Serum Calprotectin Versus Acute-Phase Reactants in the Discrimination of Inflammatory Disease Activity in Rheumatoid Arthritis Patients Receiving Tumor Necrosis Factor Inhibitors.

To compare the accuracy of serum calprotectin and acute-phase reactants (C-reactive protein [CRP] and erythrocyte sedimentation rate [ESR]) in stratifying disease activity in rheumatoid arthritis (RA) patients receiving tumor necrosis factor inhibitors (TNFi), and to correlate calprotectin levels with TNFi trough serum levels. We conducted a cross-sectional study of 87 RA patients receiving adalimumab, etanercept (ETN), or infliximab (IFX); 56 psoriatic arthritis (PsA) patients and 40 healthy blood donors were included as controls. Associations between calprotectin, CRP, and ESR and composite articular indices (Disease Activity Score in 28 joints [DAS28], Simplified Disease Activity Index [SDAI], and Clinical Disease Activity Index) were analyzed by correlation and linear regression and the accuracy and discriminatory capacity of calprotectin by receiver operator characteristic curves (area under the curve [AUC]). Calprotectin levels correlated better with all composite activity indices than CRP and ESR (all r coefficients >0.70). Calprotectin levels were significantly lower in RA and PsA patients in clinical remission compared with those with low disease activity for all articular indices. In RA, ESR discriminated between remission and low disease activity only when using DAS28, and CRP only with SDAI. In RA patients in remission/low disease activity, calprotectin but not CRP or ESR distinguished between patients with no swollen joints and those with ≥1 swollen joint (1.74 μg/ml versus 3.04 μg/ml; P = 0.010). Using DAS28 ≥2.6 as the reference variable, calprotectin showed an AUC of 0.92; the best cutoff was ≥2.47 μg/ml with a likelihood ratio of 6.3 (95% confidence interval 2.5-15.8). Calprotectin serum levels inversely correlated with trough serum drug levels of ETN (ρ = -0.671, P < 0.001) and IFX (ρ = -0.729, P = 0.017). Calprotectin may more accurately discriminate disease activity in RA patients receiving TNFi than acute-phase reactants, even in patients with low inflammatory activity.

Inciarte-Mundo J ，Victoria Hernández M ，Ruiz-Esquide V ，Raquel Cabrera-Villalba S ，Ramirez J ，Cuervo A ，Pascal M ，Yagüe J ，Cañete JD ，Sanmarti R ... -  《-》

Calprotectin and TNF trough serum levels identify power Doppler ultrasound synovitis in rheumatoid arthritis and psoriatic arthritis patients in remission or with low disease activity.

Inciarte-Mundo J ，Ramirez J ，Hernández MV ，Ruiz-Esquide V ，Cuervo A ，Cabrera-Villalba SR ，Pascal M ，Yagüe J ，Cañete JD ，Sanmarti R ... -  《-》

Calprotectin more accurately discriminates the disease status of rheumatoid arthritis patients receiving tocilizumab than acute phase reactants.

To compare the accuracy of serum calprotectin levels, CRP and ESR in stratifying disease activity in RA patients receiving tocilizumab (TCZ). Cross-sectional study of 33 RA patients receiving TCZ. DAS28, Simplified Disease Activity Index, Clinical Disease Activity Index, joint counts and serum levels of CRP, ESR, calprotectin and TCZ were measured. Associations between calprotectin, ESR and CRP and articular indices were analysed by correlation and linear regression. The accuracy and discriminatory capacity of calprotectin was assessed by receiver operating characteristic curves (area under the curve). Calprotectin levels, but not CRP or ESR, were strongly correlated with all composite indices (all r coefficients over 0.50). Calprotectin, but not CRP or ESR, was significantly lower in patients in remission compared with those with low disease activity [1.57 μg/ml (s.d. 1) vs 3.35 μg/ml (s.d. 1), P = 0.001]. In a fully adjusted model (R(2) = 0.82), DAS28-ESR increased 0.48 units per μg/ml calprotectin increase (P < 0.001). Using a DAS28 >3.2 as the reference variable, calprotectin showed an area under the curve of 0.922, and the best cut-off was 5.19 μg/ml (odds ratio 11.5). CRP levels, but not calprotectin, were dependent on detectable TCZ trough serum levels. Calprotectin serum levels seem to be an accurate biomarker for assessing disease activity in RA patients receiving TCZ.

Inciarte-Mundo J ，Ruiz-Esquide V ，Hernández MV ，Cañete JD ，Cabrera-Villalba SR ，Ramirez J ，Yagüe J ，Sanmarti R ... -  《-》

Calprotectin strongly and independently predicts relapse in rheumatoid arthritis and polyarticular psoriatic arthritis patients treated with tumor necrosis factor inhibitors: a 1-year prospective cohort study.

Inciarte-Mundo J ，Ramirez J ，Hernández MV ，Ruiz-Esquide V ，Cuervo A ，Cabrera-Villalba SR ，Pascal M ，Yagüe J ，Cañete JD ，Sanmarti R ... -  《-》

Calprotectin (S100A8/A9) and S100A12 are associated with measures of disease activity in a longitudinal study of patients with rheumatoid arthritis treated with infliximab.

Nordal HH ，Brun JG ，Hordvik M ，Eidsheim M ，Jonsson R ，Halse AK ... -  《-》