What autoimmune disease causes high calcium
What autoimmune disease causes high calcium Autoimmune diseases are conditions in which the body’s immune system mistakenly attacks its own tissues, leading to a variety of health issues. Among these, some are associated with disturbances in calcium metabolism, notably causing elevated calcium levels in the blood, a condition known as hypercalcemia. Understanding which autoimmune diseases can lead to high calcium and how they do so is crucial for proper diagnosis and management.
One autoimmune disorder that can cause hypercalcemia is sarcoidosis. Sarcoidosis is characterized by the formation of granulomas—clusters of immune cells—that can develop in multiple organs, most commonly the lungs and lymph nodes. These granulomas contain activated macrophages, which produce an enzyme called 1-alpha hydroxylase. This enzyme converts inactive vitamin D (25-hydroxyvitamin D) into its active form (1,25-dihydroxyvitamin D or calcitriol). An excess of calcitriol leads to increased intestinal absorption of calcium, resulting in elevated blood calcium levels. This mechanism is distinct from other causes of hypercalcemia because it is driven by immune cell activity rather than parathyroid hormone (PTH) regulation.
Another autoimmune condition that can contribute to hypercalcemia through immune-mediated mechanisms is certain cases of autoimmune lymphoproliferative disorders. These disorders involve abnormal immune cell proliferation and can sometimes interfere with calcium regulation, although they are less directly associated than sarcoidosis.
Typically, hypercalcemia in autoimmune diseases is not the primary feature but arises as a complication of immune activation and granuloma formation. The excess calcitriol production in sarcoidosis is a hallmark example, and it underscores the importance of considering autoimmune causes when evaluating unexplained hypercalcemia, especially in patients with systemic symptoms like fatigue, weight loss, or respiratory issues.
Furthermore, autoimmune diseases like tuberculosis, although infectious rather than autoimmune, can generate granulomatous inflammation similar to sarcoidosis, leading to increased calcitriol production and hypercalcemia. This highlights that granuloma formation, regardless of etiology, can contribute to calcium imbalance.
Management of hypercalcemia caused by autoimmune disease involves addressing the underlying immune activation. Corticosteroids are often prescribed as they suppress granuloma formation and reduce calcitriol production, thereby normalizing calcium levels. Additional treatments may include hydration, bisphosphonates, or other calcium-lowering therapies, depending on severity. Importantly, diagnosing the autoimmune nature involves measuring serum levels of calcitriol, PTH, and other markers, alongside clinical assessment.
In summary, sarcoidosis stands out as the primary autoimmune disease associated with high calcium levels due to granulomatous production of active vitamin D. Recognizing this link is vital for timely intervention and effective management, preventing complications associated with persistent hypercalcemia such as kidney stones, osteoporosis, or renal impairment.
