Definition

Nephritic syndrome is a set of symptoms that occur due to the swelling and inflammation of the glomeruli in the kidney, a condition known as glomerulonephritis. Glomeruli are the smallest filtering units in the kidney, responsible for filtering waste substances from the blood and producing urine. When there is disruption in the glomerulus, it can lead to a decreased ability of the kidneys to filter blood and produce normal urine effectively. This condition requires prompt attention as it has the potential to cause permanent kidney damage.

Read more: Nefrotic Syndrome

Causes

Nephritic syndrome is primarily caused by an immune response to infection or other diseases, with glomerulonephritis being a common underlying cause. The inflammation of glomeruli varies slightly between children and adults.

In children and adolescents, the most common causes include:

• Post-streptococcal glomerulonephritis: A kidney disorder occurring after an infection from streptococcal bacteria, which can affect the throat or skin. Glomerulonephritis typically develops within 1-3 weeks after a streptococcal infection elsewhere in the body.
• Hemolytic uremic syndrome: Infections of the gastrointestinal system can produce toxins that destroy red blood cells and cause kidney damage.
• Henoch-Schönlein purpura: A disease characterized by purplish spots on the skin, joint pain, gastrointestinal disturbances, and glomerulonephritis.
• IgA nephropathy: A disorder where IgA antibodies accumulate in kidney tissue.

In adults, the most common causes of nephrotic syndrome include:

• Abdominal abscess
• Goodpasture's syndrome: An autoimmune disorder that targets the glomeruli.
• Hepatitis B or C infection
• Endocarditis: Inflammation of the heart chambers and valves' inner layer due to bacterial infection.
• Membranoproliferative glomerulonephritis: A disorder causing inflammation and changes in kidney cells.
• Rapidly progressive glomerulonephritis: A type of glomerulonephritis leading to rapid deterioration of kidney function.
• Lupus nephritis: A complication of lupus.
• Vasculitis: Inflammation of blood vessels.
• Viral infections such as measles.

Inflammation in the glomeruli results in suboptimal blood filtration, leading to protein and blood in the urine and fluid retention in the body. Swelling occurs when the blood loses albumin protein, maintaining fluid within blood vessels. A decrease in albumin leads to fluid shifting into body tissues.

Risk factor

Some risk factors associated with the occurrence of nephritic syndrome include:

• Previous history of streptococcal infection, particularly respiratory tract or skin infections
• Having lupus or other autoimmune disorders.
• Family history of kidney disease

Symptoms

Many symptoms may indicate nephritic syndrome, but some typical ones commonly observed include:

• Blood in the urine: Urine may appear dark, brownish, or cloudy, and it may also be foamy due to the presence of protein
• High blood pressure
• Reduced urine output, sometimes to nearly nonexistent levels
• Swelling around the eyes and ankles: Eye swelling often occurs in the morning, while ankle swelling worsens at night

Other symptoms may depend on the underlying cause and can include:

• Blurred vision: This may result from burst blood vessels in the eye's retina
• Coughing up blood or phlegm: This occurs due to fluid accumulation in the lungs
• Shortness of breath
• Fatigue, tiredness, tendency to drowsiness, confusion, and headache
• Fever

Diagnosis

Diagnosis of nephritic syndrome typically involves analyzing symptoms, conducting physical examinations, and performing diagnostic tests to confirm the condition and identify the underlying cause.During a physical examination, healthcare providers may:

• Measure blood pressure, as hypertension is common in nephritic syndrome
• Examine the eyes, neck, heart, lungs, abdomen, and legs. Some findings indicative of nephritic syndrome may include:

• • High blood pressure.
  • Pale conjunctiva of the eyes.
  • Abnormal heart and lung sounds.
  • Signs of fluid overload or swelling in the hands, arms, face, and abdomen.
  • Enlargement of the liver.
  • Enlargement of the veins in the neck.

Based on the physical examination results, the doctor may recommend specific diagnostic tests to determine the cause. These tests may include:

• Urine tests are used to detect protein and blood in the urine, common indicators of nephritic syndrome
• Blood tests: These help assess electrolyte levels, urea, creatinine in the blood, complement system, and kidney filtration function indicators. Additionally, a blood culture may be necessary if accompanied by prolonged fever
• Kidney biopsy: A procedure involving removing a small amount of kidney tissue to examine inflammation in the glomerular structures, helping to identify the underlying cause
• ANA titer and other antibody tests: These tests may be performed to investigate autoimmune causes such as lupus
• Culture of specimens from the throat or skin: This can help confirm the type of microorganism infecting the body

Management

The goal of treatment for nephritic syndrome is primarily supportive, aiming to reduce inflammation in the kidneys and control blood pressure. Treatment typically involves a combination of medications and lifestyle modifications.  Medications prescribed by the doctor may include:

• Antihypertensive drugs: These medications help lower blood pressure and reduce kidney strain.
• Corticosteroids: These medications help reduce kidney inflammation and may be prescribed to suppress the immune response.
• Diuretics: These drugs help eliminate excess fluid from the body, reducing swelling and relieving symptoms of fluid overload.

In cases where an underlying infection is present, antibiotics may also be prescribed to treat the infection and prevent further complications.

In addition to medication, other management options may include:

• Total bed rest: Limiting physical activities until improvement with treatment can help reduce strain on the kidneys and promote healing.
• Dietary changes: A diet restricting salt, fluid, and potassium intake can help manage fluid retention and high blood pressure.
• Kidney dialysis or blood cleansing: In severe cases or if kidney function is significantly impaired, dialysis may be necessary to remove waste products and excess fluid from the blood.

Complications

The complications of nephritic syndrome vary depending on the underlying cause. However, the primary affected function is the blood filtration process in the kidneys, which can lead to several complications:

• Acute kidney failure
• Uncontrolled hypertension
• Electrolyte imbalance
• Heart failure
• Hypertensive encephalopathy: Severe hypertension can lead to hypertensive encephalopathy, a condition characterized by seizures, confusion, and decreased consciousness due to swelling and damage to the brain.

If nephritic syndrome is not properly treated, it can progress to chronic glomerulonephritis and chronic kidney disease. While children may recover more quickly from the condition, adults are at a higher risk of developing kidney failure, which may require routine dialysis or kidney transplantation to manage.

Prevention

Nephrotic syndrome may not always be preventable, but proactive measures can help mitigate its risk. Early detection and comprehensive treatment of underlying conditions are key strategies. By effectively managing the conditions predisposing individuals to nephrotic syndrome, the likelihood of its development can be reduced. Patients should diligently adhere to prescribed medications and maintain regular check-ups with their healthcare providers. These steps enable timely intervention, potentially averting the onset of nephrotic syndrome and its associated complications.

When to see a doctor?

You should seek prompt medical attention if you experience the symptoms mentioned above. If you have underlying conditions or are at risk of developing them, make sure to seek timely medical intervention and adhere to treatment plans diligently. Regular check-ups are crucial for maintaining overall health and detecting potential issues early on. If symptoms worsen rapidly or if you notice a significant decrease in urine output, seek immediate medical attention at the nearest healthcare facility to facilitate early intervention.

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