Acute Nephritic Syndrome

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of clinical cases of APSGN present with at least 2 manifestations of acute nephritic syndrome?

95% (correct)

80%

100%

90%

What is the typical timeline for antibody titers in patients with APSGN?

Elevated at 6 months, peaking at 1 year

Elevated at 1 week, peaking at 1 month (correct)

Elevated at 1 month, peaking at 3 months

Elevated at 3 months, peaking at 6 months

What is a common laboratory finding in patients with APSGN?

Low serum complement levels (correct)

Variable serum complement levels

Normal serum complement levels

Elevated serum complement levels

What percentage of patients with pharyngitis have positive antibody titers to extracellular products of streptococci?

95% Signup and view all the answers

What is a possible finding on chest radiographs in patients with APSGN?

Findings of congestive heart failure Signup and view all the answers

What is a urinalysis result in patients with APSGN?

Always abnormal Signup and view all the answers

What is the hallmark of nephrotic syndrome?

Massive proteinuria Signup and view all the answers

What is the cause of proteinuria in nephrotic syndrome?

Glomerular structural damage Signup and view all the answers

What is the definition of nephrotic-range proteinuria in children?

Protein excretion of more than 40 mg/m2/h Signup and view all the answers

What is the effect of decreased plasma oncotic pressure on the body?

It leads to transudation of fluid into interstitium Signup and view all the answers

What is the difference between primary and secondary nephrotic syndrome?

Primary is associated with glomerular diseases, while secondary is a renal manifestation of systemic diseases Signup and view all the answers

What is the effect of hypoalbuminemia on the body?

It decreases plasma oncotic pressure Signup and view all the answers

What is a feature in the early phase of APSGN that suggests the need for renal biopsy?

No rise in antistreptococcal antibodies Signup and view all the answers

What is a complication of APSGN in the acute phase?

Congestive heart failure Signup and view all the answers

What is the goal of symptomatic therapy in APSGN?

Control edema and blood pressure Signup and view all the answers

Why is salt and water restriction recommended in APSGN?

To prevent edema and hypertension Signup and view all the answers

What is an indication for dialysis in APSGN?

Life-threatening hyperkalemia Signup and view all the answers

How is streptococcal infection treated in APSGN?

With oral penicillin G or erythromycin Signup and view all the answers

What is the short-term prognosis of APSGN in children?

Favorable with fewer than 2% progressing to end-stage renal disease Signup and view all the answers

What may persist for several years after APSGN?

Microscopic hematuria Signup and view all the answers

What is the recommended duration of steroid treatment for infrequent relapses?

shorter duration than initial treatment Signup and view all the answers

What is the dose of prednisone given during the remission of proteinuria?

1.5 mg/kg (40 mg/m2) on alternate days Signup and view all the answers

What is the definition of frequently-relapsing nephrotic syndrome (FRNS)?

2 or more relapses within 6 months or three times or more within 1 year Signup and view all the answers

What is the recommended treatment for steroid-resistant disease and Focal Segmental GS?

CSA Signup and view all the answers

How long is CYP (2 mg/kg daily) given orally for?

8-12 weeks Signup and view all the answers

What is the definition of steroid-dependent nephrotic syndrome (SDNS)?

2 or more consecutive relapses during tapering or within 14 days of stopping steroids Signup and view all the answers

When is a diagnostic renal biopsy performed in children with steroid-resistant disease?

After 8 weeks of steroid therapy Signup and view all the answers

What is a common side effect of CYP treatment?

All of the above Signup and view all the answers

What is the most common presenting symptom in children with nephrotic syndrome?

Edema Signup and view all the answers

What percentage of childhood cases of nephrotic syndrome are caused by secondary causes?

< 10% Signup and view all the answers

Which of the following is a metabolic cause of secondary nephrotic syndrome?

Diabetes mellitus Signup and view all the answers

What are the three laboratory tests required to confirm the presence of nephrotic syndrome?

Nephrotic-range proteinuria, hypoalbuminemia, and hyperlipidemia Signup and view all the answers

What is Alport's syndrome?

A type of hereditary nephropathy Signup and view all the answers

What is a common complication of nephrotic syndrome in children?

Respiratory distress Signup and view all the answers

Study Notes

Acute Poststreptococcal Glomerulonephritis (APSGN)

APSGN is the most frequent presentation of Acute Nephritic Syndrome (ANS)
ANS presents with edema, hematuria, and hypertension with or without oliguria
Approximately 95% of clinical cases have at least 2 manifestations, and 40% have the full-blown acute nephritic syndrome

Laboratory Studies

Evidence of preceding streptococcal infection:
- Antibody titers to extracellular products of streptococci are positive in more than 95% of patients with pharyngitis and 80% of patients with skin infections
- Antistreptolysin (ASO), antinicotinamide adenine dinucleotidase (anti-NAD), antihyaluronidase (AHase), and anti-DNAse B are commonly positive after pharyngitis
- Antibody titers are elevated at 1 week, peak at 1 month, and fall toward preinfection levels after several months
Elevated BUN and creatinine values
Serologic findings: low serum complement levels
Urinalysis: results are always abnormal
Imaging Studies: chest radiographs may show findings of congestive heart failure

Treatment of Relapses

For infrequent relapses, steroids are resumed, although for a shorter duration than treatment during initial presentation
Prednisone, 2 mg/kg/d (60 mg/m2/d), is given as a single morning dose until the patient has been free of proteinuria for at least 3 days
Following remission of proteinuria, prednisone is reduced to 1.5 mg/kg (40 mg/m2) given as a single dose on alternate days for 4 weeks

Frequently Relapsing, Steroid-Dependent Disease, and Steroid-Resistant Disease

Frequently-relapsing nephrotic syndrome (FRNS) is defined as steroid-sensitive nephrotic syndrome (SSNS) with 2 or more relapses within 6 months or three times or more within 1 year period
Steroid-dependent nephrotic syndrome (SDNS) is defined as SSNS with 2 or more consecutive relapses during tapering or within 14 days of stopping steroids
For FRNS and SDNS, prednisone treatment is prescribed at 2 mg/kg/d (60 mg/m2/d) as a single morning dose until the patient has been free of proteinuria for at least 3 days
Steroid-resistant disease: children who continue to have proteinuria (2+ or greater) after 8 weeks of steroid therapy are considered steroid-resistant, and a diagnostic renal biopsy should be performed

Complications

Acute phase:
- Congestive heart failure
- Azotemia
- Early death secondary to congestive heart failure and azotemia
Chronic phase:
- Nephrotic-range proteinuria
- Chronic renal insufficiency and end-stage renal disease

Management of APSGN

Medical Care:
- Symptomatic therapy is recommended for patients with acute poststreptococcal glomerulonephritis (APSGN)
- The major goal is to control edema and blood pressure
- During the acute phase of the disease, restrict salt and water
- For hypertension not controlled by diuretics, usually calcium channel blockers or angiotensin-converting enzyme inhibitors are useful
Prognosis:
- The short-term prognosis of APSG in children is favorable
- Fewer than 2% of children progress to end-stage renal disease
- Hypertension and gross hematuria usually resolve over several weeks, although microscopic hematuria may persist for several years
- Proteinuria resolves over several months

Nephrotic Syndrome

Definition:
- Pediatric nephrotic syndrome is defined by the presence of nephrotic-range proteinuria, hypoalbuminemia, hyperlipidemia, and edema
- Nephrotic-range proteinuria in children is protein excretion of more than 40 mg/m2/h
- A urine protein/creatinine value of more than 2 mg/mg indicates nephrotic range proteinuria
Proteinuria:
- The hallmark of NS is massive proteinuria
- The cause of proteinuria is glomerular structural damage
Hypoalbuminemia:
- Excessive loss of plasma protein into urine
- Decreased plasma oncotic pressure leads to transudation of fluid into interstitium
Hypercholesterolemia:
- Increased hepatic synthesis due to hypoalbuminemia and decreased oncotic pressure
- Abnormalities in regulatory enzymes, such as lipoprotein lipase
Edema:
- Decreased plasma oncotic pressure leads to transudation of fluid into interstitium

Etiology

Primary nephrotic syndrome (PNS) is associated with glomerular diseases intrinsic to the kidney and not related to systemic causes
Secondary causes account for < 10% of childhood cases
Examples of secondary causes:
- Metabolic: as Diabetes mellitus
- Immunologic: Henoch-Schönlein purpura, SLE
- Drug-related: Interferon alfa, NSAIDs
- Neoplastic: Leukemia, Lymphomas
- Allergic: Antitoxins, Insect stings, Snake venoms
- Bacterial: Infective endocarditis
- Viral: Epstein-Barr virus infection, Hepatitis B and C

Clinical Manifestations

Edema is the presenting symptom in about 95% of children with nephrotic syndrome
Anorexia, irritability, fatigue, abdominal discomfort, and diarrhea are common
Respiratory distress can occur, due to either massive ascites and thoracic compression, frank pulmonary edema, or effusions
Children with nephrotic syndrome occasionally present with gross hematuria
Hypertension can be present

Laboratory Investigations

Laboratory tests should confirm:
- Nephrotic-range proteinuria
- Hypoalbuminemia
- Hyperlipidemia

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the clinical presentation and laboratory studies of acute nephritic syndrome, including its association with streptococcal infections.