Primary Nephrotic Syndrome in Children

Primary Nephrotic Syndrome in Children

Definition:

Primary nephrotic syndrome in children (PNSC) is a group of symptoms that manifest nephrotic syndrome, the majority of which are idiopathic (90%). The main damage occurs in the glomerulus.

Diagnostic Criteria:

PNSC is diagnosed based on biological-clinical criteria:

• Massive proteinuria: Proteinuria > 50mg/kg/24h or > 40mg/m2/hour or urine protein/creatinine ratio >= 200mg/mmol.

• Generalized edema: White, soft, pitting edema, painless, often starting abruptly from the face and spreading to the whole body.

• Hypoalbuminemia: <= 25g/l.

• Hypercholesterolemia: > 5.2mmol/l.

Clinical Manifestations:

• Edema:

• Generalized edema, white, soft, pitting, painless.

• Edema in multiple membranes (ascites, pleural effusion, pericardial effusion).

• Abdominal pain:

• Not frequent and not specific.

• May be due to abdominal distention due to excessive ascites, mesenteric vascular occlusion, digestive disorders, primary peritonitis…

Paraclinical Manifestations:

• Urinalysis:

• Proteinuria mostly > 100mg/kg/24h, selective proteinuria.

• Red blood cells are almost absent or only in mild and temporary microhematuria.

• Hyaline casts.

• Blood tests:

• Total protein significantly reduced, mostly < 40g/l.

• Serum protein electrophoresis: Serum albumin significantly reduced (< 25g/l), alpha2 Globulin and beta Globulin increased, gamma Globulin significantly reduced in the late stage.

• Immunoglobulin electrophoresis: IgM increased and IgG significantly reduced, especially when the disease is severe.

• Blood lipids and cholesterol increased.

• Blood count: Decreased red blood cells, white blood cells and platelets may increase.

• Erythrocyte sedimentation rate is usually very high in the first hour > 50mm.

• Electrolyte test: Sodium, Potassium, Calcium are usually reduced.

• Urea and Creatinine within normal limits.

Main Complications:

• Infections: Primary peritonitis, pneumonia, cellulitis, urinary tract infection, sepsis.

• Deficiency syndromes: Developmental delay, malnutrition, osteoporosis, calcium deficiency seizures (tetany), anemia, simple goiter…

• Mesenteric vascular occlusion, in the lungs, in the limbs.

• Abdominal pain: Can be due to mesenteric edema, pancreatitis, primary peritonitis, gastric ulcer…

• Complications due to corticoids: Water and electrolyte disturbances, endocrine and metabolic disturbances, affecting most organs in the body when used at high doses and for a long time.

• Complications due to immunosuppressant and cancer cell suppressant drugs: Bone marrow suppression, infertility, leukemia, infections, hemorrhagic cystitis, hair loss…

• Complications due to diuretics: Water and electrolyte disturbances (decreased blood sodium, decreased blood potassium), decreased volume (cardiovascular collapse, kidney failure) when used suddenly in large quantities.

Classification:

• Clinically:

• Pure primary NS: normal blood pressure, no renal insufficiency, no hematuria.

• Non-pure primary NS (combined NS): hypertension and/or renal insufficiency and/or hematuria.

• According to progression:

• First-time primary NS.

• Recurrent primary NS: edema and increased proteinuria when switching from attack dose to maintenance dose or after stopping maintenance dose.

• According to treatment:

• Corticosteroid-sensitive NS: urine becomes protein-free within 2 weeks.

• Corticosteroid-dependent NS: recurrence when switching dose or stopping medication.

• Corticosteroid-resistant NS: proteinuria remains high after attack treatment.

Classification according to cause, pathology and criteria for cure:

• By cause:

• Congenital: rare.

• Primary: idiopathic.

• Secondary (after systemic diseases, metabolic diseases, infections – toxins).

• According to pathology:

• Minimal change NS (85%): Hyaline sclerosis or degeneration of glomerulus partially or locally.

• Membranous proliferative NS (5%): Mesangial proliferative glomerulonephritis.

• Focal segmental glomerulosclerosis (10%): Membranous glomerulonephritis.

• Membrano-proliferative glomerulonephritis.

• Criteria for cure:

• “Cured” when treatment is stopped for more than 2 years without any recurrence.

Circumstances of discovery:

• Early onset, rapid generalized edema, white, soft, pitting, painless.

Criteria for defining NS:

• PROTEINURIA > 3.5G/24h mostly albumin or > 50mg/kg/24h for children.

• Serum protein below 60g/l and serum albumin below 25g/l.

Additional diagnostic criteria for PNSC:

• Edema.

• Hyperlipidemia.

Renal biopsy indication:

• Congenital NS (children under 1 year old).

• Combined NS.

• Corticosteroid-resistant NS.

Treatment:

• Corticosteroids are the main treatment.

• Immunosuppressants are indicated in cases of:

• Corticosteroid contraindications.

• Corticosteroid resistance.

• Corticosteroid dependence.

• Diuretics are used to reduce edema.

Multiple Choice Questions:

• Immunosuppressants are indicated in nephrotic syndrome when:

• D. All of A, B & C are correct.

• Two clinical symptoms of pure nephrotic syndrome:

• C. Edema and Proteinuria > 3.5 g/24 hours

• The sign of Proteinuria in nephrotic syndrome:

• D. Due to increased glomerular capillary permeability.

• Edema in nephrotic syndrome:

• D. Usually accompanied by oliguria

• Additional criteria for diagnosing nephrotic syndrome:

• C. Rapid, white, soft edema

• The main criteria for diagnosing nephrotic syndrome:

• C. Decreased serum protein, decreased serum albumin, proteinuria > 3.5 g/24 hours

• Differentiating pure nephrotic syndrome or combined:

• D. Based on hypertension, hematuria and renal insufficiency

• Diagnosis is very valuable in determining the damage of nephrotic syndrome

• renal biopsy

• Differentiating pure NS, non-pure NS

• Pure nephrotic syndrome: normal blood pressure, no renal insufficiency, no hematuria. Non-pure nephrotic syndrome: hypertension and/or renal insufficiency and/or hematuria.

• Primary NS occurs in

• B. More males than females.

Note: This article is for general information only and should not be considered as a substitute for professional medical advice. Please consult a doctor for appropriate diagnosis and treatment.