Case 5: Post strep infection

Question 1

Poststreptococcal Glomerulonephritis:

-Caused by prior infection with specific _______ strains of _____

Answer 1

-nephritogenic strains of GABS

Question 2

2 main nephritogenic antigens:

Answer 2

nephritis-associated plasmin receptor (NAPlr) & streptococcal pyogenic exotoxin B (SPE B)

Question 3

Poststreptococcal Glomerulonephritis:

• Occurs mostly in _______ countries
• Risk increased in which Pt populations?

Answer 3

• developing
• older patients and kids 4-15
• M>F

Question 4

What is the most common cause of acute nephritis in kids worldwide?

Answer 4

Poststreptococcal Glomerulonephritis

Question 5

Pathophysiology- PSGN

• After impetigo: develops in ____ weeks
• After pharyngitis: develops in ____ weeks

Answer 5

• 3-6

- 1-3

Question 6

PSGN:
Streptococcal nephritogenic antigens are deposited within the _______–> Immune complexes form–> _______ activated, inflammatory cells recruited.

Answer 6

• glomerulus

- complement

Question 7

Clinical Manifestations: PSGN
-Can be asymptomatic with microscopic _______

-Can have a full nephritic syndrome presentation: (describe)

Answer 7

• hematuria

- red/brown urine, proteinuria, edema, hypertension, elevated serum creatinine

Question 8

Clinical Manifestations: PSGN

-MC presenting Sx: ______

Answer 8

• Generalized edema
• Gross hematuria
• HTN

Question 9

PSGN:

-Possible systemic symptoms: ______

Answer 9

headache, malaise, anorexia, flank pain

Question 10

PSGN: Labs

• UA: _____
• BUN/Cr: _____
• Serum complement–>

Answer 10

• UA: RBCs, red cell casts, proteinuria
• Increased BUN/Cr
• Serum complement: LOW –> Complement system has been activated & complement components consumed

Question 11

PSGN: Labs (cont)

-Serology: ______

Answer 11

-ASO, anti-DNAse –> evidence of a recent streptococcal infection

Question 12

A streptozyme test measures __ different streptococcal antibodies

Answer 12

5

Question 13

Complement is part of the _____ immune system

Answer 13

innate

Question 14

Describe Complement

Answer 14

Made up of inactive proteins in the blood–> cleaved to release cytokines–> complement activation–> phagocytes stimulated –> lysis, activation of inflammatory responses, clearance of circulating immune complexes

Question 15

PSGN: dx

-what 2 things are needed to make the diagnosis?

Answer 15

-Clinical findings of acute nephritis –PLUS-
Demonstration of a recent GAS infection
-Positive throat or skin culture or serologic tests

–Renal biopsy not performed in most patients

Question 16

PSGN: tx goals

Answer 16

• Eradicate residual nephritogenic bacteria

- Provide supportive care

Question 17

PSGN: management

Answer 17

• **No specific therapy: treat the clinical manifestations, especially volume overload
• Abx treatment for the streptococcal infection
• Sodium & water restriction
• Loop diuretics (usually furosemide) reduce BP and edema

Question 18

PSGN: management

-IF hypertensive encephalopathy: treat ______

Answer 18

treat emergently to lower BP

Question 19

PSGN: management

-May need dialysis: IF _____ (3 conditions)

Answer 19

• Life-threatening fluid overload (pulmonary edema, heart failure, and HTN) refractory to medical tx
• Hyperkalemia (>6.5) unresponsive to medical tx
• Uremia with BUN between 89-100

Question 20

PSGN: Admission Criteria (5 things)

Answer 20

Severe renal dysfunction
Oliguria
Severe hypertension
CHF
Significant volume overload

Question 21

PSGN:

• do Abx alter the clinical course of the disease?
• when do some experts recommend abx?

Answer 21

• NO

- Some experts recommend abx ONLY if there’s proven active strep infection at time of diagnosis

Question 22

Others recommend treating patients with PSGN as if they have an active strep infection:
-drug of choice=

Answer 22

• **penicillin
• Alternate 1st line therapy: amoxicillin
• PCN allergy (mild): cephalexin (Keflex)
• If can’t take cephalosporins: azithromycin

Question 23

PSGN: course/prognosis

-Most Pts (esp. kids) have _____

Answer 23

a complete recovery

Question 24

PSGN: course/prognosis

-But some develop _____

Answer 24

HTN, recurrent proteinuria, and renal insufficiency long term

Question 25

PSGN: - Creatinine usually back to baseline by _____ weeks - Usually begin diuresing in __ week

Answer 25

- 3-4 | - 1

Question 26

PSGN: - Hematuria resolves in ____ - Proteinuria decreases, but much _____ - Children fare better than the _____

Answer 26

- 3-6 months - slower - elderly

Question 27

Rheumatic Fever is a multisystem disease that results from:

Answer 27

an autoimmune reaction to infection with GAS

Question 28

What is the MC cause of heart disease in kids in developing countries?

Answer 28

Rheumatic fever

Question 29

Rheumatic Fever: | is mainly a disease of _____ age

Answer 29

children, 5-14 yo

Question 30

Rheumatic fever- s/s: | -MC presentation pattern is 1 of the following:

Answer 30

-Start 10 days-several weeks after GAS infection - MC presentation pattern is one of the following: - -Acute febrile illness with joint manifestations and/or carditis - -Neurologic and behavioral manifestations with chorea

Question 31

Rheumatic fever- other s/s

Answer 31

- Fever >90% of cases - Carditis: may have dyspnea, orthopnea, CP, palpitations - Joint pain: generally large joints, migratory, dramatic response to NSAIDs/salicylates - Chorea: uncontrolled jerky movements limbs, face, tongue, usually worse on one side, stop while sleeping, often associated with emotional lability - Nodular SQ lesions: painless, resolve 1-2 weeks - Rash (erythema marginatum): nonpruritic, nonpainful, evanescent, usually on trunk. May have central pallor

Question 32

Jones Criteria: | -Need ___ major or __ major + ___ minor (and evidence of strep infection)

Answer 32

-2 major OR -1 major, 2 minor

Question 33

Jones Criteria: | List Major

Answer 33

``` Carditis & valvulitis Arthritis CNS involvement (usu. chorea) Subcutaneous nodules Erythema marginatum ```

Question 34

Jones Criteria: | List Minor

Answer 34

Arthralgia Fever Elevated acute phase reactants Prolonged PR on EKG

Question 35

CARDIAC/EKG findings

Answer 35

- PR prolongation (AV block) from myocardial inflammation affecting electrical conduction pathways - Mitral valve MC affected - Mitral regurgitation MC finding - S3: indicates failing LV in CHF/ increased volume - Hyperdynamic cardiac impulse: MR - A2 accentuated over P2: MR and pulmonary HTN can cause - Cardiomegaly: on EKG and/or CXR, LVH may be seen - Tachycardia

Question 36

Treatment- Acute Rheumatic Fever

Answer 36

-Abx tx for Streptococcal infection - NSAIDs for arthritis --> continue until all joint symptoms resolved - -Aspirin has been the traditional 1st-line therapy - -Naproxen also good choice - Carditis management: manage heart failure - Prophylaxis

Question 37

Hypersensitivity Reaction: | -Type II: Acute Rheumatic Fever

Answer 37

- Antibody directed against antigen on cells or extracellular materials (ie: basement membrane) - Ab-Ag complexes activate complement via classic pathway --> cell lysis or extracellular tissue damage

Question 38

Hypersensitivity Reaction: | Type III: Poststreptococcal glomerulonephritis

Answer 38

- Immune complexes (Ab & Ag) promote tissue damage through complement activation (alternate pathway) - Complexes deposited in tissues