経過中に血清interleukin-6高値を認めた動脈炎性後部虚血性視神経症の1例

A case of arteritic posterior ischemic optic neuropathy with increased plasma interleukin-6 levels during the follow-up

要約　目的：経過中に血清interleukin-6（IL-6）値の高値を認めた巨細胞性動脈炎（GCA）に伴う動脈炎性後部虚血性視神経症（PION）の1例を報告する。

症例：75歳女性が右眼の一過性黒内障を認めた1.5か月後に右眼の視力低下と視野異常の精査目的で受診した。

所見：矯正視力は右0.07，左1.2で，相対的瞳孔求心路障害は右眼で陽性であった。眼底に異常はなく，蛍光眼底造影検査で右眼脈絡膜血管の充盈遅延を認めた。血液検査で炎症所見，頭部MRIで浅側頭動脈の肥厚と動脈壁の信号上昇を認め，GCAに合併した動脈炎性PIONと診断し，ステロイドセミパルス療法を行った。経過中に血清IL-6の高値を認めた。

結論：全身大血管に影響を及ぼすGCAの診断は重要である。GCAに合併する動脈炎性PIONでは，血清IL-6値は上昇する。

Abstract　Objective：To report a case of arteritic posterior ischemic optic neuropathy （PION） secondary to giant cell arteritis（GCA）presenting with increased plasma interleukin-6（IL-6）levels during the follow-up.

Case：A 75-year-old woman presented with visual loss and visual-field defect in her right eye 1.5 months after right amaurosis fugax.

Findings：The corrected visual acuity was 0.07 in the right eye and 1.2 in the left eye, and the right relative afferent pupillary defect was positive. Funduscopy showed no remarkable findings, but fluorescein angiography revealed a delayed filling of choroidal vessels. A blood test showed inflammatory findings. Thickened and enhanced superficial temporal arteries were observed on the contrast-enhanced brain MRI. Finally, the patient was diagnosed with arteritic PION, secondary to GCA, underwent steroid semi-pulse therapy. The patient presented with increased plasma IL-6 levels during the follow-up.

Conclusion：It is important to diagnose macrovascular diseases associated with GCA. Increased plasma IL-6 levels were observed in arteric PION secondary to GCA.