Around one-third of patients with juvenile arthritis fail to respond to first-line treatments

When treating the symptoms of juvenile idiopathic arthritis, also called juvenile idiopathic arthritis (JIA), disease-modifying anti-rheumatic drugs (DMARDs) and anti-tumor necrosis factor (TNF) are often used. These include methotrexate (MTX), Enbrel and Humira.

Around one-third of patients with juvenile idiopathic arthritis fail to respond to MTX or TNF therapy. Even fewer achieve the American College of Rheumatology Pediatric 70% criteria for response.

In this new research, printed in The Journal of Rheumatology in January 2018, the researchers evaluated whether measuring blood levels of the protein S100A12 could be a suitable predictor for treatment outcomes in JIA patients.

Because change in serum S100-protein myeloid-related protein complex 8/14 (MRP8/14) is associated with therapeutic response, we tested granulocyte-specific S100-protein S100A12 as a potential biomarker for treatment response.

Methods 
S100A12 serum concentration was determined by ELISA in 163 patients treated with MTX or anti-TNF at baseline and follow up. Treatment response achievement of inactive disease, and improvement in Juvenile Arthritis Disease Activity Score were recorded. ELISA is enzyme-linked immunosorbent assay - a test that uses antibodies and color change to identify a substance. 

Results
Researchers found that when compared to non-responders, patients who responded to the administrated therapies had significantly higher baseline levels of blood S100A12.

Conclusion 
People who will respond to MTX or anti-TNF treatment can be identified by pre-treatment S100A12 serum concentration levels.

ARTICLE:

S100A12 Is Associated with Response to Therapy in Juvenile Idiopathic Arthritis

Faekah Gohar, Janneke Anink, Halima Moncrieffe, Lisette W.A. Van Suijlekom-Smit, 
Femke H.M. Prince, Marion A.J. van Rossum, Koert M. Dolman, Esther P.A.H. Hoppenreijs, 
Rebecca ten Cate, Simona Ursu, Lucy R. Wedderburn, Gerd Horneff, Michael Frosch, 
Dirk Foell and Dirk Holzinger

The Journal of Rheumatology January 2018, jrheum.170438; DOI: https://doi.org/10.3899/jrheum.170438