Circulating ANCA as defined by the presence of antibodies detectable by indirect immunofluorescence performed by the NIH Clinical Immunology laboratory at a titer of greater than or equal to 1:40 on two determinations done at least 4 weeks apart. Patients who are historically ANCA positive and become ANCA negative during remission induction will be eligible if they again become positive to a level of greater than or equal to 1:40 on two determinations done at least 4 weeks apart at a prednisone dose of less than or equal to 50mg QOD or within 6 months following the discontinuation of prednisone.