The purpose of this study is to examine hormonal and environmental risk factors (and possible gene-environmental interactions) involved in the etiology of lupus nephritis. Our study will focus on exposures to occupational and environmental agents that have been linked to the development of systemic lupus erythematosus (SLE) or renal disease (e.g., silica dust, smoking). We will also assess potential gene environment interactions. We will examine these exposures in 100 patients with renal biopsy with documented proliferative or membraneous nephritis. We will compare exposures in the lupus nephritis patients to lupus patients who do not have nephritis and to normal controls who have participated in the Carolina Lupus Study. One hundred lupus nephritis patients (age 18 years or older, of both genders and all races) will be identified through the Glomerular Disease Collaborative Network (GDCN) Nephropathology database and participating nephrologists at the Medical University of South Carolina, Duke University Medical Center and the East Carolina Medical School.