PATH - Nephritic syndrome

Question 1

Nephritic syndrome

Answer 1

NephrItic syndrome = Inflammatory process

When it involves glomeruli, it leads to hematuria
and RBC casts in urine

Associated with azotemia, oliguria, hypertension (due to salt retention), proteinuria.

Question 2

Acute poststreptococcal

glomerulonephritis

Answer 2

Most frequently seen in children

Occurs ∼2–4 weeks after group A streptococcal
infection of pharynx or skin.

Type III hypersensitivity
reaction

Presents with peripheral and periorbital edema,
cola-colored urine, hypertension

LM—glomeruli enlarged and hypercellular
IF—(“starry sky”) granular appearancE (“lumpy-bumpy”) B due to IgG, IgM, and C3 deposition along GBM and mesangium.
EM—subepithelial immune complex (IC) humps.

Resolves spontaneously

Question 3

Rapidly progressive (crescentic) glomerulonephritis

Answer 3

Rapidly deteriorating renal
function (days to weeks)

LM and IF—crescent moon shape. Crescents
consist of fibrin and plasma proteins (eg, C3b)

Hematuria/hemoptysis

• PR3-ANCA/c-ANCA
• MPO-ANCA/p-ANCA

Ass. w/:
-Goodpasture syndrome
-Granulomatosis with polyangiitis (Wegener)
ƒ-Microscopic polyangiitis

Question 4

Diffuse proliferative

glomerulonephritis

Answer 4

Due to *SLE or membranoproliferative
glomerulonephritis.

*present as nephrotic syndrome and nephritic syndrome concurrently.

LM—“wire looping” of capillaries.
EM—subendothelial and sometimes intramembranous IgG-based ICs often with
C3 deposition.
IF—granular

Question 5

IgA nephropathy (Berger disease)

Answer 5

Episodic gross hematuria that occurs concurrently with respiratory or GI tract
infections

LM—mesangial proliferation.
EM—mesangial IC deposits.
IF—IgA-based IC deposits in mesangium.

Renal pathology of *Henoch-Schönlein purpura

*Not to be confused with Buerger disease

Question 6

Alport syndrome

Answer 6

X-linked dominant

Mutation in type IV collagen–>thinning and splitting of glomerular basement membrane

Eye problems, glomerulonephritis, sensorineural deafness

*“Basket-weave” appearance on EM.

Question 7

Membranoproliferative
glomerulonephritis
(MPGN)

Answer 7

MPGN is a nephritic syndrome that often
copresents with nephrotic syndrome

Type I—subendothelial immune complex
(IC) deposits with granular IF
-*“tram-track” appearance on PAS stain and H&E stain
due to GBM splitting caused by mesangial
ingrowth.
-may be 2° to hepatitis B or C infection.

Type II—also called dense deposit disease.
-associated with C3 nephritic factor