Glomerulonephritis in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Glomerulonephritis refers to inflammation of the glomeruli, the tiny filtering units within the kidneys, which are responsible for filtering blood and producing urine. In children, glomerulonephritis can be acute or chronic and can result from a variety of causes, including infections, autoimmune diseases, and genetic factors. The condition may lead to impaired kidney function, causing symptoms such as blood in the urine, proteinuria, and swelling.

Aetiology

Glomerulonephritis can have different causes, which can be categorised into primary and secondary forms:

• Primary glomerulonephritis: Conditions that primarily affect the kidneys, such as IgA nephropathy and idiopathic nephrotic syndrome.
• Post-infectious glomerulonephritis: Most commonly occurs after a streptococcal throat or skin infection (post-streptococcal glomerulonephritis).
• Secondary glomerulonephritis: Results from systemic diseases such as lupus (systemic lupus erythematosus), Henoch-Schönlein purpura, or Goodpasture syndrome.

Pathophysiology

Glomerulonephritis involves immune-mediated inflammation and damage to the glomeruli. This inflammation impairs the glomerular filtration process, leading to leakage of blood (haematuria) and protein (proteinuria) into the urine. In severe cases, the inflammation can cause reduced kidney function, leading to fluid retention and high blood pressure. Over time, this can result in chronic kidney disease or end-stage renal failure if not managed appropriately.

Risk Factors

• Recent streptococcal infection (throat or skin infection).
• Autoimmune diseases such as systemic lupus erythematosus.
• Family history of kidney disease or genetic kidney disorders.
• Exposure to toxins or drugs that may affect the kidneys.
• Chronic infections (e.g., hepatitis B or C).
• Henoch-Schönlein purpura (HSP) in children.

Signs and Symptoms

Symptoms of glomerulonephritis in children can vary depending on the severity and duration of the condition but may include:

• Haematuria (blood in the urine), which may cause the urine to appear pink, brown, or red.
• Proteinuria (excessive protein in the urine), often seen as frothy urine.
• Oedema (swelling), especially around the eyes, face, abdomen, or legs.
• Hypertension (high blood pressure).
• Fatigue or weakness due to kidney dysfunction.
• Decreased urine output or oliguria in severe cases.

Investigations

Several tests may be performed to diagnose glomerulonephritis and assess kidney function:

• Urine analysis: To detect haematuria, proteinuria, and red blood cell casts.
• Blood tests: Full blood count (FBC), urea and electrolytes (U&E), and creatinine to assess kidney function.
• Renal ultrasound: To assess the size and structure of the kidneys and rule out any structural abnormalities.
• Renal biopsy: May be required in cases where the diagnosis is unclear or to determine the specific type of glomerulonephritis.

Management

The management of glomerulonephritis depends on the underlying cause, severity, and progression of the disease. The goals of treatment are to control symptoms, prevent complications, and preserve kidney function.

General Management:

• Blood pressure control: Use of antihypertensive medications such as ACE inhibitors or angiotensin receptor blockers (ARBs) to manage hypertension and reduce proteinuria.
• Diuretics: May be prescribed to help reduce oedema by increasing urine output.
• Salt and fluid restriction: In cases of oedema and hypertension, dietary restrictions may be advised.

Specific Treatments:

• Post-infectious glomerulonephritis: Typically self-limiting and managed with supportive care, including monitoring blood pressure and fluid balance.
• Immunosuppressive therapy: In cases where autoimmune diseases (e.g., lupus nephritis) are involved, corticosteroids or other immunosuppressants may be used to reduce inflammation.
• Plasma exchange: In rare, severe cases such as Goodpasture syndrome, plasma exchange may be used to remove harmful antibodies from the blood.

Follow-up and Monitoring:

• Children with glomerulonephritis require regular follow-up to monitor kidney function, blood pressure, and urine output.
• Referral to a paediatric nephrologist is often necessary for ongoing care and management.

References

1. NHS (2024). Glomerulonephritis in Children: Diagnosis and Management. Available at: NHS
2. NICE (2024). Glomerulonephritis: Guidelines for Children. Available at: NICE Guidance
3. British Medical Journal (2023). Paediatric Glomerulonephritis: A Clinical Guide. Available at: BMJ