Nephrocalcinosis - Types, Causes, Symptoms, Diagnosis and Treatment

What Is Nephrocalcinosis?

Nephrocalcinosis is a kidney problem where too much calcium builds up inside the kidneys. It happens more often in tiny babies who are born early, but grown-ups can get it too! Usually, both kidneys are affected.

Sometimes, doctors find nephrocalcinosis by accident when they take pictures of the kidneys, even if the kidneys are working just fine!

There are many different reasons why it happens, and the cause is very important because it helps doctors decide the best treatment and what might happen next.

Most kids and adults with nephrocalcinosis don’t always end up with kidney failure. But if the main cause isn’t treated, the kidneys could get worse and might even stop working over time.

What Are the Types of Nephrocalcinosis?

Nephrocalcinosis is classified based on the radiographic demonstration and calcifications of the kidneys' parenchyma (functional tissue of an organ composed of a group of similar cells).

According to the radiographic appearance, nephrocalcinosis can be:

Microscopic nephrocalcinosis:

In this type, the crystalline forms of calcium (calcium oxalate or calcium phosphate) are spread all over and can only be seen under a microscope. It is not visible on X-ray.

Macroscopic nephrocalcinosis:

This occurs when there are bigger clumps of calcium in the kidneys. They’re big enough to be seen on special pictures like CT (computed tomography) scans, ultrasounds, or X-rays.

Chemical nephrocalcinosis:

This type shows increased levels of calcium deposition in kidney cells, especially in the tubular epithelium, affecting kidney function. Doctors can measure this in tests, but you can’t see it with a microscope or on an X-ray.

Nephrocalcinosis can also be sorted into types based on where the extra calcium shows up in the kidneys:

Medullary nephrocalcinosis:

This is the most common kind (about 98 out of 100 cases!). The extra calcium gets deposited in the middle part of the kidney, called the medullary pyramids.

Cortical nephrocalcinosis:

This is rare. Here, the calcium covers the whole working part of the kidney. It’s often linked to serious health problems, such as severe metabolic disorders, such as primary hyperoxaluria (increased oxalates in the urine) or end-stage renal disease.

What Are the Causes of Nephrocalcinosis?

Nephrocalcinosis can happen for lots of different reasons! Sometimes it’s because of another health problem you already have. Other times, it can be from medicines, vitamins, or infections.

Some kids and grown-ups are born with conditions they get from their families, which can make calcium build up in the kidneys, too.

Some people are born with conditions that make nephrocalcinosis more likely, such as:

• Type 1 endocrine neoplasia (disorder affecting endocrine glands).

• Distal renal tubular acidosis (a condition where the kidney is not able to remove acid from the blood).

• Chronic granulomatous disease (a condition where the phagocytes cannot fight off the infection).

• Primary hyperoxaluria (a condition where the liver produces more oxalate).

• Bartter syndrome (a condition where the body cannot absorb sodium, leading to more salt and water loss through urine).

• Alport syndrome (a condition that affects eyes, hearing, and kidneys).

• Primary hyperaldosteronism (a condition in which there are high aldosterone levels).

• Liddle syndrome (a condition where the kidneys retain too much salt and water but excrete too much potassium).

• Williams syndrome (a condition that causes heart issues, developmental delays, and distinctive facial features).

• Medullary sponge kidney (a condition where collecting tubules in the kidneys are dilated).

• Beta-thalassemia (a blood disease).

Nephrocalcinosis can also occur because of:

• Primary hyperparathyroidism (a condition that causes high parathyroid hormone).

• Hypervitaminosis-D state (high levels of vitamin D).

• Hypercalcemia (excessive calcium levels).

• Hypocitraturia (low citrate levels in the urine).

• Sarcoidosis (a condition where clumps of inflammatory cells are formed in many organs).

• Phosphate supplementation.

• Underlying osteoporosis.

• Premature birth.

• Certain medications, like Acetazolamide, Triamterene, etc.

• Kidney diseases and AIDS (acquired immunodeficiency syndrome)-related diseases.

• Hypercalciuria (excess calcium in urine).

• Hyperoxaluria (excess oxalate in urine).

• Chronic glomerulonephritis (a condition that affects the kidneys' filtering units).

• Renal cortical necrosis (a condition where the outer layer of the kidney dies because of a lack of blood supply).

What Are the Signs and Symptoms of Nephrocalcinosis?

At first, nephrocalcinosis usually doesn’t make you feel sick, so you might not even know it’s there! But sometimes, the issues that cause it, or kidney stones that come with it, can give you symptoms.

Some common signs you might notice are:

• Fever and chills.

• Blood in the urine.

• Nausea and vomiting.

• Abdominal pain.

• Pain in the sides and back, groin region, or near the testicles.

In late stages, symptoms may be due to chronic kidney failure.

How Is Nephrocalcinosis Diagnosed?

To find out if you have nephrocalcinosis, doctors carry out these steps:

Clinical evaluation:

These include a complete medical history and a physical examination.

Diagnostic tests:

Doctors might do some tests, which include:

1. Radiographic tests:

• Ultrasound (main test).

• CT scan (sometimes with contrast).

• Abdominal X-ray.

2. Blood tests:

• Check thyroid hormone levels.

• Measure salts and minerals in your blood.

3. Urine tests:

• Look at the urine under a microscope.

• Check for organisms (urine culture).

• Measure urine pH.

• 24-hour test to check levels of calcium, oxalate, potassium, magnesium, uric acid, and citrate

4. Endoscopy:

A tiny camera is used to examine the inside of the kidney to determine whether it has nephrocalcinosis or kidney stones.

5. Kidney biopsy:

Here, a small piece of kidney tissue is taken and examined under the microscope.

6. Genetic test:

Sometimes, DNA is checked to see if the problem runs in families.

In about 83 percent of cases, nephrocalcinosis is asymptomatic and is diagnosed incidentally on ultrasound; this is especially common in children.

What Are the Treatment and Management Strategies for Nephrocalcinosis?

Doctors treat nephrocalcinosis by finding out what’s causing it and stopping more calcium from building up in the kidneys. Their goal is to keep your kidneys healthy and help you feel better.

Here are some ways doctors can help:

• In treating conditions like hypercalcemia and hypercalcemic nephropathy, in which excessive calcium levels are present in the blood, adequate hydration is provided through saline (isotonic sodium chloride solution) to prevent damage to the kidneys.

• In the case of macroscopic nephrocalcinosis, Thiazide diuretics (medication that helps release more sodium into the urine) are prescribed, and dietary restriction of salt intake is advised.

• Potassium and magnesium supplements are given.

• Potassium citrate supplementation is recommended in cases of idiopathic (unknown cause) hypercalciuria and distal tubular renal acidosis because the potassium citrate acts as a chelating agent (a chemical agent that reacts with metal ions of substances and forms a water-soluble stable component) that binds to urinary calcium and thus reduces stone formation.

• In type I hyperoxaluria, large doses of Pyridoxine are given to reduce oxalate production.

• Parathyroidectomy in case of the hyperfunctioning thyroid gland is done.

• Surgical intervention is required in case of renal stones causing obstruction and infection.

• Additionally, more fluid intake is recommended to produce at least 0.53 gallons of urine daily. Restriction of high-protein animal food and sodium intake is also important.

What Are the Possible Complications of Nephrocalcinosis?

If the problem causing nephrocalcinosis isn’t treated, it can lead to other kidney troubles. But don’t worry, doctors can help prevent these if the condition is caught early!

Here are some possible complications:

• Chronic kidney failure.

• Acute kidney injury.

• Kidney stones.

• Renal colic (pain because of kidney stones blocking the ureter).

• Renal tubular dysfunction.

• Renal infections.

• Obstructive uropathy.

• Hypertension.

• Proteinuria.

• In severe cases, end-stage kidney disease.

Conclusion:

Nephrocalcinosis does not affect life expectancy, but finding it early is really important! If doctors spot it and treat it fast, they can help the kidneys stay strong and healthy.

If someone already has kidney issues, nephrocalcinosis might not be treated. That’s why it’s best to spot it and treat it as soon as possible, so your kidneys can keep doing their important job!.

Note from iCliniq:

• Nephrocalcinosis is a condition where extra calcium builds up in the kidneys.

• It happens most often in babies who are born early.

• At first, it usually doesn’t cause any symptoms, but later it can get more serious.

• Doctors often use an ultrasound (a special picture of the inside of your body) to find it, and sometimes, they also do blood tests.

• Treatment depends on what’s causing it, and sometimes you’ll need to change what you eat.

It’s not usually life-threatening, but finding it early can stop bigger problems from happening. If you think you might have it, consult a nephrologist online at iCliniq to get the right tests and a treatment plan.