Nephritic Syndrome

Question 1

How is nephritic syndrome characterized?

Answer 1

Glomerular inflammation and bleeding

Question 2

Clinical presenations of nephritic sndrome

Answer 2

Limited proteinuria

Oliguria and azotemia

Salt retention with periorbital edema and HTN

RBC casts and dysmorphic RBCs in urine

Question 3

What is poststreptococcal glomerulonephritis (PSGN)?

Answer 3

Nephritic syndrome that arises after a group A-ß-hemolytic streptococcal infection of the skin (impetigo) or pharynx

Question 4

What strains of GAS bacteria cause PSGN?

Answer 4

Nephritogenic strains that carry the M protein virulence factor

Question 5

S/S of PSGN

Answer 5

Presentations begin 2-3 weeks after infection:

Hematuria

oliguria

HTN

Periorbital edema

Question 6

What is seen on H&E stain of PSGN?

Answer 6

Hypercellular, inflamed glomeruli

Question 7

How is PSGN mediated?

Answer 7

Immune complexe deposition

Question 8

IF of PSGN

Answer 8

Granular IF

Question 9

What is seen on EM of PSGN?

Answer 9

subepithelial humps

Question 10

Tx for PSGN

Answer 10

Tx is supportive

Children rarely progress to renal failure (1%)

Some adults develop rapidly progressive glomerulonephritis (RPGN) (25%)

Question 11

What is Rapidly Progressive Glomerulonephritis (RPGN)?

Answer 11

Nephritic syndrome that progresses to renal failure in weeks to months

Question 12

What is the defining characteristic of RPGN?

Answer 12

Characterized by crescents in Bowman space of glomeruli on H&E stain

Crescents comprised of fibrin and mscrophages

Question 13

What makes up crescents in RPGN?

Answer 13

Crescents comprised of fibrin and mscrophages

Question 14

What is the etiology of a linear IF pattern in RPGN?

Answer 14

Goodpasture syndrome

Ab against collagen in glomerular and alveolar BM; Presents as hematuria and hemoptysis

Classically seen in young, adult males

Question 15

What is the etiology of a granular IF pattern in RPGN?

Answer 15

Granular = immune complex deposition

PSGN (most common) or diffuse proliferative glomerulonephritis

Diffuse glomerulonephritis is due to diffuse Ag-Ab complex deposition, usually subendothelial; MC type of renal disease in SLE

Question 16

What is the etiology of a negative IF pattern in RPGN?

Answer 16

Wegener granulomatosis, microscopic polyangitis, and Churg-Strauss syndrome

Wegener granulomatosis is associated with c-ANCA

Microscopic polyangitis and Churg-Strauss are associated with p-ANCA

Granulomatous inflammation, eosinophils and asthma distinguish Churg-Strauss from microscopic polyangitis

Question 17

What is IgA nephropathy (Berger Dz)?

Answer 17

IgA immune complex deposition in mesangium of glomeruli

Most common nephropathy worldwide

May slowly progress to renal failure

Question 18

Clinical presentations of IgA nephropathy

Answer 18

Presents during childhood as episodic gross or microscopic hematuria with RBC casts, usually following mucosal infections

IgA production is increased during infections

Question 19

What is seen on the IF of IgA nephraopathy?

Answer 19

IgA immune complex deposition in the mesangium

Question 20

What is alport syndrome?

Answer 20

Inherited defect in type IV collagen

Most commonly X-linked

Results in thinning and splitting of glomerular BM

Question 21

S/S of alport syndrome

Answer 21

Isolated hematuria

Sensory hearing loss

Ocular disturbances

Question 22

What is seen on the LM, EM and IF of Berger’s disease?

Answer 22

LM - Mesangial proliferation

EM - mesangial IC deposits

IF - IgA based IC deposits in mesangium

Question 23

What condition can present as nephritic syndrome and nephrotic syndrome concurrently?

Answer 23

Diffuse proliferative glomerulonephritis