Effect of interferon α on calcium and bone metabolism in patients with chronic hepatitis

We investigated the changes of natural type of interferon-α (IFNα) on calcium and bone metabolism in patients with chronic hepatitis C. Natural IFNα was injected intramuscularly at daily doses of 6 million units for 2 weeks to 10 patients with chronic hepatitis caused by hepatitis C virus, and followed by 3-times-a-week administration for another 10 weeks. The markers for bone metabolism including serum bone-Gla protein (BGP) concentration and urinary excretion of pyridinolines (pyridinoline and deoxypyridinoline) were measured before and during the treatment. The twelve-week administration of IFNα reduced pyridinoline excretion from 39.7±13.3 (SD) pmol/µ mol · creatinine to 28.3±8.1 pmol/µ mol · creatinine (p<0.06), and that of deoxypyridinoline from 6.51±3.38 pmol/µ mol · creatinine to 3.91±2.07 pmol/µ mol · creatinine (p<0.01), although serum levels of BGP and parathyroid hormone (PTH) did not show any significant changes. The ratio of BGP/urinary pyridinoline increased from 0.098±0.074 to 0.198±0.093 at the end of 12th week (p<0.03), and that of BGP/deoxypyridinoline increased from 0.630±0.502 to 1.550±0.788 at 12th week (p<0.02). Serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) did not change significantly during the study. IFNα reduces bone resorption in contrast with insignificant effects on bone formation in patients with mild to moderate hepatitis. The effects on calcium and bone metabolism may give beneficial effects for patients with high turnover osteoporosis.