Search

Background: Serum levels of KL-6 are useful biomarkers for diagnosis of interstitial lung diseases (ILDs). However, its diagnostic utility in the setting of acute respiratory failure (ARF) is unknown. Aims and Objectives: We investigated how high serum KL-6 levels contributed to the differential diagnosis of ARF. Methods: We retrospectively examined consecutive 138 patients who were admitted to our department for the treatment of ARF with bilateral pulmonary infiltrates and were evaluated for serum KL-6 levels, from April 2015 to July 2018. Patients with apparent preexisting pulmonary fibrosis were excluded. Results: KL-6 values were high (≥ 500 U/mL) in 52 patients. Pulmonary diseases responsible for high KL-6 levels were detected in all patients of the high KL-6 group; ILDs associated with connective tissue diseases in 11 patients, latent chronic ILDs in 10 patients, drug-induced ILDs in 9 patients, pneumocystis pneumonia in 5 patients, radiation pneumonitis in 4 patients, and other etiologies in 13 patients. These KL-6-elevating diseases were the direct causes of ARF in 40 (77%) patients in the high KL-6 group compared to 22 (26%) patients in the normal KL-6 group (p Conclusions: In ARF with bilateral pulmonary shadows and no apparent chronic fibrotic lesions, elevated serum KL-6 levels could be a marker of causative diseases other than bacterial pneumonia that often require steroid therapy.

Background: Usual gait speed over 4-meter (4mGS) is a simple functional performance measure in older adults. The reliability and validity of the 4mGS has recently been demonstrated in patients with COPD, but there are few data in interstitial pneumonia (IP). Object: To evaluate the correlation between the 4mGS and 6-minute walk test (6MWT) in IP patients. Their underlying physiological factors were also examined. Method: In 52 IP patients, the 4mGS and 6MWT were prospectively performed. Other measurements included the health-related quality of life, modified Medical Research Council (MRC) score, arterial blood gas analyses, pulmonary function tests, muscle strength of skeletal muscle index, and physical activity. Result: 35 patients were male (68.6%) and 34 patients had IPF (66.7%). There was a significant correlation between the 4mGS and 6-minute walk distance (6MWD) (r = 0.57, P Conclusions: The 4mGS was a simple and reliable measure for IP patients.