@article {Patro731, author = {Pradeepta Sekhar Patro and Ankita Singh and Ramnath Misra and Amita Aggarwal}, title = {Myeloid-related Protein 8/14 Levels in Rheumatoid Arthritis: Marker of Disease Activity and Response to Methotrexate}, volume = {43}, number = {4}, pages = {731--737}, year = {2016}, doi = {10.3899/jrheum.150998}, publisher = {The Journal of Rheumatology}, abstract = {Objective. Myeloid-related proteins (MRP) 8/14 belong to a family of calcium-binding proteins produced by myeloid cells. Baseline serum levels of MRP8/14 have been shown to predict response to biologicals in rheumatoid arthritis (RA). Because methotrexate (MTX) is the first-line therapy in RA, we studied whether MRP8/14 levels can predict response to MTX.Methods. Patients with active RA disease who were naive to disease-modifying antirheumatic drugs were enrolled. All patients were treated with MTX only, to a maximum of 25 mg/week or the maximal tolerated dose. At 4 months, the European League Against Rheumatism response was assessed. All patients who needed rescue therapy after 2 months or who did not respond at 4 months were classified as nonresponders.Results. Ninety patients were enrolled, of whom 3 discontinued MTX within 4{\textendash}6 weeks, so 87 patients were analyzed [74 women, median (interquartile range; IQR) for the Disease Activity Score at 28 joints (DAS28) was 4.43 (4.1{\textendash}5.1)]. The median (IQR) serum MRP8/14 level at baseline was 19.95 {\textmu}g/ml (11.49{\textendash}39.06). The serum MRP8/14 had good correlation with DAS28-C-reactive protein (CRP; r = 0.35, p = 0.001). The MRP8/14 levels fell significantly after 4 months of treatment (10.28 {\textmu}g/ml, 5.95{\textendash}16.05, p \< 0.001). Among 87 patients, 69 were responders. The median (IQR) baseline level of MRP8/14 was higher among responders compared with nonresponders: 23.99 {\textmu}g/ml (15.39{\textendash}42.75) versus 9.58 {\textmu}g/ml (6.11{\textendash}24.93, p = 0.00250). The levels declined in the responders, from 23.99 {\textmu}g/ml (15.39{\textendash}42.75) to 10.41 {\textmu}g/ml (5.83{\textendash}15.61, p \< 0.001), but not in the nonresponders, from 9.58 {\textmu}g/ml (6.11{\textendash}24.93) to 9.19 {\textmu}g/ml (7.74{\textendash}21.96, p = 0.687). Receiver-operation characteristic analysis showed that MRP8/14 was a better predictor of response than CRP and erythrocyte sedimentation rate, especially with early disease onset (\< 1-yr duration).Conclusion. MRP8/14 is a good marker of disease activity in RA, and higher levels predict response to MTX.}, issn = {0315-162X}, URL = {https://www.jrheum.org/content/43/4/731}, eprint = {https://www.jrheum.org/content/43/4/731.full.pdf}, journal = {The Journal of Rheumatology} }