Nephrotic syndrome is a renal disorder characterized by the excessive loss of protein in the urine, resulting in abnormally high levels of protein excretion. Typically, this condition results from damage to the glomeruli, the kidney's tiny blood vessel clusters responsible for filtering waste and excess water from the bloodstream. As a result, individuals with nephrotic syndrome may experience swelling, particularly in the feet and ankles, and are at an increased risk of developing other health problems.
Nephrotic syndrome is characterized by a group of symptoms that indicate the kidneys are not functioning properly. These symptoms include proteinuria (excessive protein in the urine), hypoalbuminemia (low albumin levels in the blood), edema (swelling in parts of the body), and hyperlipidemia (high cholesterol and lipid levels in the blood). The kidneys are composed of approximately one million filtering units called nephrons, each consisting of a glomerulus and a tubule.
Normally, the glomeruli in healthy kidneys filter waste products while retaining essential cells and proteins in the blood. But in nephrotic syndrome, damaged glomeruli fail to filter properly, causing proteins like albumin to leak into the urine. If left untreated, nephrotic syndrome can cause significant damage to the kidneys and increase the risk of complications. In fact, individuals with nephrotic syndrome may lose three or more grams of protein in their urine over 24 hours, which is significantly higher than the amount allowed by healthy glomeruli.
Who Is at Higher Risk of Developing Nephrotic Syndrome?
Nephrotic syndrome is a condition that can affect individuals of any age, from children to adults. While nephrotic syndrome can impact individuals across various age groups, but it predominantly affects children, with the majority of diagnoses occurring between the ages of 1 and 6. Interestingly, boys within this age range are more likely to be affected by the condition. In adults, additionally certain factors can increase an adult's risk of developing nephrotic syndrome, including pre-existing kidney issues, use of specific medications, and infections such as HIV, hepatitis, or malaria, with a slightly higher incidence in men.
MedBound Times consulted with Dr. Vaishnavi Pochineni, MD, FACP, FASN, a renowned Consultant Nephrologist and Kidney Transplant Physician, to gain her expert insights on Nephrotic Syndrome.
Dr Vaishnavi Pochineni says nephrotic syndrome is significantly more prevalent in India compared to the West, largely because a higher number of cases are observed in children.
A common misconception is that "nephrotic syndrome is solely caused by kidney failure" however, this is not always the case. While nephrotic syndrome encompasses a broad spectrum of kidney-related diseases, in many cases, especially in children, are reversible with proper treatment.Dr Vaishnavi Pochineni, Consultant Nephrologist & Kidney Transplant Physician, Srikara Hospitals & Preeti Urology & Kidney Hospital
A common misconception is that "nephrotic syndrome is solely caused by kidney failure" however, this is not always the case. While nephrotic syndrome encompasses a broad spectrum of kidney-related diseases, in many cases, especially in children, are reversible with proper treatment. Only the most severe and refractory cases progress to chronic kidney disease, necessitating advanced interventions states Dr Vaishnavi Pochineni.
What is nephrotic syndrome in children also called?
Healthcare professionals categorize nephrotic syndrome in children based on the age of onset:
Congenital Nephrotic Syndrome: Symptoms appear from birth to 3 months.
Infantile Nephrotic Syndrome: Symptoms appear between 3 to 12 months.
Childhood Nephrotic Syndrome: Symptoms appear at 12 months or older.
Nephrotic syndrome can be classified into two main categories based on its cause:
Primary Nephrotic Syndrome: Caused by a kidney disease that only affects the kidneys.
Secondary Nephrotic Syndrome: Caused by external factors such as diseases affecting other parts of the body, infections, or certain medications.
Identifying the Signs and Symptoms of Nephrotic Syndrome:
Common Symptoms:
Severe swelling (edema), particularly around the eyes, ankles, feet, legs, abdomen, hands, face, or other parts of the body
Foamy or bubbly urine is a common symptom of proteinuria, or excess protein in the urine
Weight gain due to fluid retention
Fatigue or feeling tired
Loss of appetite
Muscle cramps
Blood in the urine (in some cases)
Abdominal pain
Low levels of albumin in the blood (hypoalbuminemia)
Additional Symptoms in Children:
Swelling around the eyes, usually greater in the morning
Growth problems due to loss of essential minerals and vitamins, such as calcium and vitamin D
Weakened hair and nails due to osteoporosis
Other Possible Symptoms:
High levels of fat and cholesterol in the blood, also known as hyperlipidemia
Increased risk of infections
Increased risk of blood clots
What are the underlying causes of nephrotic syndrome?
Primary Causes (Diseases that affect only the kidneys):
Minimal Change Disease (MCD): A kidney disease that causes abnormal kidney function.
Focal Segmental Glomerulosclerosis (FSGS): A disease that causes scarring of some of the glomeruli.
Membranous Nephropathy: A kidney condition characterized by thickening of the glomerular basement membrane, disrupting normal kidney function.
Secondary Causes (Diseases that affect multiple parts of the body):
Diabetes: Damage to the kidneys due to high blood sugar levels.
Systemic Lupus Erythematosus (SLE): An autoimmune disease that can cause inflammation and damage to the kidneys.
Amyloidosis: A disorder that occurs when amyloid proteins accumulate in the kidneys.
Infections: Including HIV, hepatitis B, and hepatitis C.
Genetic Disorders: Such as congenital nephrotic syndrome.
Types of Nephrotic Syndrome:
Primary Nephrotic Syndrome: Caused by diseases that affect only the kidneys.
Secondary Nephrotic Syndrome: Caused by diseases that affect multiple parts of the body.
Common Causes in Children and Adults:
In kids, Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome.
In adults, Focal Segmental Glomerulosclerosis (FSGS) is the primary cause of nephrotic syndrome.
What complications can arise from nephrotic syndrome?
Nephrotic Syndrome can lead to the following serious complications:
Blood clots that can cause thrombosis
Higher risk of infection due to the loss of immunoglobulins
High blood pressure (hypertension)
High cholesterol
Brief or long-lasting kidney problems, including: Chronic kidney disease, Kidney failure, Acute kidney injury
Anemia (A condition characterized by a shortage of healthy red blood cells, which are essential for delivering oxygen throughout the body)
Coronary artery disease (plaque buildup in heart arteries)
Hypothyroidism (underactive thyroid gland)
These complications can be severe and potentially life-threatening, emphasizing the importance of prompt medical attention and proper management of Nephrotic Syndrome.
Understanding Nephrotic Syndrome: Diagnosis, Treatment, and Management
Diagnosis of Nephrotic Syndrome:
Nephrotic syndrome is typically diagnosed through a combination of physical examination, medical history, and laboratory tests. These tests may include:
Urine tests to detect abnormalities, such as large amounts of protein
To diagnose nephrotic syndrome, blood tests are used to identify low protein levels and related issues
Imaging tests, such as a kidney ultrasound
Kidney biopsy to confirm the diagnosis and identify the underlying cause
Treatment of Nephrotic Syndrome:
Treatment for nephrotic syndrome often involves a multifaceted approach, incorporating both medications and lifestyle changes. Medications may include:
Corticosteroids to reduce inflammation and protein loss
Immunosuppressants to control the immune system
Diuretics to manage swelling
Cholesterol-reducing medications to lower cholesterol levels
Blood thinners to prevent blood clots
Prevention and Management:
While a cure for nephrotic syndrome remains elusive, prompt diagnosis and treatment can significantly alleviate symptoms and decelerate disease progression. Implementing lifestyle modifications, such as reducing salt and fluid consumption, adopting a low-fat diet, and engaging in regular physical activity, can also play a crucial role in managing symptoms and improving overall well-being.
Dr Vaishnavi Pochineni points that a low-salt and low-fat diet is fundamental in managing nephrotic syndrome. In addition, monitoring blood pressure, ensuring adequate protein intake, and preventing infections are critical components of care.
Diet and Nutrition:
Although diet and nutrition do not cause or prevent nephrotic syndrome, if you've developed the condition, your doctor may suggest the following dietary adjustments:
Limit intake of sodium (salt) and fluids
Limit dietary fat and cholesterol intake
Eat a low-salt diet to help control swelling
Nephrotic Syndrome in Children:
Nephrotic syndrome can affect children, and while the diagnostic approach and treatment principles are similar to those for adults, pediatric cases often necessitate closer monitoring and more frequent adjustments to their treatment regimen to ensure optimal management and accommodate their unique needs.
Diagnosing Nephrotic Syndrome in Children:
Nephrotic syndrome in children is diagnosed with:
Medical and family history
Physical exam
Urine tests to look for excess urine proteins
Blood tests are performed to assess kidney function and diagnose underlying conditions.
Treating Nephrotic Syndrome in Children:
Treatment for nephrotic syndrome in children typically involves:
Corticosteroids to reduce inflammation and protein loss
Immunosuppressants to control the immune system
Diuretics to manage swelling
Cholesterol-reducing medications to lower cholesterol levels
Congenital Nephrotic Syndrome:
Congenital nephrotic syndrome is most often caused by genetic abnormalities or infections passed from mother to child during fetal development. Treatment options differ based on the underlying cause and may involves:
Albumin infusions to replace lost protein
Medications to reduce swelling and lower blood pressure
Dialysis to filter wastes from the blood
Significant research is underway in areas such as genetic mutations, podocyte-targeted therapies, and novel biological treatments, offering hope for improved outcomes in the future says Dr Vaishnavi Pochineni.
Note: This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits.
References:
Mayo Clinic. "Nephrotic Syndrome: Symptoms and Causes." Last modified October 11, 2022. Accessed December 8, 2024. https://www.mayoclinic.org/diseases-conditions/nephrotic-syndrome/symptoms-causes/syc-20375608.
Mayo Clinic. "Nephrotic Syndrome: Diagnosis and Treatment." Last modified October 11, 2022. Accessed December 8, 2024. https://www.mayoclinic.org/diseases-conditions/nephrotic-syndrome/diagnosis-treatment/drc-20375613.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). "Nephrotic Syndrome in Adults." Last reviewed May 2021. Accessed December 8, 2024. https://www.niddk.nih.gov/health-information/kidney-disease/nephrotic-syndrome-adults.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). "Nephrotic Syndrome in Children." Last reviewed May 2021. Accessed December 8, 2024. https://www.niddk.nih.gov/health-information/kidney-disease/children/nephrotic-syndrome-children.
American Kidney Fund. "Nephrotic Syndrome: Treatments, Causes, and Symptoms." Accessed December 8, 2024. https://www.kidneyfund.org/all-about-kidneys/other-kidney-problems/nephrotic-syndrome-treatments-causes-symptoms.
National Health Service (NHS). "Nephrotic Syndrome." Last reviewed June 29, 2023. Accessed December 8, 2024. https://www.nhs.uk/conditions/nephrotic-syndrome/.
Cleveland Clinic. "Nephrotic Syndrome." Last reviewed September 23, 2022. Accessed December 8, 2024. https://my.clevelandclinic.org/health/diseases/5989-nephrotic-syndrome.