HLA-A26陽性ベーチェット病との鑑別に苦慮した真菌性眼内炎の1例

A case of fungal endophthalmitis that was difficult to distinguish from HLA-A26-positive Behçet's disease

要約　目的：HLA-A26陽性ベーチェット病との鑑別に苦慮した真菌性眼内炎の1例を報告する。

症例：41歳，女性。1年前にカンジダ膣症で婦人科通院歴あり。右眼の視力低下・飛蚊症を自覚し，X−2月に近医を受診した。右矯正小数視力は0.2で，眼底後極部に滲出斑および黄斑部浮腫を認めた。ステロイド点眼・内服および抗菌薬点眼で治療を開始したが，経過中に硝子体混濁が生じ改善がみられなかったため，精査加療目的で名古屋大学医学部附属病院（当院）に紹介され受診となった。当院初診時の右矯正視力は0.02で，前眼部は微細な角膜後面沈着物および前房蓄膿を伴っており，前房フレア値は右141.7±12.6pc/msであった。硝子体混濁および白斑の散在を認め，光干渉断層計では網膜外層から硝子体側へ伸展する隆起性病変を認めた。血液検査，前房水PCRでは有意な所見はなかった。ヒト白血球抗原検査はHLA-A26が陽性で，口腔内アフタ性潰瘍，外陰部潰瘍所見を認め不全型ベーチェット病の診断基準を満たしていた。ベーチェット病としてステロイド点眼・内服を主とした治療を継続したものの硝子体混濁は改善せず，硝子体切除術および生検を施行した。生検で得られた硝子体液の培養検査からはCandida albicansが検出され，ホスフルコナゾール点滴にて治療となった。

結論：ベーチェット病の診断基準を満たすぶどう膜炎でも，治療中に増悪する場合には感染性を含め他のぶどう膜炎に留意すべきであり，とりわけ光干渉断層計の所見が診断の一助になると考えられた。

Abstract　Purpose：To report a case of anterior chamber inflammation with HLA-A26 positive that did not respond to steroid therapy and showed fungal endophthalmitis caused by Candida species on vitreous biopsy.

Case：The patient was a 41-year-old woman with a history of a gynecological visit a year earlier for candidal vaginosis. She became aware of floaters and decreased vision in her right eye and visited her primary care ophthalmologist 2 months before presenting to our hospital. The best-corrected visual acuity of the right eye was 0.2 and there were posterior pole exudative spots, macular edema, and uveitis in the right eye. Treatment was initiated with eye drops, oral steroids, and antibiotic eye drops. However, vitreous opacity occurred and there was no improvement. Therefore, the patient was referred to our hospital for further examination and treatment. At the time of the initial visit at our hospital, the best-corrected visual acuity of the right eye was 0.02, there were fine keratic precipitates and hypopyon, and the laser flare meter showed 141.7±12.6（pc/ms）in the anterior chamber in the right eye. Vitreous opacity and scattered white spots were observed in the fundus, and optical coherence tomography（OCT）showed a bulging lesion that penetrated from the outer retina to the vitreous side. Blood tests and aqueous humor polymerase chain reaction revealed no obvious findings of infection. Meanwhile, analysis of human leukocyte antigen revealed positivity for HLA-A26. Further, oral aphthous ulcers and genital aphthosis were noted and she met the diagnostic criteria for Behçet's disease. However, steroid-based therapy did not improve vitreous opacity and thus vitrectomy biopsy was performed. Vitreous biopsy cultures revealed the presence of Candida albicans and she was treated with intravenous fosfluconazole.

Conclusion：Even in cases of uveitis that satisfy the diagnostic criteria for Behçet's disease, other types of uveitis including those caused by infections should be considered if the condition worsens during treatment. Especially, OCT findings may be able to aid in the diagnosis of uveitis.