Number 1, Hunter Mail Region Centre, Newcastle, New South Wales 2310, Australia.
authors.forename: Huy A
authors.initials: HA
authors.lastname: Tran
authors.affiliation: Hepatitis C Service, Gastroenterology Department, John Hunter Hospital and University of Newcastle, Locked Bag Number 1, Hunter Mail Region Centre, Newcastle, New South Wales 2310, Australia.
authors.forename: Tracey L
authors.initials: TL
authors.lastname: Jones
authors.affiliation: Hepatitis C Service, Gastroenterology Department, John Hunter Hospital, Locked Bag Number 1, Hunter Mail Region Centre, Newcastle, New South Wales 2310, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Ianna
authors.affiliation: Hunter Area Pathology Service and University of Newcastle, Locked Bag Number 1, Hunter Mail Region Centre, Newcastle, New South Wales 2310, Australia.
authors.forename: Glenn Em
authors.initials: GE
authors.lastname: Reeves