Omalizumab is a humanized IgG1 monoclonal antibody against human IgE. It is approved by the FDA for the treatment of asthma. Omalizumab was shown to effectively deplete circulating IgE and decrease basophil action. In this study we propose to assess the safety of omalizumab in moderately active lupus patients and to assess its effect on circulating IgE autoantibodies and basophil activation. We will also collect preliminary data about its clinical efficacy.