Lupus nephritis is one manifestation of systemic problems related to immune complex deposition, including fever, arthralgias, myalgias, pancytopenia, and serositis with pericarditis and pleuritis, which are characteristic of systemic lupus erythematosus (SLE). Renal disease is common in SLE, and a renal biopsy helps to determine the severity of involvement and the appropriate therapy. Anti-centromere antibody is most specific for limited scleroderma (formerly CREST syndrome), which is unlikely to have renal involvement. Anti-DNA topoisomerase I antibody is more specific for diffuse scleroderma, which does have renal involvement, although usually, this manifests as vascular disease and not as glomerulonephritis. The anti-glomerular basement membrane antibody is characteristic of Goodpasture syndrome, in which the IgG antibody is deposited in a linear fashion along glomerular capillary basement membranes. Anti-histone antibody may be present in drug-induced lupus. ANCAs can be seen in some forms of vasculitis, such as ANCA-associated granulomatous vasculitis or microscopic polyangiitis. Antiribonucleoprotein is present in mixed connective tissue disease, which has some features of SLE but usually does not include severe renal involvement.