Objective. To study two neutrophil activation markers, myeloid-related protein (MRP) 8/14 and neutrophil elastase (NE), for their ability to predict treatment response and flare in patients with... Show moreObjective. To study two neutrophil activation markers, myeloid-related protein (MRP) 8/14 and neutrophil elastase (NE), for their ability to predict treatment response and flare in patients with JIA.Methods. Using samples from two cohorts (I and II), we determined MRP8/14 and NE levels of 32 (I) and 81 (II) patients with new-onset, DMARD-naive arthritis and compared patients who responded to treatment (defined as fulfilling >= adjusted ACRpedi50 response and/or inactive disease) with non-responders (defined as fulfilling < adjusted ACRpedi50 response and/or active disease) at 6 and 12 months. Secondly, we compared biomarker levels of 54 (I) and 34 (II) patients with clinically inactive disease who did or did not suffer from a flare of arthritis after 6 or 12 months. Receiver operating characteristic analyses were carried out to study the predictive value of MRP8/14 and NE for treatment response and flare.Results. For both cohorts, baseline MRP8/14 and NE levels for patients who did or did not respond to treatment were not different. Also, MRP8/14 and NE levels were not different in patients who did or did not flare. Receiver operating characteristic analysis of MRP8/14 and NE demonstrated areas under the curve <0.7 in both cohorts.Conclusion. In our cohorts, MRP8/14 and NE could not predict treatment response. Also, when patients had inactive disease, neither marker could predict flares. Show less
Moel, E.C. de; Rech, J.; Mahler, M.; Roth, J.; Vogl, T.; Schouffoer, A.; ... ; Woude, D. van der 2019
Objective: To investigate whether calprotectin (S100A8/A9 or MRP8/14), an inflammatory complex released by monocytes, could indicate residual subclinical inflammation in rheumatoid arthritis (RA)... Show moreObjective: To investigate whether calprotectin (S100A8/A9 or MRP8/14), an inflammatory complex released by monocytes, could indicate residual subclinical inflammation in rheumatoid arthritis (RA) patients who are in stable remission on disease-modifying anti-rheumatic drugs (DMARDs) and serve as a marker for disease flare after DMARD tapering.Methods: We used data from two trials. Patients from the IMPROVED study had early (< 2 years) RA, and when they achieved disease activity score remission (DAS44 < 1.6), they stopped methotrexate to attempt drug-free remission. Patients from the RETRO study had established RA in stable remission (DAS28 < 2.6) and either tapered by 50% or stopped (biological or conventional) DMARDs. Circulating calprotectin at the tapering time point was determined by ELISA, and its predictive value for flare (loss of remission) within 12 months of DMARD tapering/stopping was determined.Results: In both IMPROVED (n = 104) and RETRO (n = 57), patients that flared within 12 months had higher calprotectin at the moment of DMARD tapering/stopping. Twofold higher calprotectin at the moment of DMARD tapering/stopping was associated with an increased risk (odds ratio) of flare of 1.07 (95% CI 0.98-1.18, p = 0.14) in the IMPROVED and 3.62 (95% CI 1.76-7.46, p < 0.001) in the RETRO. Correcting for clinical predictors of flare (DAS at study inclusion, anti-CCP2 positivity, gender) did not change these estimates. The area under the receiver operating curve of calprotectin levels for predicting flare within 12 months was 0.63 (95% CIs 0.51-0.76) in the IMPROVED study and 0.80 (95% CIs 0.69 to 0.92) in the RETRO study.Conclusion: Circulating calprotectin levels in RA patients in remission on DMARDs are higher in patients that will flare upon DMARD tapering/stopping. Since the differences between the cohorts precluded definitive conclusions, more research is needed to determine whether calprotectin has prognostic value in predicting flare after attempting drug tapering in RA. Show less
