Background/Aims: Various side effects have been reported in patients t
reated with alpha interferon, but their incidence and prognosis remain
unknown, Methods: Nine hundred and eighty-seven patients with chronic
active hepatitis C received 6 to 10 MU of alpha interferon per day fo
r 2 weeks and 3 times per week for 22 weeks, Autoantibodies, thyroid f
unction tests, and fasting plasma glucose concentrations were evaluate
d prior to alpha interferon therapy, Results: Of the 987 patients, 310
were required reduction in the dose of alpha interferon to 3 MU/day o
r cessation of alpha interferon therapy because of adverse reactions s
uch as flu-like symptoms, leukopenia, and thrombocytopenia, Of the rem
aining 677, five developed diabetes mellitus, 12 had hyperthyroidism,
and six acquired hypothyroidism, Of the 18 with thyroid disorders, fiv
e demonstrated antimicrosomal antibodies before therapy, Forty-four pa
tients revealed high or low concentrations of thyroid stimulating horm
one at the end of alpha interferon therapy, Three patients developed i
nterstitial pneumonia, one acquired systemic lupus erythematosus-like
syndrome, two had autoimmune hepatitis, two developed rheumatoid arthr
itis, and one developed autoimmune thrombocytopenic purpura, No patien
ts had a history of an autoimmune disorder, One patient experienced su
dden hearing impairment and one had retinal detachment, Melena was see
n in three patients; two of these cases were compatible with ischemic
colitis, Symptoms of depression were seen in 23 patients, and one pati
ent manifested memory loss, Conclusion: High-dose alpha interferon the
rapy induces various adverse effects, Most of the side effects cannot
be predicted, but are reversible.