Renal- Pathology Flashcards
Note that the presence of casts in urine indicates that hematuria/pyuria is of glomerular or renal tubular origin
Bladder cancer, kidney stones- no casts, hematuria present
Acute cystitis- pyuria, no casts
When are RBC casts seen in urine?
Glomerulonephritis, malignant HTN
When are WBC casts seen in urine?
tubulointerstitial inflammation, acute pyelonephritis, transplant rejection
When are fatty casts seen in urine?
nephrotic syndrome

When are granular (muddy brown) casts seen in urine?

Acute tubular necrosis
When are waxy casts seen in urine?
ESRD/chronic renal failure

When are hyaline casts seen urine?
nonspecific, can be a normal finding, and often seen in concentrated urine samples
What is focal glomerular disease?
less than 50% of glomeruli involved (e.g. focal segmental glomerulosclerosis)
diffuse= 50+%
“Membranous” renal disease means what?
thickening of the glomerular basement membrane (e.g. membranous nephropathy)
Describe nephritic syndrome
an inflammatory process that leads to disruption of the GBM. When it involves the glomeruli, it leads to hematuria and RBC casts in the urine
What are the other signs of nephritic syndrome?
HTN (due to salt retention)
elevated BUN and creatine
oliguria
proteinuria often in the subnephrotic range (less than 3.5g/day) but can be worse
What diseases fall under the umbrella of nephritic syndrome?
Acute poststreptococcal glomerulonephritis
Rapidly progressive glomerulonephritis
IgA nephropathy (Berger disease)
Alport syndrome
Membranoproliferative glomerulonephritis
Describe Acute poststreptococcal glomerulonephritis
acute disease seen commonly in children, appearing ~2 weeks after a group A strep infection of the pharynx or skin (resolves spontaneously), and caused by deposition of immune complexes in the kidneys (Type III hypersensitivity)
What is this?

Acute poststreptococcal glomerulonephritis, marked by enlarged and hypercellular glomeruli
Acute poststreptococcal glomerulonephritis with the classic ‘starry sky’ granular appearance. What causes this?

due to IgG, IgM, and C3 deposition along the GBM and mesangium
Below: EM showing classic subepithelial humps

What additional lab findings are seen in acute poststreptococcal glomerulonephritis?
elevated anti-DNase B titers
decreased complement levels
How does acute poststreptococcal glomerulonephritis present?
nephritic syndrome
peripheral and periorbital edema
cola-colored urine and HTN
Describe rapidly progressive (cresentic) glomerulonephritis (RPGN)
Onset of rapidly deteriorating renal function (days to weeks) (poor prognosis) that can be seen in Goodpasture syndrome, microscopic polyangiitis, and granulomatosis with polyangiitis (Wegener)
What is Goodpoasture syndrome?
type II hypersensitivity with Abs to GBM and alveolar basement membrane (linear IF-below)

What is the classic appearance of RPGN in LM?
crescent moon shape formation (consists of fibrin and plasma proteins (e.g. C3b) with glomerular parietal cells, monocytes, and macrophages

What ANCA is associated with Wegener?
PR3-ANCA (aka c-ANCA)
What ANCA is associated with Microscopic polyangiitis?
MPO-ANCA (p-ANCA)
Diffuse proliferative glomerulonephritis (DPGN)
due to SLE and membranoproliferative glomerulonephritis (most common cause of death in SKE)
often presents as nephrotic and nephritic syndrome concurrently
IgA nephropathy findings on LM, IF, and EM
LM- mesangial proliferation
EM- mesangial IC deposits
IF- IgA based IC deposits in mesangium

























