Amyloidosis of the kidneys is one of the types of disorders of protein metabolism. At the same time, an insoluble protein – amyloid-is deposited in organs and tissues. Amyloidosis of the kidneys is characterized by a violation of the function of the organ, up to chronic renal failure. Amyloid literally permeates the kidney tissue, preventing the kidneys from performing their main function – to filter the blood and remove excess water, salts and harmful substances from the body. Let’s find out what is associated with kidney amyloidosis and what symptoms it manifests. We will also analyze the methods of treatment of this disease, according to the clinical recommendations for the treatment of kidney amyloidosis.
Kidney amyloidosis-causes and symptoms
Amyloidosis is a systemic disease. It is worth noting that not only the kidneys suffer, but also the heart, joints, thyroid gland, nervous and digestive systems, including the liver.
The cause of kidney amyloidosis is a violation of protein synthesis in the body. The abnormal protein enters the bloodstream. The immune system reacts to it with hostility, and the processes characteristic of allergies occur. Antibodies are produced that interact with the foreign agent. As a result of this reaction, a new protein is obtained, which is a precursor of amyloid. Then an abnormal protein is formed from this compound, which is the cause of the pathology.
Amyloid is similar in structure to collagen. It does not dissolve and is not excreted from the body, being deposited in the tissues. In fact, kidney amyloidosis is a manifestation of systemic pathology. At the same time, the work of the main structural unit – the nephron-is disrupted. Dystrophic processes occur – the kidney tissue is replaced by connective tissue, losing its function. In medical practice, amyloidosis of the kidneys is called amyloid dystrophy.
Classification of kidney amyloidosis
There are primary and secondary amyloidosis of the kidneys. The primary occurs spontaneously, for an unknown reason. To date, science has not found an answer to the question of why metabolic disorders begin to occur in the body for no apparent reason. Primary kidney amyloidosis and myeloma have been linked, but this disease does not always lead to abnormal protein synthesis.
Secondary amyloidosis of the kidneys is a consequence of long-term chronic inflammation and cancer. The most common cause of kidney amyloidosis is rheumatoid arthritis, tuberculosis, syphilis, .
In addition, the disease can be hereditary. That is, violations of protein metabolism in parents are a risk factor for a similar pathology in children.
Age also plays a role. It is noted that the risk of the disease after 50 years increases several times. And after 80 years, kidney amyloidosis is diagnosed in 80% of people.
The symptoms of amyloidosis of the kidneys depend on the degree of their damage. The initial stage of the disease can last up to five years, and the person does not notice any discomfort. The safety margin of the kidneys is quite high, because the function of the failed nephrons is performed by others. But as amyloid accumulates, the disease begins to show characteristic symptoms. Let’s look at the symptoms of kidney amyloidosis in the dynamics of the course of the disease.
Stages of kidney amyloidosis, symptoms of the disease
- Asymptomatic or latent. Amyloid is gradually deposited along the course of the renal vessels. Their permeability is disturbed and a slight edema develops. Over time, the abnormal protein accumulates in the brain and cortical matter of the kidney. The latent stage develops for a long time — from 3 to 5 years, during which a person may not even know about the disease. All this is due to the mechanism of compensation of kidney nephrons.
- Proteinuric. At this stage, kidney function is impaired and nephron atrophy occurs. The permeability of the glomerular capillaries increases, and the proteins come out with the urine. This phenomenon is called proteinuria (the presence of protein in the urine). The nephrons lose their function and are replaced by connective tissue. The so-called nephrotic syndrome develops with characteristic signs
-High level of protein in the urine-pronounced proteinuria;
– Low protein content in the blood-hypoproteinemia;
– High cholesterol in the blood-hypercholesterolemia;
– Edema, due to fluid retention in the body.
Due to sclerosis (replacement of connective tissue), the kidneys become dense, increase in size, and acquire a grayish-pink matte color. At the same time, the liver and spleen often increase.
Edema in amyloidosis of the kidneys is not removed by diuretics. This is another clinical sign of kidney amyloidosis.
- Nephrotic (edematous) the stage of amyloidosis of the kidneys is manifested by a massive deposition of amyloid in all parts of the nephron. The loss of protein in the urine is 3-5 grams per day. It should be noted that this is quite significant for the body and affects the health of all organs and systems. The density of the kidneys increases, edema becomes more pronounced, and blood pressure decreases. There are pains in the kidneys, muscles, weight loss is observed. Chronic inflammation worsens, and shortness of breath occurs after physical exertion. This stage lasts about 6 years.
- Terminal (uremic) the stage is characterized by almost complete loss of kidney function. It decreases in size, compacts, and shrinks.
Amyloidosis of the kidneys in the photo:
The end stage is accompanied by chronic renal failure with the progression of all symptoms. At the same time, the whole body suffers. Signs of end-stage kidney amyloidosis, in addition to the typical renal symptoms, include diarrhea, arrhythmia, shortness of breath, and general weakness.
Kidney amyloidosis is a chronic disease that develops over many years and even decades. The symptoms of the disease gradually increase, and the degree of their manifestation depends on the stage of the disease.
Symptoms of kidney amyloidosis:
- recurrent pain in the kidneys
- temperature rise
- swelling of the hands, feet, and face
- nausea, diarrhea
- pain in the heart area
- muscle pain
- weight loss
- shortness of breath during exercise
- combination of rash, deafness, and kidney damage
- exacerbation of chronic diseases
If you have such symptoms, you should immediately consult a doctor. Kidney diseases are dealt with by a narrow specialist-a nephrologist.
The prognosis of kidney amyloidosis depends on the stage of the disease. If the patient is treated on time, at the 1-2 stage of the disease, then there are ways to help him and prevent relapses.
Diagnosis of kidney amyloidosis
Until the onset of clinical symptoms of kidney amyloidosis, it is extremely difficult to diagnose the disease. Not all people take care of their health and undergo regular medical examinations. Meanwhile, the most banal general analysis of urine helps to identify the early signs of the disease. As a rule, they see a doctor only at the second stage of amyloidosis of the kidneys. It is during this period that alarming symptoms appear.
Diagnosis of kidney amyloidosis requires a careful approach, since the symptoms of the disease are similar to pyelonephritis and a number of other pathologies.
To clarify the diagnosis, you need:
- A general urine test that will show the presence of elevated levels of protein, white blood cells, cylinders, and red blood cells. This indicates a violation of the work of the nephrons and inflammation.
- A biochemical blood test, which reveals signs of a violation of protein and water-salt metabolism – high levels of albumin, globulin, bilirubin, sodium, calcium, cholesterol and other indicators.
- A general blood test, which will determine the signs of inflammation and anemia.
- Ultrasound of the kidneys and internal organs. Amyloidosis of the kidneys on ultrasound has characteristic signs – a clear increase in the size of the organ, the so-called “large fat kidneys”. Most often, the liver and spleen increase in parallel.
- Kidney biopsy is the most reliable method for amyloidosis. The resulting amyloid is stained with a special dye, and under polarized light is observed under a microscope. Amyloid has a specific glow, which can determine its variety. A biopsy for amyloidosis of the kidneys is very helpful in determining the treatment strategy.
Clinical recommendations for the treatment of kidney amyloidosis
Kidney amyloidosis can be caused by a variety of causes. The treatment strategy depends on the concomitant diseases and is selected strictly individually. Age, heredity and concomitant diseases are taken into account. Since the end-stage amyloidosis of the kidneys can lead to a radical measure – the removal of the kidney, the treatment is quite aggressive. Therapy of kidney amyloidosis is aimed at reducing the level of amyloid precursor proteins and restoring the functioning of vital organs.
First of all, it is necessary to cure the chronic inflammation that led to the formation of an abnormal protein.
Here is a list of drugs that are used to treat kidney amyloidosis:
- Colchicine-stops the progression of amyloidosis and inflammatory reactions. Prescribe for a long time, 1.8 — 2 g per day. In amyloidosis of the kidneys, it is used until the normalization of renal function. In some cases, it is recommended for life.
Colchicine is considered the drug of choice for the treatment of kidney amyloidosis. It is proved that this drug is safe for long-term use and prevents relapse of the disease.
- Dimethylsulfoxide-leads to resorption (resorption) of amyloid deposits. As a rule, it is prescribed in high doses, at least 10 g per day.
- Glucocorticoids (dexamethasone, prednisone) are hormonal drugs that effectively suppress inflammation. However, they have a number of side effects that do not allow them to be used for a long time.
- Melphalan-stops protein synthesis. Apply in the event that the cause of amyloidosis of the kidneys is myeloma.
- Thalidomide-has anti-inflammatory and immunomodulatory effects. It is used for the treatment of autoimmune diseases, that is, in the case when amyloidosis of the kidneys provoked rheumatoid arthritis.
Treatment of amyloidosis of the kidneys is a responsible issue, since if the wrong approach is taken, the kidney must be removed. In case of renal failure, hemodialysis is indicated – artificial blood purification. All this can be avoided with a timely visit to the doctor.
Take care of your health, and contact a specialist in time!