ACTA ENDOCRINOLOGICA (BUC)

Context. Primary hyperparathyroidism (PHPT) is often associated with thyroid disorders like nodular goiter, Hashimoto’s thyroiditis (HT) and Graves’ disease. Objective. Our aim was to explore whether the coexistence with HT affects bone metabolism in patients with PHPT. Design. This was a comparative cross-sectional study carried out in a tertiary inpatient endocrine center from January 2018 through December 2020. Subjects and Methods. A total of 234 patients were diagnosed with PHPT at our endocrine center. One hundred of them were included in the study - 50 with PHPT only and 50 with PHPT and HT. Two control groups were defined: 37 with HT and 37 without PHPT and HT. Serum markers of calcium-phosphate metabolism, bone markers (RANKL, Osteoprotegerin, β-CTX, Osteocalcin) and interleukin-17A were measured. Results. The frequency of HT among patients with PHPT was 37.6% (95% CI 31-43%) and did not differ significantly from that in the general population, 32.5% (95% CI 30-35%). Age, BMI, markers of calciumphosphate metabolism, bone markers and interleukin-17A weren’t significantly different in PHPT with and without HT or between the two control groups. The participants with PHPT had higher levels of interleukin-17A, β-CTX and Osteocalcin (p<0.05) than those without the PHPT. RANKL and Osteoprotegerin in these groups did not differ. Interleukin-17A correlated positively with serum calcium, PTH and RANKL and negatively with serum inorganic phosphate and 25(OH)D. Controlling for HT and age did not change the correlation. Conclusions. In our study, HT has not additional effect on bone metabolism in the patients with PHPT. Higher levels of interleukin-17A in PHPT suggest a possible role in the PTH-induced bone remodeling.

Context. Thyrotropin-receptor antibodies (TRAb) are biomarkers of Graves’ disease (GD) and Graves’ orbitopathy (GO). Elevated immunoglobulin E (IgE) and antinuclear antibodies (ANA) were also found in GD patients. Objective. We aimed to assess TRAb, IgE and ANA in GD and GO patients and to evaluate the relationship between the immunological markers and smoking. Design. This was a comparative cross-sectional study carried out in a single tertiary care center from June 2018 to January 2020. Subjects and Methods. A total of 103 GD patients (mean age 51.2, 84 females) were divided into three subgroups: moderate-to-severe GO (n=36), mild GO (n=32) and “only GD” subgroup (n=35). Forty healthy controls (HC) (mean age 51.2, 36 females) were also included. TRAb were measured by a thyrotropin-binding inhibitory immunoglobulin (TBII) assay in GD patients; IgE and ANA - by an enzyme-linked immunosorbent assay in all subjects. Results. GD patients had higher IgE-positivity rate (p=0.04) and similar ANA-positivity compared to HC. Moderate-to-severe GO subgroup had the highest TBII (p<0.01), the lowest TBII-negativity rate (p<0.01) and the highest ANA-positivity rate (p=0.03) and was the only subgroup whose IgE-positivity rate was significantly higher than HC (25% vs. 7.5%). Mild GO and “only GD” patients had comparable TBII, TBII-negativity rate, IgE and ANA. Both GO subgroups had significantly higher smoking rate than “only GD” patients. Smoking was positively associated with IgE positivity (φ=0.22, p=0.03), and negatively with TBII negativity rate (φ=-0.24, p=0.02). Conclusions. GD patients exhibit different immunological patterns depending on the presence and severity of GO. Smoking might be just one of the factors responsible for the clinical and immunological variety of GD. Further studies are needed.