RESUMO
INTRODUCTION: Several studies associate the presence of higher serum concentrations of infliximab (IFX) with fistula healing in perianal Crohn's disease (CD). This study aimed to evaluate serum IFX concentrations in patients with perianal fistulizing CD (PFCD) in the presence or absence of general, clinical, and radiological activities. METHODS: This was a cross-sectional study in patients with PFCD during maintenance treatment with IFX from two centers. Serum IFX concentrations were measured before their next infusion and anal fistulas were evaluated by clinical examination and magnetic resonance imaging (MRI), whenever possible, performed 90 days before or after serum collection. According to clinical scores, radiological activity, and disease markers, patients were classified as in remission or active disease. Mean serum IFX concentrations were compared between the groups. RESULTS: Thirty-eight patients with PFCD were included. Demographic characteristics were similar in patients with remission or active disease. The overall mean serum IFX concentration of the entire sample (n = 38) was 5.21 ± 4.75 µg/mL (median 3.63; IQR 1.44-8.82). Serum IFX levels were 6.25 ± 5.34 µg/mL (median 3.62; IQR 1.95-11.03) in the 23 (60.5%) patients in remission and 3.63 ± 3.24 µg/mL (median 3.63; IQR 1.32-6.43; p = 0.226) in the 15 (39 .5%) who presented active disease. When evaluating general, clinical, and radiological activity of PFCD, and deep remission in isolation, no statistical difference between the groups was observed (p = 0.226, p = 0.418, p = 0.126, and p = 0.232, respectively). The 13 (34.2%) patients with an optimized dose of IFX had significantly higher serum concentrations than the remaining 25 (65.8%) with a standard dose: 8.33 ± 4.41 µg/mL (median 8.36; IQR 3.82-11.20) vs. 3.59 ± 4.13 µg/mL (median 1.97; IQR 1.18-3.85) -p = 0.002. Patients in remission and with an optimized IFX dose had significantly higher serum IFX concentrations than those with a standard dose (p = 0.006), whereas no significant difference was observed among those with active disease (p = 0.083). CONCLUSION: There were no differences in IFX serum concentrations in patients with clinical or radiological active PFCD as compared with those in remission. Patients with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose. Patients in remission and with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose.
Assuntos
Doença de Crohn , Fármacos Gastrointestinais , Infliximab , Imageamento por Ressonância Magnética , Fístula Retal , Humanos , Doença de Crohn/sangue , Doença de Crohn/complicações , Doença de Crohn/tratamento farmacológico , Estudos Transversais , Fístula Retal/sangue , Fístula Retal/etiologia , Fístula Retal/tratamento farmacológico , Infliximab/sangue , Infliximab/uso terapêutico , Infliximab/administração & dosagem , Masculino , Feminino , Adulto , Fármacos Gastrointestinais/sangue , Fármacos Gastrointestinais/uso terapêutico , Fármacos Gastrointestinais/administração & dosagem , Pessoa de Meia-Idade , Adulto Jovem , Índice de Gravidade de Doença , Indução de RemissãoRESUMO
OBJECTIVES: To study infliximab (IFX) pharmacokinetics in children with inflammatory bowel disease (IBD) during induction therapy to predict outcome and explore if other covariates influenced outcome. STUDY DESIGN: All children with IBD starting IFX therapy (5 mg/kg at weeks 0, 2, 6, and 12) for active luminal disease from May 2017 to May 2019 were included and followed prospectively. Patients were sampled at multiple timepoints during induction (trough concentrations and peak concentration at weeks 0, 2, 6, and 12, and intermediate concentration at weeks 1-4). IFX concentrations and cumulative drug exposure were correlated with outcome at 6 months. Endoscopic remission was defined as Simple Endoscopic Score for Crohn's Disease of <3 or Mayo endoscopic subscore of 0, and deep remission as endoscopic with clinical remission (Pediatric Ulcerative Colitis Activity Index/Pediatric Crohn's Disease Activity Index of <10). RESULTS: There were 252 serum induction concentrations obtained from 32 patients (81% on concomitant thiopurines). Children in endoscopic remission (all in deep remission) at 6 months had significantly higher drug concentrations from week 4 onward. A receiver operating characteristics curve analysis identified IFX trough concentrations at week 12 of ≥5.0 µg/mL and area under the curve at weeks 0-12 of ≥4056.0 µg∗day/mL as the minimal target to achieve endoscopic remission at 6 months (area under the receiver operating characteristics curve, 0.796 [95% CI, 0.62-0.97] and area under the receiver operating characteristics curve, 0.778 [95% CI, 0.61-0.94], respectively). In addition, our findings suggest that proteomic analysis may help to understand IFX response. CONCLUSIONS: Higher IFX exposure during induction therapy in pediatric patients with IBD is associated with significantly better endoscopic and deep remission rates at 6 months. Drug concentrations differentiate remitters from nonremitters from week 4 after induction onward.
Assuntos
Endoscopia do Sistema Digestório , Fármacos Gastrointestinais/sangue , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/sangue , Indução de Remissão , Adolescente , Criança , Pré-Escolar , Monitoramento de Medicamentos , Feminino , Seguimentos , Fármacos Gastrointestinais/uso terapêutico , Humanos , Infliximab/uso terapêutico , Masculino , Estudos ProspectivosRESUMO
RATIONALE: Heightened inflammatory bowel disease (IBD) activity during pregnancy is associated with higher rates of preterm birth, miscarriage, and low birth weight. Therefore, its adequate treatment is essential, considering the risk-benefit of medication use. Although previous literature has described the management of IBD during pregnancy, few studies have assessed the pharmacokinetics of IBD drugs in the newborn. In this case report, we describe the management of ulcerative colitis during pregnancy and discuss the benefits of checking serum levels of infliximab in newborns exposed to the medication during pregnancy. PATIENT CONCERN: A 37-year-old patient with ulcerative colitis in clinical and endoscopic remission had been undergoing treated with infliximab since 2008. The patient became pregnant in 2018. DIAGNOSIS AND INTERVENTION: Infliximab medication was discontinued at the 29th week of pregnancy. OUTCOMES: The pregnancy was uneventful, and the levels of infliximab in the umbilical cord were >20âµg/dL. Live vaccinations were postponed until the baby was 6âmonths old, when a new serum drug level proved to be undetectable. LESSONS: Our case suggests that the use of infliximab is safe in pregnancy, and drug discontinuation could be considered from the 24th week of pregnancy onward to reduce placental transfer to the newborn in patients at low risk of relapse. Vaccines with live attenuated organisms should be delayed for at least 6âmonths or until the serum level of the medication is undetectable.
Assuntos
Colite Ulcerativa/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/sangue , Infliximab/uso terapêutico , Inibidores do Fator de Necrose Tumoral/sangue , Inibidores do Fator de Necrose Tumoral/uso terapêutico , Adulto , Feminino , Fármacos Gastrointestinais/sangue , Humanos , Lactente , Recém-Nascido , Gravidez , Complicações na Gravidez , Nascimento Prematuro/induzido quimicamente , Resultado do TratamentoRESUMO
OBJECTIVES: The aim of this study was to evaluate the quantitative serum level of infliximab (IFX) as well as the detection of anti-infliximab antibodies (ATIs) in patients with Crohn's disease (CD). METHOD: Forty patients with CD under treatment at a tertiary center in southeastern Brazil were evaluated. Their use of infliximab was continuous and regular. We analyzed and compared the differences in the IFX and ATI levels between the patients with active CD (CDA) and those with CD in remission (CDR). RESULTS: There was no difference in the IFX level between the CDA and CDR groups (p>0.05). Eighty percent of all patients had IFX levels above the therapeutic concentration (6-10 µg/mL). Two (9%) of the 22 patients with active disease and four (22.2%) of the 18 patients in remission had undetectable levels of IFX. Four (66.6%) of the six patients with undetectable levels of IFX had positive ATI levels; three of these patients were in remission, and one had active disease. In addition, the other two patients with undetectable levels of IFX presented ATI levels close to positivity (2.7 and 2.8 AU/ml). None of the patients with therapeutic or supratherapeutic IFX levels had positive ATI levels. CONCLUSIONS: The undetectable levels of IFX correlated with the detection of ATIs, which was independent of disease activity. Immunogenicity was not the main factor for the loss of response to IFX in our study, and the majority of patients in both groups (CDA and CDR) had supratherapeutic levels of IFX.
Assuntos
Anticorpos Monoclonais/sangue , Doença de Crohn/sangue , Monitoramento de Medicamentos , Fármacos Gastrointestinais/sangue , Infliximab/sangue , Adolescente , Adulto , Idoso , Brasil , Doença de Crohn/tratamento farmacológico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Fármacos Gastrointestinais/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Infliximab/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto JovemRESUMO
OBJECTIVES: The aim of this study was to evaluate the quantitative serum level of infliximab (IFX) as well as the detection of anti-infliximab antibodies (ATIs) in patients with Crohn's disease (CD). METHOD: Forty patients with CD under treatment at a tertiary center in southeastern Brazil were evaluated. Their use of infliximab was continuous and regular. We analyzed and compared the differences in the IFX and ATI levels between the patients with active CD (CDA) and those with CD in remission (CDR). RESULTS: There was no difference in the IFX level between the CDA and CDR groups (p>0.05). Eighty percent of all patients had IFX levels above the therapeutic concentration (6-10 μg/mL). Two (9%) of the 22 patients with active disease and four (22.2%) of the 18 patients in remission had undetectable levels of IFX. Four (66.6%) of the six patients with undetectable levels of IFX had positive ATI levels; three of these patients were in remission, and one had active disease. In addition, the other two patients with undetectable levels of IFX presented ATI levels close to positivity (2.7 and 2.8 AU/ml). None of the patients with therapeutic or supratherapeutic IFX levels had positive ATI levels. CONCLUSIONS: The undetectable levels of IFX correlated with the detection of ATIs, which was independent of disease activity. Immunogenicity was not the main factor for the loss of response to IFX in our study, and the majority of patients in both groups (CDA and CDR) had supratherapeutic levels of IFX.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Fármacos Gastrointestinais/sangue , Doença de Crohn/sangue , Monitoramento de Medicamentos , Infliximab/sangue , Anticorpos Monoclonais/sangue , Fármacos Gastrointestinais/uso terapêutico , Brasil , Doença de Crohn/tratamento farmacológico , Estudos Prospectivos , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Infliximab/uso terapêutico , Imunossupressores/uso terapêuticoRESUMO
Background: Primary non-response and secondary loss of response (LOR) are significant problems of biological therapy for inflammatory bowel disease (IBD). Therapeutic drug monitoring (TDM) in IBD patients receiving these drugs can improve outcomes. Aim: To measure serum infliximab levels and anti-infliximab antibodies (ATI) in patients with IBD post-induction phase and during maintenance therapy assessing the clinical course of IBD. Patients and Methods: Prospective study of IBD patients receiving infliximab between July 2016-May 2017. Group-A included patients who received induction therapy while Group-B included patients who were in maintenance therapy. TDM was performed in serum samples collected at weeks-14 and 30 in Group-A and before the infliximab maintenance dose in Group-B. Clinical scores, fecal calprotectin and endoscopic score were also evaluated. Results: Of 14 patients in Group-A, 57% achieved endoscopic response. Median serum infliximab concentrations at week-14 and 30 were 2.65 AU/mL (0.23-32.58) and 2.3 AU/mL (0.3-16.8), respectively. Patients with mucosal healing had non-significantly higher median infliximab concentrations at week- 14, as compared to week 30 (median 3.2 vs 2.2 AU/ml, respectively, p 0.6). ATI >10 ug/mL were found in one and seven patients at week-14 and 30, respectively. At 52 weeks of follow-up, four patients (31%) had LOR. Group-B included 36 patients, 33% had LOR. Median serum concentrations of infliximab were 1.4 AU/mL (0.27-7.03). No significant differences in serum infliximab concentration were observed between patients in remission and those with inflammatory activity. Seventeen patients had ATI >10 ug/mL. Conclusions: Clinical algorithms using TDM might help to optimize the pharmacological therapy of IBD.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Fármacos Gastrointestinais/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Monitoramento de Medicamentos/métodos , Infliximab/uso terapêutico , Valores de Referência , Índice de Gravidade de Doença , Fármacos Gastrointestinais/sangue , Ensaio de Imunoadsorção Enzimática , Colite Ulcerativa/diagnóstico por imagem , Doença de Crohn/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes , Colonoscopia , Resultado do Tratamento , Estatísticas não Paramétricas , Infliximab/sangueRESUMO
BACKGROUND: Infliximab (IFX) therapeutic drug monitoring is an important tool to guide therapeutic decision in inflammatory bowel disease patients. Currently, there are two methods to measure trough levels of IFX, ELISA assays or rapid tests. Despite that the ELISA assay is the most used method in therapeutic drug monitoring, the results take long to be available for clinical use, and it needs to be performed by trained personnel. In contrary, the results of a rapid test take 20 to 30 minutes to be available and can be performed by non-trained lab personnel. OBJECTIVE: The aim of the study was to compare a rapid test (QB-IFX) for quantitative determination of IFX level to one ELISA assay in a cohort of inflammatory bowel disease patients. METHODS: Cross-sectional multicentric study with 49 inflammatory bowel disease patients on maintenance therapy with IFX. Blood samples for IFX serum levels were collected immediately before infusion. IFX serum levels were classified as undetectable, low (<3.0 µg/mL), adequate (3.1-7.0 µg/mL) or high (>7.1 µg/mL). A sensitivity and specificity of each test and a comparison between tests was based on ROC curves. RESULTS: Thirty-four Crohn's disease patients and 15 ulcerative colitis patients in clinical remission were evaluated. The majority of patients had low or adequate serum levels of IFX. In relation to the serum levels proportions with the two methods, there was no significant difference (P=0.84). The ROC analysis identified a concentration threshold >2.9 µg/mL with the QB-IFX test (area under the ROC, 0.82; P<0.0001, sensitivity, 100%; specificity, 61.9%), and >3.83 µg/mL using the ELISA assay (area under the ROC, 0.96; P<0.0001, sensitivity, 100%; specificity, 92.9%). CONCLUSION: QB-IFX and ELISA assays to measure IFX levels were comparable. Both methods had accurate sensitivity and specificity to detect undetectable, low and adequate levels, but had showed low specificity for supra therapeutic levels of IFX.
Assuntos
Colite Ulcerativa/sangue , Doença de Crohn/sangue , Ensaio de Imunoadsorção Enzimática , Fármacos Gastrointestinais/sangue , Infliximab/sangue , Adulto , Idade de Início , Anticorpos/sangue , Biomarcadores/sangue , Estudos de Coortes , Estudos Transversais , Monitoramento de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto JovemRESUMO
ABSTRACT BACKGROUND: Infliximab (IFX) therapeutic drug monitoring is an important tool to guide therapeutic decision in inflammatory bowel disease patients. Currently, there are two methods to measure trough levels of IFX, ELISA assays or rapid tests. Despite that the ELISA assay is the most used method in therapeutic drug monitoring, the results take long to be available for clinical use, and it needs to be performed by trained personnel. In contrary, the results of a rapid test take 20 to 30 minutes to be available and can be performed by non-trained lab personnel. OBJECTIVE: The aim of the study was to compare a rapid test (QB-IFX) for quantitative determination of IFX level to one ELISA assay in a cohort of inflammatory bowel disease patients. METHODS: Cross-sectional multicentric study with 49 inflammatory bowel disease patients on maintenance therapy with IFX. Blood samples for IFX serum levels were collected immediately before infusion. IFX serum levels were classified as undetectable, low (<3.0 μg/mL), adequate (3.1-7.0 μg/mL) or high (>7.1 μg/mL). A sensitivity and specificity of each test and a comparison between tests was based on ROC curves. RESULTS: Thirty-four Crohn's disease patients and 15 ulcerative colitis patients in clinical remission were evaluated. The majority of patients had low or adequate serum levels of IFX. In relation to the serum levels proportions with the two methods, there was no significant difference (P=0.84). The ROC analysis identified a concentration threshold >2.9 μg/mL with the QB-IFX test (area under the ROC, 0.82; P<0.0001, sensitivity, 100%; specificity, 61.9%), and >3.83 μg/mL using the ELISA assay (area under the ROC, 0.96; P<0.0001, sensitivity, 100%; specificity, 92.9%). CONCLUSION: QB-IFX and ELISA assays to measure IFX levels were comparable. Both methods had accurate sensitivity and specificity to detect undetectable, low and adequate levels, but had showed low specificity for supra therapeutic levels of IFX.
RESUMO CONTEXTO: A monitorização dos níveis séricos do infliximabe (IFX) é uma importante ferramenta para guiar a tomada de decisão nos pacientes com doença inflamatória intestinal. No presente momento existem dois tipos de métodos para quantificar nível sérico de IFX disponíveis no mercado: o ELISA e o teste rápido. O método ELISA é o mais usado em todo o mundo, todavia os resultados demoram de 1 a 2 dias para estar disponíveis para uso clínico. Além disso, o ELISA é um método que requer um técnico especializado para realizá-lo. Ao contrário, os resultados do teste rápido estão disponíveis em 20 a 30 minutos e esse pode ser realizado por um funcionário não especializado. OBJETIVO: O objetivo deste estudo foi comparar o teste rápido (QB-IFX) com o teste ELISA para determinação quantitativa do nível sérico de IFX em uma coorte de pacientes com doença inflamatória intestinal. MÉTODOS: Foi realizado um estudo transversal multicêntrico com inclusão de 49 pacientes em terapia de manutenção com IFX. Amostra sanguínea para dosagem sérica do IFX foi coletada imediatamente antes da infusão. A dosagem sérica do IFX foi classificada em indetectável, baixo (<3,0 μg/mL), adequado (3,1-7,0 μg/mL) ou alto (>7,1 μg/mL). A sensibilidade e a especificidade de cada teste e a comparação entre os testes foram avaliados através de curva ROC. RESULTADOS: Foram avaliados 34 pacientes com doença de Crohn e 15 pacientes com retocolite ulcerativa em remissão clínica da doença. A maioria dos pacientes apresentou níveis baixos ou adequados do IFX sérico de acordo com ambos os métodos de dosagem. Não houve diferença significativa entre os métodos quando avaliados categoricamente (P=0,84). A análise da curva ROC identificou limites de concentrações >2,9 μg/mL com o teste rápido QB-IFX (AUC ROC, 0,82; P<0,0001, sensibilidade: 100%; especificidade: 61.9%), e >3,83 μg/mL usando o método ELISA (AUC ROC, 0,96; P<0,0001, sensibilidade: 100%; especificidade: 92,9%). CONCLUSÃO: Os testes QB-IFX e ELISA foram comparáveis para dosagem do nível sérico de IFX. Ambos os métodos são acurados e apresentaram boa sensibilidade e especificidade para detecção de níveis indetectáveis, níveis baixos e níveis adequados, porém mostraram pouca especificidade para níveis supra terapêuticos da droga.
Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Fármacos Gastrointestinais/sangue , Ensaio de Imunoadsorção Enzimática , Colite Ulcerativa/sangue , Doença de Crohn/sangue , Infliximab/sangue , Biomarcadores/sangue , Estudos Transversais , Curva ROC , Estudos de Coortes , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Monitoramento de Medicamentos , Idade de Início , Pessoa de Meia-Idade , Anticorpos/sangueAssuntos
Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Monitoramento de Medicamentos/métodos , Fármacos Gastrointestinais/uso terapêutico , Infliximab/uso terapêutico , Adolescente , Adulto , Criança , Colite Ulcerativa/diagnóstico por imagem , Colonoscopia , Doença de Crohn/diagnóstico por imagem , Ensaio de Imunoadsorção Enzimática , Feminino , Fármacos Gastrointestinais/sangue , Humanos , Infliximab/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Resultado do Tratamento , Adulto JovemRESUMO
ABSTRACT BACKGROUND: Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases. In such pathologies, there is an increased production of alpha tumor necrosis factor (TNF-α). Patients, in whom the conventional immunosuppressant treatment fails, require the use of immunobiological therapy, such as anti-TNF-α, a monoclonal antibody. Infliximab is an anti-TNF-α drug, a chimerical immunoglobulin, with a murine component, which is responsible for the generation of immunogenicity against the drug and formation of anti-TNF-α antibodies. The presence of anti-drug antibodies may be responsible for adverse events and reduction of the drug's effectiveness. Patients with inflammatory bowel diseases undergoing therapy with biological medication, such as infliximab, can relapse overtime and this may not be translated into clinical symptoms. Thus, there is a need for a method to evaluate the efficacy of the drug, through the measurement of serum infliximab levels, as well as antibodies research. OBJECTIVE: This study aimed to measure serum infliximab levels and anti-infliximab antibodies in patients with inflammatory bowel diseases post-induction phase and during maintenance therapy, and describe the therapeutic modifications that took place based on the serum levels results. METHODS: It was a retrospective study, that included forty-five patients, with a total of 63 samples of infliximab measurement. RESULTS: Twenty-one patients had an adequate infliximab serum level, 31 had subtherapeutic levels and 11 had supratherapeutic levels. Seven patients had their medication suspended due to therapeutic failure or high levels of antibodies to infliximab. CONCLUSION: In conclusion, only a third of the patients had adequate infliximab levels and 36% presented with subtherapeutic levels at the end of the induction phase. Therapy optimization occurred based in about 46% of the samples results, demonstrating the importance of having this tool to help the clinical handling of patients with inflammatory bowel diseases ongoing biologic therapy.
RESUMO CONTEÚDO: Doença de Crohn e retocolite ulcerativa são doenças inflamatórias intestinais crônicas. Nelas, ocorre aumento da produção de fator de necrose tumoral alfa (TNF-α). Pacientes que falham no tratamento convencional imunossupressor, requerem uso de terapia imunobiológica, que são anticorpos monoclonais, principalmente os anti-TNF-α. O infliximabe é uma droga anti-TNF-α, uma imunoglobulina quimérica, com componente murino. Este é responsável pela imunogenicidade da droga e a formação de anticorpos. Presença de anticorpos antidroga pode ser responsável pelos eventos adversos e redução da eficácia da droga. Pacientes com doenças inflamatórias intestinais, em terapia imunossupressora com medicação biológica como o infliximabe, podem ter recaída da doença e muitas vezes isso não se relaciona com a sintomatologia do paciente. Por isso há a necessidade de um método de avaliação do efeito da droga como a dosagem do nivel sérico do infliximabe, bem como da pesquisa de anticorpos. OBJETIVO: O estudo tem como objetivo conhecer os níveis séricos do infliximabe e dos anticorpos anti-infliximabe em pacientes com doença inflamatória intestinal em terapia de manutenção ou pós-indução e descrever as condutas terapêuticas que foram modificadas em função dos níveis séricos de infliximabe e anticorpos para infliximabe. MÉTODOS: Trata-se de estudo restrospectivo, com análise da dosagem dos níveis séricos de infliximabe e anticorpos para Infliximabe. Foram incluídos 45 pacientes, num total de 63 coletas de dosagem de infliximabe. RESULTADOS: Vinte e um paciente estavam com o nível sérico de infliximabe adequado, níveis subterapêuticos em 31 pacientes e níveis supraterapêuticos em 11 pacientes. Sete pacientes tiveram a medicação suspensa por falha terapêutica ou altos níveis de anticorpos para infliximabe. CONCLUSÃO: Apenas um terço dos pacientes apresentavam níveis adequados de infliximabe e 36% dos pacientes apresentavam níveis subterapêuticos ao término da indução. Em cerca de 46% das amostras a conduta adotada se baseou nos níveis de infliximabe e anticorpos para infliximabe demonstrando a importância de se ter esta ferramenta para auxílio no manejo clínico dos pacientes portadores de doenças inflamatórias intestinais em terapia biológica.