Secondary hyperparathyroidism exacerbation: a rare side-effect of interferon-alpha?

Recombinant human interferon alpha (alpha IFN) is the only treatment with p roven benefit for chronic hepatitis C virus (HCV) infection. Nevertheless i ts use in some susceptible individuals has led to the development or aggrav ation of different autoimmune conditions. We report the case of a 20 year o ld woman on peritoneal dialysis with chronic lobular hepatitis secondary to HCV infection who developed de novo psoriasis 9 months after starting trea tment with alpha-IFN. In addition to psoriasis, alpha-IFN prescription was also concurrent with an unexpected and refractory secondary hyperparathyroi dism exacerbation initially characterized by a marked reduction of serum ca lcium levels and a consequential increase of PTH. Both complications disapp eared after drug withdrawal. The clinical sequence makes an alpha-IFN-induc ed autoimmune side effect the most plausible hypothesis. The case is discus sed and some possible etiopathogenic factors are briefly reviewed.