RETINAL COMPLICATIONS WITH ELEVATED CIRCULATING PLASMA C5A ASSOCIATEDWITH INTERFERON-ALPHA THERAPY FOR CHRONIC ACTIVE HEPATITIS-C

Retinal hemorrhage is a complication of interferon therapy of unknown pathogenesis. We report two chronic active hepatitis C patients who de veloped retinal hemorrhage and/or cotton wool patches during interfero n-a therapy 4 and 12 wk after beginning treatment. At the time of the hemorrhage, plasma-activated complement 5, a known potent intravascula r aggregator of granulocytes, increased to 54 ng/ml in one patient and to 29 ng/ml in the other patient. When the hemorrhage resolved, it de creased to under 5 ng/ml. Our cases suggest that complement activation occurs in patients treated with interferon-cu and that activation of complement 5 can lead to retinal capillary infarction and retinal hemo rrhage. High levels of activated complement 5 may predict retinal arte ry infarction or perhaps microvascular emboli in the other organs.