Classic distal renal tubular acidosis (dRTA) is a medical condition characterized by impaired acid secretion in the distal tubules of the kidneys, leading to a buildup of acid in the bloodstream. It is considered a type of renal tubular acidosis and is often chronic in nature.
In individuals with classic dRTA, the distal tubules of the kidneys fail to effectively excrete hydrogen ions and reabsorb bicarbonate, resulting in a decreased ability to regulate the body's acid-base balance. This leads to an accumulation of acid in the blood, a condition known as metabolic acidosis.
The main features of classic dRTA include a high urinary pH (above 5.5) despite a low blood pH, due to impaired acidification of urine in the distal tubules. This acidification defect can result in a variety of symptoms, such as frequent urination, increased thirst, fatigue, muscle weakness, and growth delay in children.
Classic dRTA may be either inherited or acquired. Inherited forms are usually present from birth and are associated with genetic mutations that affect the functioning of the transport proteins in the distal tubules. Acquired forms can develop later in life due to various factors, including autoimmune disorders, medications, or chronic kidney diseases.
Treatment for classic dRTA aims to correct the acid-base imbalance and manage symptoms. This typically involves oral administration of alkali supplements, such as sodium bicarbonate or potassium citrate, to neutralize excess acid and restore optimal pH levels. Additionally, underlying causes or associated conditions should be addressed to improve overall kidney function and prevent further complications.
