Immune cells are an important part of the abnormal autoimmune response in SLE. The B cell is a significant part of this autimmune response because it produces the antibodies which can react with normal tissue of the body. B cells have the ability to accumulate and promote the development of SLE. The purpose of this study is to determine how B cell subsets and autoantibodies are related to disease remission after rituximab treatment in subjects with SLE.