From the Guidelines
Renal medullary nephrocalcinosis is a condition characterized by calcium deposits in the renal medulla, which can lead to chronic kidney disease and eventual kidney failure if left untreated, as supported by the most recent study 1.
Causes and Risk Factors
The condition is often caused by disorders that increase calcium levels in the blood and urine, such as:
- Hyperparathyroidism
- Renal tubular acidosis
- Medullary sponge kidney
- Excessive vitamin D intake Other causes include certain medications, chronic urinary tract infections, and genetic disorders, as noted in 1.
Diagnosis and Treatment
Diagnosis typically involves imaging studies like ultrasound, CT scans, or X-rays, along with blood and urine tests to identify underlying causes, as recommended in 1. Treatment focuses on addressing the underlying condition causing the calcium deposits, maintaining proper hydration, and sometimes using medications to reduce urinary calcium excretion, as suggested in 1 and 1.
Key Considerations
- Patients may experience symptoms like flank pain, blood in urine, frequent urination, or kidney stones, though many remain asymptomatic until kidney function becomes impaired.
- Genetic counseling may be offered for families with probands with confirmed clinical and/or genetic diagnosis of BS, as recommended in 1.
- The use of nonsteroidal anti-inflammatory drugs (NSAIDs) and other therapies, such as potassium-sparing diuretics, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers, may be considered, but evidence supporting their efficacy, tolerability, and safety is limited, as noted in 1.
From the Research
Definition of Renal Medullary Nephrocalcinosis
- Renal medullary nephrocalcinosis is a renal disease characterized by the deposition of calcium salts into the renal medulla 2, 3.
- It can result from various causes, including organic, iatrogenic, hereditary, and extrarenal diseases 2, 4.
- Nephrocalcinosis is often associated with renal stone formation (nephrolithiasis) and can be a result of impaired renal calcium handling 5.
Characteristics and Associations
- Renal medullary nephrocalcinosis is typically located in the renal medulla 2, 3.
- It can be associated with various metabolic and genetic disorders, including tubulopathies, medullary sponge kidney, and hyperparathyroidism 2, 6, 4.
- The condition can also be linked to extrarenal diseases, such as short bowel syndrome, hypothyroidism, and thalassemia 2.
Clinical Manifestations and Treatment
- Patients with renal medullary nephrocalcinosis may be asymptomatic or present with symptoms such as failure to thrive, abdominal pain, and proteinuria/hematuria 2.
- Treatment of the underlying condition is associated with catch-up growth and stabilization of renal function in most patients, but not with the reduction of the degree of nephrocalcinosis 2.
- Potassium citrate treatment can be effective in preventing renal stones in patients with medullary sponge kidney, a condition often associated with nephrocalcinosis 6.