Nephrotic syndrome according to the ICD (International Classification of Diseases) is not an independent kidney disease, but a group of symptoms, the totality of which shows that the kidneys do not work as well as they should.
Small blood vessels (venules, arterioles, and capillaries) in the kidneys function as microfilters, removing toxins, end metabolic products, and excess water from the blood. This waste material and water enter the bladder and leave our body with urine. Normally, there should be no protein in the urine.
Renal vessels are part of the glomerular network, a filtering system of the kidneys. When the filter network is damaged, too much protein passes through the filters into the urine. The consequence of this is nephropathic syndrome, i.e., progressive destruction of the working tissue of the kidneys (nephrons).
This kidney disease affects both adults and children.
Signs of Kidney Disease
Most people who were diagnosed with this pathology did not know about it until the usual clinical trials took place during a routine medical examination.
Symptoms of nephropathology include:
- Excessive urinary protein excretion (proteinuria).
- Low plasma protein. The medical card may say: “hypoalbuminemia”.
- High cholesterol in the blood. The medical term for this is hyperlipidemia.
- High levels of neutral fats in the blood, the so-called triglycerides.
- Swelling of the face, hands, feet and ankles.
- Weight gain.
- Constant feeling of tiredness.
- Foamy urine.
- Decreased hunger.
If, according to the results of general tests, you have a clinical nephrotic syndrome, your doctor will need to find out the cause of this problem. This may require additional tests and diagnostic procedures to identify the root cause.
Kidney diseases often do not have clinical symptoms until the working tissue of the kidneys is severely damaged (70-80%).
Everyone needs proteins
There are many types of proteins, our body consumes proteins in various ways: including the formation of bones, muscles and other tissues that make up the organs, as well as the fight against infections.
When the kidney tissue suffers, the kidneys stop functioning normally, thereby allowing a protein called albumin to pass through its filtration system into the urine.
Albumin helps the body get rid of excess fluid. With a lack of albumin in the blood, fluid accumulates in the body, causing swelling in the face and lower parts of the body.
Cholesterol as an important component of the body
Our body needs cholesterol, which is produced in it independently. In addition to this, cholesterol also comes from food. Excessive intake of cholesterol in the blood harms blood vessels, since droplets of this substance stick together on the walls of veins and arteries and can form blood clots (complete or partial blockage of the lumen of the vessel). Blood clots in the vessels complicate the work of the heart and the flow of blood to organs and tissues, which can subsequently result in myocardial infarction or stroke.
Triglycerides - a type of "energy" fat in the blood
When we eat food, our body consumes calories from the food we eat to generate energy. If we consume more calories than we consume, then excess calories are converted to triglycerides.
Triglycerides are stored in fatty tissue and, when absolutely necessary, they are used as energy to maintain normal cell activity. The presence of a high level of triglycerides in the blood indicates a high predisposition to heart disease.
Who is prone to nephrotic syndrome?
People of all ages, genders, and ethnic groups may be prone to this pathology, but, according to the Russian Ministry of Health (Ministry of Health), it is more common in men than in women.
Nephrotic syndrome in children usually manifests itself between the ages of 2 to 6 years.
Some factors increase the likelihood of progressive kidney disease, these include:
- Nephropathology (glomerulonephritis, nephrolithiasis, etc.).
- Urolithiasis is an urolithiasis.
- Long-term use of medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and antibiotics.
- Infections: HIV, viral hepatitis, malaria.
- Diabetes, lupus, and amyloidosis.
Etiological factors (causes)
The syndrome can be caused by various kidney diseases, as well as other factors.
If the disease affects only the kidneys, then they are called the primary causes of nephrotic syndrome. Other factors that affect the entire body, including the kidneys, are called secondary causes.
Most people suffer from advanced kidney disease due to secondary causes.
The most common primary cause in adults is a disease called focal segmental glomerulosclerosis (FSH). FSGS causes microscopic scarring on kidney filters called glomeruli.
Various autoimmune diseases and chronic immune diseases can seriously damage the kidneys.
Amyloidosis is a genetically determined disease in which an accumulation of a protein substance called amyloid in the blood occurs. It is deposited on the walls of blood vessels, in various organs, including the kidneys.
The most common secondary factor in adults is diabetes. The pathology is accompanied by a kidney disease known as renal (renal) diabetes.
The most common primary factor in renal syndrome in children is Minimal Change Disease (BMI). A disease with minimal changes causes hidden damage to the kidneys, which can only be detected with a very powerful microscope.
The most common secondary factor in children is diabetes.
In all forms, the hallmark of this disease is the progressive destruction of the renal glomeruli.
Kidney diseases that affect the tubules and interstitium, such as interstitial nephritis, do not cause nephrotic syndrome.
Diagnostic Features
- A blood test to determine the glomerular filtration rate of the kidneys (eGFR, Estimated Glomerular Filtration) is an rapid test to assess the functional ability of the kidneys. Your eGFR is a number based on your serum creatinine and urea levels. Primary urine is formed by filtering blood plasma through the glomerular barrier; in humans, the glomerular filtration rate (GFR) is 125 ml / min.
- Clinical examination of urine. With severe damage to the kidneys, a large amount of protein passes into the urine. This may be one of the earliest signs of nephrotic kidney syndrome. To check the presence of protein in the urine (the so-called proteinuria), it is necessary to pass a general urine test with microscopy of the sediment. The physiological value of plasma albumin is 0.1%, which normally can pass through the glomerular filtration barrier.
- Ultrasound examination of the kidneys and bladder for the diagnosis of nephrotic syndrome. Allows you to evaluate the morphological (structural) state of the kidneys and blood circulation. Ultrasound also helps to identify concomitant pathologies of the urinary system.
Kidney pathology can be suspected after an express analysis of urine with a test strip. With a high reference value of proteinuria, the indicator strip will change color.
A clinical blood test showing a low serum protein called albumin will confirm the diagnosis.
In some cases, when the prescribed treatment is ineffective, a kidney biopsy will be prescribed. To do this, a very small sample of kidney tissue is removed with a needle and viewed under a microscope.
Renal proteinuria is the loss of three or more grams of protein per day through urine or, with a single collection of urine, the presence of 2 g of protein per gram of creatinine urine.
Nephrotic syndrome is characterized by a combination of nephrotic proteinuria with hypoalbuminemia in the blood serum and edema of the facial space and lower parts of the body.
Complicating factors of renal syndrome
Proteins perform many different functions. With a low level of serum (in the blood) protein, the body becomes predisposed to problems with blood coagulation and the occurrence of infections (given that immunoglobulins, the main cells of the immune system, enter the protein fraction of the blood).
The most common bacterial and viral complications are acute sepsis, pneumonia, and peritonitis.
Venous thrombosis and pulmonary thromboembolism (pulmonary embolism) are well-known consequences of acute nephrotic syndrome.
Other complications include:
- Anemia (anemia).
- Cardiomyopathy, including ischemia.
- High blood pressure - systemic hypertension.
- Chronic edema.
- Acute and chronic renal failure (acute renal failure, chronic renal failure).
Therapeutic options for kidney disease
There is no definite treatment for nephrotic syndrome, all treatment methods, as a rule, are only symptomatic (stop symptoms and complications) and preventive (prevent further destruction of renal tissue).
It is important to know that with complete kidney failure (end-stage renal failure), dialysis and further kidney transplantation are required to save life.
The attending physician prescribes medications to relieve certain symptoms. These can be drugs to control hypertension and cholesterol to reduce the risks of cardiovascular disease.
Drugs to reduce arterial hypertension, called ACE inhibitors (angiotensin converting enzyme) and ARB (angiotensin II receptor blockers), which reduce the pressure in the capillaries and prevent the release of protein into the urine.
Diuretics are prescribed to help the body get rid of excess water, as well as to control blood pressure and reduce edema.
Blood-thinning medications (anticoagulants) are recommended in cases of risk of blood clots to prevent a heart attack (myocardial infarction) and stroke.
A very important role in the treatment is played by a change in diet; A low-fat diet helps control blood cholesterol. Give preference to fish or low-fat meat.
Limit your intake of salt (sodium chloride) to reduce the formation of edema and keep your blood pressure at a healthy level.
Immunosuppressive drugs suppress the excessive response of the immune system, with glomerulonephritis and systemic lupus erythematosus, such as glucocorticosteroids (Prednisolone, Decortin, Medopred, etc.).
How to prevent progressive destruction of the kidneys?
The only way to prevent this syndrome is to prevent diseases that can cause it.
If you have a disease that could harm your kidneys, consult your doctor to develop clinical guidelines for nephrotic syndrome to control your underlying disease and prevent kidney damage.
Also discuss with your doctor the possibility of specific tests to determine the functional ability of the kidneys.
This is very important for people with diabetes, high blood pressure, or a family history of kidney disease. Damage to the kidneys is always irreversible, their cells after death are not restored. But if you have identified an underlying disease at an early stage and timely treatment is prescribed, then there is a chance to prevent the condition from worsening.
Pathology of the kidneys in children
Although nephrotic syndrome can affect people of any age, it is usually diagnosed for the first time in children aged 2 to 5 years.
Pathology affects more boys than girls. Each year, about 50,000 children are diagnosed with glomerulonephritis with nephrotic syndrome. It is generally more common in families with a history of kidney or autoimmune diseases, or in the Asian diaspora, although it is still unclear why.
Symptoms of Kidney Disease in Children
As in adults, edema is first noticeable around the eyes, then in the lower legs and other parts of the body.
Immunoglobulins are antibodies that are a specialized group of proteins in the blood that fight infections. When the body loses protein, children are much more likely to get an infectious disease.
Changes in urine are observed - sometimes a high level of protein entering the urine causes it to become foamy.
Most children with nephrotic syndrome have a “disease with minimal change." This means that their kidneys appear to be normal or nearly normal by analysis until a tissue sample obtained by biopsy is examined under a microscope. The cause of the disease with minimal change is unknown.
With hereditary nephrotic syndrome of the Finnish type, the gene for nephrine, a protein in the filtration gap, mutates, which leads to kidney disease in infancy.
It also occurs as a result of problems with the kidneys or in other conditions, for example:
- glomerulosclerosis - when the internal structure of the kidneys becomes damaged;
- glomerulonephritis - inflammation in the filtration system of the kidneys;
- infections - for example, HIV or hepatitis B and C;
- systemic lupus erythematosus;
- diabetes;
- sickle cell anemia;
- in very rare cases, some types of cancer - such as leukemia, multiple myeloma, or lymphoma.
But these problems are more common in adults than in children.
Symptoms of nephrotic syndrome in children can be controlled with steroid drugs.
Most children respond well to steroids, and the risk of kidney failure is minimized. However, a small number of children have a (inherited) congenital nephrotic syndrome, and it is usually less amenable to therapy. Ultimately, their syndrome ends in chronic renal failure, and such children require a kidney transplant.
In most children who respond positively to therapy, the symptoms are controlled, remission occurs - a temporary suspension of the development of the disease, then after a while the symptoms return again - relapse occurs.
In most cases, relapses become less frequent, as children get older, nephrotic syndrome often stops in their teens.
Pathological condition monitoring
Parents need to contact a specialist with a child (pediatric nephrologist) to receive recommendations on nephrotic syndrome, tests and special treatment.
The main treatment method is steroids (GCS - glucocorticosteroids), but additional treatment methods can also be used if the child develops significant side effects.
Most children relapse until late adolescence, and during these periods they need to take steroids.
Children with congenital nephrotic syndrome are usually prescribed at least a 4-week course of Prednisolone, and then a reduced dose every other day for another four weeks. This prevents proteinuria.
When Prednisone is prescribed for short periods of time, there are usually no serious or long-term side effects, although some children have:
- increased appetite;
- weight gain;
- facial redness;
- frequent mood swings.
Most children respond well to the treatment of nephrotic syndrome with Prednisolone, with protein often disappearing from their urine and swelling disappearing within a few weeks. During this period, remission sets in.
Diuretics, or diuretics, can also be used to reduce fluid buildup. They work by increasing the amount of urine produced.
Penicillin is an antibiotic and can be given during relapses to reduce the chance of getting an infection.
Dietary nutrition is important. You need to reduce the amount of salt in your child’s diet to prevent further retention of water in the body and the formation of edema.