Nigro Angelo
Department of Rheumatology of Lucania - UOSD of Rheumatology, "Madonna delle Grazie" Hospital, Matera, Italy.
Respir Med Case Rep. 2025 Jan 2;53:102165. doi: 10.1016/j.rmcr.2025.102165. eCollection 2025.
Anti-Ku antibodies are autoantibodies directed against the Ku protein complex involved in DNA repair. They are typically associated with overlap syndromes featuring polymyositis and systemic sclerosis. Isolated pulmonary involvement without myositis is exceedingly rare.
We report the case of a 70-year-old male, a former smoker with an 18-year smoking history who quit 20 years ago, presenting with a one-year history of progressive dyspnea and dry cough. High-resolution computed tomography (HRCT) revealed pulmonary fibrosis with areas of ground-glass opacities. Laboratory tests showed antinuclear antibodies at a titer of 1:2560 with a speckled pattern and positivity for anti-Ku antibodies. Creatine phosphokinase levels were within normal limits. There were no clinical signs of myositis, myalgia, skin manifestations, or Raynaud's phenomenon.
This case underscores the rarity of pulmonary fibrosis as the sole clinical manifestation associated with anti-Ku antibody positivity in the absence of myositis. Clinicians should consider testing for anti-Ku antibodies in patients with idiopathic interstitial lung disease, even when muscular and cutaneous symptoms are absent.
抗Ku抗体是针对参与DNA修复的Ku蛋白复合物的自身抗体。它们通常与以多发性肌炎和系统性硬化症为特征的重叠综合征相关。无肌炎的孤立性肺部受累极为罕见。
我们报告一例70岁男性病例，该患者曾有18年吸烟史，20年前戒烟，出现进行性呼吸困难和干咳1年。高分辨率计算机断层扫描（HRCT）显示肺部纤维化伴磨玻璃影区域。实验室检查显示抗核抗体滴度为1:2560，呈斑点状，抗Ku抗体阳性。肌酸磷酸激酶水平在正常范围内。无肌炎、肌痛、皮肤表现或雷诺现象的临床体征。
该病例强调了在无肌炎情况下，肺纤维化作为抗Ku抗体阳性相关的唯一临床表现的罕见性。临床医生在特发性间质性肺疾病患者中，即使没有肌肉和皮肤症状，也应考虑检测抗Ku抗体。
