Comparative study of a point-of-care test and an enzyme-linked immunosorbent assay (ELISA) for infliximab levels.

BACKGROUND: Proactive therapeutic drug monitoring (TDM) is often challenged by long turnaround time when using enzyme-linked immunosorbent assays (ELISAs), especially when analyses are centralised. Point-of-care tests (POCTs) allow rapid assessments, but data on their agreement with existing in-house methodologies are scarce. OBJECTIVE: To examine the agreement between a POCT by ProciseDx (San Diego, CA) and the most frequently used in-house ELISA for infliximab (IFX) quantification in Sweden. METHODS: Serum samples were analysed using the in-house ELISA, Karolinska University Hospital, Stockholm, Sweden and a POCT by ProciseDx (San Diego, CA). Agreement was assessed and differences were examined. RESULTS: Samples from 61 inflammatory bowel disease (IBD) patients were analysed with a median IFX concentration of 7.9 µg/mL (interquartile range (IQR) 5.5-13) for the POCT and 7.9 µg/mL (IQR 5.2-12) for the ELISA (Pearson's correlation coefficient = 0.95 (95% CI 0.92-0.97, p < .01)). A Passing-Bablok regression yielded an intercept of -0.44 and a slope of 1.09. The Bland-Altman plot showed a systemic bias of -0.77 µg/mL (95% CI -0.18 to -1.4) between the methods. The upper limit of agreement was 3.7 (95% CI 2.7-4.8) (µg/mL), whereas the lower limit agreement was -5.3 (95% CI -6.3 to -4.3) (µg/mL). An excellent reliability was observed, intraclass correlation showed = 0.94 (95% CI 0.89-0.96, p < .0001). When defining IFX concentration as subtherapeutic (<3.0 µg/mL), therapeutic (3.0-7.0 µg/mL) or supratherapeutic (>7.0 µg/mL) drug levels, Kappa statistics showed a substantial agreement (0.79). CONCLUSIONS: The POCT by ProciseDx (San Diego, CA) demonstrated a good agreement with the in-house ELISA, supporting its use for rapid IFX quantification.

Long-term outcomes of vedolizumab in inflammatory bowel disease: the Swedish prospective multicentre SVEAH extension study.

Background: Real-world data on long-term outcomes of vedolizumab (VDZ) are scarce. Objective: To assess long-term outcomes (up to 3 years) of VDZ in treating inflammatory bowel disease (IBD). Design: A nationwide, prospective multicentre extension of a Swedish observational study on VDZ assessing Effectiveness And Healthcare resource utilization in patients with IBD (SVEAH). Methods: After re-consent, data of patients with Crohn's disease (CD) (n = 68) and ulcerative colitis (UC) (n = 46) treated with VDZ were prospectively recorded using an electronic case report form integrated with the Swedish IBD Register (SWIBREG). The primary outcome was clinical remission (defined as Harvey-Bradshaw Index ⩽4 in CD and partial Mayo score ⩽2 in UC) at 104 and 156 weeks in patients with a response and/or remission 12 weeks after starting VDZ. Secondary outcomes included health-related quality of life (HRQoL) and biochemical outcomes. Results: VDZ continuation rates were high at weeks 104 and 156, 88% and 84%, respectively, for CD and 87% and 78%, respectively, for UC. Of the 53 CD patients with a response/remission at 12 weeks, 40 (75%) patients were in remission at 104 weeks and 42 (79%) patients at 156 weeks. For UC, these numbers were 25/31 (81%) and 22/31 (71%), respectively. Improvements were seen in the Short Health Scale (p < 0.01 for each dimension; CD, n = 51; UC, n = 33) and the EuroQol 5-Dimensions, 5-levels index value (p < 0.01; CD, n = 39; UC, n = 30). Median plasma-C-reactive protein concentrations (mg/L) decreased from 5 at baseline to 4 in CD (p = 0.01, n = 53) and from 5 to 4 in UC (p = 0.03, n = 34) at 156 weeks. Correspondingly, median faecal-calprotectin (µg/g) decreased from 641 to 114 in CD patients (p < 0.01, n = 26) and from 387 to 37 in UC patients (p = 0.02, n = 17). Conclusion: VDZ demonstrated high continuation rates and was associated with improvements in clinical outcomes, HRQoL measures and inflammatory markers at 2 and 3 years after treatment initiation in this prospective national SVEAH extension study. Registration: ENCePP registration number: EUPAS22735.

The Risk of Serious Infections Before and After Anti-TNF Therapy in Inflammatory Bowel Disease: A Retrospective Cohort Study.

BACKGROUND: Serious infections have been observed in patients with inflammatory bowel disease (IBD) on anti-TNF use-but to what extent these infections are due to anti-TNF or the disease activity per se is hard to disentangle. We aimed to describe how the rates of serious infections change over time both before and after starting anti-TNF in IBD. METHODS: Inflammatory bowel disease patients naïve to anti-TNF treatment were identified at 5 centers participating in the Swedish IBD Quality Register, and their medical records examined in detail. Serious infections, defined as infections requiring in-patient care, the year before and after the start of anti-TNF treatment were evaluated. RESULTS: Among 980 patients who started their first anti-TNF therapy between 1999 and 2016, the incidence rate of serious infections was 2.19 (95% CI,1.43-3.36) per 100 person years the year before and 2.11 (95% CI, 1.33-3.34) per 100 person years 1 year after treatment start. This corresponded to an incidence rate ratio 1 year after anti-TNF treatment of 0.97 (95% CI, 0.51-1.84). Compared with before anti-TNF therapy, the incidence of serious infection was significantly decreased more than 1 year after treatment (incidence rate ratio 0.56; 95% CI, 0.33-0.95; P = .03). CONCLUSIONS: In routine clinical practice in Sweden, the incidence rate of serious infection among IBD patients did not increase with anti-TNF therapy. Instead, serious infections seemed to decrease more than 1 year after initiation of anti-TNF treatment.

The incidence rate of serious infection among inflammatory bowel disease patients did not increase with anti-TNF therapy compared with 1 year before treatment start. A decrease in incidence rate could be seen more than 1 year after initiation of anti-TNF.

Clinical effectiveness of golimumab in ulcerative colitis: a prospective multicentre study based on the Swedish IBD Quality Register, SWIBREG.

OBJECTIVES: Clinical trials demonstrated that golimumab is effective in anti-TNF naïve patients with ulcerative colitis. We aimed to assess the clinical effectiveness of golimumab in a real-world setting. MATERIALS AND METHODS: This was a prospective cohort study, conducted at 16 Swedish hospitals. Data were collected using an electronic case report form. Patients with active ulcerative colitis, defined as Mayo endoscopic subscore ≥2 were eligible for inclusion. The primary outcomes were clinical effectiveness at 12 weeks and 52 weeks, i.e. response (defined as a decrease in Mayo score by ≥3 points or 30% from baseline) and remission (defined as a Mayo score of ≤2 with no individual subscores >1). RESULTS: Fifty patients were included. At study entry, 70% were previously exposed to anti-TNF, 16% to vedolizumab, and 96% to immunomodulators. The 12 and 52-week drug continuation rates were 37/50 (74%) and 23/50 (46%), respectively. The 12-week response rate was 14/50 (28%), the remission rate, 8/50 (16%) and the corresponding figures at week 52 were 13/50 (26%) and 10/50 (20%). Among patients who continued golimumab, the median Mayo score decreased from 7 (6-9) at baseline to 1 (0-5) at 52 weeks (p < .01) and the faecal calprotectin decreased from 862 (335-1759) µg/g to 90 (34-169) µg/g (p < .01). Clinical response at week 12 was highly predictive of clinical remission at week 52 (adjusted OR: 73.1; 95% CI: 4.5‒1188.9). CONCLUSIONS: The majority of golimumab treated patients represented a treatment refractory patient-group. Despite this, our results confirm that golimumab is an effective therapy in ulcerative colitis.

Predictors of drug survival: A cohort study comparing anti-tumour necrosis factor agents using the Swedish inflammatory bowel disease quality register.

BACKGROUND: Whether long-term effectiveness differs between anti-tumour necrosis factor (anti-TNF) agents is unknown. AIMS: To examine drug survival of first-line anti-TNF agents and identify predictors of discontinuation. To reduce channelling bias, we also compared drug survival of the second anti-TNF. METHODS: Biologic-naïve patients (N = 955) recorded in the Swedish IBD Quality Register (SWIBREG) were examined. We used propensity score matching, comparing drug survival over up to three years of follow-up. Cox regression estimated adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs). RESULTS: In Crohn's disease, discontinuation because of lack/loss of response was 32% [95%CI = 26%-38%] for infliximab versus 16% [95%CI = 11%-21%] for adalimumab. Infliximab [vs adalimumab; aHR = 1.96; 95%CI = 1.20-3.21] and colonic disease (L2) [vs no L2; aHR = 2.17; 95% CI = 1.26-3.75] were associated with higher discontinuation rates, whereas normalised CRP at three months [aHR = 0.40; 95% CI = 0.19-0.81] with a lower rate. Consistently, patients who switched from adalimumab to infliximab (vs infliximab to adalimumab) had earlier discontinuation (P = 0.04). Concomitant use of immunomodulators was associated with a lower adverse drug reaction-mediated discontinuation rate [aHR = 0.46; 95% CI = 0.28-0.77], in part explained by fewer infusion reactions [aHR = 0.27; 95% CI = 0.08-0.89]. In ulcerative colitis, the probability of discontinuation because of lack/loss of response was 40% [95% CI = 33%-47%] for infliximab versus 37% [95% CI = 21%-53%] for adalimumab. Disease duration ≥10 years [aHR = 0.25; 95% CI = 0.10-0.58] and normalised CRP after three months [aHR = 0.39; 95% CI = 0.18-0.84] were associated with lower discontinuation rates. CONCLUSIONS: Clinical characterisation of patients may aid decision-making on anti-TNF treatment. The consistently shorter drug survival for infliximab (vs adalimumab) in Crohn's disease, suggests a potential difference between the two drugs.

The use of ICD codes to identify IBD subtypes and phenotypes of the Montreal classification in the Swedish National Patient Register.

Introduction: Whether data on International Classification of Diseases (ICD)-codes from the Swedish National Patient Register (NPR) correctly correspond to subtypes of inflammatory bowel disease (IBD) and phenotypes of the Montreal classification scheme among patients with prevalent disease is unknown.Materials and methods: We obtained information on IBD subtypes and phenotypes from the medical records of 1403 patients with known IBD who underwent biological treatment at ten Swedish hospitals and retrieved information on their IBD-associated diagnostic codes from the NPR. We used previously described algorithms to define IBD subtypes and phenotypes. Finally, we compared these register-generated subtypes and phenotypes with the corresponding information from the medical records and calculated positive predictive values (PPV) with 95% confidence intervals.Results: Among patients with clinically confirmed disease and diagnostic listings of IBD in the NPR (N = 1401), the PPV was 97 (96-99)% for Crohn's disease, 98 (97-100)% for ulcerative colitis, and 8 (4-11)% for IBD-unclassified. The overall accuracy for age at diagnosis was 95% (when defined as A1, A2, or A3). Examining the validity of codes representing disease phenotype, the PPV was 36 (32-40)% for colonic Crohn's disease (L2), 61 (56-65)% for non-stricturing/non-penetrating Crohn's disease behaviour (B1) and 83 (78-87)% for perianal disease. Correspondingly, the PPV was 80 (71-89)% for proctitis (E1)/left-sided colitis (E2) in ulcerative colitis.Conclusions: Among people with known IBD, the NPR is a reliable source of data to classify most subtypes of prevalent IBD, even though misclassification commonly occurred in Crohn's disease location and behaviour and also among IBD-unclassified patients.