Lipoid nephrosis (Podocyte disease, Idiopathic nephrotic syndrome of children). Lipoid nephrosis (idiopathic NS of children, minimal change nephropathy)

enough rare disease. This is one of the forms of nephrotic syndrome, in which kidney damage occurs primarily dystrophic nature.

The reason is most often some general illness:

- tuberculosis,

- osteomyelitis,

- syphilis,

- malaria,

- diphtheria,

- dysentery,

- chronic enterocolitis,

- polyarthritis,

- lymphogranulomatosis,

- lead and mercury intoxication, etc.

If the cause of dystrophic changes in the kidneys cannot be identified, the disease is designated as lipoid nephrosis. Its causes are severe metabolic disorders in the body, mainly fat and protein. As a result, the processes of cellular nutrition and the permeability of capillary walls are disrupted. renal glomeruli.

Protein particles and lipoids, in large quantities contained in the primary urine of patients, penetrate the wall of the tubules, causing severe dystrophic changes in the epithelial cells. IN Lately revealed big influence on the development of this kidney pathology of the autoimmune mechanism.

Symptoms and diagnosis of lipoid nephrosis

Lipoid nephrosis develops gradually. People affected by it usually do not experience any pain and discomfort. The only complaints are significant swelling, which is embarrassing and disturbing. A patient with lipoid nephrosis has enlarged kidneys, the weight of one reaches 250 g. The capsule is easily removed, the surface is usually smooth, pale gray in color. Cortical layer significantly expanded and yellowish-gray in color. Doctors call this kidney a large white kidney.

The main symptom of lipoid nephrosis - increased content protein in urine. Its amount can reach 20–50% or more, which leads to a strong decrease in protein content in the blood. This leads to the formation of large edema. But since vascular system the kidneys are not affected, blood pressure remains normal, there are no red blood cells in the urine, and the concentrating ability of the kidneys is not impaired. In addition to protein, urine contains leukocytes, cells renal epithelium and various casts: epithelial, granular, hyaline, and sometimes waxy. The latter appear in the urine in severe chronic kidney diseases.

Patients with lipoid nephrosis complain, except severe swelling throughout the body, for weakness, decreased performance, chilliness, loss of appetite, extreme thirst.

Excessive swelling does not appear immediately. First, the amount of protein in the urine begins to exceed normal values. Then the face turns pale, mild swelling and decreased facial expressions occur. The swelling gradually increases, covering the entire subcutaneous tissue. Deformation of the face and torso begins. But swelling is especially noticeable on the face: it becomes puffy, the eyelids swell, the eyes narrow and open with difficulty in the morning.

Liquid accumulating in internal organs, in the abdominal and pleural cavities, sometimes in the pericardium, maintains swelling for months and even years. They become very soft, mobile, and when pressed with a finger, a quickly disappearing deep hole remains in this place. The skin in places of swelling becomes tense, becomes shiny and can burst with the release of milky liquid.

The edematous fluid contains few proteins and many salts, in particular chlorides, and the amount of lipoproteins is increased. The volume of edematous fluid in some cases reaches 20 liters or more. Skin breaks are very dangerous as they can become infected, leading to erysipelas and other diseases.

For lipoid nephrosis arterial pressure normal or reduced. Muffled heart sounds and bradycardia are possible, but angiospastic symptoms and signs of heart failure are absent. Sometimes the liver becomes slightly enlarged. On later diseases with pronounced edema a decrease in urine output to 400–300 ml per day and a significant increase in its relative density are observed.

Dysproteinemia and hypoproteinemia are characteristic of lipoid nephrosis. The content of albumin in the blood plasma is especially strongly reduced, which leads to a decrease in the albumin-globulin coefficient to 1–0.5 and below. Accordingly, the amount of globulins in the blood increases, mainly due to alpha-2- and beta-globulins. The level of gamma globulins is reduced.

Severe lipidemia and cholesterolemia are persistent symptoms diseases. The level of cholesterol in the blood plasma increases to 500 mg or more, the amount of lecithin increases and fatty acids. At the same time, it is observed hypochromic anemia, lymphocytosis, eosinophilia, increase in ESR.

On late stages the disease is destroyed epithelial cells tubules with development connective tissue, subsequent atrophy and hyalinization of the glomeruli. As a result, the kidneys decrease in volume - they are formed nephrotically shriveled bud. Similar symptoms and the same course of the disease was noticed in chronic nephritis nephrotic type.

The diagnosis of lipoid nephrosis is based on the presence of protein in the patient’s urine, the amount of which exceeds normal values, a decrease total protein in the blood and increased cholesterol levels, as well as complaints of prolonged persistent swelling in the absence of hematuria, arterial hypertension and azotemia.

It is necessary to carry out differential diagnosis with the following diseases:

- renal amyloidosis (to identify renal amyloidosis, the absence of chronic, purulent, syphilitic, tuberculosis or other infection in the body is important)

- nephrotic form of chronic diffuse glomerulonephritis,

- diabetic glomerulosclerosis,

- some vasculitis.

Treatment of lipoid nephrosis

To combat edema, the patient is prescribed bed rest and diuretics: Lasix, hypothiazide, Novurit and others. Recently, corticosteroid drugs and immunosuppressants have become the mainstay of treatment. Taking corticosteroids usually leads to long-term remission, subsidence of edema, normalization of the structure of the walls of the glomerular capillaries with a decrease in their permeability and a decrease in protein excretion by the kidneys.

The administration of polyglucin is recommended as a means of increasing plasma colloid osmotic pressure. After swelling disappears, you can use it to improve protein synthesis. steroid hormones. During all periods of illness, it is necessary to use funds replacement therapy: vitamins and enzymes.

A patient with lipoid nephrosis is prescribed a protein diet - at the rate of 2–2.5 g of protein per 1 kg of his body weight, excluding edema, and vitamins

Lipoid nephrosis (LZ) - genetically determined diffuse damage to podocytes (epithelial lining of glomerular capillaries). Lipoid nephrosis is an independent nosological entity, fundamentally different from glomerulonephritis, characterized by non-immune predominantly diffuse damage to the subcytic apparatus of the renal glomerulus, clinically manifested by reversible NS.

Etiology. A genetically determined podocyte defect is observed, which under unknown circumstances can manifest itself in the form of independent pathological changes.
This notion is supported by the frequent association of lipoid nephrosis with HLA-B12Ag.

Epidemiology. LND is the cause of 70-80% of all cases of NS in children and 10-20% in adults.
Average age adult patients - 42.7 years. In adults, the incidence rate is similar in men and women.
Children get sick with a frequency of 12-30 cases per 1 million population, adults and the elderly - 1.8-2.7.

Pathogenesis. Available genetic defect the podocytes themselves.
However, the essence of increasing permeability is not clear.
According to one of the hypotheses of pathogenesis, the factor that increases glomerular vascular permeability, produced by T lymphocytes, is of primary importance. Subsequently, several lymphokines were described that enhance vascular permeability, the content of which is increased in patients with minimal changes glomeruli. It has been established that IL-2 and IL-4 have such properties. The experiment showed that the administration of recombinant IL-2 to rats leads to a decrease in the anionic layer of the GBM and the disappearance of podocyte feet. The possible role of TNF, plasma protease 100 KF, etc. is discussed.
It is necessary to keep in mind secondary nonspecific dystrophic changes in podocytes at the most various diseases(from glomerulonephritis to arterial hypertension). Clinical picture.

Often the disease develops after an infection of the upper respiratory tract, allergic reactions (food allergy, insect bites, medications, vaccination) and is often combined with atonic diseases, allergic disorders (asthma, eczema, milk intolerance, hay fever). Sometimes other infections precede it. The role of streptococcus has not been proven; antistreptococcal AT titers are sometimes lower than in healthy individuals. Described individual cases connections with neoplastic diseases (lymphomas, intestinal cancer, lung cancer, etc.), but less common than with MN.
Familial cases are known, more often among siblings, which suggests the possibility genetic predisposition.
The majority of patients experience NS - with severe edema, anasarca, massive proteinuria, severe hypoalbuminemia, hypovolemia, very pronounced lipidemia; Children often develop ascites, sometimes accompanied by abdominal pain.
With severe hypovolemia, the development of nephrotic crisis with abdominal pain and skin erythema and cardiovascular shock with circulatory failure and cold extremities is possible. However, such isolated NS (in its “pure” form) is not always observed: moderate erythrocyturia is detected in 20-25% of patients, diastolic hypertension is detected in 10% of children and 30-35% of adults.
IN in rare cases retention of nitrogenous wastes or even acute renal failure develops, which may be based on severe hypovolemia, intranephron blockage with protein precipitates, pronounced podocyte adhesions with the closure of gaps in the basement membrane, severe interstitial edema, hypercoagulation.

It is in this form that GCS therapy is most effective, often leading to the disappearance of edema within 1 week.
IN further illness may take a relapsing course with the development of steroid dependence, but chronic renal failure rarely develops.

Among the complications, the most severe are hypovolemic shock, nephrotic crises, thrombosis, severe infections.
In the past - before the use of antibiotics and corticosteroids - these complications led to death in the first 5 years of the disease in more than 60% of children.

Today, the prognosis is quite favorable, despite the possibility of relapses and complications: 5-year survival rate is 95% or higher.

Diagnostics. Laboratory research.
All patients have high (more than 3 g/day) proteinuria, usually selective.
Proteinuria is characterized by extreme variability: a sharp increase during overload, colds and a rapid, often spontaneous decrease. Hematuria is diagnosed more often in adults (40-50%), less often in children (10-15%).
The presence of persistent hematuria casts doubt on the correctness of the diagnosis. Leukocyte- and cylindruria are also rarely detected.

Characteristic laboratory symptoms of NS are hypoalbuminemia and hyperlipidemia.
ESR is sharply increased.
During exacerbations, the level of IgG is usually reduced, the level of IgE or IgM, fibrinogen may be increased. The level of C3 complement is always normal, and sometimes even elevated. Morphological changes.
Glomerular changes are reduced to diffuse global changes in podocytes, visible only in electron microscope. These changes are described as destruction, swelling, spreading of small processes of podocytes on outside glomerular basement membrane. Microvilli and droplets of reabsorbed protein are visible in the cytoplasm of podocytes. There is some thinning of the basement membrane.
Thus, EM reveals destruction of small processes of podocytes and a small number of deposits in the mesangium.

Immunopathological examination reveals negative IgM/IgG and granular deposits of IgG/S3 or IgA.

Treatment.
The diet should provide for adequate replenishment of protein lost in urine and restriction table salt in the presence of edema.
Since most typical option Since the course of LND is benign with spontaneous recovery, treatment issues relate mainly to complications or an unusual course.
In this case, i.e. in case of an unusual course, drugs are used that are described in detail in the sections on GN.
This will allow us to only name these means in this section. So, if LN accepts protracted course, then heparin therapy should be started. The application scheme is usual.
In case of insufficient effect or its absence, the drugs of choice are GCS. The regimen for using prednisolone is the same as for GN.
Steroid-resistant forms of FN are possible.
In such cases, cytostatic agents are forced to be used, in particular mustargen.

It should be recalled that all components of the pathogenesis of these diseases are direct promoters of the occurrence and increase of renal failure.
To what has already been said, it must be added that erythropoietin has a significant renoprotective effect, the effect of which goes significantly beyond the normalization of hematopoiesis.
Due to the significant effect of erythropoietin on oxygen capacity blood and oxygen delivery to tissues, erythropoietin helps improve the metabolism of all organs and tissues, reducing atherogenesis, sclerosis, degenerative changes vascular wall etc.

Characterized by kidney damage of a predominantly dystrophic nature. Previously, lipoid nephrosis was considered as an independent type of kidney pathology. It later became clear that this group of kidney lesions is heterogeneous. Most of it consists of cases of nephrotic syndrome, which is one of the manifestations of any general illness(tuberculosis, dysentery, polyarthritis, lymphogranulomatosis, lead and mercury, etc.). Cases where the cause of dystrophic changes in the kidneys remains unclear are referred to as lipoid nephrosis.

Symptoms:

The buds are enlarged (the weight of one bud reaches 250 g), the capsule is easily removed, the surface is smooth, pale gray in color (large white bud). The cortical layer is significantly expanded, yellowish-gray in color.

At histological examination detect changes mainly in cells proximal part renal tubules. Lipid deposits are found in the basal parts of epithelial cells. The glomeruli are dystrophically altered, especially podocytes and endothelial cells, which are associated with the permeability of the glomerular membrane.

In the later stages of the disease, destruction of tubular epithelial cells is observed with the development of connective tissue and subsequent atrophy and hyalinization of the glomeruli. As a result, the kidneys decrease in volume and a nephrotically shriveled kidney is formed.

Lipoid nephrosis develops gradually. TO early complaints patients include: weakness, decreased performance, loss of appetite, thirst, chilliness.

Typically, patients consult a doctor due to the appearance of edema. The pre-edema period is often long and characterized by severe proteinuria. Then, swelling and pallor of the face and decreased facial expressions gradually appear. grow and take over the entire subcutaneous tissue (anasarca), deforming the face and torso, but they are especially pronounced on the face.

The patient's face is puffy, the eyelids are swollen, the palpebral fissures are narrow, and in the morning the eyes open with difficulty. Fluid also accumulates in the internal organs and serous cavities - abdominal, pleural, and less often in the pericardium. Swelling persists long time(for months and even years). They are very soft, mobile, and when pressed with a finger, a quickly disappearing deep hole remains. The amount of edematous fluid in some cases reaches 20 liters or more.

The skin over the areas of swelling becomes shiny from tension and may burst with fluid leaking out. In the future, infection (erysipelas, etc.) is possible. The appearance of edema is associated with hypoproteinemia and a decrease in colloid osmotic pressure. The edematous fluid is poor in proteins and rich in salts, in particular chlorides. The liquid has a milky tint, the amount of lipoproteins in it is increased.

Blood pressure is normal or low. There is a muted heart sound. There are no angiospastic symptoms and signs. Sometimes the liver is slightly enlarged. At the height of the disease with severe edema, oliguria is observed (the amount of urine decreases to 400-300 ml per day), a significant increase in the relative density of urine (up to 1.040-1.060).

Urine brown color and contains a large amount of protein (up to 10-20% and above). Sometimes the daily loss of protein reaches 10-15 g. It is based on increased glomerular permeability, decreased protein reabsorption in the tubules and increased protein filtration associated with changes in its properties. The presence of persistent and severe albuminuria is one of the most characteristic features diseases. Among the proteins in urine, finely dispersed albumin molecules predominate.

The urine sediment contains a large number of hyaline, granular and waxy casts and renal epithelial cells. There are no red blood cells in the urine sediment or only single ones. There are often many leukocytes, but they differ from urine leukocytes found in infectious and inflammatory diseases of the kidneys, pyelonephritis, since they are well stained with safronin according to Stenheimer-Malbin.

The amount of chlorides excreted in the urine is reduced (up to 1 g), which is normally 10-15 g per day. This is explained by their fluid retention, as well as increased production of aldosterone, which increases the reabsorption of sodium ions in the tubules. Nephrosis is characterized by severe dysproteinemia and pshoproteinemia (up to 3-5 g%). The content of albumin in the blood plasma is especially strongly reduced (due to severe albuminuria), which leads to a change in the albumin-globulin coefficient to 1-0.5 and lower (normally 1.5-2).

Accordingly, the amount of globulins in the blood increases, mainly due to alpha-2- and beta-globulins. The level of gamma globulins is reduced. Dysproteinemia leads to a decrease in the osmotic pressure of proteins, while the liquid is not retained in the blood and enters the tissues.

A constant symptom of the disease is severe lipidemia and cholesterolemia. The level of cholesterol in the blood plasma rises to 500 mg (1360 mmol/l) and higher. The amount of lecithin and fatty acids increases. These changes are obviously of secondary origin and are associated with impaired protein metabolism and hypoproteinemia. In addition, hypochromic and increased ESR are observed. The blood-purifying function of the kidneys is not impaired and is not observed. Only in the later stages, with a wrinkled kidney, nitrogenous wastes are retained in the body and develops. Basic functional tests kidneys remain normal for a long time. Glomerular filtration and tubular reabsorption are usually increased. There is an increased hydrophilicity of the tissues, which is confirmed by the McClure-Aldrich blister test, in which the resorption of intradermally injected isotonic solution sodium chloride (0.2 ml) occurs rapidly - in 10-20 minutes (30-40 minutes is normal). The disease is long lasting, up to 15-20 years or more. There is an alternation of a long pre-edematous stage with an edematous stage, during which patients lose their ability to work. Swelling is extremely persistent and can last for years. Patients in the edematous stage, due to severe hypogammaglobulinemia and tissue swelling, are very sensitive to infectious agents. They often experience repeated erysipelas of the skin, etc., from which previously, before the discovery of antibiotics, patients died.

Causes:

It is believed that the cause of lipoid nephrosis and nephrotic syndrome are severe metabolic disorders, mainly fat and protein, as a result of which the trophism and permeability of the capillary walls of the renal glomeruli are disrupted. Protein particles and lipoids, contained in large quantities in the primary urine of patients, infiltrate the wall of the tubules, causing gross dystrophic changes in the epithelial cells. Moreover, recently great importance The development of this kidney pathology is attributed to the autoimmune mechanism.

Treatment:

For treatment the following is prescribed:

Currently, these complications can be treated with antibiotics and sulfa drugs. In addition, it was noted frequent occurrence in patients with vascular thrombosis. When lipoid nephrosis is combined with renal amyloidosis, it can develop resulting in uremia.

Lipoid nephrosis- a rare disease. This is one of the forms of nephrotic syndrome, in which kidney damage occurs, predominantly of a dystrophic nature. Previously, lipoid nephrosis was considered independent disease, but later it turned out that its cause is almost always some kind of general disease (tuberculosis, osteomyelitis, syphilis, malaria, diphtheria, dysentery, chronic enterocolitis, polyarthritis, lymphogranulomatosis, lead and mercury intoxication, etc.). In cases where the cause of dystrophic changes in the kidneys cannot be identified, the disease is designated as lipoid nephrosis.

It is believed that its causes are severe metabolic disorders in the body, mainly fat and protein. As a result, the processes of cellular nutrition and the permeability of the walls of the capillaries of the renal glomeruli are disrupted. Protein particles and lipoids, contained in large quantities in the primary urine of patients, penetrate the wall of the tubules, causing severe dystrophic changes in the epithelial cells. In addition, recently a great influence on the development of this kidney pathology of the autoimmune mechanism has been revealed.

Symptoms and course of lipoid nephrosis

Lipoid nephrosis develops gradually. People affected by it usually do not experience any pain or discomfort. The only complaints are significant swelling, which is embarrassing and disturbing. A patient with lipoid nephrosis has enlarged kidneys, the weight of one reaches 250 g. The capsule is easily removed, the surface is usually smooth, pale gray in color. The cortex is significantly expanded and has a yellowish-gray color. Doctors call this kidney a large white kidney.

A sure symptom of lipoid nephrosis is increased protein content in the urine. Its amount can reach 20-50% or more, which leads to a strong decrease in protein content in the blood. This, in turn, leads to the formation of large edema. But since the vascular system of the kidneys is not affected, blood pressure remains normal, there are no red blood cells in the urine, and the concentrating ability of the kidneys is not impaired.

In addition to protein, the urine contains leukocytes, renal epithelial cells and various casts: epithelial, granular, hyaline, and sometimes waxy. The latter appear in the urine in severe chronic kidney diseases.

Typically, patients with lipoid nephrosis consult a doctor due to the appearance of severe swelling throughout the body, while at the same time complaining of weakness, decreased performance, loss of appetite, severe thirst, and chilliness. Excessive swelling does not appear immediately. First, the amount of protein in the urine begins to exceed normal values. Then the face turns pale, mild swelling and decreased facial expressions occur. The swelling gradually increases, covering the entire subcutaneous tissue. Deformation of the face and torso begins. But swelling is especially noticeable on the face: it becomes puffy, the eyelids swell, the eyes narrow and open with difficulty in the morning.

Fluid, accumulating in the internal organs, in the abdominal and pleural cavities, sometimes in the pericardium, maintains swelling for months and even years. They become very soft, mobile, and when pressed with a finger, a quickly disappearing deep hole remains in this place. The skin in places of swelling becomes tense, becomes shiny and can burst with the release of milky liquid. The edematous fluid contains few proteins and many salts, in particular chlorides, and the amount of lipoproteins is increased. The volume of edematous fluid in some cases reaches 20 liters or more. Skin breaks are very dangerous as they can become infected, leading to erysipelas and other diseases.

Blood pressure in lipoid nephrosis is normal or low. Muffled heart sounds and bradycardia are possible, but angiospastic symptoms and signs of heart failure are absent. Sometimes the liver becomes slightly enlarged. In the later stages of the disease, with severe edema, a decrease in urine output (up to 400-300 ml per day) and a significant increase in its relative density are observed.

Lipoid nephrosis is characterized by dysproteinemia and hypoproteinemia. The content of albumin in the blood plasma is especially strongly reduced, which leads to a decrease in the albumin-globulin coefficient to 1-0.5 and below. Accordingly, the amount of globulins in the blood increases, mainly due to alpha-2- and beta-globulins. The level of gamma globulins is reduced.

Constant symptoms of the disease are severe lipidemia and cholesterolemia. The level of cholesterol in the blood plasma rises to 500 mg or more, the amount of lecithin and fatty acids increases. At the same time, hypochromic anemia, lymphocytosis, eosinophilia, and an increase in ESR are observed.

In the later stages of the disease, destruction of the epithelial cells of the tubules occurs with the development of connective tissue, followed by atrophy and hyalinization of the glomeruli. As a result, the kidneys decrease in volume - a nephrotically shriveled kidney is formed. Similar symptoms and the same course of the disease are observed in chronic nephritis of the nephrotic type.

The disease can last 15-20 years or more. At this time, a long pre-edema stage alternates with an edematous stage, during which patients lose their ability to work.

Diagnosis of lipoid nephrosis

The diagnosis of lipoid nephrosis is based on the presence of protein in the patient’s urine, the amount of which exceeds normal values, a decrease in total protein in the blood and an increase in the cholesterol content in it, as well as complaints of prolonged persistent swelling in the absence of hematuria, arterial hypertension and azotemia.

Doctors should conduct a differential diagnosis with renal amyloidosis, nephrotic form of chronic diffuse glomerulonephritis, diabetic glomerulosclerosis and some vasculitis. To identify renal amyloidosis, the absence of chronic, purulent, syphilitic, tuberculosis or other infection in the body is important.

Treatment and prevention of lipoid nephrosis

A patient with lipoid nephrosis is prescribed protein diet(at the rate of 2-2.5 g of protein per 1 kg of body weight, excluding edema) and vitamins. The amount of table salt is reduced to 1.5-2.5 g per day, and the amount of liquid consumed is moderately limited. Also carried out with the help of antibiotics active treatment foci of infection.

To combat edema, the patient is prescribed bed rest And diuretics: Lasix, hypothiazide, Novurit and others. Recently, the main place in treatment has begun to be occupied by corticosteroid drugs And immunosuppressants. Taking corticosteroids usually leads to long-term remission, subsidence of edema, normalization of the structure of the walls of the glomerular capillaries with a decrease in their permeability and a decrease in protein excretion by the kidneys. The administration of polyglucin is recommended as a means of increasing plasma colloid osmotic pressure. After swelling disappears, steroid hormones can be used to improve protein synthesis. During all periods of illness it is necessary to use replacement therapy: vitamins and enzymes.

As for the prevention of the disease, as already noted, lipoid nephrosis as independent illness develops very rarely. Therefore, all its prevention comes down to prevention and timely disposal of diseases that cause it, as well as treatment of focal or chronic infection. In addition, during the period of relative remission it is recommended Spa treatment in places with a dry climate, like Bayram Ali in Central Asia.