Vol.23 No.2

Original Article

A retrospective study of serum KL-6 levels during treatment with biological disease-modifying antirheumatic drugs in rheumatoid arthritis patients: a report from the Ad Hoc Committee for Safety of Biological DMARDs of the Japan College of Rheumatology

Authors

Akito Takamura1 , Shintaro Hirata2 , Hayato Nagasawa3 , Hideto Kameda4 , Yohei Seto5 , Tatsuya Atsumi6 , Makoto Dohi7 , Takao Koike8 , Nobuyuki Miyasaka1,10 , Masayoshi Harigai1,9

  • Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
  • The First Department of Internal Medicine, University of Occupational and Environmental Health, Japan, Kitakyushu, Japan
  • Department of Rheumatology/Clinical Immunology, Saitama Medical Center, Saitama Medical University, Kawagoe, Japan
  • Division of Rheumatology and Clinical Immunology, Department of Internal Medicine, Faculty of Medicine, Keio University, Tokyo, Japan
  • Institute of Rheumatology, Tokyo Women’s Medical University, Tokyo, Japan
  • Department of Internal Medicine II, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
  • Department of Allergy and Rheumatology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
  • Sapporo Medical Center NTT EC, Sapporo, Hokkaido, Japan
  • Department of Pharmacovigilance, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
  • Global Center of Excellence Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, Tokyo, Japan
Received:

16 January 2012

Accepted:

19 April 2012

Published online:

10 May 2012

Full Text

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Abstract

Objective We investigated associations between treatment with methotrexate (MTX) or biological diseasemodifying antirheumatic drugs (DMARDs) and elevation of serum Krebs von den Lungen-6 (KL-6) levels in Japanese patients with rheumatoid arthritis (RA).
Methods Using a standardized form, data were collected retrospectively from medical records and analyzed descriptively.
Results Of a total of 198RA patients with KL-6 serum levels measured at initiation of treatment (month 0) and two or more times by month 12, 27 (17.9 %) of 151 RA patients treated with biological DMARDs, including infliximab, etanercept, adalimumab, and tocilizumab (the biological DMARDs group), and 5 (10.6 %) of 47 patients treated without biological DMARDs but with MTX (MTX group),met criterion B (max. KL-6 ≥500 U/ml and >1.5-fold from baseline) by 12 months. The majority of patients (n = 28) meeting criterion B had no apparent interstitial lung disease or malignancy. Of these 28 patients, 21 had serum KL-6 levels available after reaching their maximum level, and 13 (61.9 %) of the 21 then met criterion R [decrease to less than 500 U/ml or to less than (baseline + 0.5 × (maximum - baseline))] by month 12.
Conclusion Serum KL-6 levels may increase during treatment with MTX or these biological DMARDs without significant clinical events.

Key words

Rheumatoid arthritis - Biological disease-modifying antirheumatic drug - KL-6