Renal tubular acidosis is a group of diseases that arise when the kidneys are unable to remove acidic substances from the blood to be eliminated in the urine, due to defects in the ability of the renal tubules to perform their functions, causing an accumulation of acidity in the bloodstream, resulting in symptoms such as muscle weakness, decreased reflexes, or delay in the child’s development.
Renal tubular acidosis, or RTA, can affect both children and adults, and can be caused by hereditary diseases, such as Falconi syndrome or sickle cell anemia, but can also arise as a consequence of other health conditions that can affect the kidneys, such as rheumatoid arthritis or lupus, for example.
The treatment of renal tubular acidosis is carried out by a nephrologist who may recommend the use of medicines to reduce blood acidity, diuretics or even corticosteroids, which depends on the severity of the symptoms and the type of renal tubular acidosis.
Symptoms of renal tubular acidosis
The main symptoms of renal tubular acidosis are:
- Delay in development and growth;
- Difficulty for children to gain weight;
- Rickets;
- Mild dehydration;
- Kidney stone;
- Recurrent urinary infections;
- Muscle weakness or paralysis;
- Cardiac arrhythmia;
- Decreased reflexes;
- Delay in language development;
- Greater fragility in bones and increased risk of fractures;
- Bone pain;
- Hearing Loss;
- Blindness.
Renal tubular acidosis often does not cause symptoms, however, as the disease progresses, some symptoms may appear, especially if there is no maturation of the excretory system.
Furthermore, symptoms vary according to the type of renal tubular acidosis, and it is important to consult a pediatrician or nephrologist so that the diagnosis can be made, the cause and type of acidosis identified, and the most appropriate treatment can be initiated.
How to confirm the diagnosis
The diagnosis of renal tubular acidosis is made by a pediatrician or nephrologist through evaluation of symptoms, health history and blood and urine tests.
In the blood test, the concentration of bicarbonate, chloride, sodium and potassium is evaluated and blood pH is also measured. In addition, your doctor may request an assessment of blood levels of aldosterone or other hormones that may be related to renal tubular acidosis.
In the urine test, the acidity of the urine is measured, in addition to the levels of bicarbonate, ammonia and hydrogen.
In addition, an ultrasound of the kidneys may be indicated to check for the presence of kidney stones, or an X-ray of the hands or feet, for example, so that the doctor can check for bone changes that could interfere with development. of child.
Types of renal tubular acidosis
Renal tubular acidosis can be classified into different types, the main ones being:
- Distal renal tubular acidosis or type 1: affects the distal renal tubule, which is responsible for transporting sodium, chloride and potassium from the blood to the urine. This type of ATR is more common in adults, caused by other health conditions, but can also affect children;
- Proximal tubular acidosis or type 2: affects the proximal renal tubule, leading to a lack of ability to reabsorb sodium bicarbonate from urine, increasing its elimination, resulting in increased blood acidity. This type of ATR is more common in newborns due to hereditary conditions;
- Hyperkalemic renal tubular acidosis or type 4: This type of ATR is caused by a deficiency of the hormone aldosterone or by changes in the kidneys that do not respond to this hormone. Aldosterone is responsible for acting on the kidneys, increasing the elimination of potassium, and when this ion is not eliminated adequately through urine, its levels increase in the blood, this condition being called hyperkalemia.
Furthermore, another type of RTA is mixed renal tubular acidosis or type 3, which is a combination of distal and proximal RTA (type 1 and type 2), caused by the deficiency of an enzyme, carbonic anhydrase, responsible for regulating acidity. of the blood.
Possible causes
Renal tubular acidosis is caused by a loss of the ability of the renal tubules to eliminate acids from the blood through urine or to absorb sodium bicarbonate from urine, resulting in increased acidity in the blood, called acidosis.
Some genetic, hereditary factors or other diseases may contribute to the development of renal tubular acidosis, such as:
In addition, renal tubular acidosis can also be caused by the use of medicines, such as lithium, amphotericin B, valproic acid, ifosfamide, spironolactone, amiloride, atenolol, propranolol, captopril, enalapril, non-steroidal anti-inflammatory drugs, tetracyclines or antivirals, for example. example.
Renal tubular acidosis can also arise due to exposure or poisoning by heavy metals, such as lead, for example.
How the treatment is carried out
The treatment of renal tubular acidosis is carried out under the guidance of a nephrologist or pediatrician, in the case of children, and depends on the type of RTA and the levels of ions in the blood and the severity of the symptoms.
Thus, the doctor may recommend the use of sodium bicarbonate or potassium citrate to correct blood acidity, to prevent damage to bones, muscles or the development of kidney stones, for example.
Additionally, the doctor may recommend the use of thiazide diuretics, such as hydrochlorothiazide or indapamide, for example, to increase the absorption of sodium bicarbonate from urine into the blood, especially in the treatment of type 2 ATR.
In some cases, the doctor may also recommend the use of vitamin D or phosphorus supplements, or the use of corticosteroids, which depends on the type of renal tubular acidosis.
It is important that the treatment is carried out according to the doctor’s recommendation to avoid the occurrence of complications related to excess acid in the body, such as bone deformations, the appearance of calcifications in the kidneys and kidney failure, for example.
Renal tubular acidosis in children
Children diagnosed with ART can live a completely normal life with quality of life as long as they undergo treatment correctly to avoid complications. However, it is possible that they become more susceptible to infections due to the greater fragility of their immune system.
In some cases, the symptoms of renal tubular acidosis may disappear between the ages of 7 and 10 due to the maturation of the kidneys, and there is no need for treatment, just medical monitoring to assess whether the kidneys are functioning correctly.
