Nephrotic Syndrome

Nephrotic syndrome is a kidney disorder characterized by excessive protein loss in the urine, leading to low levels of protein in the blood, swelling (edema), and other systemic complications. It is not a disease itself but a collection of symptoms that signal significant kidney damage. Understanding the disease requires delving into its underlying causes, risk factors, symptoms, diagnostic procedures, and management strategies.

What is Nephrotic Syndrome?

It occurs when the kidneys’ filtering units, known as glomeruli, become damaged. The glomeruli are responsible for filtering blood, retaining essential proteins, and removing waste products through urine. When these structures are damaged, they allow large amounts of protein, especially albumin, to leak into the urine. This condition disrupts the balance of fluids in the body, causing swelling and other complications.

Key Features of Nephrotic Syndrome

The hallmark features include:

1. Proteinuria
   • Excessive protein in the urine (>3.5 grams per day).
2. Hypoalbuminemia
   • Low levels of albumin in the blood.
3. Edema
   • Swelling, particularly in the legs, feet, ankles, and around the eyes.
4. Hyperlipidemia
   • Elevated levels of cholesterol and triglycerides in the blood.
5. Foamy Urine
   • Resulting from high protein content in the urine.

Causes

Nephrotic syndrome can be primary (originating in the kidneys) or secondary (resulting from systemic conditions).

Primary Causes

1. Minimal Change Disease (MCD)
   • The most common cause in children, it involves subtle changes in kidney tissues visible only under an electron microscope.
2. Focal Segmental Glomerulosclerosis (FSGS)
   • Characterized by scarring in some parts of the glomeruli.
3. Membranous Nephropathy
   • A condition involving thickened glomerular membranes due to immune deposits.

Secondary Causes

1. Diabetes Mellitus
   • Diabetic nephropathy is a leading cause of secondary nephrotic syndrome.
2. Lupus Nephritis
   • A kidney complication of systemic lupus erythematosus.
3. Infections
   • Hepatitis B, hepatitis C, HIV, and malaria can trigger nephrotic syndrome.
4. Medications
   • Certain drugs, such as NSAIDs and antibiotics like penicillamine, can induce nephrotic syndrome.
5. Amyloidosis
   • The deposition of abnormal proteins in kidney tissues.

Symptoms of Nephrotic Syndrome

Beyond the key features, individuals may experience:

• Fatigue and lethargy.
• Weight gain due to fluid retention.
• Reduced urine output.
• Susceptibility to infections due to loss of immunoglobulins in the urine.
• Blood clots, as the condition can lead to a hypercoagulable state.

Diagnosis

Diagnosis involves a combination of clinical assessment, laboratory tests, and imaging studies.

Laboratory Tests

1. Urinalysis
   • Measures protein levels and detects the presence of red and white blood cells.
2. Blood Tests
   • Evaluate levels of albumin, cholesterol, and kidney function markers such as creatinine and urea.
3. 24-Hour Urine Collection
   • Quantifies the amount of protein lost in urine.
4. Serological Tests
   • Identify underlying conditions like lupus or hepatitis.

Imaging and Biopsy

1. Kidney Ultrasound
   • Assesses kidney size and structure.
2. Kidney Biopsy
   • A definitive diagnostic tool to examine kidney tissue and determine the underlying cause.

Complications

Nephrotic syndrome, if left untreated, can lead to serious complications:

1. Acute Kidney Injury (AKI)
   • Sudden loss of kidney function.
2. Chronic Kidney Disease (CKD)
   • Progressive and irreversible kidney damage.
3. Infections
   • Increased vulnerability to bacterial and viral infections.
4. Thromboembolism
   • Formation of blood clots due to altered coagulation factors.
5. Malnutrition
   • Loss of essential proteins can lead to muscle wasting and poor growth in children.

Management and Treatment

The treatment of nephrotic syndrome depends on its underlying cause and severity. The goals are to reduce protein loss, control symptoms, and prevent complications.

Medications

1. Corticosteroids
   • Often the first line of treatment for conditions like minimal change disease.
2. Immunosuppressive Drugs
   • Used for immune-mediated nephrotic syndrome (e.g., cyclophosphamide, tacrolimus).
3. Diuretics
   • Help reduce swelling by promoting fluid excretion.
4. ACE Inhibitors and ARBs
   • Reduce proteinuria and protect kidney function.
5. Statins
   • Address hyperlipidemia.
6. Anticoagulants
   • Used to manage or prevent blood clots.

Dietary Management

1. Low Sodium Diet
   • Helps control edema and blood pressure.
2. Moderate Protein Intake
   • Prevents excessive kidney strain while meeting nutritional needs.
3. Low Fat Diet
   • Reduces the risk of cardiovascular complications.

Lifestyle Changes

• Regular exercise to improve overall health.
• Avoiding nephrotoxic substances like certain medications and alcohol.

Prognosis

The outlook for nephrotic syndrome depends on its cause and response to treatment. Children with minimal change disease often achieve remission with corticosteroids. However, conditions like FSGS and membranous nephropathy may progress to chronic kidney disease despite treatment.

Advances in Research

Research into nephrotic syndrome continues to uncover new treatment modalities:

1. Biologic Therapies
   • Target specific immune pathways involved in kidney damage.
2. Genetic Studies
   • Explore inherited forms of nephrotic syndrome for tailored interventions.
3. Novel Medications
   • Development of safer immunosuppressive agents with fewer side effects.

Nephrotic syndrome is a serious condition that requires timely diagnosis and comprehensive management. While it can pose significant challenges, advances in medical care have improved outcomes for many patients. Awareness of its symptoms, causes, and treatments empowers individuals to seek prompt care and make informed decisions about their health.

By addressing nephrotic syndrome holistically, patients can minimize complications and improve their quality of life.

To consult a Nephrologist for treatment of Nephrotic Syndrome at Sparsh Diagnostic Centre, call our helpline number 9830117733.

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Disclaimer:

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Additional Reading:

• https://my.clevelandclinic.org/health/diseases/5989-nephrotic-syndrome