Robbin's 20: The Kidney Flashcards
Give the expected BUN:creatinine ratio for azotemia due to dilated cardiomyopathy.
>20:1 Azotemia - high SG, low FE-Na, high BUN:creatinine ratio, pre-renal when associated with HF
Give the expected BUN:creatinine ratio for BPH
BPH - post-renal (obstructive) 10:1 - 20:1
What would you expect to see on urinalysis of a patient with SLE and nephritic syndrome?
RBC casts, RBCs
Give an example of a type I hypersensitivity rxn in the kidney:
Allergic nephritis; drug-induced acute interstitial nephritis
Give an example of a type IV hypersensitivity rxn in the kidney.
Renal transplant rejection; SOME cases of drug-induced acute interstitial nephritis Transplant rejection - T-cell injury with tubulitis
Give an example of a type III hypersensitivity rxn in the kidney.
SLE: immune-mediated glomerular injury with antigen-antibody complex deposition –> decreased levels of complement –> nephritis
Give an example of a type II hypersensitivity rxn in the kidney.
Goodpasture syndrome, other anti-glomerular BM diseases
Juxtaglomerular cells secrete:
renin
Parietal epithelial cells line the Bowman capsule and may proliferate with severe glomerular injury to produce:
crescents
Podocytes are visceral epithelial cells that form what part of the kidney?
The filtration barrier
Thrombotic microangiopathies are most likely to be damaged with:
endothelial cells
What kind of cell proliferates in membranoproliferative glomerulonephritis?
Mesangial cells phagocytic fx and can proliferate in response to injury
What defines nephrotic syndrome?
Podocyte injury, the loss of >3.5g protein per day in the urine
What is the exotoxin responsible for the development of poststreptococcal glomerulonephritis?
Pyogenic exotoxin B (SpeB) Most children with poststreptococcal GN recover, although 1% develop a rapidly progressive GN characterized by crescent formation. Progression to chronic renal failure occurs in 40% of affected adults.
What is a more common cause of PSGN in the US than Strep pyogenes?
Staph Aureus (with IgA antibodies)
Patients with Goodpasture syndrome (type I anti-glomerular BM disease) require what kind of treatment?
Plasmapheresis
Give an example of a type II crescentic GN.
Immune complex disease: Type II crescentic GN can occur in systemic lupus erythematosus, in Henoch-Schönlein purpura, and after infections.
What are some causes of type III crescentic GN?
Type III - absense of anti-GBM antibodies or immune complexes Causes of type III crescentic GN include granulomatosis with polyangiits (ANCA-associated vasculitis) and microscopic polyangiitis.
Give the dx: Malaise, nausea and reduced urine output for 3 days; Afebrile, normotensive; creatinine 7.5; Hematurea, no pyuria or glucosuria; renal biopsy shows crescents
Rapidly progressive GN Crescentic GN is divided into three groups on the basis of immunofluorescence: type I (anti–glomerular basement membrane [GBM] disease); type II (immune complex disease); and type III (characterized by the absence of anti-GBM antibodies or immune complexes).
Antibodies are seen against what part of the BM in Goodpasture syndrome?
The noncollagenous domain of the alpha-3 chain of type IV collagen
The anti-streptolysin O titer is increased in what kidney disease?
poststreptococcal GN –granular pattern of immune complex deposition
Immune complex deposition of granular or linear in Goodpasture syndrome?
Linear
HIV infection can lead to a nephropathy that resembles FSGS, with what deposition?
IgM and C3 are deposited in the mesangial areas of affected glomeruli
Give the dx: LACK of immune deposits; periorbital edema; BUN:creatinine >10:1; Oliguria with cloudy brown appearance; focal necrosis in glomeruli with glomerular BM breaks and no crescents; Anti-neutrophil cytoplasmic antibody detected in serum
Pauci-immune crescentic glomerulonephritis Cases can be idiopathic, associated with ANCAs, and limited to the kidney.
Anti-DNA topoisomerase antibody is seen in:
scleroderma (mainly affects vasculature of kidney)