ステロイド投与中にうつ状態を呈したSystemic Lupus Erythematosus患者に対するリチウムの効果—症例報告

Antidepressant Effect of Lithium in Patients with Systemic Lupus Erythematosus (SLE) Treatment with Corticosteroid: a case report

　【抄録】Systemic Lupus Erythematosus（SLE）の治療目的でprednisolone 50mg/日投与中に出現したうつ状態に対して，リチウムによる治療を行った。本症例においてはCNS lupusとの鑑別目的で種々の免疫学的検査も行った。うつ状態はリチウム 600mg/日，血中濃度0.6mEq/lで軽快したが，リチウムの中止により再燃し再投与にて軽快した。prednisolone 20mg/日へ減量後リチウムを中止した場合には精神症状の再燃はみられなかった。またリチウム投与中に重篤な副作用も認められなかった。以上のことからステロイド剤によりうつ状態が現れた場合，リチウム投与が有効な可能性があることが示唆された。

　In the present study, we reported a case showing an antidepressant effect of lithium in a patient with SLE treated with prednisolone.

　Case: The patient was a 24-year-old female with SLE. She received prednisolone (PSL) 50 mg/ day and then presented a depressive state about 4 weeks after PSL administration.

　We diagnosed this case as steroid psychosis rather than CNS lupus because the time of onset was related to the initiation of PSL therapy and values of some immune parameters such as IgG, antibodies to ribosomal P proteins and interferon-α were negative. Because of the severity of SLE, PSL could not be reduced. Then 600mg/day of lithium was administered for the treatment of the depressive state. The patient's depressive symptoms disappeared completely within 4 weeks after lithium administration and recurred after lithium discontinuation. When lithium was readministered, depressive symptoms were improved again. Recurrence did not occur while she was on 20 mg/day prednisolone after lithium discontinuation, and there were no severe side effects of lithium therapy.