Antithyroid drug induced syndrome that lies in between ANCA vasculitis and lupus-like syndrome in a 40-year-old female with Graves' disease under methimazole therapy: A Case report

[Thiamazole-induced arthritis]

Wir berichten über den Fall eines 42-jährigen Patienten mit akuter asymmetrischer Polyarthritis der großen und mittelgroßen Gelenke sowie Fieber und erhöhten serologischen Entzündungszeichen. Die Symptomatik begann kurz nach Beginn einer Thiamazol-Therapie bei neu diagnostiziertem Morbus Basedow. Eine durch Thionamide ausgelöste Arthritis wird auch als „antithyroid arthritis syndrome“ (AAS) bezeichnet und ist eine seltene unerwünschte medikamentöse Nebenwirkung. Klinisch kann sich das Krankheitsbild mit Myalgien, Arthralgien, Fieber, Hautausschlag und Polyarthritis präsentieren. Bei Verdacht auf ein AAS sollte die Thionamid-Medikation in Rücksprache mit dem Endokrinologen nach Möglichkeit zeitnah abgesetzt oder umgestellt werden. In einigen Fällen ist eine antiinflammatorische Therapie mit NSAR oder Glukokortikoiden zur Symptomkontrolle nötig.

[Predictors of the efficacy of radioiodine therapy of Graves' disease in children and adolescents]

RATIONALE

Insufficient world-wide clinical experience in radioiodine therapy (RIT) for Graves' disease (GD) in children and adolescents, and limited knowledge of the predictors of RIT efficacy.

AIMS

Analysis and identification of the most significant predictors of the efficacy of RIT in children and adolescents with Graves' disease.

MATERIALS AND METHODS

A total of 55 patients (48 females and 7 males) aged from 8 to 18 years receiving primary RIT for GD were enrolled. RIT planning was based on the dosimetric method. Analyzed parameters included gender, age, ultrasound thyroid volume before and 6 months after treatment, the presence of endocrine ophthalmopathy, duration of antithyroid drug (ATD) therapy, relapse of thyrotoxicosis after ATD dose reduction, blood fT3, fT4 and TSH levels initially and at 1, 3, 6 months after treatment, TSH receptor Ab initially and at 3 and 6 months after treatment, thyroid 99mTc-pertechnetate uptake at 10-20 minutes (%), maximum thyroid 131I uptake (%), specific 131I uptake (MBq/g) and therapeutic 131I activity (MBq). Fisher exact test, non-parametric Mann-Whitney test, Wilcoxon signed-rank test, logistic regression modelling, ROC-analysis, proportional hazard model (the Cox regression), the Kaplan-Meier method and log-rank test were used for statistical analysis as appropriate.

RESULTS

Six months after RIT, hypothyroidism was achieved in 45 (81.8%), euthyroid state - in 2 (3.6%), and in 8 (14.6%) patients thyrotoxicosis persisted. On univariate statistical analysis, the smaller thyroid volume, higher fT4 and lower TSH receptor Ab levels, lower 99mTc-pertechnetate uptake and higher specific 131I uptake were associated with hypothyroidism. On multivariate logistic regression analysis, the older patient's age (p=0.011), smaller thyroid volume (p=0.003) and higher fT4 (p=0.024) were independent predictors of RIT efficacy. Thyroid volume was also the only variable associated with achievement of hypothyroidism in time after RIT (p=0.011).

CONCLUSION

The efficacy of dosimetry-based RIT in children and adolescents with GD 6 months after treatment was 81.2%. Older patients' age, smaller thyroid volume and higher fT4 level were independent predictors of therapy success. Smaller thyroid volume was also a predictor of the favorable time-related outcome. Statistical models obtained in this work may be used to prospectively estimate the chance of efficient RIT for GD in pediatric patients.