Serum analysis often aids in the diagnosis of a specific underlying disease. The presence of anti-glomerular basement membrane (GBM) antibodies suggests type I<unk> ; antinuclear antibodies (ANA) may support a diagnosis of systemic lupus erythematosus and type II<unk> ; and type III and idiopathic<unk>  are frequently associated with anti-neutrophil cytoplasmic antibodies (ANCA)-positive serum. Impaired kidney function in an individual who has had the condition for fewer than three months is characteristic of<unk> . An ultrasonographic examination of the abdomen should be obtained. Although the presence of sediment in the urine on examination can indicate proliferative glomerulonephritis, many cases of<unk>  need a renal biopsy to make a diagnosis. Classification Crescentic glomerulonephritis<unk>  can be classified into three types, based upon the immunofluorescence patterns: Type I Accounting for approximately 20% of<unk> , type I<unk> , also called anti-GBM glomerulonephritis, is characterized by the presence of autoantibodies directed against type IV collagen (specifically, the noncollagenous region of its α3 chain) in the glomerular basement membrane (GBM). Some cases are associated with antibodies directed against the basement membrane of lung alveoli, producing Goodpasture syndrome. The majority of type I disease, however, features anti-GBM antibodies alone; these cases are considered idiopathic. Type II Characterized by deposition of immune complexes in glomerular tissues, type II<unk>  accounts for 25% of cases. Any immune complex disease—including systemic lupus erythematosus, acute proliferative glomerulonephritis, Henoch–Schönlein purpura, and IgA nephropathy—that involves the glomerulus may progress to<unk>  if severe enough. Type III Also known as pauci-immune<unk> , type III<unk>  accounts for 55% of<unk>  and features neither immune complex deposition nor anti-GBM antibodies. Instead, the glomeruli are damaged in an undefined manner, perhaps through the activation of neutrophils in response to ANCA. Type III<unk>  may be isolated to the glomerulus (primary, or idiopathic) or associated with a systemic disease (secondary). In most cases of the latter, the systemic disease is an ANCA-associated vasculitis such as granulomatosis with polyangiitis, microscopic polyangiitis or eosinophilic granulomatosis with polyangiitis.
Rapidly progressive glomerulonephritis
Focal proliferative nephritis
Diffuse proliferative nephritis
Transplant glomerulopathy
Membranous glomerulonephritis
Membranoproliferative glomerulonephritis
Acute proliferative glomerulonephritis
Mesangial proliferative glomerulonephritis