The Presence of Anti-TPO Antibodies Increase the Likelihood of Post-I131 Hypothyroidism.

The use of radioactive iodine in the treatment of hyperthyroidism is common practice. However, a standardized treatment protocol with regard to radioactive iodine treatment (RAI) remains subject to discussion. We retrospectively analyzed 100 patient records. Patient diagnosis, age, gender, body mass index (BMI), dose of radioactive iodine, thyroid size, the 24 h radioiodine uptake (24 h RAIU) and protein bound iodine (PBI) were deducted, as well as the use of antithyroid drugs prior to RAI. Biochemical parameters were obtained, such as TSH, fT4, fT3, Anti-TPO, Anti-TG antibodies and thyroid stimulating antibodies. After 5 years of follow-up, 46% of the patients proved to be hypothyroid, whereas 8% of the patients were not cured after one dose of RAI. One year after RAI, a larger proportion of patients with a toxic nodule developed hypothyroidism compared to patients with a multinodular goiter (MNG) (44.2% vs. 21.2%). Radioactive iodine dose, PBI, RAIU, BMI, size of the thyroid gland, diagnosis, age and TPO-antibodies showed statistically significant differences in the development of hypothyroidism. Furthermore, thiamazole pretherapy was shown to be a predictor of hypothyroidism, as well as a high PBI value, exhibiting a positive predictive value of 85.2% when the PBI exceeded 0.16. We suggest a standardized measurement of TPO-Ab's to further determine their role in the development of hypothyroidism after RAI. The empirical dosing regimen was very effective, illustrating a 92% cure rate after 1 dose.

Undetectable thyroglobulin makes 123I whole-body scan and stimulated thyroglobulin obsolete in follow-up care of differentiated thyroid cancer: a retrospective study.

BACKGROUND: Differentiated thyroid cancer (DTC) is a common malignancy with increasing incidence. Follow-up care for DTC includes thyroglobulin (Tg) measurement and ultrasound (US) of the neck, combined with 131I remnant ablation when indicated. Diagnostic precision has evolved with the introduction of the new high-sensitive Tg-assays (sensitivity ≤0.1 ng/mL). The aim of the study was to determine the prognostic utility of high-sensitive Tg and the need for other diagnostic tests in DTC. METHODS: This was a retrospective, observational study. Patients with pathologically confirmed DTC, treated with total thyroidectomy and 131I remnant ablation, who had their complete follow-up care in our institution were selected (October 2013-December 2018). Subjects with possible thyroglobulin autoantibody interference were excluded. Statistical analysis was performed using the IBM SPSS® Statistics 24 software package. RESULTS: Forty patients were eligible for analysis. A total of 24 out of the 40 patients (60%) had an undetectable high-sensitive Tg 6 months after total thyroidectomy. None of these patients had a stimulated Tg above 1 ng/mL, or remnant on the 123I Whole-Body Scan (WBS) after 1 year of follow-up. Ultrasound of the neck, performed between 6 and 12 months postoperative, was negative in 21 out of the 24 patients. CONCLUSIONS: This study shows that an undetectable high-sensitive Tg can change the management of patients with DTC and decrease the use and need of stimulated Tg and 123I WBS.

A Systematic Review and Meta-Analysis of Endocrine-Related Adverse Events Associated with Immune Checkpoint Inhibitors.

Monoclonal antibodies targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4), programed cell death 1 (PD-1), or its ligand (PD-L1) have become the mainstay for advanced malignancies. The incidence of endocrine adverse events provoked by these immune checkpoint inhibitors (ICI) is based on data from randomized controlled trials, which have their drawbacks. PubMed was searched through August 22nd, 2017, by 2 reviewers independently (J.d.F. and C.E.A.). Early phase I/II, phase III experimental trials, prospective and retrospective observational studies were included. The weighted incidence and risk ratio were estimated for hypophysitis, primary thyroid disease, primary adrenal insufficiency, and diabetes mellitus. Their management is discussed in a systematic review. A total of 101 studies involving 19 922 patients were included. Ipilimumab-treated patients experienced hypophysitis in 5.6% (95% CI, 3.9-8.1), which was higher than nivolumab (0.5%; 95% CI, 0.2-1.2) and pembrolizumab (1.1%; 95% CI, 0.5-2.6). PD-1/PD-L1 inhibitors had a higher incidence of thyroid dysfunction - particularly hypothyroidism (nivolumab, 8.0%; 95% CI, 6.4-9.8; pembrolizumab, 8.5%; 95% CI, 7.5-9.7; PD-L1, 5.5%; 95% CI, 4.4-6.8; ipilimumab, 3.8%; 95% CI, 2.6-5.5). Combination therapy was associated with a high incidence of hypothyroidism (10.2-16.4%), hyperthyroidism (9.4-10.4%), hypophysitis (8.8-10.5%), and primary adrenal insufficiency (5.2-7.6%). Diabetes mellitus and primary adrenal insufficiency were less frequent findings on monotherapy. Our meta-analysis shows a high incidence of endocrine adverse events provoked by single agent checkpoint blockade, further reinforced by combined treatment.