To Örebro University

BACKGROUND AND AIMS: The diagnostic and prognostic properties of anti-integrin αvβ6 IgG autoantibodies in ulcerative colitis (UC) are poorly understood. We aimed to assess the diagnostic performance of anti-integrin αvβ6 autoantibodies and examine their association with disease outcomes.

METHODS: Serum samples from a Swedish inception cohort of patients with suspected inflammatory bowel disease (IBD, n=473) were analysed using an in-house fluorescence enzyme immunoassay based on EliA™technology. Findings were validated in a Norwegian population-based inception cohort (n=570). Diagnostic performance was assessed by calculating the area under the curve (AUC) with 95% confidence intervals (CIs) and determining sensitivity and specificity. Reclassification was evaluated using the net reclassification index.

RESULTS: In the discovery cohort, patients with UC, IBD-unclassified, or colonic Crohn's disease exhibited higher median autoantibody levels compared to symptomatic and healthy controls. In the validation cohort, the autoantibody demonstrated 79% sensitivity and 94% specificity for UC vs symptomatic controls at a cut-off of 400 UA/l. Its diagnostic performance (AUC=0.92, 95%CI 0.89-0.95) was superior to hs-CRP (AUC=0.65, 95%CI 0.60-0.70, P<0.001) and faecal calprotectin (fcalpro) (AUC=0.88, 95%CI 0.84-0.92, P=0.09). Combining the autoantibody with fcalpro further improved diagnostic accuracy (AUC=0.97, 95%CI 0.95-0.98) and patient reclassification (P<0.001). Autoantibody positivity was associated with a severe phenotype of UC, characterised by increased inflammatory activity and higher IL-17A and granzyme B levels. Higher autoantibody levels were linked to an aggressive disease course, remaining stable in aggressive UC but decreasing in indolent disease (P=0.003).

CONCLUSIONS: Anti-integrin αvβ6 is a reliable diagnostic and prognostic marker for UC, with potential clinical implementation.

BACKGROUND: Recent genetic and transcriptomic data highlight the need for improved molecular characterisation of inflammatory bowel disease (IBD). Proteomics may advance the delineation of IBD phenotypes since it accounts for post-transcriptional modifications. AIM: We aimed to assess the IBD spectrum based on inflammatory serum proteins and identify discriminative patterns of underlying biological subtypes across multiple European cohorts.

METHODS: Using proximity extension methodology, we measured 86 inflammation-related serum proteins in 1551 IBD patients and 312 healthy controls (HC). We screened for proteins exhibiting significantly different levels among IBD subtypes and between IBD and HC. Classification models for differentiating between Crohn's disease (CD) and ulcerative colitis (UC) were employed to explore the IBD spectrum based on estimated probability scores.

RESULTS: Levels of multiple proteins, such as IL-17A, MMP-10, and FGF-19, differed (fold-change>1.2; FDR<0.05) between ileal vs colonic IBD. Using multivariable models, a protein signature reflecting the IBD spectrum was identified, positioning colonic CD between UC and ileal CD, which were at opposite ends of the spectrum. Based on area under the curve (AUC) estimates, classification models more accurately differentiated UC from ileal CD (median AUCs>0.73) than colonic CD (median AUCs<0.62). Models differentiating colonic CD from ileal CD demonstrated intermediate performance (median AUCs 0.67-0.69).

CONCLUSION: Our findings in serum proteins support the presence of a continuous IBD spectrum rather than a clear separation of CD and UC. Within the spectrum, disease location may reflect a more similar disease than CD vs UC, as colonic CD resembled UC more closely than ileal CD.

Purpose: There is a need for diagnostic and prognostic biosignatures to improve long-term outcomes in inflammatory bowel disease (IBD). Here, we describe the establishment of the Swedish Inception Cohort in IBD (SIC-IBD) and demonstrate its potential for the identification of such signatures.

Participants: Patients aged >= 18 years with gastrointestinal symptoms who were referred to the gastroenterology unit due to suspected IBD at eight Swedish hospitals between November 2011 and March 2021 were eligible for inclusion.

Findings to date: In total, 367 patients with IBD (Crohn's disease, n=142; ulcerative colitis, n=201; IBD-unclassified, n=24) and 168 symptomatic controls were included. In addition, 59 healthy controls without gastrointestinal symptoms were recruited as a second control group. Biospecimens and clinical data were collected at inclusion and in patients with IBD also during follow-up to 10 years. Levels of faecal calprotectin and high-sensitivity C-reactive protein were higher in patients with IBD compared with symptomatic controls and healthy controls. Preliminary results highlight the potential of serum protein signatures and autoantibodies, as well as results from faecal markers, to differentiate between IBD and symptomatic controls in the cohort. During the first year of follow-up, 37% (53/142) of the patients with Crohn's disease, 24% (48/201) with ulcerative colitis and 4% (1/24) with IBD-U experienced an aggressive disease course.

Future plans: We have established an inception cohort enabling ongoing initiatives to collect and generate clinical data and multi-omics datasets. The cohort will allow analyses for translation into candidate biosignatures to support clinical decision-making in IBD. Additionally, the data will provide insights into mechanisms of disease pathogenesis.

Background: Inter-individual differences in drug clearance are common in inflammatory bowel disease (IBD) patients treated with biologics. Associations between inflammatory markers, clinical features, and drug levels may indicate that the inflammatory immune response influences the pharmacokinetics of biologics. We assessed the impact of inflammatory and immunity-related proteins on drug levels in IBD.

Methods: Serum samples from 144 IBD patients initiating biologics in a prospective multicentre cohort were analysed using AFIAS-3 (Boditech Med Inc. Korea). The primary outcome was drug levels after the end of induction treatment (post-induction), analysed as continuous variables or categorised into high or low groups based on the median. Correlations were assessed using the Pearson’s correlation coefficients with false discovery rate (FDR) adjustment. Predictive capacity of clinical and protein data was evaluated with regularised linear regression models. Analyses were stratified by treatment (infliximab, adalimumab, vedolizumab) and diagnosis (Crohn’s disease (CD), ulcerative colitis (UC)).

Results: Patient demographics and clinical characteristics are provided in Table 1. Median (interquartile range, IQR) post-induction infliximab levels were 5.3 (2.2-9.5) μg/ml in patients with CD (n=34) and 3.8 (1.7-5.6) μg/ml in UC (n=33). The corresponding levels were 12.5 (7.0-16.1) μg/ml (n=36) and 8.8 (5.7-12.7) μg/ml (n=13) for adalimumab, 13.9 (6.4-24.4) μg/ml (n=19) and 17.7 (9.8-22.6) μg/ml (n=9) for vedolizumab. Principal component analyses revealed potential baseline protein profile differences between patients with high vs low post-induction levels for infliximab (p=0.09) and adalimumab (p=0.07) in CD, but no differences for vedolizumab (p=0.78) or UC. Individual protein analyses indicated that patients with higher drug levels post-induction seemed to display lower baseline estimates of inflammatory proteins compared to those with lower drug levels. However, statistical significance after correction for multiple comparisons was only observed for CDCP1 in adalimumab-treated CD patients (PFDR=0.04) (Figure 1). Additionally, baseline Flt31 (r=-0.57, PFDR=0.03) and Wisp1 (r=-0.61, PFDR=0.02) correlated with post-induction s-adali-mumab levels in CD, while Mcp3 (r=-0.89, PFDR=0.04) and Frgamma (r=-0.87, PFDR=0.05) correlated in UC. Integrating baseline protein data in prediction models for post-induction drug levels did not improve their accuracy compared to models based on only clinical and biochemical variables.

Conclusion: Inflammatory protein levels may influence post-induction drug levels in IBD, particularly in adalimumab treated CD patients. This insight could aid in optimising personalised treatment.

The prospective Kiel Inflammatory Bowel Disease (IBD) Family Cohort Study (KINDRED cohort) was initiated in 2013 to systematically and extensively collect data and biosamples from index IBD patients and their relatives, a population at high risk for IBD development. Regular follow-ups were conducted to collect updated health and lifestyle information, to obtain new biosamples, and to capture the incidence of IBD during development. By combining microbial data collected at successive time points with extensive anthropometric, medical, nutritional, and social information, this study aimed to characterize the factors influencing the microbiota in health and disease via detailed ecological analyses. Using a microbial dysbiosis metric based on the German KINDRED cohort, we identified strong and generalizable gradients within and across different external IBD cohorts for validation. These community gradients correspond strongly with IBD pathologies, physiological manifestations of inflammation (e.g. Bristol stool score, ASCA IgA, ASCA IgG), and genetic risk for IBD. Anthropometric and medical factors influencing fecal transit time strongly modify bacterial communities. Various Enterobacteriaceae (e.g. Klebsiella sp.) and opportunistic Clostridia pathogens (e.g. C. XIVa clostridioforme), characterize in combination with ectopically colonizing oral taxa (e.g. Veillonella sp. Cand. Saccharibacteria sp. Fusobacterium nucleatum) the distinct and chaotic IBD-specific communities. Weak community and physiological changes are further traceable in a small number of individuals, who developed IBD in the study's runtime. Our findings demonstrate broad-scale ecological patterns which indicate drastic state transitions of communities in IBD patients. These patterns appear to be universal across cohorts and influence physiological signs of inflammation, display increased resilience, but show only limited heritability/intrafamily transmission.

BACKGROUND: For unidentified reasons, possibly due to increased immune surveillance, patients with collagenous colitis (CC) and lymphocytic colitis (LC), both forms of microscopic colitis (MC), have lower risk of colorectal cancer than controls and ulcerative colitis (UC) patients. Levels of secreted and cell-bound mediators in MC patients with active disease and in histological remission (HR) compared to UC patients and controls were investigated.

METHODS: Median fluorescence intensity of 54 analytes in colonic biopsies from patients with active CC (n = 21), LC (n = 11), and UC (n = 19); CC-HR (n = 6), LC-HR (n = 9), UC in remission (n = 19), non-diarrhea controls (n = 48), and diarrhea controls (n = 25) was measured using Luminex.

RESULTS: Granzyme B and CCL5 levels were higher in active CC than in UC, whereas CCL4 and CD163 levels were similar in CC and UC, and both groups had higher levels of matrix metalloproteinase (MMP)-1, MMP-3, and tumor necrosis factor receptor II than both control groups. APRIL, BAFF, BCMA, CCL20, CXCL8, chitinase 3-like 1, pentraxin-3, Fas, and IL-33 were higher in UC than MC. Increases in 4-1BB and perforin in MC compared to controls were lower than in UC. Levels of gp130 and IL-6Rα were decreased in MC but increased in UC compared to controls.

CONCLUSIONS: Microscopic colitis patients exhibit increased levels of several analytes, including some associated with CD8+ T lymphocytes, suggesting a different pathogenesis of MC compared to UC. Higher levels of MMP-1 and MMP-3 in CC than LC indicate separate disease entities.

BACKGROUND AND AIMS: Biomarkers are needed to identify individuals at elevated risk of inflammatory bowel disease (IBD). This study aims to identify protein signatures predictive of IBD.

METHODS: Using large population-based cohorts (n≥180,000), blood samples were obtained from individuals who later in life were diagnosed with IBD and compared to age and sex-matched controls, free from IBD during follow-up. 178 proteins were measured on Olink platforms. We used machine learning methods to identify protein signatures of preclinical disease in the discovery cohort (n=312). Their performance was validated in an external preclinical cohort (n=222) and assessed in an inception cohort (n=144) and a preclinical twin cohort (n=102).

RESULTS: In the discovery cohort, a signature of 29 proteins differentiated preclinical Crohn's disease (CD) cases from controls, with an area under the curve (AUC) of 0.85. Its performance was confirmed in the preclinical validation (AUC=0.87) and the inception cohort (AUC=1.0). In preclinical samples, downregulated (but not upregulated) proteins related to gut barrier integrity and macrophage functionality correlated with time to diagnosis of CD. The preclinical ulcerative colitis (UC) signature had a significant, albeit lower, predictive ability in the discovery (AUC=0.77), validation (AUC=0.67), and inception cohorts (AUC=0.95). The preclinical signature for CD demonstrated an AUC of 0.89 when comparing twins with preclinical CD to matched external healthy twins, but its predictive ability was lower (AUC=0.58; P=.04) when comparing them with their healthy twin siblings, i.e., when accounting for genetic and shared environmental factors.

CONCLUSION: We identified protein signatures for predicting a future diagnosis of CD and UC, validated across independent cohorts. In the context of CD, the signature offers potential for early prediction.

Background: Mental health (MH) has been reported to be poorer among patients with inflammatory bowel disease (IBD) than general population. However, it is not known whether MH is more driven by inflammation itself or related to gastrointestinal (GI) symptoms. Also, the dynamics of MH following IBD diagnosis is not well understood.

Methods: In the Swedish Inception Cohort of IBD (SIC-IBD), patients with Crohn’s disease (CD), ulcerative colitis (UC) and unclassified IBD (IBD-U) as well as symptomatic controls (SC) and healthy controls (HC) filled in Patient Health Questionnaire-9 (PHQ-9), a validated screening tool for depression. Patients completed PHQ-9 at diagnosis and at one year follow-up while the controls completed it once. Disease outcome was defined at one year based on requirement of advanced treatments/ surgery.

Results: In total, 286 individuals (16 HC, 89 SC, 62 CD, 104 UC, 15 IBD-U) completed the questionnaire at baseline. HC had significantly lower PHQ-9 score, (fewer depressive symptoms), at baseline compared to all the other groups (p<0.01). The baseline PHQ-9 score was not significantly different between SC and CD, UC and IBD-U patients (p=0.06).

At one year follow-up, 38 CD and 53 UC patients completed the PHQ-9. Between baseline and follow-up, UC patients had a significant drop in their PHQ-9 score (p<0.0000001), whereas CD patients did not have any significant change in their PHQ-9 score (p=0.06). Furthermore, UC patients had significantly lower PHQ-9 score compared with CD patients at follow-up (p=0.04, Figure 1).

Baseline PHQ-9 score was not correlated with calprotectin at baseline neither in UC nor CD patients (p=0.7 and 0.5 respectively). Also, there was no positive correlation between PHQ-9 score change and calprotectin change in either UC or CD patients, and neither baseline nor follow-up PHQ-9 scores were significantly different in patients with poor or good outcome (p>0.05). When analysed separately by sex, there was still no correlation between baseline PHQ-9 score and outcome in neither CD nor UC patients (p>0.05)

Conclusion: IBD patients have at the time of diagnosis more depressive symptoms than HC, but not different from SC. Depressive symptoms are more related to GI symptoms than IBD specific inflammation or disease outcome. UC patients show more of an improvement in their depressive symptoms one year after diagnosis than CD patients.

BACKGROUND: Sepsis is defined as a dysfunctional host response to infection. The diverse clinical presentations of sepsis pose diagnostic challenges and there is a demand for enhanced diagnostic markers for sepsis as well as an understanding of the underlying pathological mechanisms involved in sepsis. From this perspective, metabolomics has emerged as a potentially valuable tool for aiding in the early identification of sepsis that could highlight key metabolic pathways and underlying pathological mechanisms.

OBJECTIVE: The aim of this investigation is to explore the early metabolomic and lipidomic profiles in a prospective cohort where plasma samples (n = 138) were obtained during ambulance transport among patients with infection according to clinical judgement who subsequently developed sepsis, patients who developed non-septic infection, and symptomatic controls without an infection.

METHODS: Multiplatform metabolomics and lipidomics were performed using UHPLC-MS/MS and UHPLC-QTOFMS. Uni- and multivariable analysis were used to identify metabolite profiles in sepsis vs symptomatic control and sepsis vs non-septic infection.

RESULTS: Univariable analysis disclosed that out of the 457 annotated metabolites measured across three different platforms, 23 polar, 27 semipolar metabolites and 133 molecular lipids exhibited significant differences between patients who developed sepsis and symptomatic controls following correction for multiple testing. Furthermore, 84 metabolites remained significantly different between sepsis and symptomatic controls following adjustment for age, sex, and Charlson comorbidity score. Notably, no significant differences were identified in metabolites levels when comparing patients with sepsis and non-septic infection in univariable and multivariable analyses.

CONCLUSION: Overall, we found that the metabolome, including the lipidome, was decreased in patients experiencing infection and sepsis, with no significant differences between the two conditions. This finding indicates that the observed metabolic profiles are shared between both infection and sepsis, rather than being exclusive to sepsis alone.

Background: Faecal biomarkers can be used to assess inflammatory bowel disease (IBD).

Aim: To explore the performance of some promising biomarkers in diagnosing and predicting disease course in IBD.

Methods: We included 65 patients with treatment-na & iuml;ve, new-onset Crohn's disease (CD), 90 with ulcerative colitis (UC), 67 symptomatic controls (SC) and 41 healthy controls (HC) in this prospective observational study. We analysed faecal samples for calprotectin (FC), myeloperoxidase (MPO), human neutrophil lipocalin (HNL), eosinophil cationic protein ECP and eosinophil-derived neurotoxin (EDN) and compared markers among groups. We assessed the diagnostic capability of biomarkers with receiver operating characteristic curves. Clinical disease course was determined for each patient with IBD and analysed the association with biomarkers by logistic regression.

Results: All markers were elevated at inclusion in patients with IBD compared with HC (p < 0.001) and SC (p < 0.001). FC (AUC 0.85, 95% CI: 0.79-0.89) and MPO (AUC 0.85, 95% CI: 0.80-0.89) showed the highest diagnostic accuracy in distinguishing IBD from SC. The diagnostic ability of biomarkers differed between IBD subtypes with the highest performance for FC and MPO in CD. The diagnostic accuracy was further improved by combining FC and MPO (p = 0.02). Levels of FC, MPO and HNL at inclusion were predictive of an aggressive disease course with MPO showing the strongest association (p = 0.006).

Conclusions: This study provides new insight into the diagnostic and prognostic capability of neutrophil and eosinophil biomarkers in IBD and suggests that MPO, alone or in combination with FC, may add to the diagnostic power of faecal biomarkers.