Discussion
We reported a case of SLE presented with hypoparathyroidism. Acquired
hypoparathyroidism results from deficient PTH secretion following
surgery, radiation or autoimmune damage to the parathyroid glands, and
storage or infiltrative diseases of the parathyroid glands (5).
Postsurgical and idiopathic hypoparathyroidism are the most common
causes (5, 6). An autoimmune reason for idiopathic hypoparathyroidism
(IH) has been suggested because of the close association between IH and
other autoimmune and autoantibodies against parathyroid cells antigens.
These antibodies include calcium-sensing receptors and mitochondrial
antigens in the serum of patients with hypoparathyroidism(6).CaSR senses
calcium concentration and stimulates PTH secretion by the parathyroid
and calcium reabsorption by the renal tubules. When CaSR is destroyed,
PTH secretion and calcium absorption are depleted(7).
SLE associated with hypoparathyroidism is underestimated and usually has
subclinical manifestation. Hypoparathyroidism associated with SLE is
extremely rare, and to the best of our knowledge, only 10 cases have
been reported(8-13). In 80% of cases, hypoparathyroidism presented
before or simultaneous with SLE. In 20% of cases, autoimmune thyroid
disease co-exists with hypoparathyroidism. Thyroid autoimmunity is more
common, reported in 6-60% of SLE patients. Anti-TPO antibody and
Hashimoto’s thyroiditis have been reported in up to 33% and 8% of
patients with SLE, respectively (1).