What Is Nephrotic Syndrome?
Nephrotic syndrome is a kidney disorder characterized by symptoms such as excretion of a large amount of protein in the urine, high cholesterol and low albumin levels in the blood, and swelling of the extremities and face.
Glomeruli are the filtering part of the kidney's filtering unit called the nephron. These are small blood vessels that filter the waste products and extra fluid from the body. This waste product ends up in the urinary bladder via ureters. These glomeruli get inflamed in a nephrotic syndrome which causes the infiltration of the protein into the urine. As a result, the glomeruli become incapable of filtering the protein from the blood, which leads to the leaking of protein into the urine. This condition is called proteinuria.
What Are the Types Of Nephrotic Syndrome?
Primary and secondary are the two types of nephrotic syndrome.
The primary nephrotic syndrome is caused by:
1. Focal Segmental Glomerulonephritis: This disease affects the glomerulus, which is a section of the nephron (the filtering of the unit of the kidney).
2. Membranous Nephropathy: This disease affects the glomerular basement membrane and blocks it by the deposition of protein.
3. Minimal Change Disease: This is the main cause of nephropathy in children.
Secondary nephrotic syndrome is always associated with some underlying diseases such as diabetes mellitus, amyloidosis, hepatitis B and C, HIV (human immunodeficiency virus), or lupus.
What Are The Causes Of Secondary Nephrotic Syndrome?
Diabetes mellitus is mainly responsible for the development of Secondary nephrotic syndrome.
Other causes include:
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Systemic lupus erythematosus - It is an autoimmune disease affecting healthy organs by causing inflammation.
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Amyloidosis - Abnormal deposition of amyloid protein in the body.
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Multiple myeloma - A type of cancer of plasma cells that can damage kidneys.
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Viral infections such as Hepatitis B or C, Malaria.
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Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS).
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Streptococcal infection - A type of bacterial infection affecting the throat.
What Are The Symptoms Of Secondary Nephrotic Syndrome?
Following are the common symptoms of secondary nephrotic syndrome:
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Proteinuria (when there are more than 3 to 3.5 grams of protein in urine).
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Low serum albumin level (decrease in blood albumin levels).
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Hyperlipidemia (increase in total cholesterol level in blood).
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Thromboembolism (arterial and venous blood clots).
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Bacterial infections such as cellulitis, peritonitis, and sepsis in patients on long-term corticosteroid therapy.
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Weight gain.
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Fatigue.
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Edema in the lower extremities, periorbital region, and or genital region.
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Ascites (fluid collection in the lower abdomen).
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Pleural effusion (fluid collection in the layers of lungs - pleura).
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Pericardial effusion (fluid collection in the protecting layers of the heart).
How To Diagnose Secondary Nephrotic Syndrome?
Laboratory tests are sufficient to diagnose nephrotic syndrome.
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Urine tests - Urine analysis is done to confirm the presence of protein in urine and to determine the protein and creatinine ratio.
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Blood test - To confirm serum creatinine, serum albumin, serum lipid levels, and hyperglycemia (to confirm diabetes).
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To confirm other underlying systemic diseases:
- The human immunodeficiency virus screening test to confirm AIDS.
- Serum or urine protein electrophoresis to confirm amyloidosis.
- Fluorescent treponemal antibody absorption (FTA-ABS) test to confirm syphilis.
How To Treat Secondary Nephrotic Syndrome?
To Control Edema - Low sodium intake balance will help reduce edema till the underlying disease is treated or as renal inflammation reduces. Sodium intake should be reduced to three grams per day and fluid intake to less than one and a half liters per day.
Diuretics for Weight Management - Diuretics, such as furosemide or bumetanide given intravenously because of the poor absorption of oral drugs. Thiazide diuretics, potassium-sparing diuretics, or Metolazone may be useful as adjunctive diuretics.
To Control Proteinuria - Angiotensin-converting enzyme (ACE) inhibitors are used to reduce proteinuria in patients with nephrotic syndrome.
To Treat Hypoalbuminemia - Intravenous albumin can help in diuresis because edema can be caused by hypoalbuminemia.
Corticosteroids - treatment with corticosteroids may help in improving proteinuria and renal function in patients with minimal change disease, but not in membranous nephropathy or proliferative glomerulonephritis.
To Control Hyperlipidemia - Hyperlipidemia should be controlled as it can cause atherosclerosis in patients with nephrotic syndrome. The treatment regimen should be the same as other patients.
To Control Infection - Any opportunistic infection should be controlled and treated well in patients with nephrotic syndrome.
To Treat Thromboembolism - Patients who are at high risk of thromboembolism or with a history of it should be considered a high priority for prophylactic medications against developing secondary nephrotic syndrome.
How To Prevent Secondary Nephrotic Syndrome?
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Diet Management - Dietary changes should be made by limiting the intake of sodium and fluids to control swelling. Reduction in the amount of cholesterol in the diet can help to control blood cholesterol levels. Weight management to control obesity.
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Management of Hypertension - Medications should be taken to control high blood pressure. Routine examination and a healthy diet should be maintained. Diabetes mellitus is the major cause of the secondary nephrotic syndrome, and it should be well maintained using hypoglycemics.
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Vaccination against infectious diseases like hepatitis should be taken. Antibiotics should be taken as and when prescribed by the physician. Once the underlying disease is treated, nephrotic syndrome can be treated easily.
What Are The Complications Of Secondary Nephrotic Syndrome?
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Venous Thromboembolism - Blood clots in the veins and arteries that may lead to thrombosis.
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Acute Renal Failure - Failure of the kidney to filter the blood.
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Bacterial Infection - This may be caused by the loss of antibodies which are proteins that are lost in the urine.
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Hypertension - High blood pressure chronic or long-standing kidney diseases cause renal failure.
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Malnutrition - Loss of protein in blood can cause weight reduction.
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Anemia - Decrease in red blood cells carrying oxygen anemia is caused.
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Loss of appetite.
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Tiredness.
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Hypoalbuminemia - Low levels of albumin in the blood.
Conclusion
A nephrotic syndrome caused secondary to system diseases is the secondary nephrotic syndrome. To treat any kidney disease, it is mandatory to prioritize the underlying systemic disease. There is no specific treatment for nephrotic syndrome, but it can be treated once the system of disease is known. Treatment of diabetes and controlling hyperglycemia can even prevent the occurrence of kidney diseases. Maintaining a dietary habit of low sodium intake can help prevent swelling. Vaccination against opportunistic infections can help prevent infection. Examination of the underactive thyroid gland should be done to know if there is a presence of hypothyroidism. Cholesterol levels should be maintained by patients by changing dietary habits.
