Lupus nephritis - Causes, symptoms and treatment. MF.

Lupus nephritis is a kidney damage in systemic lupus erythematosus. Systemic lupus erythematosus is a disease associated with a defect in the immune system, which is accompanied by the formation of specific autoantibody proteins, which, when interacting with various tissues of the body, lead to the development of inflammation. Inflammation is formed in the skin, joints, heart, lungs, but the most dangerous for life is the damage to the kidneys and the central nervous system. It is established that nephritis develops in 50-70% of cases of the disease. Women suffer from systemic lupus erythematosus nine times more often than men.

Causes of lupus nephritis

The exact cause of the disease is not established. But there are a number of factors that can serve as triggers for the development of systemic lupus erythematosus. These include:

• Genetic predisposition. It has been established that systemic lupus erythematosus often develops in individuals with a certain genotype, as well as with close relatives of the diseased. There is also a link between the onset of the disease and race. It was found that the mortality from complications of systemic lupus erythematosus in black women is 10 times higher than in the general population.

• Female sex hormones, in particular estrogens. They are able to suppress the protective mechanisms of the immune system, and under certain conditions can contribute to the development of the disease. Indeed, the disease prevails in women of childbearing age. Often the manifestation of the disease occurs during pregnancy. Recently, in connection with the appointment of estrogen-containing drugs in menopause, cases of systemic lupus erythematosus in women in menopause are described.

• The most important factors of the environment include ultraviolet irradiation. Many patients indicated the occurrence of the disease after a long stay in the sun. It is believed that damage to the skin under the influence of ultraviolet rays contributes to the activation of the immune system and the development of immune inflammation.

• The use of certain medicinal substances( isoniazid, methyldopa), as well as the transferred infectious diseases play an important role in the development of the disease.

Under the influence of predisposing factors, the activation of cells of the immune system( B-lymphocytes) occurs, which is accompanied by the production of a large number of antibodies to various proteins of the body. When they interact, immune complexes are formed. Immune complexes cause damage to body tissues with the development of inflammation. Localization of inflammation in one or another organ determines the external manifestations of the disease.

The formation of antibodies to double-stranded DNA of kidney cells is especially important for the development of lupus nephritis. As a result, the body, protecting itself from pathological proteins, activates a number of mechanisms of the immune system that destroy cells containing immune complexes. This leads to a disruption in the function of the organs.

Symptoms of lupous nephritis

External manifestations of the disease are diverse and are composed of common symptoms and signs specific for systemic lupus erythematosus.

• Increased body temperature, sometimes to high digits.
• Skin lesion: erythema( red coloration of the skin due to the expansion of the subcutaneous capillaries) on the face in the form of a butterfly, and rashes of other localization are also possible.

Cutaneous erythema in systemic lupus erythematosus.

• Joint damage: arthritis, usually of small joints.
• Vascular damage: capillaritis( inflammation of small vessels) of fingertips, less often soles and palms.

Capillaritis in systemic lupus erythematosus.

• Lesion of the lungs: fibrosing alveolitis( common lung tissue damage with subsequent scarring), pleurisy( inflammatory pleural lesion).
• Heart attack: myocarditis( inflammation of the middle heart of the heart-myocardium), endocarditis of Liebman-Saks( inflammation of the inner shell of the heart-endocardium), pericarditis( inflammation of the outer shell of the heart-pericardium).
• Central nervous system involvement: lupus cerebrovascular disease( brain disease associated with blood vessel pathology).
• Kidney damage: lupus nephritis.

The manifestations of lupus nephritis are extremely diverse and depend on the severity of the pathological process. In accordance with the severity of the flow, there are:

• Active forms of nephritis: is rapidly progressive and slow progressing with nephrotic syndrome( a condition characterized by the release of large amounts of protein in the urine, a decrease in the protein concentration of the blood, a violation of fat metabolism, development and spread of swelling up to accumulation of fluid in the body cavities: abdominal, thoracic, pericardial cavity) or pronounced urinary syndrome( the appearance of an increased amount of protein and blood in the urine in the absence of external manifestations of the disease);

• Inactive forms of nephritis: with minimal urinary syndrome or mild proteinuria( appearance of protein in urine. Normally, there is no protein in the urine).

Rapidly progressive nephritis is a life-threatening condition and is characterized by a malignant course with rapid development of renal failure. This disease is characterized by a pronounced nephrotic syndrome, hematuria( blood in the urine), the appearance of severe arterial hypertension, which, as a rule, is difficult to treat. Often, rapidly progressive nephritis occurs with DIC-syndrome( a critical condition, which is based on a violation of blood coagulability).This form of lupus nephritis manifests in the first year of systemic lupus erythematosus. It was found that the 5-year survival rate in these patients, in spite of the ongoing treatment, is only 29%.

Slowly progressive nephritis with nephrotic syndrome is characterized by the appearance of protein in the urine, arterial hypertension. With lupus nephritis, massive proteinuria is not detected, such as in amyloidosis, and as a consequence, there is no pronounced edematous syndrome. This form of the disease occurs in approximately 40% of cases of lupus nephritis.

Slowly progressive nephritis with severe urinary syndrome is characterized by proteinuria, hematuria, in some cases, the appearance of white blood cells in the urine. As a rule, proteinuria and hematuria rarely occur in isolation. An increase in the number of white blood cells in the urine indicates the attachment of secondary inflammation( eg, pyelonephritis).Half of the patients also have arterial hypertension, but it is characterized by a milder flow and, as a rule, is controlled by drugs. But increasing pressure in itself has a damaging effect on blood vessels, which also contributes to the formation of renal failure. Therefore, adequate control of blood pressure plays a big role in predicting the course of the disease.

Ten-year survival in patients with nephrotic syndrome without arterial hypertension is 60-70%.If there is a urinary syndrome, the prognosis of the course of the disease is more favorable. Lupus nephritis with minimal urinary syndrome is diagnosed with a protein concentration in the urine of less than 0.5 g / day, absence of hematuria, white blood cells in the urine and arterial hypertension. The kidney function is normal or slightly decreased. Outwardly, signs of damage to other organs, characteristic of systemic lupus erythematosus, are revealed.

Diagnosis of lupous nephritis

Lupus nephritis is diagnosed on the basis of clinical and laboratory data. As a rule, the disease develops in young women under the influence of predisposing factors and is manifested by fever, joint pains and skin rashes, usually on the face. In laboratory analyzes, the acceleration of the rate of erythrocyte sedimentation, the reduction of the number of leukocytes, attracts.

The disease occurs with periodic exacerbations and periods of absence of external manifestations. And, as a rule, after 1-2 months after one of such exacerbations, protein and / or erythrocytes in urine are determined during examination, which characterizes the development of jade.

The most reliable signs of the presence of systemic lupus erythematosus are the detection of LE cells and antibodies to DNA in blood tests. Therefore, these tests are necessary for the detection of isolated proteinuria.

Treatment of lupus nephritis

Therapeutic tactics depend on the form of the disease. The drugs of choice are hormonal drugs( dexamethasone), and cytostatics( cyclosporine).Effectively their joint application. For fast-progressing nephritis, pulse therapy is recommended-the use of maximum doses of drugs in a short time, usually three days, with a repetition of treatment after a few months.

In terminal renal failure, hemodialysis sessions are shown as a substitute therapy. Transplantation( transplantation) of the kidney is the method of choice for the treatment of the disease, but it should be performed only with a decrease in the activity of immune inflammation. Otherwise, there is a high probability of damage to the donor kidney by circulating immune complexes in the blood.

Doctor therapist, nephrologist Sirotkina EV