NEPHRITIC/NEPHROTIC SYNDROMES

Question 1

PSGN classically occurs in children _____________-after infection (e.g., impetigo) and manifests with periorbital (or generalized) edema and gross hematuria (“cola-colored” urine)

Answer 1

PSGN classically occurs in children 1–6 weeks after infection (e.g., impetigo) and manifests with periorbital (or generalized) edema and gross hematuria (“cola-colored” urine)

Question 2

Answer 2

Fluorescence microscopy (immunofluorescence staining for C3; high magnification)

Granular deposits of C3 are visible, resulting in a starry sky pattern.

Starry Sky pattern on immunofluorescence:
“Starry sky = Immune complex deposition → Think PSGN or Lupus Nephritis”

Question 3

Where do we see a starry sky pattern on immunofluroescence?

Answer 3

Poststreptococcal Glomerulonephritis (PSGN) → Classic “Starry Sky”

Acute Lupus Nephritis (Diffuse Proliferative Glomerulonephritis - DPGN)

“Starry sky = Immune complex deposition → Think PSGN or Lupus Nephritis”

Question 4

Lupus nephritis is what kind of nephropathy?

Answer 4

It presents with both nephritic and nephrotic syndromes, it is also the main cause of DIFFUSE PROLIFERATIVE GLOMERULONEPHRITIS

Question 5

mutation in type IV collagen, can manifest with gross hematuria (“cola-colored” urine) and facial edema. Also can present with sensorineural hearing loss.

Answer 5

Alport

Question 6

Most common cause of nephrotic syndrome in black and hispanic populations

Answer 6

focal segmental sclerosis

Question 7

A condition characterized by focal segmental glomerular lesions with sclerosis and hyalinosis on light microscopy and effacement of podocytes on electron microscopy. On immunofluorescence microscopy, nonspecific IgM, C3, and C1 deposits may be present. Can be idiopathic or secondary to other conditions. Associated with HIV, intravenous drug use, and massive obesity.

Answer 7

Focal segmental glomerulosclerosis (FSGS)

Question 8

the most common cause of nephrotic syndrome in childhood

Answer 8

Minimal change disease (MCD)

Question 9

___________________usually occurs concurrently with nonspecific respiratory, or less commonly, gastrointestinal or urinary tract infections.

Answer 9

IgA nephropathy usually occurs concurrently with nonspecific respiratory, or less commonly, gastrointestinal or urinary tract infections.
post infection happens LATER

Question 10

is a common cause of nephrotic syndrome in white adults

Answer 10

Membranous nephropathy (MN)

Question 11

Answer 11

Rapidly progressive glomerulonephritis (RPGN)

Photomicrograph of a kidney biopsy sample (PAS stain; very high magnification)

The glomerulus shows a hypercellular, crescent-shaped zone (green overlay) with an inflammatory infiltrate (examples of macrophages indicated by arrowheads).

Glomerular crescent formation is a characteristic histological finding in RPGN.

Question 12

RPGN is associated with

Answer 12

RPGN is associated with Goodpasture syndrome, lupus nephritis, granulomatosis with polyangiitis, and microscopic polyangiitis.

Question 13

Fibrin formation inside the Bowman space is characteristic of

Answer 13

RPGN

Question 14

Effacement of podocyte foot processes is an electron microscopy finding in

Answer 14

minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS).

Question 15

mesangial matrix expansion and eosinophilic nodular glomerulosclerosis

Answer 15

Expansion of the mesangial matrix is seen in diabetic nephropathy, which would cause nephrotic syndrome and chronic renal failure, and a renal biopsy would typically show eosinophilic nodular glomerulosclerosis (Kimmelstiel-Wilson nodules).

Question 16

Answer 16

Focal segmental glomerulosclerosis (FSGS)

Photomicrograph of a kidney biopsy specimen (PAS stain; very high magnification)

A cross-section of a glomerulus is visible at the center of the image. The perihilar region is hypercellular and contains hyaline deposits (examples indicated by blue overlay). Loss of the capillary lumens and diffuse sclerosis is also present.

These are the typical features of focal segmental glomerulosclerosis (perihilar type).

Question 17

Deposition of immunoglobulin light chains is characteristic of

Answer 17

primary amyloidosis, which typically occurs in patients with multiple myeloma and causes nephrotic syndrome or chronic renal failure

Question 18

Answer 18

a renal biopsy in patients with long-term severe or malignant hypertension would predominantly show hyperplastic arteriolosclerosis, characterized by an onion-skin appearance of the arteriolar wall due to vascular smooth muscle proliferation, as well as fibrinoid necrosis.

Question 19

What happens to the glomerulus in diabetes mellitus?

Answer 19

In diabetes mellitus, chronic hyperglycemia promotes the attachment of carbohydrates to proteins, a process known as nonenzymatic protein glycation (NEPG), which alters the structure and function of the glycated protein. NEPG of the glomerular basement membrane renders it permeable to plasma proteins, which accumulate within the walls of the glomerular arterioles, causing arteriolar thickening and narrowing. This protein accumulation appears as pink amorphous material within the vascular wall on H&E staining and is known as hyaline arteriolosclerosis.