Affiliation:
1. Division of Rheumatology, Department of Internal Medicine Tokyo Women's Medical University School of Medicine Tokyo Japan
2. Division of Multidisciplinary Management of Rheumatic Diseases Tokyo Women's Medical University School of Medicine Tokyo Japan
3. Department of Internal Medicine, Adachi Medical Center Tokyo Women's Medical University School of Medicine Tokyo Japan
4. Department of Dermatology, Graduate School of Medical and Dental Science Tokyo Medical and Dental University Tokyo Japan
Abstract
AbstractAimTo evaluate whether seasonal changes influence fluctuations in serum Krebs von den Lungen‐6 (KL‐6) levels in systemic sclerosis‐related interstitial lung disease (SSc‐ILD).MethodsSummer was defined as the period between July and September, and winter as between December and February. The study was conducted between 2015 and 2016, with a focus on these two seasons. A diagnosis of ILD and ILD progression overtime were evaluated using chest computed tomography. Among patients with SSc‐ILD, those with data on serum KL‐6 and lactate dehydrogenase (LDH) levels in the 2015 winter, 2015 summer, and 2016 winter seasons were included. Patients with comorbidities that could affect serum KL‐6 levels were excluded.ResultsOf 60 patients with SSc‐ILD, 52 (86.7%) had stable ILD, 5 (8.3%) had worsened ILD, and 3 (5.0%) had improved ILD. Serum KL‐6 levels were significantly higher during the winter than those during the summer (2015 winter vs. 2015 summer: 649 U/mL vs. 585 U/mL, p < .0001; 2016 winter vs. 2015 summer: 690 U/mL vs. 585 U/mL, p < .0001). No significant differences were observed between the winters of 2015 and 2016 (649 U/mL vs. 690 U/mL, p = .78). However, serum LDH levels did not exhibit seasonal fluctuations (2015 winter vs. 2015 summer: 203 U/L vs. 199 U/L, p = .3; 2016 winter vs. 2015 summer: 201 U/L vs. 199 U/L, p = .6; 2015 winter vs. 2016 winter: 203 U/L vs. 201 U/L, p = .24).ConclusionSeasonal fluctuations in serum KL‐6 levels were observed in patients with SSc‐ILD.