University of Oulu

Levälampi, T., Kärki, J., Rebane, K. et al. Etanercept for patients with juvenile idiopathic arthritis: drug levels and influence of concomitant methotrexate: observational study. Pediatr Rheumatol 21, 27 (2023).

Etanercept for patients with juvenile idiopathic arthritis : drug levels and influence of concomitant methotrexate: observational study

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Author: Levälampi, Tiina1; Kärki, Johanna2; Rebane, Katariina1;
Organizations: 1Pediatric Research Center, New Children’s Hospital, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
2Department of Pediatrics, Kanta-Häme Central Hospital, Hämeenlinna, Finland
3PEDEGO Research Unit, University of Oulu, Oulu, Finland
4Department of Pediatrics, Oulu University Hospital, Oulu, Finland
5Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland
6Department of Pediatrics, Tampere University Hospital, Tampere, Finland
7Department of Pediatrics, Kuopio University Hospital, Kuopio, Finland
8Department of Pediatrics, Turku University Hospital, Turku, Finland
9Department of Paediatrics, The Wellbeing Services County of Ostrobothnia, Vaasa, Finland
10Department of Pediatrics, Päijät-Häme Central Hospital, Lahti, Finland
11Primary Health Care Unit, Kuopio University Hospital, Kuopio, Finland
12Folkhälsan Research Center, Helsinki, Finland
13Department of Bacteriology and Immunology, University of Helsinki, MedicumHelsinki, Finland
14Tammer BioLab Ltd, Tampere, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
Persistent link:
Language: English
Published: Springer Nature, 2023
Publish Date: 2023-04-14


Background: Etanercept (ETN) is widely used tumour necrosis factor (TNF) blocker in the treatment of juvenile idiopathic arthritis (JIA) when traditional synthetic disease modifying antirheumatic drug (sDMARD) therapy is not sufficient. There is limited information about the effects of methotrexate (MTX) on serum ETN concentration in children with JIA. We aimed to investigate whether ETN dose and concomitant MTX would effect ETN serum trough levels in JIA patients, and whether concomitant MTX have an influence on the clinical response in patients with JIA receiving ETN.

Methods: In this study, we collected the medical record data of 180 JIA patients from eight Finnish pediatric rheumatological centres. All these patients were treated with ETN monotherapy or combination therapy with DMARD. To evaluate the ETN concentrations, blood samples of the patients were collected between injections right before the subsequent drug. Free ETN level was measured from serum.

Results: Ninety-seven (54%) of the patients used concomitant MTX, and 83 (46%) received either ETN monotherapy or used sDMARDs other than MTX. A significant correlation was noted between ETN dose and drug level [r = 0.45 (95% CI: 0.33–0.56)]. The ETN dose and serum drug level were correlated (p = 0.030) in both subgroups — in MTX group [r = 0.35 (95% CI: 0.14–0.52)] and in non-MTX group [r = 0.54 (95% CI: 0.39–0.67)].

Conclusion: In the present study, we found that concomitant MTX had no effect on serum ETN concentration or on clinical response. In addition, a significant correlation was detected between ETN dose and ETN concentration.

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Series: Pediatric rheumatology
ISSN: 1546-0096
ISSN-E: 1546-0096
ISSN-L: 1546-0096
Volume: 21
Issue: 1
Article number: 27
DOI: 10.1186/s12969-023-00801-2
Type of Publication: A1 Journal article – refereed
Field of Science: 3123 Gynaecology and paediatrics
Funding: Open Access funding provided by University of Helsinki including Helsinki University Central Hospital. The first author (Tiina Levälampi) received research funding from The Finnish Society for Rheumatology /Maire Lisko Foundation and Johanna Kärki received part time Government Research Funding during the study period.
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