Predictors of Prolonged Euthyroidism After Radioactive Iodine Treatment for Graves' Disease: A Pilot Study.

OBJECTIVE: Patients with Graves' disease who remain hyperthyroid under the treatment of antithyroid drugs (ATD) or cannot tolerate ATD usually receive radioactive iodine (RAI) to control disease activity. This pilot study aimed to identify predictors of prolonged euthyroidism > 12 months after receiving RAI. METHODS: Demographic, clinical, and laboratory data from 117 patients receiving RAI were retrospectively collected, including age, gender, body surface area, smoking status, free thyroxine, thyrotropin, thyrotropin binding inhibiting immunoglobulin, microsomal antibody, thyroglobulin antibody, medication history, and thyroid volume. Only 85 patients without missing values were included in statistical analysis. The calculated RAI dose was the estimated thyroid volume × 0.4. The difference and ratio between the actual and calculated RAI doses were examined. A stepwise logistic regression analysis was conducted to identify important predictors of prolonged euthyroidism > 12 months. The cut-off values for discretizing continuous covariates were estimated by fitting generalized additive models. RESULTS: Among the 85 patients on RAI, 18 (21.2%) achieved prolonged euthyroidism > 12 months, 38 (44.7%) remained hyperthyroid with decreased ATD doses, but 29 (34.1%) suffered permanent hypothyroidism and needed long-term levothyroxine. Logistic regression analysis revealed that patients with age > 66 years, 33 < age ≤ 66 years, quitting smoking vs nonsmoking or current smoking, 600 < micorsomal antibody ≤ 1729 IU/mL, 47% < thyrotropin binding inhibiting immunoglobulin ≤ 81%, 7 < thyroglobulin antibody ≤ 162 IU/mL, 0.63 < ratio between actual and calculated RAI doses ≤ 1.96, or taking hydroxychloroquine would have a higher chance of reaching prolonged euthyroidism > 12 months after receiving RAI. Its area under the Receiver Operating Characteristic (ROC) curve was 0.932. CONCLUSION: Patients with Graves' disease who received an actual RAI dose close to the calculated RAI dose achieved prolonged euthyroidism > 12 months if they also took hydroxychloroquine during RAI treatment.

Cortisol-producing adenoma-related somatic mutations in unilateral primary aldosteronism with concurrent autonomous cortisol secretion: their prevalence and clinical characteristics.

Objective: Concurrent autonomous cortisol secretion (ACS) in patients with primary aldosteronism (PA) is being reported more frequently. Several somatic mutations including PRKACA, GNAS, and CTNNB1 were identified in cortisol-producing adenomas (CPAs). The presence of these mutations in unilateral PA (uPA) patients concurrent with ACS (uPA/ACS) is not well known. This study aimed to investigate the prevalence of these mutations and their clinical vs pathological characteristics in uPA/ACS. Design: This is a retrospective cohort study. Methods: Totally 98 uPA patients from the Taiwan Primary Aldosteronism Investigation registry having overnight 1-mg dexamethasone suppression test (DST) and adrenalectomy from 2016 to 2018 were enrolled. Their adrenal tumors were tested for PRKACA, GNAS, and CTNNB1 mutations. Results: 11 patients had CPA-related mutations (7 PRKACA and 4 GNAS). The patients carrying these mutations had higher post-DST cortisol (5.6 vs 2.6 µg/dL, P = 0.003) and larger adenoma (2.2 ± 0.3 vs 1.9 ± 0.7 cm, P = 0.025). Adenomas with these mutations had a higher prevalence of non-classical uPA (72.7% vs 26.3%, P = 0.014). Numerically, slightly more complete clinical success of uPA patients with these mutations was noticed after adrenalectomy, although it was statistically non-significant. Post-DST cortisol levels, adenoma size >1.9 cm, and the interaction of adenoma size >1.9 cm with potassium level were found to be associated with the presence of these mutations. Conclusion: Our study showed that CPA-related mutations were detected in 36.7% of uPA/ACS adenomas. The presence of these mutations was associated with higher post-DST cortisol levels, larger adenoma sizes, and a high percentage of non-classical uPA. However, these mutations did not significantly affect the clinical and biochemical outcomes after adrenalectomy of uPA/ACS patients but they showed a better trend.

Chromosomal variations of Lycoris species revealed by FISH with rDNAs and centromeric histone H3 variant associated DNAs.

Lycoris species have various chromosome numbers and karyotypes, but all have a constant total number of chromosome major arms. In addition to three fundamental types, including metacentric (M-), telocentric (T-), and acrocentric (A-) chromosomes, chromosomes in various morphology and size were also observed in natural populations. Both fusion and fission translocation have been considered as main mechanisms leading to the diverse karyotypes among Lycoris species, which suggests the centromere organization playing a role in such arrangements. We detected several chromosomal structure changes in Lycoris including centric fusion, inversion, gene amplification, and segment deletion by using fluorescence in situ hybridization (FISH) probing with rDNAs. An antibody against centromere specific histone H3 (CENH3) of L. aurea (2n = 14, 8M+6T) was raised and used to obtain CENH3-associated DNA sequences of L. aurea by chromatin immunoprecipitation (ChIP) cloning method. Immunostaining with anti-CENH3 antibody could label the centromeres of M-, T-, and A-type chromosomes. Immunostaining also revealed two centromeres on one T-type chromosome and a centromere on individual mini-chromosome. Among 10,000 ChIP clones, 500 clones which showed abundant in L. aurea genome by dot-blotting analysis were FISH mapped on chromosomes to examine their cytological distribution. Five of these 500 clones could generate intense FISH signals at centromeric region on M-type but not T-type chromosomes. FISH signals of these five clones rarely appeared on A-type chromosomes. The five ChIP clones showed similarity in DNA sequences and could generate similar but not identical distribution patterns of FISH signals on individual chromosomes. Furthermore, the distinct distribution patterns of FISH signals on each chromosome generated by these five ChIP clones allow to identify individual chromosome, which is considered difficult by conventional staining approaches. Our results suggest a different organization of centromeres of the three chromosome types in Lycoris species.