Nishioka Ken, Yamaguchi Shintaro, Hashiguchi Akinori, Yoshimoto Norifumi, Tajima Takaya, Yasuda Itaru, Uchiyama Kiyotaka, Kaneko Kenji, Aso Mitsuhiro, Yoshino Jun, Monkawa Toshiaki, Kanda Takeshi, Hayashi Kaori, Itoh Hiroshi
Division of Endocrinology, Metabolism, and Nephrology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
Department of Pathology, Keio University School of Medicine, Tokyo, Japan.
SAGE Open Med Case Rep. 2023 Aug 31;11:2050313X231197324. doi: 10.1177/2050313X231197324. eCollection 2023.
The common histopathology of antineutrophil cytoplasmic antibody-associated vasculitis comprises pauci-immune crescentic glomerulonephritis with concomitant tubulointerstitial nephritis. Tubulointerstitial nephritis in the absence of glomerular involvement in patients with antineutrophil cytoplasmic antibody-associated vasculitis is uncommon. We report a case of antineutrophil cytoplasmic antibody-associated vasculitis-associated acute kidney injury manifesting as tubulointerstitial nephritis without glomerulonephritis. A 75-year-old woman with fever, cough, and myalgia developed kidney dysfunction with inflammatory reactions and tubular-type proteinuria, without glomerular hematuria. A kidney biopsy revealed tubulointerstitial nephritis with arteritis. We ruled out important underlying etiologies of tubulointerstitial nephritis, including infection, drug reactions, and autoimmune diseases. Since chest high-resolution computed tomography demonstrated mild interstitial pneumonia in bilateral lower lung fields, myeloperoxidase antineutrophil cytoplasmic antibody was measured and found to be positive. Therefore, we diagnosed the patient with antineutrophil cytoplasmic antibody-associated vasculitis-associated tubulointerstitial nephritis but not glomerulonephritis, and interstitial pneumonia. The patient's kidney function and symptoms markedly improved with prednisolone treatment. Clinicians should maintain high-level vigilance for antineutrophil cytoplasmic antibody-associated vasculitis as a possible underlying component of tubulointerstitial nephritis, particularly when kidney function deteriorates with tubulointerstitial injuries without glomerular features.
抗中性粒细胞胞浆抗体相关性血管炎的常见组织病理学表现为少免疫性新月体性肾小球肾炎，并伴有肾小管间质性肾炎。在抗中性粒细胞胞浆抗体相关性血管炎患者中，无肾小球受累的单纯肾小管间质性肾炎并不常见。我们报告一例抗中性粒细胞胞浆抗体相关性血管炎相关的急性肾损伤，表现为无肾小球肾炎的肾小管间质性肾炎。一名75岁女性，有发热、咳嗽和肌痛症状，出现肾功能不全，伴有炎症反应和肾小管型蛋白尿，无肾小球血尿。肾脏活检显示为伴有动脉炎的肾小管间质性肾炎。我们排除了肾小管间质性肾炎的重要潜在病因，包括感染、药物反应和自身免疫性疾病。由于胸部高分辨率计算机断层扫描显示双侧下肺野有轻度间质性肺炎，检测髓过氧化物酶抗中性粒细胞胞浆抗体呈阳性。因此，我们诊断该患者为抗中性粒细胞胞浆抗体相关性血管炎相关的肾小管间质性肾炎而非肾小球肾炎，并伴有间质性肺炎。患者接受泼尼松龙治疗后，肾功能和症状明显改善。临床医生应高度警惕抗中性粒细胞胞浆抗体相关性血管炎可能是肾小管间质性肾炎的潜在病因，尤其是当肾功能因肾小管间质损伤而恶化且无肾小球特征时。
