RPGN - Clinical Features, Treatment and Prognosis

Abstract

Rapidly progressive glomerulonephritis (RPGN) is one of the nephrology emergencies which needs special attention. RPGN is a clinical description which determines by symptoms and signs of glomerulonephritis (GN); edema, hypertension and gross hematuria, and evidence of acute renal failure(severe decrease in glomerular filtration rate presents as oliguria or anuria, and increased serum levels of BUN and creatinine). Definite diagnosis of the disorder is based on kidney biopsy's findings. Early diagnosis and appropriate treatment plays a critical role in renal saving and preventing permanent glomerular damage. This chapter will focus on clinical manifestations, therapeutic protocols and prognostic factors in patients with different subtypes of RPGN. Rapidly progressive glomerulonephritis (RPGN) is defined as a syndrome with abrupt or insidious onset of hematuria, proteinuria, anemia, and rapidly progressing acute renal failure(ARF), and special findings on light microscopy examination of kidney biopsy's specimen; crescentic lesions which usually involved most glomerular architectures (Hirayama, et al., 2008; Rutgersetal., 2004). It also characterized by rapid loss of renal function (GFR 50 % of glomeruli (Couser, 1988). RPGN can be primary or secondary. Secondary forms occur in any form of severe glomerulonephritis including membranoproliferative GN, IgA nephropathy, post infectious GN, and systemic lupus erythematous (SLE). Primary RPGN is an autoimmune disease which is divided into three immunopathologic categories:(Rutgerset al., 2004; Haas .& Eustace, 2004): Type 1 RPGN: glomerulonephritis with antibodies directed against the glomerular basement membrane (GBM) (anti -GBM mediated GN) Type II RPGN: immune-complex induced glomerulonephritis Type III RPGN: Antineutrophil cytoplasmic antibody associated glomerulonephritis (ANCA-associated glomerulonephritis or pauci-immune GN) RPGN type 1 and 2 are responsible for 10 -20 % and 40 % of all cases respectively. RPGN type 2 can be found in different forms of systemic disease such as post infectious GN(PSGN), Ig-A nephropathy, Henoch–Schonlein purpura (HSP), SLE, membranous GN(MGN) or membranoproliferative GN(MPGN). A few cases of idiopathic immune complex-mediated RPGN have been reported (Jindal, 1999).