抗ヒト好中球細胞質抗体関連腎炎に伴った網膜血管炎の1症例

Retinal vasculitis in a case of antineutrophil cytoplasmic antibody nephritis

　56歳男性が，10日前からの左眼視力低下で受診した。右眼は4年前に，網膜中心静脈閉塞症に続発した硝子体出血に対して硝子体手術を受けていた。矯正視力は右0.02，左0.05であつた。右眼眼底に広範な網脈絡膜萎縮，左眼上方の2象限に出血を伴う網膜血管炎があった。全身検査で腎機能が低下し，抗ヒト好中球細胞質抗体myeloperoxidase-antrneutrophil cytoplasmic antibody（MPO-ANCA）が高値であった。腎生検所見と合わせて，ANCA関連腎炎と診断した。内科治療に伴ってANCA抗体値が低下し，左眼眼底所見が改善し，左眼視力は最終的に0.8になった。本症例では，網膜血管炎にANCA関連血管炎が関与していることが推測された。

A 56-year-old male presented with blurred vision in his left eye since 10 days before. He had received vitrectomy in his right eye for vitreous hemorrhage secondary to central retinal vein occlusion 4 years before. The corrected visual acuity was 0.02 right and 0.05 left. The right eye showed extensive retinochoroidal atrophy. The left eye showed retinal vasculitis with hemorrhage in the superior quadrants. Laboratory studies showed renal dysfunction and elevated level of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) . Additional kidney biopsy led to the diagnosis of ANCA-associated nephritis. Systemic treatments induced decrease in MPO-ANCA level followed by improved fundus findings in the left eye. The left visual acuity later improved to 0.8. The retinal vasculitis in this case was interpreted as a manifestation of MPO -ANCA -related vasculitis syndrome.