Browsing by Author "Portela, Francisco"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Rapid test detection of anti-infliximab antibodies: performance comparison with three different immunoassaysPublication . Rocha, Cátia; Lago, Paula; Fernandes, Samuel; Correia, Luís; Portela, Francisco; Vieira, Ana Isabel; Patita, Marta; Arroja, Bruno; Ministro, Paula; Alves, Catarina; Dias, Cláudia Camila; Magro, FernandoBackground and aims: Therapeutic drug monitoring (TDM) of infliximab (IFX) and anti-infliximab antibodies (ATIs) is essential for treatment optimisation in inflammatory bowel disease (IBD) patients. The aim of this study was to estimate and compare the agreement and accuracy between a new rapid test and three established enzyme-linked immunosorbent assays (ELISAs) to quantify ATIs levels, and to evaluate the impact of exogenous IFX on the performance of these assays. Methods: We analysed 200 serum samples from 57 IBD outpatients in IFX induction or maintenance therapy at six IBD centres in Portugal. ATI levels were quantified using the rapid test Quantum Blue® (QB) Anti-Infliximab (Bühlmann) and three established ELISAs: In-House, Theradiag (Lisa Tracker Anti-Infliximab), and Immundiagnostik (IDKmonitor Infliximab). ATIs were quantified in patients' serum samples and spiked samples with exogenous IFX, based on analytical and clinical cutoffs. Qualitative agreement and accuracy were estimated by Cohen's kappa (k) with 95% confidence intervals. Results: ATIs quantification with clinical cutoffs showed a slight agreement between QB rapid test and In-House [k = 0.163 (0.051-0.276)] and Immundiagnostik [k = 0.085 (0.000-0.177)]. Regarding IFX/ATIs status, the QB rapid test showed a substantial agreement with Theradiag [k = 0.808 (0.729-0.888)] and a fair agreement with In-House [k = 0.343 (0.254-0.431)] and Immundiagnostik [k = 0.217 (0.138-0.297)]. The QB rapid test could not detect ATI-positive levels in samples with exogenous IFX at 5-300 µg/ml. Interference on ATIs detection was observed at exogenous IFX ⩾30 µg/ml for In-house and Immundiagnostik assays. Conclusion: QB rapid test is only suitable to detect ATI-positive levels in the absence of IFX.
- Soluble human Suppression of Tumorigenicity 2 is associated with endoscopic activity in patients with moderate-to-severe ulcerative colitis treated with golimumabPublication . Magro, Fernando; Lopes, Susana; Silva, Marco; Coelho, Rosa; Portela, Francisco; Branquinho, Diogo; Correia, Luís; Fernandes, Samuel; Cravo, Marília; Caldeira, Paulo; Tavares de Sousa, Helena; Patita, Marta; Lago, Paula; Ramos, Jaime; Afonso, Joana; Redondo, Isabel; Machado, Patrícia; Philip, George; Lopes, Joanne; Carneiro, FátimaBackground: Suppressor of Tumorigenicity 2 (ST2) is an IL33 receptor detected in the mucosa and serum of ulcerative colitis (UC) patients. We evaluated soluble ST2 (sST2) as a surrogate biomarker of disease outcome and therapeutic response, in moderate-to-severe UC patients treated with golimumab. Methods: We conducted an open-label single-arm multicentre prospective study. At screening/baseline, week 6 (W6) and week 16 (W16), clinical and endoscopic activity (total Mayo score), histologic activity (Geboes index) and biomarkers were evaluated. Results: From 38 patients, 34 (89.5%) completed W6 and 29 (76.3%) completed W16. Mean age (±SD) was 34.6 ± 12.6 years; 55.9% were female. At W16, 62.1% achieved clinical response. Patients with endoscopic activity at W6 (n = 20) had higher baseline sST2 (median, 24.5 versus 18.7 ng/ml, p = 0.026) and no decrease from baseline (median change, 0.8 versus -2.7, p = 0.029). At W6, sST2 levels correlated with endoscopic activity (rs = 0.45, p = 0.007) but not with histological activity (rs = 0.25, p = 0.151). The best cut-offs for endoscopic activity were sST2 = 16.9 ng/ml (sensitivity = 85%; specificity = 71%) and faecal calprotectin (FC) = 353 μg/g (sensitivity = 90%, specificity = 67%). Patients with histological activity at W6 (n = 27) had higher baseline ST2 levels (median, 23.0 versus 13.7 ng/ml, p = 0.035). sST2 did not correlate with FC or serum C-reactive protein. FC levels correlated with histological activity and baseline FC were higher when Geboes ⩾3.1 at W6. Conclusions: sST2 may be a surrogate biomarker of UC activity and therapeutic response as it correlates with endoscopic and clinical activity at W6 of golimumab treatment, and subjects with endoscopic and histological activity at W6 had higher baseline ST2 levels.