ULS_10.1-MED-Artigos
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- Detection of anti-infliximab antibodies is impacted by antibody titer, infliximab level and IgG4 antibodies: a systematic comparison of three different assaysPublication . Afonso, Joana; Lopes, Susana; Gonçalves, Raquel; Caldeira, Paulo; Lago, Paula; Sousa, Helena Tavares; Ramos, Jaime; Gonçalves, Ana Rita; Ministro, Paula; Rosa, Isadora; Vieira, Ana Isabel; Coelho, Rosa; Tavares, Patrícia; Soares, João; Sousa, Ana Lúcia; Carvalho, Diana; Sousa, Paula; Silva, João Pereira da; Meira, Tânia; Ferreira, Filipa Silva; Dias, Cláudia Camila; Chowers, Yehuda; Ben-Horin, Shomron; Magro, FernandoBackground: There is scant information on the accuracy of different assays used to measure anti-infliximab antibodies (ADAs), especially in the presence of detectable infliximab (IFX). We thus aimed to evaluate and compare three different assays for the detection of IFX and ADAs and to clarify the impact of the presence of circulating IFX on the accuracy of the ADA assays.Methods: Blood samples from 79 ulcerative colitis (UC) patients treated with infliximab were assessed for IFX levels and ADAs using three different assays: an in-house assay and two commercial kits, Immundiagnostik and Theradiag. Sera samples with ADAs and undetectable levels of IFX were spiked with exogenous IFX and analyzed for ADAs.Results: The three assays showed 81-96% agreement for the measured IFX level. However, the in-house assay and Immundiagnostik assays detected ADAs in 34 out of 79 samples, whereas Theradiag only detected ADAs in 24 samples. Samples negative for ADAs with Theradiag, but ADA-positive in both the in-house and Immundiagnostik assays, were positive for IFX or IgG4 ADAs. In spiking experiments, a low concentration of exogenous IFX (5 mu g/ml) hampered ADA detection with Theradiag in sera samples with ADA levels of between 3 and 10 mu g/ml. In the Immundiagnostik assay detection interference was only observed at concentrations of exogenous IFX higher than 30 mu g/ml. However, in samples with high levels of ADAs (> 25 mu g/ml) interference was only observed at IFX concentrations higher than 100 mu g/ml in all three assays. Binary (IFX/ADA) stratification of the results showed that IFX+/ADA and IFX-/ADAs + were less influenced by the assay results than the double-positive (IFX+/ADAs+) and double-negative (IFX-/ADAs-) combination.Conclusions: All three methodologies are equally suitable for measuring IFX levels. However, erroneous therapeutic decisions may occur when patients show double-negative (IFX-/ADAs) or double-positive (IFX+/ADAs+) status, since agreement between assays is significantly lower in these circumstances.
- The influence of subclinical active inflammation on IFX pharmacokinetic modeling and disease progression assessment: findings from a prospective real-world study in inflammatory bowel disease patientsPublication . Magro, Fernando; Fernandes, Samuel; Patita, Marta; Arroja, Bruno; Lago, Paula; Rosa, Isadora; Sousa, Helena Tavares; Ministro, Paula; Mocanu, Irina; Vieira, Ana; Castela, Joana; Moleiro, Joana; Roseira, Joana; Cancela, Eugénia; Sousa, Paula; Portela, Francisco; Correia, Luís; Moreira, Paula; Dias, Sandra; Afonso, Joana; Danese, Silvio; Peyrin-Biroulet, Laurent; Vucicevic, Katarina M; Santiago, MafaldaBackground and aims: Effective management of inflammatory bowel disease (IBD) relies on a comprehensive understanding of infliximab (IFX) pharmacokinetics (PK). This study’s primary goal was to develop a robust PK model, identifying key covariates influencing IFX clearance (CL), while concurrently evaluating the risk of disease progression during the maintenance phase of IBD treatment. Methods: The multicenter, prospective, real-world DIRECT study was conducted in several care centers, which included 369 IBD patients in the maintenance phase of IFX therapy. A two-compartment population PK model was used to determine IFX CL and covariates. Logistic and Cox regressions were applied to elucidate the associations between disease progression and covariates embedded in the PK model. Results: The PK model included the contributions of weight, albumin, antidrug antibody (ADA), and fecal calprotectin (FC). On average, higher ADA, FC concentration and weight, and lower albumin concentration resulted in higher IFX CL. In the multivariate regression analyses, FC levels influenced the odds of disease progression in the majority of its definitions, when adjusted for several confounding factors. Additionally, alongside FC, both IFX and CL demonstrated a significant impact on the temporal aspect of disease progression. Conclusion: In this 2-year real-world study, readily available clinical covariates, notably FC, significantly impacted IFX availability in IBD patients. We demonstrated that subclinical active inflammation, as mirrored by FC or CRP, substantially influenced IFX clearance. Importantly, FC emerged as a pivotal determinant, not only of IFX pharmacokinetics but also of disease progression. These findings underscore the need to integrate FC into forthcoming IFX pharmacokinetic models, amplifying its clinical significance.
- 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; Sousa, Helena Tavares; Patita, Marta; Lago, Paula; Ramos, Jaime; Afonso, Joana; Redondo, Isabel; Machado, Patrícia; Philip, George; Lopes, Joanne; Carneiro, FátimaSuppressor 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.