Lipoid nephrosis

Lipoid nephrosis - an independent form of kidney damage only in children with minimal (podotsitarnymi) glomerular changes.

Lipoid nephrosis is a disease of young children (mostly 2-4 years), more often boys. Lipoid nephrosis is a kidney disease, in which only minimal changes are morphologically. WHO experts define lipid nephrosis as minimal changes in the "small podcitis process", which undergo dysplastic changes, the membrane and mesangium react for a second time.

Electron microscopy reveals only minimal changes in the glomeruli of the kidney with the damage or disappearance of small processes (pedicula) of podocytes, their displacement and spreading along the basal membrane of glomerular capillaries.

Immunohistochemical examination of kidney biopsy specimens with lipid nephrosis gives a negative result and helps to differentiate lipoid nephrosis and other types of glomerulonephritis. The most important evidence is, according to immunofluorescence data, the absence in lipid nephrosis of deposits containing IgG, IgM, complement and the corresponding antigen.

The causes of lipid nephrosis are unknown.

In the pathogenesis of lipid nephrosis, dysfunction plays a role in the T-cell immunity system, increased activity of the T-suppressor subpopulation and hyperproduction of cytokines. In the blood serum, the patients showed increased activity of IL-2, IL-4, IL-8, IL-10. Interleukin-8 plays an important role in the pathogenesis of the glomerular filter selectivity disorder. There is a loss of the charge-selective function of the glomerular filtration barrier, as a result of which the permeability of capillaries for the protein, especially negatively charged albumins, increases. Proteinuria develops (mainly albuminuria). Increased filtration of the glomerular capillaries of the protein leads to a functional overstrain of the tubular apparatus. In connection with increased reabsorption of the filtered protein, resorptive tubular insufficiency occurs.

Developing hypoalbuminemia leads to a decrease in the oncotic pressure of the blood plasma and creates the possibility for it of transudation from the vascular bed into the interstitial space. This, in turn, leads to a decrease in the volume of circulating blood (BCC). Reduction of BCC leads to a decrease in perfusion pressure in the kidneys, which activates the renin-angiotensin-aldosterone system (RAAS). Activation of RAAS stimulates sodium reabsorption in the distal tubules. Reduced bcc stimulates the release of an antidiuretic hormone (ADH), which enhances the reabsorption of water in the collecting tubes of the kidney. In addition, the disturbance of transport processes in the collecting tubes of the tubules of the kidneys and the formation of edema is facilitated by the atrial natriuretic peptide.

Reabsorbed sodium and water enter the interstitial space, which increases edema in lipid nephrosis.

An additional pathogenetic factor in the development of edema in lipid nephrosis is functional insufficiency of the lymphatic system of the kidneys, that is, the disturbed lymph drainage.

Pronounced edema with lipoid nephrosis occurs when the serum albumin level is below 25 g / l. Developing hypoproteinemia stimulates protein synthesis in the liver, including lipoproteins. However, lipid catabolism is reduced due to a decrease in the plasma level of lipoprotein lipase, the main enzyme system affecting the removal of lipids. As a result, hyperlipidemia and dyslipidemia develop: an increase in the content of cholesterol, triglycerides, and phospholipids in the blood.

The loss of protein by the kidneys leads to a violation of immune reactions - the loss of IgG, IgA in the urine, a decrease in the synthesis of immunoglobulins and the development of secondary immunodeficiency. Patients with lipoid nephrosis are susceptible to viral and bacterial infections. This is facilitated by the loss of vitamins, microelements. Massive proteinuria is reflected in the transport of thyroid hormones.

The development of the disease and relapses are almost always preceded by ARVI or bacterial infections. With age, when the maturation of the thymus occurs, the tendency to relapse of lipid nephrosis is clearly reduced.

Symptoms of lipid nephrosis. Lipoid nephrosis develops gradually (gradually) and at first is imperceptible for the parents of the child and those around him. In the initial period, weakness, fatigue, and a decrease in appetite can be expressed. There is a pasty on the face and legs, but parents recall it in retrospect. Edemas accrue and become noticeable - this is the reason for going to the doctor. Swelling spreads to the lumbar region, genital organs, ascites and hydrothorax often develop. With lipid nephrosis swelling is loose, easily moving, asymmetric. Skin pale, there are signs of hypopolyvitaminosis A, C, B ₁, B ₂. Cracks can develop on the skin, dry skin is noted. With large edema appear shortness of breath, tachycardia, a functional systolic murmur at the apex of the heart is heard. Blood pressure is normal. At the height of formation of edema appears oliguria with a high relative density of urine (1,026-1,028).

In the study of urine, pronounced proteinuria, protein content 3-3.5 g / day to 16 g / day or more. Cylindrarium. Erythrocytes - individual. At the beginning of the disease there may be leukocyturia associated with the main process in the kidneys, it is an indicator of the activity of the process. Glomerular filtration by endogenous creatinine is normal or normal. The albumin level in the blood is below 30-25 g / l, sometimes the albumin content is 15-10 g / l in the patient. The degree of decrease in albumin in the blood determines the severity of the course of lipid nephrosis and the degree of edematous syndrome. The blood content of all major lipid fractions is increased. They can reach very high figures: cholesterol above 6.5 mmol / l and up to 8.5-16 mmol / l; phospholipids 6,2-10,5 mmol / l. The serum protein is below 40-50 g / l. Characterized by an elevated ESR of 60-80 mm / h.

The course of lipoid nephrosis is undulating, spontaneous remissions and relapses of the disease are characteristic. Exacerbation may cause SARS, bacterial infections; In children with allergic reactions, the corresponding allergen can play a role.

Remission is diagnosed when the blood albumin level reaches 35 g / l, in the absence of proteinuria. Relapse of lipoid nephrosis is diagnosed with the appearance of significant proteinuria within 3 days.

Treatment of lipid nephrosis.

Mode - bed rest in active phase, with pronounced swelling for 7-14 days. In the future, the regime does not provide for limitations, on the contrary, an active motor regime is recommended to improve the processes of metabolism, blood and lymph circulation. The patient must provide access to fresh air, hygienic procedures, exercise therapy.

The diet should be full, taking into account the age. In the presence of allergies - hypoallergenic. The amount of protein given the age norm, with pronounced proteinuria, is the addition of the amount of protein lost per day in urine. Fats are mainly vegetable. With severe hypercholesterolemia, reduce meat consumption, preference for fish and poultry. Saline-free diet - 3-4 weeks with the subsequent gradual introduction of sodium chloride to 2-3 g. Hypochloride diet (up to 4-5 g) is recommended to the patient for many years. The liquid is not limited, as the kidney function is not impaired, especially since the restriction of fluid against hypovolemia and glucocorticosteroid (GCS) treatment worsens the rheological properties of the blood and may contribute to thrombosis. During the descent of edema and the maximum doses of glucocorticosteroids, it is necessary to prescribe products containing potassium - baked potatoes, raisins, dried apricots, prunes, bananas, pumpkin, zucchini.

During the period of remission, the child does not need to restrict diet and physical activity.

Medicamentous treatment of lipid nephrosis The treatment of lipoid nephrosis debut basically reduces to the appointment of glucocorticosteroids, the therapy of which is pathogenetic. Against the background of glucocorticosteroids, antibiotics are first prescribed. Semisynthetic penicillins, amoxiclav, and in the presence of a patient in an anamnesis of allergic reactions to penicillin - cephalosporins III and IV generation are used.

Prednisolone is prescribed at a rate of 2 mg / kg / day in 3 or 4 doses daily to 3-4 consecutive negative daily urine tests per protein. Usually this happens at 3-4 weeks from the start of treatment. Then 2 mg / kg is administered every other day for 4-6 weeks; further 1,5 mg / kg every other day - 2 weeks; 1 mg / kg every other day - 4 weeks; 0,5 mg / kg every other day - 2 weeks with the subsequent cancellation of prednisolone. Course 3 months. Predicting the results of treatment with glucocorticosteroids can be done by assessing the development of a diuretic response in 4-7 days from the start of treatment. With the rapid development of steroid diuresis, it can be assumed that treatment will be successful. In the absence of a steroid response to diuresis or its late development (3-4 weeks), treatment is in most cases ineffective. You should look for the cause of the lack of effect, kidney dysplasia is possible. A survey is conducted on the possibility of hidden foci of infection and sanation of foci of infection.

With steroid resistance - no effect of treatment with glucocorticosteroids for 4-8 weeks - cyclophosphamide is prescribed 1.5-2.5 mg / kg / day for 6-16 weeks in combination with prednisolone 0.5-1 mg / kg / day; in the future, the course of maintenance therapy in a half dose of cytotoxic for another 3-6 months continuously.

With the participation in the recurrence of lipid nephrosis, atopy in children with a history of allergic anamnesis is recommended to be used in the treatment of intal, zaditen.

In ARVI use reaferon, interferon, anaferon for children.

Clinical follow-up is performed by a pediatrician and a nephrologist, they correct the treatment if necessary. It is necessary to consult the ENT doctor and dentist 2 times a year.

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