12.4: Nephritic syndrome

Question 1

What are the two hallmark findings of nephritic syndrome?

Answer 1

Glomerular inflammation and bleeding, leading to oliguria and azotemia

Question 2

What is the amount of proteinuria in nephritic syndrome? Nephrotic syndrome?

Answer 2

Nephritic = less than 3.5 g /day

Nephrotic = more than 3.5 g /day

Question 3

Where does edema present with nephritic syndrome, if at all? Why does this occur?

Answer 3

around the eyes d/t salt retention

Question 4

What are the urinary findings with nephritic syndrome?

Answer 4

RBC casts and dysmorphic RBCs in urine

Question 5

Why is there HTN with nephritic syndrome?

Answer 5

Salt retention

Question 6

Why are there casts with nephritic syndrome?

Answer 6

Necrotic RBCs get stuck in the tubules, forming the shape (cast) of the tubule

Question 7

A bx of the glomerulus with nephritic syndrome will reveal what?

Answer 7

Inflamed, hypercellular glomeruli

Question 8

What is the underlying pathophysiology of nephritic syndrome?

Answer 8

Immune complex deposition, which activates complement (C5a) and attracts PMNs

Question 9

What complement is activated by the immune complexes deposited in nephritic syndrome, and mediates the PMN damage?

Answer 9

C5a

Question 10

What causes the hypercellularity within the glomerulus with nephritic syndrome?

Answer 10

PMNs are attracted to the C5a produced by immune complex deposition

Question 11

What is post-streptococcal glomerulonephritis?

Answer 11

Nephritic syndrome that arises after group A, beta-hemolytic strep infection of the SKIN or PHARYNX

Question 12

What is the virulence factor carried by the GAS species that mediate PSGN? What is the function of this protein, and how does this cause PSGN?

Answer 12

• M protein

- Antigen variation/mimicry

Question 13

True or false: PSGN only occurs with GAS

Answer 13

False- can occur with other, non-strep organisms as well

Question 14

What are the s/sx of PSGN (4), and when do these occur, relative to the initial strep infection?

Answer 14

• 2-3 weeks after infx
• Hematuria (cola-urine)
• Oliguria
• HTN
• Periorbital edema

Question 15

In whom is PSGN usually seen in?

Answer 15

Children

Question 16

What are the findings of PSGN in LM, EM, and IF?

Answer 16

LM = hypercellular, inflamed glomeruli
EM = Subepithelial humps
IF = granular IF

Question 17

What causes the subepithelial humps seen with PSGN?

Answer 17

immune complexes build up in the BM, translocate to the epithelium, and aggregate

Question 18

What is the treatment and prognosis for PSGN?

Answer 18

Supportive and benign, but rarely progresses to renal failure

Question 19

What is RPGN?

Answer 19

Nephritic syndrome that progresses to renal failure within weeks to months

Question 20

What are the LM findings of RPGN?

Answer 20

Crescents in bowman’s space

Question 21

What are the crescents comprised of that fill Bowman’s space with RPGN? (2)

Answer 21

Fibrin and macrophages

Question 22

What RPGN disease has a linear immunofluorescence? Why is it linear?

Answer 22

Goodpasture syndrome.

Linear because there is a line of antibodies against the BM

Question 23

What is Goodpasture syndrome? S/sx? Who does this usually occur in?

Answer 23

Antibody against collagen IV, leading to hematuria and hemoptysis

Young male adults affected

Question 24

What are the two causes of granular appearance of immune complexes on IF, in order of incidence?

Answer 24

1. PSGN

2. Diffuse proliferative glomerulonephritis

Question 25

What causes the granular appearance on IF of PSGN and diffuse proliferative glomerulonephritis?

Answer 25

Subendothelial deposits of antigen complexes

Question 26

What is the most common renal disease found in SLE?

Answer 26

Diffuse proliferative glomerulonephritis

Question 27

What is the cause of nephritic and nephrotic syndrome with SLE pts? Which is more commonly seen?

Answer 27

**Nephritic = diffuse proliferative glomerulonephritis** Nephrotic = Membranous nephropathy

Question 28

What is pauci-immune pattern of immune complexes? In which nephritic syndromes (3) is this seen?

Answer 28

Negative IF: - Wegener's granulomatosis - Microscopic polyangiitis - Churg-Strauss syndrome

Question 29

What is the next step in the workup of a pt with a pauci-immune IF?

Answer 29

ANCA

Question 30

What is the basis of the ANCA test? Results (2)

Answer 30

Take a PMN on a slide, and apply ab. If ab binds to nucleus = pANCA If ab binds in cytoplasm - cANCA

Question 31

cANCA is associated with what disease? pANCA?

Answer 31

cANCA = Wegener's granulomatosis pANCA = Churg-strauss syndrome

Question 32

What are the three locations that are involved with Wegener's granulomatosis?

Answer 32

- Lungs - Kidneys - *Nasopharynx*

Question 33

Pt with hematuria, nephritic crescent syndrome, and hemoptysis = ? What about if they also have pharynx associated problems?

Answer 33

Goodpasture Wegener's with pharynx

Question 34

What are the three things that will be present in Churg-Strauss syndrome that are *not* present in microscopic polyangiitis?

Answer 34

1. Granulomatous inflammation 2. Eosinophilia 3. Asthma

Question 35

What is the most common cause of nephropathy worldwide?

Answer 35

IgA nephropathy

Question 36

What is the underlying pathophysiology of IgA nephropathy?

Answer 36

IgA immune complex deposition in the *mesangium* of the glomeruli

Question 37

When does IgA nephropathy usually present? What are the s/sx?

Answer 37

- Childhood, following mucosal infx | - Episodic gross or microscopic hematuria with RBC casts

Question 38

What is the prognosis for IgA nephropathy?

Answer 38

May slowly progress to renal failure

Question 39

Where does IgA deposit in the glomerulus?

Answer 39

In the mesangium

Question 40

What is Alport syndrome? What is the inheritance pattern? How does it present (3)?

Answer 40

XLR defect in type IV collagen, resulting in thinning and splitting of the glomerular BM Presents as isolated hematuria, sensory hearing loss, and ocular disturbances

Question 41

What causes the hearing loss and ocular disturbances with Alport syndrome?

Answer 41

Damage to BM in both cases, caused by crappy type IV collagen