Normalization of Fecal Calprotectin Within 12 Months of Diagnosis Is Associated With Reduced Risk of Disease Progression in Patients With Crohn's Disease.

BACKGROUND & AIMS: The level of fecal calprotectin (FC) correlates with endoscopic evidence of inflammation in Crohn's disease (CD). A treat-to-target algorithm for patients with CD, that incorporates FC, outperforms a treatment strategy based on symptoms alone in the induction of mucosal healing at 12 months. We investigated whether normalization of FC within 12 months of diagnosis of CD is associated with a reduction in disease progression. METHODS: We performed a retrospective cohort study at a tertiary IBD centre in the United Kingdom. We identified all incident cases of CD diagnosed from 2005 through 2017. Patients with a FC measurement ≥250 µg/g at diagnosis who also had at least 1 follow-up FC measurement within the first 12 months of diagnosis and >12 months of follow up were included. The last FC measurement within 12 months of diagnosis was used to determine normalization (cut-off <250 µg/g). The primary endpoint was time to first disease progression (composite of progression in Montreal disease behavior B1 to B2/3, B2 to B3, or new perianal disease; CD-related surgery; or CD-related hospitalization). Cox proportional hazards regression analysis was used to determine independent factors associated with time to first disease progression. RESULTS: A total of 375 patients out of 1389 incident cases were included, with a median follow up of 5.3 years (interquartile range, 3.1-7.4 years). Normalization of FC within 12 months of diagnosis was confirmed in 43.5% of patients. Patients with normalized levels of FC had a significantly lower risk of composite disease progression (hazard ratio [HR], 0.36; 95% CI, 0.24-0.53; P < .001). They also had a lower risk of reaching any of the separate progression endpoints (progression in Montreal behavior or new perianal disease HR, 0.22; 95% CI, 0.11-0.45; P < .001; hospitalization HR, 0.33; 95% CI, 0.21-0.53; P <.001; surgery HR, 0.39; 95% CI, 0.19-0.78; P = .008) CONCLUSIONS: Normalization of FC within 12 months of diagnosis is associated with a reduced risk of progression of CD.

Impact of routine clinic measurement of serum C-peptide in people with a clinician-diagnosis of type 1 diabetes.

AIMS/HYPOTHESIS: The aim of this study was to determine the impact of the routine use of serum C-peptide in an out-patient clinic setting on individuals with a clinician-diagnosis of type 1 diabetes. METHODS: In this single-centre study, individuals with type 1 diabetes of at least 3 years duration were offered random serum C-peptide testing at routine clinic review. A C-peptide ≥200 pmol/L prompted further evaluation of the individual using a diagnostic algorithm that included measurement of islet cell antibodies and genetic testing. Where appropriate, a trial of anti-diabetic co-therapies was considered. RESULTS: Serum C-peptide testing was performed in 859 individuals (90% of the eligible cohort), of whom 114 (13.2%) had C-peptide ≥200 pmol/L. The cause of diabetes was reclassified in 58 individuals (6.8% of the tested cohort). The majority of reclassifications were to type 2 diabetes (44 individuals; 5.1%), with a smaller proportion of monogenic diabetes (14 individuals; 1.6%). Overall, 13 individuals (1.5%) successfully discontinued insulin, while a further 16 individuals (1.9%) had improved glycaemic control following the addition of co-therapies. The estimated total cost of the testing programme was £23,262 (~€26,053), that is, £27 (~€30) per individual tested. In current terms, the cost of prior insulin therapy in the individuals with monogenic diabetes who successfully stopped insulin was approximately £57,000 (~€64,000). CONCLUSIONS/INTERPRETATION: Serum C-peptide testing can easily be incorporated into an out-patient clinic setting and could be a cost-effective intervention. C-peptide testing should be strongly considered in individuals with a clinician-diagnosis of type 1 diabetes of at least 3 years duration.

Short-term outcomes of a COVID-adapted triage pathway for colorectal cancer detection.

AIM: The dramatic curtailment of endoscopy and CT colonography capacity during the coronavirus pandemic has adversely impacted timely diagnosis of colorectal cancer (CRC). We describe a rapidly implemented COVID-adapted diagnostic pathway to mitigate risk and maximize cancer diagnosis in patients referred with symptoms of suspected CRC. METHOD: The 'COVID-adapted pathway' integrated multiple quantitative faecal immunochemical tests (qFIT) to enrich for significant colorectal disease with judicious use of CT with oral contrast to detect gross pathology. Patients reporting 'high-risk' symptoms were triaged to qFIT+CT and the remainder underwent an initial qFIT to inform subsequent investigation. Demographic and clinical data were prospectively collected. Outcomes comprised cancer detection frequency. RESULTS: Overall, 422 patients (median age 64 years, 220 women) were triaged using this pathway. Most (84.6%) were referred as 'urgent suspicious of cancer'. Of the 422 patients, 202 (47.9%) were triaged to CT and qFIT, 211 (50.0%) to qFIT only, eight (1.9%) to outpatient clinic and one to colonoscopy. Fifteen (3.6%) declined investigation and seven (1.7%) were deemed unfit. We detected 13 cancers (3.1%), similar to the mean cancer detection rate from all referrals in 2017-2019 (3.3%). Compared with the period 1 April-31 May in 2017-2019, we observed a 43% reduction in all primary care referrals (1071 referrals expected reducing to 609). CONCLUSION: This COVID-adapted pathway mitigated the adverse effects on diagnostic capacity and detected cancer at the expected rate within those referred. However, the overall reduction in the number of referrals was substantial. The described risk-mitigating measures could be a useful adjunct whilst standard diagnostic services remain constrained due to the ongoing pandemic.

Implementation of CT-P13 via a Managed Switch Programme in Crohn's Disease: 12-Month Real-World Outcomes.

BACKGROUND: Switching from Remicade to CT-P13 allows for significant cost savings and has been shown to be non-inferior to continued therapy with Remicade for the treatment of Crohn's disease. AIM: The aim of this work was to prospectively evaluate clinical outcomes in a cohort of patients with Crohn's disease switching from Remicade to CT-P13. METHODS: A prospective service evaluation was performed. The Harvey-Bradshaw index, CRP, faecal calprotectin and serum for infliximab/antibody levels were collected prior to patients' final Remicade infusion and at 6 and 12 months after switching to CT-P13 as part of routine clinical care. All adverse events during follow-up were also recorded. RESULTS: One hundred and ten patients on Remicade switched to CT-P13. No significant difference was observed between the Harvey-Bradshaw Index (p = 0.07), CRP (p = 0.13), faecal calprotectin (p = 0.25) or trough infliximab levels (p = 0.47) comparing before and at 6 and 12 months after the switch to CT-P13. Seven patients developed new infliximab antibodies after switching from Remicade to CT-P13. The majority of patients remained on CT-P13 at 12 months (84.5%) and the rate of adverse events and serious adverse events was 53.8 and 13.5 per 100 patient-years of follow-up, respectively. Switching to CT-P13 resulted in a cost saving of approximately 46.4%. CONCLUSION: The transition to CT-P13 from Remicade for the treatment of Crohn's disease is safe and has no negative effect on clinical outcomes at 12 months.

Serum Calprotectin: A Novel Diagnostic and Prognostic Marker in Inflammatory Bowel Diseases.

OBJECTIVES: There is an unmet need for novel blood-based biomarkers that offer timely and accurate diagnostic and prognostic testing in inflammatory bowel diseases (IBD). We aimed to investigate the diagnostic and prognostic utility of serum calprotectin (SC) in IBD. METHODS: A total of 171 patients (n=96 IBD, n=75 non-IBD) were prospectively recruited. A multi-biomarker model was derived using multivariable logistic regression analysis. Cox proportional hazards model was derived to assess the contribution of each variable to disease outcomes. RESULTS: SC correlated strongly with current biomarkers, including fecal calprotectin (FC) (n=50, ρ=0.50, P=1.6 × 10-4). SC was the strongest individual predictor of IBD diagnosis (odds ratio (OR): 9.37 (95% confidence interval (CI): 2.82-34.68), P=4.00 × 10-4) compared with other markers (C-reactive protein (CRP): OR 8.52 (95% CI: 2.75-28.63), P=2.80 × 10-4); albumin: OR 6.12 (95% CI: 1.82-22.16), P=0.004). In a subset of 50 patients with paired SC and FC, the area under receiver operating characteristic discriminating IBD from controls was better for FC than for SC (0.99, (95% CI 0.87-1.00) and 0.87 (95% CI:0.78-0.97), respectively; P=0.01). At follow-up (median 342 days; interquartile range: 88-563), SC predicted treatment escalation and/or surgery in IBD (hazard ratio (HR) 2.7, 95% CI: 1.1-4.9), in particular Crohn's disease (CD) (HR 4.2, 95% CI 1.2-15.3). A model incorporating SC and either CRP or albumin has a positive likelihood ratio of 24.14 for IBD. At 1 year, our prognostic model can predict treatment escalation in IBD in 65% of cases (95% CI: 43-79%) and 80% (95% CI: 31-94%) in CD if ≥2 blood marker criteria are met. CONCLUSIONS: A diagnostic and prognostic model that combines SC and other blood-based biomarkers accurately predicts the inflammatory burden in IBD and has the potential to predict disease and its outcomes. Our data warrant further detailed exploration and validation in large multicenter cohorts.

Stability of maternal serum free ß-hCG following whole blood sample transit: First trimester Down's syndrome screening in Scotland.

BACKGROUND: Maternal serum free beta human chorionic gonadotrophin (free ß-hCG) is used as a biomarker in first trimester screening for fetal Down's syndrome. Production of free ß-hCG can occur in vitro in a time- and temperature-dependent manner; thus, the current Scottish screening protocol states samples must be received by the laboratory within 72 h. To assess the validity of the protocol, an audit was conducted to determine the impact of transit time on maternal serum free ß-hCG multiple of median (MoM) values in the Scottish screened population. METHODS: Corrected MoM values from antenatal screening carried out over one year (April 2017 to March 2018) were stratified according to sample transit time and compared. To investigate possible environmental temperature effects, the data were split according to season and maternal serum free ß-hCG concentrations from summer and winter compared. RESULTS: Of the 28,368 samples included in the study, 24,368 were received on the day of phlebotomy or after one day in transit. Only 1.5% of samples were received after 3 days in transit. The difference in maternal serum free ß-hCG MoM values due to transit time was not significant. No statistical difference was found between maternal serum free ß-hCG concentrations from samples collected in summer and winter months. CONCLUSION: The current sample receipt protocol in use by the Scottish Down's syndrome screening programme is fit for purpose.

Association of trough vedolizumab levels with clinical, biological and endoscopic outcomes during maintenance therapy in inflammatory bowel disease.

OBJECTIVE: To establish the relationship between trough vedolizumab levels and outcomes during maintenance therapy. DESIGN: Cross-sectional service evaluation was performed on patients with inflammatory bowel disease (IBD) receiving maintenance vedolizumab therapy (minimum of 12 weeks following induction). Prior to infusion, data on clinical activity (Harvey-Bradshaw Index or partial Mayo score), trough C-reactive protein (CRP)/vedolizumab levels and faecal calprotectin were collected. Endoscopic data (±8 weeks from vedolizumab level testing) were obtained by review of medical records. Vedolizumab levels were processed using the Immundiagnostik monitor ELISA. SETTING: The Edinburgh IBD Unit, Western General Hospital (tertiary IBD referral centre). PATIENTS: Seventy-three patients (30 ulcerative colitis and 43 Crohn's disease) were identified who fulfilled inclusion criteria and had vedolizumab levels matched with clinical activity scores, CRP and faecal calprotectin. Of these, 40 patients also had matched endoscopic data. MAIN OUTCOME MEASURES: The association of trough vedolizumab levels with clinical remission (Harvey-Bradshaw Index <5 or partial Mayo <2), biologic remission (faecal calprotectin <250 µg/g+CRP <5 mg/L) and endoscopic remission (Mayo score 0/no inflammation and ulceration on colonoscopy). RESULTS: The median trough vedolizumab levels were similar between patients in and not in clinical remission (10.6 vs 9.9 µg/mL, p=0.54); biologic remission (10.6 vs 9.8 µg/mL, p=0.35) and endoscopic remission (8.1 vs 10.2 µg/mL, p=0.21). Quartile analysis revealed no significant increase in the proportion of patients in clinical remission, biologic remission or endoscopic remission with increasing trough vedolizumab levels (p<0.05). CONCLUSIONS: In this cohort, trough vedolizumab levels were not associated with clinical, biological or endoscopic outcomes during maintenance therapy.

Higher Adalimumab Drug Levels During Maintenance Therapy for Crohn's Disease Are Associated With Biologic Remission.

BACKGROUND: Adalimumab is an established treatment for Crohn's disease. Limited data are available regarding the relationship between adalimumab drug levels and serum/fecal markers of gut inflammation. We therefore aimed to characterize the relationship between adalimumab levels and biologic remission during maintenance therapy. METHODS: A single-center prospective cross-sectional study was undertaken on Crohn's disease patients who had received adalimumab therapy for a minimum of 12 weeks after induction. Data on clinical activity (Harvey-Bradshaw Index), C-reactive protein (CRP), adalimumab drug and antibody levels, and fecal calprotectin were collected. Biologic remission was defined as a CRP <5 mg/L and fecal calprotectin <250 µg/g. Adalimumab drug and antibody levels were processed using the Immundiagnostik monitor enzyme-linked immunosorbent assay. RESULTS: One hundred fifty-two patients had drug and antibody samples matched with CRP and fecal calprotectin. Patients in biologic remission had significantly higher adalimumab levels compared with others (12.0 µg/mL vs 8.0 µg/mL, P < 0.0001). Receiver operating characteristic curve analysis demonstrated an optimal adalimumab level of >8.5 µg/mL (sensitivity, 82.2%; specificity, 55.7%; likelihood ratio, 1.9) for predicting biologic remission. Multivariable logistic regression revealed that adalimumab levels >8.5 µg/mL were independently associated with biologic remission (odds ratio, 5.27; 95% confidence interval, 2.43-11.44; P < 0.0001). CONCLUSIONS: Higher adalimumab levels are associated with biologic remission. An optimal level of >8.5 µg/mL was identified.

Serum free light chains; the need to establish local reference intervals.

BACKGROUND: The purpose of this study was to compare The Binding Site serum free light chain assay on two analytical platforms; the Dade Behring BNII and the Olympus AU400. Reference intervals were subsequently established on each analyser. METHODS: In total, 112 serum samples routinely submitted to the laboratory for protein electrophoresis were used for the comparison study. Reference interval data was generated from 126 ostensibly healthy anonymous individuals. RESULTS: Serum free light chain results on the BNII and AU400 analysers are not directly comparable. The BNII produces results which are significantly higher than the AU400. CONCLUSIONS: Laboratories using The Binding Site serum free light chain assay are strongly advised to establish local reference intervals.

The value of serum free light chains in a case of Waldenstrom's macroglobulinaemia that produces a type I cryoglobulinaemia.

Lymphoplasmacytic lymphoma (Waldenstrom's macroglobulinaemia) is a low-grade small-cell lymphoma that produces monoclonal IgM. Usually, clinical features are related to growth of the tumour and include weakness and fatigue, an increased bleeding tendency, and neurological and visual disturbances. We present a case of lymphoplasmacytic lymphoma with type I cryoglobulinaemia that presented with clinical symptoms associated with hyperviscosity syndrome. Quantitation of the paraprotein was not possible using conventional serum protein electrophoresis due to the high serum viscosity, and therefore monitoring was carried out using serial serum free light chain measurements.

Crystallization of the oligopeptide-binding protein AppA from Bacillus subtilis.

AppA is the membrane-anchored extracellular receptor component of an ABC transporter responsible for the uptake of oligopeptides into Bacillus subtilis. AppA has been overexpressed as a cleavable maltose-binding protein fusion in Escherichia coli. Following removal of the fusion portion, AppA has been crystallized from morpholinoethanesulfonic acid-buffered solutions at pH 6.5 containing polyethylene glycol and zinc acetate. A complete X-ray diffraction data set extending to 2.3 A spacing has been collected.