Predictors of relapse in graves' hyperthyroidism after treatment with antithyroid drugs

Abstract

Original Article introduCtionGraves' hyperthyroidism is the most common cause of hyperthyroidism. [1] Treatment options include antithyroid drugs (ATDs), radioactive iodine, or surgical resection, although none of these options target the mechanism of the disease, and there is no single treatment that can target both hyperthyroidism and the main extrathyroidal manifestation (orbitopathy). [2] ATDs act by inhibiting thyroid hormone synthesis, but they have some immunosuppressive action. In Europe and Japan, ATDs are still the first-line treatment, [1] but in North America, radioactive-iodine is much preferred. [3,4] Endocrinologists in the Middle East and North Africa (MENA) seemed to practice in a hybrid fashion between these two groups depending on previous training and current affiliations. [5] Background: Choice of the treatment for patients with Graves' hyperthyroidism depends on local preference, the higher recurrence risk, comorbidities, and the patient's preferences. About half of the patients relapse after a course of a standard antithyroid drug (ATD) therapy for Graves' disease. Objectives: The objective of this study was to determine the clinical and biochemical features of Graves' hyperthyroidism that can predict the relapse of the disease after a standard course of ATD therapy. Patients and Methods: We conducted a retrospective 6-month study of 79 patients with Graves' hyperthyroidism who were treated with ATD (carbimazole) therapy for 12-18 months and went into remission for at least 1 year after ATD withdrawal. Results: The relapse rate in Graves' hyperthyroidism after 1 year in remission was 40.5%; patients with younger age (<40 years) and with severe biochemical disease correlated significantly with relapse. Gender, presence of a palpable goiter, orbitopathy, and smoking habits were not significant predictors of relapse, perhaps because of the small sample size. Conclusions: Forty percent of Graves' hyperthyroidism relapsed after 1 year of remission. Younger age and severe biochemical disease at diagnosis predicted relapse.

Azathioprine as an adjuvant therapy in severe Graves’ disease: a randomized controlled open-label clinical trial

“…Additionally, Struja et al. ( 32 ) conducted a systematic review and meta-analysis, which supports our study findings. They found that the addition of immunosuppressive drugs to standard GD treatment can significantly reduce the risk of relapse in GD patients.…”

“…Randomization is a key feature of clinical trials that helps to minimize bias and ensure that the treatment groups are comparable. However, a limitation of the study is that the follow-up period was only 12 months after the cessation of treatment, which may have been relatively short to evaluate long-term remission status, even though most GD recurrences tend to occur within the first 12 months after ATD withdrawal ( 32 , 36 ). Also as, there was no blinding of participants or researchers there might be an unintentional influence on the study outcomes.…”

Relapse Rate and Clinical Risk Factors Affecting the Treatment of Graves’ Disease

“…13 Compared with rates from previous studies in Europe and Africa, the relapse rate was 30 -49% after one year of discontinuation. [28][29][30] The clinical factors related to relapse were < 40 years of age; smoking; TAO; thyroid size by ultrasound; serum FT4, FT3, and TRAb levels; and total T4 levels ≥ 2 times the upper normal range. 30 The clinical factors related to remission were female sex, nonsmoking status, no TAO and duration of treatment of more than 2 years.…”

“…[28][29][30] The clinical factors related to relapse were < 40 years of age; smoking; TAO; thyroid size by ultrasound; serum FT4, FT3, and TRAb levels; and total T4 levels ≥ 2 times the upper normal range. 30 The clinical factors related to remission were female sex, nonsmoking status, no TAO and duration of treatment of more than 2 years. 28 This study showed a relapse rate similar to that of previous studies and confirmed that some clinical risk factors influence relapse in both Asian and Western countries.…”

“…7 The GD relapse and remission rates vary among geographical areas due to varying in the duration of treatment and different iodine status. [8][9][10][11][12][13][14][15] In the USA, the remission rate after ATD use for at least 12-18 months is 20-30% 10 , while that in Europe is 50-60% after medication use for 5-6 years. 11 In Sweden, the relapse rate is 30.2% after stopping ATDs within 1 year.…”