This study will collect white blood cells or plasma (the liquid part of the blood), or both, from healthy volunteers and from patients with rheumatic or kidney disorders for research purposes. Rheumatic disorders involve abnormalities of the immune system, the body s defense against disease. The immune system consists of white blood cells such as lymphocytes and monocytes, which produce substances such as antibodies and cytokines. White cells and plasma will be collected through a procedure called apheresis (described below).