Chiba Yosuke, Kido Takashi, Tahara Masahiro, Oda Keishi, Noguchi Shingo, Kawanami Toshinori, Yokoyama Mitsuru, Yatera Kazuhiro
Department of Respiratory Medicine, University of Occupational and Environmental Health, Japan.
Shared-Use Research Center, University of Occupational and Environmental Health, Japan.
Tohoku J Exp Med. 2019 Jan;247(1):51-58. doi: 10.1620/tjem.247.51.
Hard metal lung disease (HMLD) is a pneumoconiosis caused by occupational exposure to hard metals such as tungsten carbide and cobalt, but the treatment strategies for HMLD have not been well established. A 68-year-old Japanese man with occupational history as a grinder of hard metals for 18 years referred to our hospital because of dry cough and dyspnea. A chest computed tomography (CT) on admission revealed centrilobular micronodules, ground-glass opacities, and reticular opacities in the peripheral zone of both lungs. Mineralogic analyses of lung tissues detected components of hard metals, such as tungsten, titanium and iron, and the same metals were also detected in the sample of the dust of his workplace. Thus, the patient was diagnosed as having HMLD based on occupational exposure history and radiologic and mineralogic analyses of the lung. Corticosteroid therapy was initiated, which resulted in partial improvements in his symptoms, radiological and pulmonary functional findings. In a review of the 18 case reports of HMLD treated with corticosteroids, including our case, the majority of patients (77.8%) showed favorable responses to corticosteroid treatment. Furthermore, the presence of fibrotic changes, such as reticular opacity, in radiological examinations was associated with the resistance to corticosteroids. In conclusion, the majority of patients with HMLD are expected to favorable response to corticosteroid treatment, whereas chest CT findings such as fibrotic changes may be predictive of the resistance of corticosteroid treatment. Lastly, proper prevention of hard metal exposure is most important as the first step.
硬质金属肺病（HMLD）是一种因职业接触碳化钨和钴等硬质金属而引起的尘肺病，但HMLD的治疗策略尚未完全确立。一名68岁的日本男性，有18年硬质金属研磨工的职业史，因干咳和呼吸困难转诊至我院。入院时胸部计算机断层扫描（CT）显示双肺外周区域有小叶中心性微结节、磨玻璃影和网状影。肺组织的矿物学分析检测到了硬质金属成分，如钨、钛和铁，其工作场所灰尘样本中也检测到了相同的金属。因此，根据职业接触史以及肺部的放射学和矿物学分析，该患者被诊断为患有HMLD。开始使用皮质类固醇治疗，其症状、放射学和肺功能检查结果有部分改善。在对包括我们的病例在内的18例接受皮质类固醇治疗的HMLD病例报告的回顾中，大多数患者（77.8%）对皮质类固醇治疗有良好反应。此外，放射学检查中出现的纤维化改变，如网状影，与对皮质类固醇的耐药性有关。总之，大多数HMLD患者预计对皮质类固醇治疗有良好反应，而胸部CT表现如纤维化改变可能预示着对皮质类固醇治疗的耐药性。最后，作为第一步，正确预防硬质金属接触最为重要。
