GN Associated with Infections

Question 1

Four classic characteristics of acute nephritic syndrome

Answer 1

Sudden onset of 1) Gross hematuria 2) Edema 3) Hypertension 4) Renal insufficiency

Question 2

Nephritogenic strains of GABHS that infect the throat

Answer 2

M1, M4, M25, some M12

Question 3

Nephritogenic strains of GABHS that infect the skin

Answer 3

M49

Question 4

Glomeruli appear enlarged and relatively bloodless and show diffuse mesangial cell proliferation, with an increase in mesangial matrix

Answer 4

APSGN

Question 5

In APSGN, infiltration of ___ cells is common in glomeruli during the early stage of the disease

Answer 5

Polymorphonuclear leukocyte

Question 6

In APSGN, immunofluorescence microscopy reveals a ___ pattern on the glomerular basement membrane and in the mesangium

Answer 6

“lumpy-bumpy”

Question 7

Lumpy bumpy pattern in immunofluorescence of kidneys of patients with APSGN represent

Answer 7

Deposits of immunoglobulin and complement

Question 8

On electron microscopy of kidneys affected by APSGN, electron-dense deposits, or “humps,” are observed on the ___ side of the glomerular basement membrane

Answer 8

Epithelial

Question 9

Circulating immune complex formation with streptococcal antigens and subsequent glomerular deposition is thought likely to be a pathogenic mechanism of APSGN

Answer 9

F, LESS LIKELY

Question 10

Poststreptococcal GN is most common in children ages ___ and uncommon before the age of ___

Answer 10

5-12 yr, 3 yr

Question 11

Typical APSGN patient develops an acute nephritic syndrome ___ after an antecedent streptococcal pharyn- gitis or ___ after a streptococcal pyoderma

Answer 11

1-2 wk, 3-6 wk

Question 12

T/F In APSGN, nephrotic syndrome develops in a minority (less than 5%) of childhood cases

Answer 12

T

Question 13

In individuals who present with a purpuric rash and renal disease, it is difficult to distinguish APSGN from ___ without a renal biopsy

Answer 13

Henoch-Schönlein purpura

Question 14

The acute phase of APSGN generally resolves within ___

Answer 14

6-8 wk

Question 15

In APSGN, urinary protein excretion and hypertension usually normalize by ___ after onset

Answer 15

4-6 wk

Question 16

In APSGN, persistent microscopic hematuria can persist for ___ after the initial presentation

Answer 16

1-2 yr

Question 17

Anemia seen in APSGN

Answer 17

Mild normochromic

Question 18

Mild normochromic anemia may be seen in APSGN due to

Answer 18

Hemodilution and low-grade hemolysis

Question 19

In APSGN, the serum C3 level is significantly reduced in >90% of patients in the ___ phase

Answer 19

Acute

Question 20

C3 levels in APSGN returns to normal ___ after onset

Answer 20

6-8 wk

Question 21

T/F Serum CH50 is commonly depressed in APSGN

Answer 21

T

Question 22

T/F C4 is most often depressed in APSGN

Answer 22

F, Normal or only mildly depressed

Question 23

T/F Confirmation of the diagnosis of APSGN requires clear evidence of a prior streptococcal infection

Answer 23

T

Question 24

A positive ___ might support the diagnosis of APSGN or might represent the carrier state

Answer 24

Throat culture report

Question 25

A ___ confirms a recent streptococcal infection

Answer 25

Rising antibody titer to streptococcal antigen(s)

Question 26

___ is commonly elevated after a pharyngeal infection but rarely increases after streptococcal skin infections

Answer 26

Antistreptolysin O titer

Question 27

The best single antibody titer to document CUTANEOUS streptococcal infection is the ___

Answer 27

Antideoxyribonuclease B level

Question 28

Measures multiple antibodies to different streptococcal antigens

Answer 28

Streptozyme screen

Question 29

T/F Serologic evidence for streptococcal infections is more sensitive than the history of recent infections

Answer 29

T

Question 30

T/F Serologic evidence for streptococcal infections is far more sensitive than positive bacterial cultures obtained at the time of onset of acute nephritis

Answer 30

T

Question 31

MRI of the brain is indicated in APSGN patients with severe neurologic symptoms and can demonstrate ___

Answer 31

Posterior reversible encephalopathy syndrome in the parietooccipital areas on T2-weighted images

Question 32

Renal biopsy in patients with APSGN should be considered only in the presence of (5)

Answer 32

1) Acute renal failure 2) Nephrotic syndrome 3) Absence of evidence of streptococcal infection 4) Normal complement levels 5) Hematuria and proteinuria, dimin- ished renal function, and/or a low C3 level persist more than 2 mo after onset

Question 33

___ can indicate a chronic form of postinfectious GN or another disease such as membranoproliferative GN

Answer 33

Persistent hypocomplementemia

Question 34

Acute postinfectious GN can also follow other infections with (3)

Answer 34

1) Coagulase-positive and coagulase-negative staphylococci 2) Streptococcus pneumoniae 3) Gram-negative bacteria

Question 35

Viral etiologies that are particularly notable as causes of acute GN (2)

Answer 35

1) Influenza 2) Parvovirus

Question 36

Acute complications of APSGN result from ___ and ___

Answer 36

1) Hypertension 2) Acute renal dysfunction

Question 37

Hypertension is seen in ___% of patients with APSGN

Answer 37

60

Question 38

Hypertension in APSGN is associated with Hypertensive encephalopathy in ___% of cases

Answer 38

10

Question 39

T/F Early systemic antibiotic therapy for streptococcal throat and skin infections eliminates the risk of GN

Answer 39

F, Does not eliminate

Question 40

T/F Antibiotic therapy (10-day course of penicilin) does NOT affect the natural history of APSGN

Answer 40

T

Question 41

Complete recovery occurs in ___% of children with APSGN

Answer 41

>95

Question 42

T/F Recurrences of APSGN are extremely rare

Answer 42

T

Question 43

Pathogenesis of HIV-associated nephropathy

Answer 43

Direct viral infection of nephrons occurs because renal cells express a variety of lymphocyte chemokine receptors that are essential for and facilitate viral invasion

Question 44

Classic histopathologic lesion of HIV-associated nephropathy is ___

Answer 44

Focal segmental glomerulosclerosis

Question 45

GN with no immune deposits

Answer 45

RPGN

Question 46

GN with granular IgG and C3 on IF

Answer 46

PSGN

Question 47

GN with linear IgG and C3 on IF

Answer 47

Goodpasture syndrome

Question 48

GN with no deposits on electron microscopy

Answer 48

Goodpasture syndrome and RPGN

Question 49

Treatment for Goodpasture syndrome

Answer 49

Plasma exchange, steroids, cyclophosphamide

Question 50

Treatment for RPGN

Answer 50

Steroid pulse therapy

Question 51

Common GN with decreased complement level

Answer 51

SLE, APSGN, MPGN

Question 52

Common GN with normal complement level

Answer 52

HSP, Goodpasture, IgA nephropathy, RPGN, nonstreptococcal postinfectious GN