From the Guidelines
Hypercalcemia is not always present in sarcoidosis, and its presence is estimated to occur in approximately 10-20% of patients. The diagnosis and detection of sarcoidosis, as outlined in the American Thoracic Society clinical practice guideline 1, emphasize the importance of baseline serum calcium testing to screen for abnormal calcium metabolism, even in asymptomatic patients. This approach is based on the understanding that hypercalcemia can have significant implications for patient management and outcomes.
Key Considerations
- Hypercalcemia in sarcoidosis results from increased production of 1,25-dihydroxyvitamin D (calcitriol) by activated macrophages in granulomas, leading to enhanced intestinal calcium absorption and bone resorption.
- The guideline suggests measuring both 25- and 1,25-OH vitamin D levels before vitamin D replacement if assessment of vitamin D metabolism is necessary, highlighting the complexity of calcium and vitamin D metabolism in sarcoidosis patients 1.
- Monitoring calcium levels is crucial, especially in patients with renal involvement, as persistent hypercalcemia can lead to nephrocalcinosis and kidney damage.
- Treatment of hypercalcemia in sarcoidosis typically involves corticosteroids to suppress granuloma formation and vitamin D production, along with adequate hydration and sometimes limiting dietary calcium and vitamin D intake.
Clinical Implications
- The presence or absence of hypercalcemia has significant implications for the management of sarcoidosis, underscoring the need for regular monitoring and tailored treatment approaches.
- Given the variability in calcium levels among sarcoidosis patients, a one-size-fits-all approach to management is not appropriate, and individualized care based on serum calcium testing and other clinical factors is recommended, as suggested by the guideline 1.
From the Research
Hypercalcemia in Sarcoidosis
- Hypercalcemia is a complication of sarcoidosis, but its presence is not always consistent across all patients 2, 3.
- The prevalence of hypercalcemia in sarcoidosis patients varies widely, ranging from 2-63% depending on the population studied 2.
- Hypercalcemia in sarcoidosis is often related to high serum 1,25-dihydroxyvitamin D (1,25-OHD) concentrations, but it can also occur with normal 1,25-OHD levels 4.
- Contributing factors to hypercalcemia in sarcoidosis may include dehydration, increased uptake of oral calcium, and decreased calcium excretion, especially in mild renal insufficiency 4.
Treatment of Hypercalcemia in Sarcoidosis
- Treatment of hypercalcemia in sarcoidosis depends on the serum level of hypercalcemia and its persistence, and may involve hydration, glucocorticosteroid therapy, and avoidance of sun exposure and vitamin D-rich foods 2, 3.
- Glucocorticosteroids, such as prednisone, are often used to treat hypercalcemia in sarcoidosis by inhibiting the overly active 1alpha-hydroxylase activity of macrophages 2, 3.
- Alternative treatments, such as chloroquine, ketoconazole, and denosumab, may also be effective in managing hypercalcemia in sarcoidosis 5, 6.
- In some cases, infliximab may be used to treat severe hypercalcemia from sarcoidosis that is unresponsive to steroids or other conventional treatments 5.