Thyrotropin receptor antibodies and a genetic hint in antithyroid drug-induced adverse drug reactions

Clinical manifestations and early effectiveness of methimazole in patients with graves' hyperthyroidism-related severe hepatic dysfunction

BACKGROUND

Graves' hyperthyroidism (GH) is often accompanied by mild to moderate liver injury, but severe hepatic dysfunction (SHD) is relatively rare. Whether patients with GH-related SHD can be treated with methimazole (MMI) remains controversial. This study aimed to determine the clinical characteristics and to evaluate the role of low-dose MMI for such patients.

METHODS

33 patients with GH-related SHD were selected for this retrospective study in the Fifth Medical Center of Chinese PLA General Hospital from January 2017 to July 2022. The clinical manifestations, therapeutic responses, and effectiveness of MMI were evaluated.

RESULTS

Systemic jaundice (100.0%), yellow urine (100.0%), fatigue (87.9%), and goiter (66.7%) were the main symptoms. Total bilirubin (TBIL) had no linear correlation with free triiodothyronine (FT3) (r = -0.023, p = .899), free thyroxine (FT4) (r = 0.111, p = .540), T3 (r = -0.144, p = .425), and T4 (r = 0.037, p = .837). On the 14th day after admission, FT3, FT4, T3, T4, TBIL, direct bilirubin (DBIL), alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT), and international normalized ratio (INR) decreased compared with the baseline (p < .05). The decrease rates of FT3, FT4, T3, T4, TBIL, and DBIL in the MMI group were higher than those in the non-MMI group (p < .05). The improvement rate of the MMI group (77.8%) was higher than that of the non-MMI group (9.5%, p = .001). MMI treatment is an independent predictor affecting the early improvement of patients (OR = 0.022, p = .010).

CONCLUSIONS

The main clinical manifestations of patients with GH-related SHD were symptoms related to liver disease. Low-dose MMI was safe and effective for them.

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.

Acute Drug-Induced Cholestatic Syndrome in Basedow Graves’ Disease

Introduction: Graves’ disease (GD), an autoimmune disorder caused by high levels of auto-antibodies against the thyroid-stimulating hormone receptor, is considered the most common cause of thyrotoxicosis, characterized by features such as goiter, ophthalmopathy and dermopathy. In our country, the administration of antithyroid drugs (ATD) is the first line of treatment in this disease. Side effects are rare but some of them, such as agranulocytosis or liver damage, may become serious.

Case presentation: We report the case of a 20-year-old female patient who was diagnosed with GD after being previously diagnosed with viral hepatitis A. Treatment was initiated with methimazole 30 mg/day, and three weeks later she developed intense hepatic cytolysis and cholestatic syndrome, therefore the ATD was stopped. A suspicion of autoimmune liver disease was raised, and a liver biopsy was performed in order to establish the diagnosis. The next therapeutic option for hyperthyroidism was radioactive iodine (RAI). Three months following RAI, the patient presented severe hypothyroidism, thereupon treatment with levothyroxine was initiated.

Conclusions: Although severe acute liver injury is rare, mild liver dysfunction is quite common in patients with GD. The overproduction of thyroid hormones, or the treatment with ATD through immune mediated processes or drug reactions, represent possible mechanisms responsible for liver damage.

Thyroid-stimulating hormone receptor antibodies during follow-up as remission markers in childhood-onset Graves' disease treated with antithyroid drugs

Graves' disease is uncommon in children. The remission rate after antithyroid drugs (ATD) therapy is lower than in adults. We evaluated the clinical course of ATD therapy in children with Graves' disease in southern Taiwan to determine whether their biochemical markers could be used to predict remission in these patients. We retrospectively reviewed the clinical data of 53 children diagnosed with Graves' disease between 2009 and 2019. Clinical and biochemical parameters were analyzed for predictors of remission. About three-fourths of the patients were female. Their median age at diagnosis was 13 years. No sex differences were found in most clinical characteristics. There was no correlation between thyroid-stimulating hormone receptor antibody (TRAb) levels at diagnosis and thyroid function or adverse reactions to ATD. Relapse occurred in 62% of patients after discontinuation of first-course ATD therapy. Three variables-good initial response to ATD, a decrease in TRAb levels during the first year after diagnosis, and a decrease in TRAb levels during the second year after diagnosis-were significant predictors of remission for more than 18 months. In conclusion, children with Graves' disease who had early ATD-controlled Graves' disease and decreased TRAb levels during the first 2 years are likely to enter remission for more than 18 months.