Nephrotic syndrome is a clinical complex of symptoms caused by damage to the glomeruli of the kidneys, characterized by severe proteinuria, hypoalbuminemia, edema, and hyperlipidemia. This condition can develop as a primary disease or secondarily against the background of various chronic pathologies. It is the result of increased permeability of glomerular filtration due to changes in the structure and function of the glomeruli, which leads to leakage of albumin and other proteins from the blood into the urine. Decreased albumin content in the blood causes edema, as the oncotic pressure of the plasma decreases. Nephrotic syndrome can be associated with various pathologies, including minimal changes, focal segmental glomerulosclerosis, diabetic nephropathy, secondary processes in infections, tumors, and systemic diseases.
History of the disease and interesting historical facts
The history of nephrotic syndrome goes back more than a hundred years. One of the first descriptions of this condition can be considered the work of the German physician Gustav Grim, who in 1903 identified nephrotic syndrome as a separate entity characterized by specific clinical manifestations. Then, in the 1950s, the English pathologist J. B. Paxter conducted a significant number of studies showing the relationship between changes in the structure of the renal glomeruli and the development of nephrotic syndrome. An important contribution to the study of this condition was also made by works devoted to understanding the pathogenesis and therapy of the syndrome in the 1970-1980s. Modern research is focused on the study of the molecular mechanisms leading to capillary damage and the possibility of using specific biomarkers for diagnosis and prognosis of the course of the disease.
Epidemiology
Nephrotic syndrome is increasing in the population, but its prevalence varies by age and race. According to statistics, primary nephrotic syndrome is most common in children, where its prevalence is about 2-7 cases per 100,000 population under 16 years of age. Among adults, this disease is most often diagnosed in the age group from 30 to 50 years. According to the World Health Organization (WHO), secondary nephrotic syndrome is observed in 20-30% patients with chronic kidney disease. Analysis of cases shows that boys suffer from nephrotic syndrome 2-3 times more often than girls. Given gender characteristics, further study of the influence of sex hormones on the pathogenesis of the disease is necessary.
Genetic predisposition to this disease
Some forms of nephrotic syndrome have a genetic predisposition associated with certain mutations in genes responsible for the structure and function of podocytes. For example, more than 30% cases of primary nephrotic syndrome in children are associated with mutations in the genes NPHS1 (encodes nephrin), NPHS2 (encodes a podocytic protein) and WT1 (affects the development of the kidneys and genitals). The study of gene mutators, such as PODXL and PLCE1, helped to identify new mechanisms leading to changes in the permeability of the glomerular membrane. There are also cases of hereditary nephrotic syndrome transmitted in an autosomal recessive manner, which requires attention from geneticists and nephrologists for early diagnosis and management of the disease.
Risk factors for the development of this disease
There are several factors that increase the risk of developing nephrotic syndrome:
- Infectious diseases such as hepatitis B and C, HIV, which can cause secondary nephrotic syndrome;
- Autoimmune diseases including systemic lupus erythematosus and vasculitis;
- Metabolic disorders such as diabetes leading to diabetic nephropathy;
- Certain medications, including nonsteroidal anti-inflammatory drugs and chemotherapeutic agents;
- Environmental factors such as exposure to toxic substances and heavy metals.
These factors can affect renal tissue, leading to inflammatory changes and dysfunction of the glomeruli, which is manifested in the clinical picture of nephrotic syndrome.
Diagnosis of this disease
Diagnosis of nephrotic syndrome is based on clinical symptoms and laboratory tests. The main symptoms include:
- Swelling, most often seen on the face and legs;
- Decreased urine volume and change in its color;
- General weakness and fatigue.
Laboratory tests needed to make a diagnosis include:
- Urine proteinuria test is one of the main tests that shows high levels of protein in the urine;
- Biochemical blood test for albumin and lipid levels;
- Immunochemical tests to determine specific markers.
Radiological examinations such as renal ultrasound may be used to evaluate the size and structure of the kidneys, excluding other causes of edema. The differential diagnosis should include other conditions causing proteinuria, such as non-fatal diseases, including simple hyperlipidemia and associated diseases.
Treatment
Treatment of nephrotic syndrome is aimed at implementing symptomatic therapy and treating the underlying disease. General recommendations include:
- Limiting salt intake to reduce swelling;
- Reducing dietary protein intake depending on the level of proteinuria;
- Adequate fluid intake;
- Control of blood pressure and blood sugar levels.
Pharmacological treatment includes:
- Corticosteroids (prednisolone) to reduce inflammation;
- ACE inhibitors to control blood pressure and reduce proteinuria;
- Statin drugs for normalizing lipid profile.
In some cases, surgical intervention aimed at restoring kidney function (eg, kidney transplant) may be required. Treatment of secondary diseases is also indicated.
List of medications used to treat this disease
- Prednisolone
- Memetization of corticosteroids
- ACE inhibitors: enalapril, captopril
- Statins: atorvastatin, simvastatin
- Diuretics: furosemide
These drugs can significantly improve the patient's condition, thereby reducing the manifestations of nephrotic syndrome.
Disease monitoring
Monitoring of nephrotic syndrome involves regular observation of the patient's condition and renal function. Control steps should include:
- Regular urine and blood tests to assess albumin levels and proteinuria;
- Blood pressure assessment;
- Monitoring for possible complications such as blood clots and infections.
The prognosis for nephrotic syndrome varies depending on its causes. In most cases, remission can be achieved with proper treatment. However, some patients may experience disease progression and chronic renal failure, which requires closer monitoring.
Age-related features of the disease
The symptoms and course of nephrotic syndrome can vary significantly depending on the age group. Children often experience minimal changes and may fully recover if complications do not develop. In older people, nephrotic syndrome can present with more severe symptoms and is associated with a higher risk of developing chronic kidney failure and other diseases.
Questions and Answers
- What is nephrotic syndrome? Nephrotic syndrome is a clinical complex of symptoms caused by damage to the renal glomeruli, manifested by proteinuria, edema and hypoalbuminemia.
- What are the main causes of nephrotic syndrome? Underlying causes may include primary kidney diseases (eg, minimal change) and secondary diseases (eg, diabetes or systemic diseases).
- What diagnostic methods are used to detect nephrotic syndrome? Diagnosis includes urine analysis for proteinuria, blood biochemistry tests, and ultrasound examination of the kidneys.
- How is nephrotic syndrome treated? Treatment involves reducing swelling, using corticosteroids, and controlling coexisting conditions such as hypertension.
- What is the prognosis for patients with nephrotic syndrome? The prognosis depends on the cause of the disease; many patients can achieve remission with adequate treatment, but some may progress to chronic renal failure.
