間質性肺異常を有する患者における肺がん-6（KL-6）の血清レベルを反映するバイオマーカーとして

Data associating progression of interstitial lung abnormalities (ILA) and serum biomarkers, including white blood cell differential counts and Krebs von den Lungen-6 (KL-6) are sparse. This study aimed to explore the clinical characteristics and evaluate the relationship between disease progression and serum biomarkers in patients with ILA.

This retrospective cohort study collected data, such as clinical characteristics, pulmonary function test, chest computed tomography (CT), complete blood cell counts, and KL-6 levels from 159 patients (63 with ILA and 74 with interstitial lung diseases [ILDs]) from October 2021 to September 2022. In 52 patients who had previously undergone chest CT, the utility of serum biomarkers in reflecting radiologic progression were evaluated using the receiver operating characteristic curve analysis.

Patients with ILA (n=63) had clinical characteristics similar to patients with idiopathic pulmonary fibrosis. Serum KL-6 levels did not correlate with forced vital capacity or diffusing capacity of the lung for carbon monoxide in patients with ILA. Among the 52 patients with ILA, 13 showed radiological progression. Serum KL-6 showed moderate performance with area under the curves ranging from 0.57-0.89 (p = 0.014) for radiological progression. KL-6 > 400 U/mL were frequently observed in patients with radiological progression (61.5% vs. 20.5%, p =0.006). In multivariate analysis, age and KL-6 was independently associated with the radiological progression in patients with ILA.

Serum KL-6 level could be a potential indicator reflecting the progression of ILA in asymptomatic patients. Patients with serum KL-6>400U/mL require careful observation for radiological progression.