急性扁桃炎として発症した抗甲状腺剤による重症汎血球減少症

Antithyroid Drug-Induced Severe Pancytopenia:A Case Report

　はじめに

　抗甲状腺剤の重篤な副作用として無顆粒球症は広く知られている^1）。また顆粒球だけではなく二次性再生不良性貧血の原因となって汎血球減少症をきたすことも知られてはいるが，その頻度はきわめて低い。最近われわれはバセドウ病に対して抗甲状腺剤チアマゾール（以下MMI）が使用され，重篤な汎血球減少症に至ったまれな症例を経験したので報告する。

A 43-year-old woman was complaining of sore throat and fever. She had been treated for Grave's disease with antithyroid drug for three weeks.

Hematological study showed pancytopenia with hemoglobin 9.1 g/dl and platelets 4.4 x 10⁴ on admis-sion, subsequently 5.0 g/dl and 1.2 × 10⁴ respectively. The white blood cell count was 900/mm³ with 3% neutrophils and 91% lymphocytes.

The patient was treated with broad-spectrum antibiotics, G-CSF and transfusion of platelets. She was discharged on day 23 with normal blood count. Two months after the initial discharge, total thyroidectomy was performed for thyrotoxicosis.