UA + RBCs, protein; Urine microscopy w/rbc casts, dysmorphic RBCs; Serum: decline in GFR
Often renal bx required to make specific dx
Additional tests may include: c-anca (GPA); p-anca (MPA); ANA (SLE); anti ds-dna, anti-smibth ab (SLE); C3 and/or C4 (SLE, post-infectious, cryo, membranoprolif); anti-gbm ab; hep c (cryo); cryoglobulins (cryo); CH50 (post-infectious); RF (cryo); other based on history, exam, co-morbidities