Analytical and clinical evaluation of DiaSorin Liaison® Calprotectin fecal assay adapted for serum samples.

BACKGROUND: Calprotectin is a calcium-binding protein that can be measured in serum, plasma, and feces. Increased serum and plasma calprotectin concentrations have been found in chronic inflammatory rheumatic disorders. An analytical and clinical evaluation of the DiaSorin Liaison® fecal Calprotectin assay using LIAISON® XL was performed. METHODS: The protocol included an analytical and clinical evaluation in which imprecision, the linearity of dilution, differences between serum and plasma samples and method comparison with CalproLab™ ELISA kit were assessed. Serum calprotectin concentrations in active (n = 26) and remission (n = 23) rheumatoid arthritis (RA) patients were compared. RESULTS: The intra-day and inter-day analytical imprecision CVs ranged from 2.9% to 4.0% and 2.7% to 10.4%, respectively. Correlation between measured and expected values was high (R > 0.99), indicating good linearity. The Wilcoxon signed-rank test showed that serum and plasma matched samples presented statistically significant differences (p < 0.001) being the highest concentrations of calprotectin observed in serum samples. Deming regression equation was as follows: Diasorin calprotectin (µg/ml) = -0.32 (95% CI: -0.65 - -0.05) +1.58 (95% CI: 1.42-1.79).* Calprolab calprotectin (µg/ml). Significantly higher serum calprotectin levels were found in RA patients with active disease when compared to patients with low disease activity or in clinical remission (mean ± SD) [(3.35 µg/ml ± 1.55) vs. (1.63 µg/ml ± 0.52), p < 0.001] and these levels correlated well with all disease activity indices. CONCLUSIONS: The DiaSorin Liaison® fecal Calprotectin assay adapted for serum samples showed adequate technical performances and the clinical performances were similar to other assays.

Correlation of fatigue with other disease related and psychosocial factors in patients with rheumatoid arthritis treated with tocilizumab: ACT-AXIS study.

To assess the hypothesis if tocilizumab (TCZ) is effective on disease activity, and also its effect in fatigue and other clinical and psychological disease-related factors in patients with rheumatoid arthritis (RA) treated with TCZ.A 24-week, multicenter, prospective, observational study in patients with moderate to severe RA receiving TCZ after failure or intolerance to disease-modifying antirheumatic drugs or tumor necrosis factor-alpha was conducted.Of the 122 patients included, 85 were evaluable for effectiveness (85% female, 51.9 ±â€Š12.5 years, disease duration 8.7 ±â€Š7.4 years). Mean change in C-reactive protein level from baseline to week 12 was -11.2 ±â€Š4.0 (P < .001). Mean Disease Activity Index score (DAS28) decreased from 5.5 ±â€Š1.0 at baseline to 2.7 ±â€Š1.3 (P < .001) at week 24. Mean change in Functional Assessment of Chronic Illness Therapy score was -5.4 ±â€Š11.2 points at week 24. Multiple regression analysis showed that the improvement in DAS28, sleep, and depression explained 56% and 47% of fatigue variance at week 12 and 24, respectively.Tocilizumab is effective in reducing disease activity and results in a clinically significant improvement in fatigue, pain, swollen joint count, morning stiffness, sleepiness, depression, and DAS28; the last 3 were specifically identified as factors explaining fatigue variance with the use of TCZ in RA patients.