-Original-

Change in Serum KL-6 Level during Biologic Treatment for Psoriasis

Toshihiko Hoashi¹, Shun Miyazaki¹, Saeko Ozaki¹, Susumu Ichiyama¹, Michiko Ito¹, Naoko Kanda² and Hidehisa Saeki¹

¹Department of Dermatology, Nippon Medical School, Tokyo, Japan
²Department of Dermatology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan

Background: We previously analyzed data from blood examination screenings, including serum Krebs von den Lungen (KL)-6 level, before starting biologic treatment for psoriasis in a real-world setting. However, we did not follow change in KL-6 level after the initiation of biologics. Furthermore, there has been no follow-up study of certolizumab pegol, risankizumab, or tildrakizumab. This study evaluated change in serum KL-6 levels in patients during treatment with biologics, including certolizumab pegol, risankizumab, and tildrakizumab.
Methods: We analyzed data from 111 patients. Change in KL-6 level was regarded as significant if it increased to greater than 500 U/mL at least once and if the maximum level after treatment with biologics was at least 1.5 times that of the baseline level.
Results: KL-6 level significantly changed during treatment with TNF inhibitors, IL-17 inhibitors, and IL-23 inhibitors in 9 (20.9%), 2 (6.3%), and 2 (5.6%) patients, respectively. Mean age, mean baseline KL-6 level, and frequency of TNF inhibitor use were higher in patients with a significant change in KL-6 level than those in patients without a significant change. Ten patients had minor interstitial changes on chest CT scans but no clinical signs suggesting interstitial pneumonia.
Conclusions: Older patients with psoriasis and high baseline KL-6 levels must be carefully monitored during treatment with biologics, especially TNF inhibitors. Monitoring of KL-6 level and chest CT scans is necessary to exclude the possibility of drug-induced interstitial pneumonia.

J Nippon Med Sch 2023; 90: 194-201

Keywords
Krebs von den Lungen-6 (KL-6), biologics, changes, psoriasis, tumor necrosis factor inhibitor

Correspondence to
Hidehisa Saeki, MD, Department of Dermatology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
h-saeki@nms.ac.jp

Received, October 3, 2022
Accepted, December 2, 2022