CRESCENTIC GLOMERULONEPHRITIS

Crescentic glomerulonephritis, defined by the presence of epithelial crescents in over 50 % of glomeruli, often occurs in patients with an infectious or systemic disease although it is clinically isolated in some instances. Flocculus lesions range from diffuse or focal mesangial proliferation to necrotizing glomerulitis. Three types have been identified : 1) glomerulonephritis with anti-glomerular basement membrane antibodies; 2) glomerulonephritis with immune complexe; 3) and glomerulonephritis with few or no immune deposits. In the latter group, antoantibodies directed against neutrophil cytoplam and monocyte lysosomes have been identified. Two common etiological groups are membranoproliferative glomerulonephritis (14 %) and nephritis with mesangial IgA deposits (Henoch-Schonlein purpura and Berger's disease - 23 %). Systemic lupus erythematosus and acute streptococcal glomerulonephritis account for 20 % of cases. Glomerulonephritis with antiglomerular basement membrane antibodies is infrequent and in forms of unclear etiology antineutrophil cytoplasmic antibodies should be looked for. End-stage renal failure is the outcome in 46 % of patients with crescentic glomerulonephritis. Available treatments sometimes involve risks to the patient and are inconsistently effective. Methylprednisolone pulse therapy seems beneficial in rapidly progressive idiopathic glomerulonephritis and in nephritis with IgA deposits (Berger's disease and Henoch Schonlein purpura). In conditions other than antiglomerular basement membrane antibody glomerulonephritis, it seems reasonable to use methylprednisolone pulses before resorting to plasmapheresis which is more expensive and more hazardous. Severe lupus glomerulonephritis can also be treated with methylprednisolone pulses and cyclophosphamide boluses (0.5 to 1 g/m2) . Glomerulonephritis with antineutrophil cytoplasmic antibodies seems to respond to combination treatment with cyclophosphamide and corticosteroids.