Validity of anti-nuclear antibodies, double strand DNA antibodies and other parameters in autoimmune hypoparathyroidism

Abstract

Background: Hypoparathyroidism is the destruction of the parathyroid gland by the immune system, as part of a multiple endocrine insufficiency syndrome. Tissue resistance to PTH's activities can occur in rare cases, resulting in hypoparathyroidism with increased PTH levels. Hypothyroidism is more common in females than males. 1,25-dihydroxyvitamin D3 (active vitamin D) levels must be evaluated to rule out vitamin D deficiency as a contributor to or cause of hypocalcemia. Hypocalcemia and phosphatemia are common symptoms of hypoparathyroidism. Antinuclear antibodies (ANA) and double strand DNA (DsDNA) are the important biomarkers for diagnosis and prognosis of patients with autoimmune diseases. ANA and DsDNA occur in different endocrine disorders including thyroid disorders like hypoparathyroidism.

Methods: Thirty Hypoparathyroidism patients with age range 21-74 years with (20 female and 10 male) were attending international Baghdad Medical Hospital, during the period from December 2019 to February 2021 and thirty apparently healthy were chosen as healthy control groups respectively. For these two study groups, the blood samples were collected to evaluate the serum level of serum phosphorus, calcitonin, Calcium, Vitamin D3, DsDNA and ANA. The type of kits used for serum DsDNA and ANA in humans were an indirect enzyme immunoassay (ELISA) and the kits for serum level of serum Vitamin D3 and calcitonins were a sandwich ELISA. Finally, these kits for the calcium and phosphorus inorganic Colorimetric method were used.

Results: Using Student's t-test, the present study's data revealed a statistically significant difference in the mean of age group cases and controls (P=0.005), as well as a statistically significant difference in serum mean values of each Serum phosphorus (P=0.005), calcitonin (P=0.005), calcium (P=0.002), and vitamin D3 centration (P=0.005) between these two groups . By using Chi-square test sex was not significant between hypoparathyroid and control (P=0.787) and DsDNA was not significantly more positive in hypoparathyroid subjects than control (P=0.112); while ANA was significant (P=0.024).

Conclusion: The study sheds light on the necessity to screen the hypo parathyroid patients for vitamin D, calcium and phosphorous levels and calcitonin for better prognosis of patients and for each of antinuclear antibodies (ANA) and double strand DNA (DsDNA).

Keywords: Hypoparathyroidism; Phosphate; Calcium; Calcitonin; Vitamin D; ANA; DsDNA