Distal Renal Tubular Acidosis (dRTA)
What is distal renal tubular acidosis (dRTA)?
Distal renal tubular acidosis (dRTA) is a kidney disease that occurs when the kidneys don’t remove acids from the blood into the urine properly. The body’s normal functions produce acid, which the kidneys take from the blood and excrete into urine. When too much acid remains (acidosis), the blood becomes too acidic, which leads to imbalances and problems with cell functions.
dRTA (also sometimes called classical dRTA) is the type 1 form of renal tubular acidosis. What differentiates it from other types is the “distal” part of its name. Distal means distant, and it refers to the point where the defect occurs in the tube of the kidney that forms urine. It’s relatively distant from the point where fluid from the blood enters the tiny tube (tubule) that collects fluid and wastes to form urine. The defect causes acid to build up in the blood.
dRTA can occur on its own, but it is often a symptom of another disease.
What are the symptoms of distal renal tubular acidosis?
Common symptoms of dRTA include the following:
- Low potassium levels
- Stunted growth in children
- Confusion or decreased alertness
- Severe weakness
- Kidney stones
- Irregular heartbeat
- Muscle cramps and pain
- Pain in the back, abdomen, and/or bones
- Decreased output of urine
- Buildup of calcium in the kidneys
- Progressive kidney and bone disease in adults
What causes distal renal tubular acidosis?
dRTA can be inherited from a person’s father and mother; however, it usually occurs as a symptom of another disease that affects many parts of the body. Possible culprits include: sickle cell anemia
, high levels of calcium in the blood, amyloidosis
, Fabry disease
, Sjögren syndrome
, lupus, Wilson disease
, hyperparathyroidism, hyperthyroidism, chronic active hepatitis, rejection of a transplanted kidney, renal medullary cystic disease, chronic urinary tract infections, and use of certain medicines like lithium, amphotericin B, and analgesics.
How is distal renal tubular acidosis diagnosed?
dRTA is diagnosed using the following procedures:
- Thorough physical exam
- Arterial blood gas
- Blood chemistry
- Urine pH and acid-loading test
What are the treatments for distal renal tubular acidosis?
The major goal of therapy is to restore normal growth and prevent kidney stones. dRTA treatment includes, but is not limited to:
- Correcting acidosis with medications like sodium bicarbonate and sodium citrate (also called alkali therapy)
- Treating the underlying disease causing dRTA
- Potassium supplements for newborns
Where can I find out more about distal renal tubular acidosis?