Glomerulopathies Flashcards
What is post streptococcal glomerulonephritis?
It is a nephritic syndrome that arises after infection from group A beta hemolytic streptococcal infection of the skin (impetigo) or pharynx. Presentation is 2-3 weeks after infection with signs of hematuria, oliguria, hypertension, and periorbital edema. Usually seen in children aged 6-10 but may occur in adults (usually worse off if found in adults). Mediated by sub epithelial immune complex deposition in a granular pattern that is shown as “humps.” Deposits are IgG, IgM, and C3 containing. Usually is an acute reversible disease with spontaneous recovery, but some adults can progress to rapidly progressive glomerulonephritis.
What is a crescent made up of?
Consists of proliferation of parietal epithelial cells intermixed with mononuclear phagocytes. See lots of fibrin within these deposits
What is rapidly progressive glomerulonephritis?
Nephritic syndrome that progresses to renal failure within weeks to months. Associated with severe glomerular injury and see crescents in Bowman space due to proliferation of parietal epithelial cells.
What is type 1 RPGN?
Renal limited and due to anti-GBM antibody; presents with linear deposit deposition with antibody (IgG) against collagen in glomerular and alveolar basement membranes. Presents as hematuria and hemoptysis. In Goodpasture, the antibody is against the alpha-3 chain of type IV collagen in the GBM.
What is type 2 RPGN?
Due to immune complex and thus includes post infectious glomerulonephritis, nephritic SLE, IgA nephropathy, and Henoch-Schoenlein.
Generally presents as granular with it being the most common type of renal disease in SLE patients.
What is type 3 RPGN?
Due to circulating ANCA’s - in Wegener’s these are c-ANCA’s and in microscopic polyangiitis, they are p-ANCA’s.
What is membranous nephropathy?
Most common cause of nephrotic syndrome in Caucasian adults. Presents with non-selective proteinuria and can be associated with hepatitis B or C infection as well as solid tumors (esp. of the lung). Morphologically, can see a prominent and thickened capillary loop but overall cellularity is not increased. Immune complex deposition is due to sub epithelial deposits that have a ‘spike and dome’ appearance with a granular staining pattern. Pathogenesis includes the C5b-C9 pathway that forms the membrane attack complex against epithelial and mesangial cells that causes capillary wall injury and increased protein leakage. Clinically, there’s an insidious onset with nonselective proteinuria, hematuria, and mild hypertension. Characterized by a poor response to steroids and progression to chronic renal failure.
What is minimal change disease?
Most common cause of nephrotic syndrome in children - usually idiopathic in origin but can be associated with NSAID’s or Hodgkin lymphoma. Clinically, see massive proteinuria, good renal function, no hypertension or hematuria. Histologically, see diffuse effacement of foot processes of visceral epithelial cells with the glomeruli pretty much appearing normal otherwise. Long-term prognosis is good and response well to steroid therapy.
What is focal-segmental glomerulosclerosis?
Most common cause of nephrotic syndrome or heavy proteinuria in Hispanics and African Americans it is also associated with HIV infection and heroin (IV drug) use as well as sickle cell. Will see non-selective proteinuria, hematuria, progression to chronic renal failure, and poor response to corticosteroids. Epithelial damage is the hallmark of the disease with damage localized to the slit diaphragm and podocyte cytoskeletal structures. Will also see effacement of foot processes. Does not respond well to steroids.
What is membranoproliferative glomerulonephritis?
Morphologically, see thick GBM that has a “tram-track” appearance. There is splitting/duplication of the BM since it starts to synthesize in response to sub endothelial immune complex deposition.
Type 1 - subendothelial immune complex deposition
Type 2 - dense deposit disease associated with C3 nephritic factor (deposits form mesangial rings)
What is IgA nephropathy?
Most common nephropathy worldwide, it is due to complexes attaching to fibronectin or type IV collagen in ECM and causes hypercellularity of the glomerulus. Presents during childhood as episodic/recurrent gross/microscopic hematuria with RBC casts and usually follows mucosal infections (i.e. gastroenteritis). Older adults present with proteinuria, microscopic hematuria, and hypertension. Mild proteinuria present and can progress slowly to chronic renal failure.
What is Henoch-Schoenlein purpura?
Essentially similar to IgA nephropathy with children having a good prognosis but adults having a more severe disease course. Presents as purpuric skin lesions on arms, legs, and buttocks as well as sub epidermal hemorrhages and necrotizing vasculitis.
What is Alport syndrome?
Due to a genetically X-linked mutation leading to a defect in type IV collagen. Presents with GBM alternative thickening and thinning with nonspecific finding being interstitial form due to proteinuria. If has a defect in the alpha3 chain of collagen, protected against Goodpasture disease. Clinically, see isolated hematuria, sensory hearing loss, and ocular disturbances.
What is thin basement membrane lesion?
Diffuse thinning of GBM due to defective collagen genes. Presents as benign familial hematuria and usually found incidentally.
What are the renal manifestations of SLE?
Renal symptoms include microscopic or gross hematuria, nephritic syndrome, nephrotic syndrome, chronic renal failure, and HTN. It commonly leads to renal failure and intercurrent infections. Most visceral lesions are due to immune complexes (i.e. a type III hypersensitivity).
