 The objective of this study is to evaluate the safety and tolerability of pegylated interferon alpha-2b PEG-Intron in patients with severe complications related to Hereditary Hemorrhagic Telangiectasia HHT. Participants will be randomized to the treatment arm or control arm and then crossed over to the alternate arm at 6 months for the remainder of the 12-month study. Study treatment will consist of weekly subcutaneous injections of pegylated interferon alpha-2b PEG-Intron, 1 microgramkilogramweek. Adverse events as well as monitoring and treatment of toxicities will be followed as stated in the protocol. Adverse events will be graded according to the Modified NCI Common Toxicity Criteria. After every five participants have completed one month of treatment, an independent data safety monitoring board will review any adverse events. 