Paulo Caldeira

Phenotype–genotype profiles in Crohn's disease predicted by genetic markers in autophagy‐related genes (GOIA study II)

Background:About 70 loci are associated with susceptibility to Crohns disease (CD), particularly in pathways of innate immunity, autophagy, and pathogen recognition. Phenotype–genotype associations are inconsistent. Methods:CD susceptibility polymorphisms ATG16L1 rs2241880, ICAM1 rs5498, IL4 rs2070874, IL17F rs763780, IRGM rs13361189, ITLN1 rs2274910, LRRK2 rs11175593, and TLR4 rs4986790 were genotyped in a Portuguese population (511 CD patients, 626 controls) and assessed for association with CD clinical characteristics. Results:There is a significant association of CD with the single nucleotide polymorphisms (SNPs) in ATG16L1 (odds ratio [OR] 1.36 [1.15–1.60], P = 2.7 × 10−4 for allele G), IRGM (OR 1.56 [1.21–1.93], P = 3.9 × 10−4 for allele C), and ITLN1 (OR 1.55 [1.28–1.88], P = 4.9 × 10−6 for allele C). These SNPs are associated with ileal location (OR, respectively, 1.49, 1.52, and 1.70), ileocolonic location (OR, respectively, 1.31, 1.57, and 1.68), and involvement of the upper digestive tract (OR, respectively for ATG16L1 and IRGM, 1.96 and 1.95). The risk genotype GG in ATG16L1 is associated with patients who respond to steroids (OR 1.89), respond to immunosuppressants (OR 1.77), and to biologic therapy (OR 1.89). The SNPs in ITLN1 and IRGM are both associated with a positive response to biologic therapy. The risk for ileal, ileocolonic, and upper digestive tract locations increases with the number of risk alleles (OR for three alleles, respectively, 7.10, 3.54, and 12.07); the OR for positive response to biologic therapy is 3.66. Conclusions:A multilocus approach using autophagy-related genes provides insight into CD phenotype–genotype associations and genetic markers for predicting therapeutic responses.

Crohn's disease in a southern European country: Montreal classification and clinical activity

Background: Given the heterogeneous nature of Crohns disease (CD), our aim was to apply the Montreal Classification to a large cohort of Portuguese patients with CD in order to identify potential predictive regarding the need for medical and/or surgical treatment. Methods: A cross‐sectional study was used based on data from an on‐line registry of patients with CD. Results: Of the 1692 patients with 5 or more years of disease, 747 (44%) were male and 945 (56%) female. On multivariate analysis the A2 group was an independent risk factor of the need for steroids (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1–2.3) and the A1 and A2 groups for immunosuppressants (OR 2.2; CI 1.2–3.8; OR 1.4; CI 1.0–2.0, respectively). An L3+L34 and L4 location were risk factors for immunosuppression (OR 1.9; CI 1.5–2.4), whereas an L1 location was significantly associated with the need for abdominal surgery (P < 0.001). After 20 years of disease, less than 10% of patients persisted without steroids, immunosuppression, or surgery. The Montreal Classification allowed us to identify different groups of disease severity: A1 were more immunosuppressed without surgery, most of A2 patients were submitted to surgery, and 52% of L1+L14 patients were operated without immunosuppressants. Conclusions: Stratifying patients according to the Montreal Classification may prove useful in identifying different phenotypes with different therapies and severity. Most of our patients have severe disease. (Inflamm Bowel Dis 2009)

Estimating the prevalence of inflammatory bowel disease in Portugal using a pharmaco-epidemiological approach.

To estimate inflammatory bowel disease (IBD) prevalence in Portugal from 2003 to 2007, and to obtain disease, sex and age specific estimates.

Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point‐of‐care quantitative test with two established ELISA assays

Therapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA‐based, with a turnaround time of approximately 8 h, and delaying the target dosage adjustment to the following infusion.

Ulcerative colitis in a Southern European country: a national perspective

Background:The incidence, prevalence, and even the clinical behavior of ulcerative colitis (UC) are highly variable in different world regions. In previous studies, Portugal was reported as having a milder clinical behavior. The aim of this study was to apply the Montreal Classification in a large group of UC Portuguese patients in order to describe their clinical characteristics and evaluate variables potentially useful for outcome prediction. Methods:A cross‐sectional study based on data collected from a nationwide online registry was undertaken. Results:In all, 2863 patients with UC were included. Twenty‐one percent had ulcerative proctitis, 52% left‐sided colitis, and 28% extensive colitis. Sixty percent of patients had taken steroids, 14% immunosuppressors, 1% biologicals, and 4.5% were submitted to surgery. Patients with extensive colitis had more severe activity, needing more steroids, immunosuppressors, and surgery. At the time of diagnosis 61% were less than 40 years old and 5% less than 16. Younger patients also had a more aggressive initial course. Thirty‐eight percent of patients had only taken salicylates during the disease course and were characterized by a lower incidence of systemic symptoms at presentation (3.8% versus 8.8%, P < 0.001), fewer extraintestinal manifestations (7.7% versus 24.0%, P < 0.001), and a higher prevalence of proctitis (32.1% versus 10.0%). Conclusions:A more aggressive phenotype was found in extensive colitis and in the initial course of younger patients, with an increased need for steroids and immunosuppressors. In addition, a significant percentage of patients, particularly with proctitis, showed a milder clinical evolution and were maintained in remission only with salicylates. (Inflamm Bowel Dis 2009)

Detection of anti-infliximab antibodies is impacted by antibody titer, infliximab level and IgG4 antibodies: a systematic comparison of three different assays:

Background: 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 µg/ml) hampered ADA detection with Theradiag in sera samples with ADA levels of between 3 and 10 µg/ml. In the Immundiagnostik assay detection interference was only observed at concentrations of exogenous IFX higher than 30 µg/ml. However, in samples with high levels of ADAs (>25 µg/ml) interference was only observed at IFX concentrations higher than 100 µg/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.

Impact of Early Surgery and Immunosuppression on Crohnʼs Disease Disabling Outcomes

Background and Aims: The definition of early therapeutic strategies to control Crohns disease aggressiveness and prevent recurrence is key to improve clinical practice. This study explores the impact of early surgery and immunosuppression onset in the occurrence of disabling outcomes. Methods: This was a multicentric and retrospective study with 754 patients with Crohns disease, who were stratified according to the need for an early surgery (group S) or not (group I) and further divided according to the time elapsed from the beginning of the follow-up to the start of immunosuppression therapy. Results: The rate of disabling events was similar in both groups (S: 77% versus I: 76%, P = 0.700). The percentage of patients who needed surgery after or during immunosuppression therapy was higher among group S, both for first surgeries after the index event (38% of groups S versus 21% of group I, P < 0.001) and for reoperations (38% of groups S versus 12% of group I, P < 0.001). The time elapsed to reoperation was shorter in group I (HR = 2.340 [1.367–4.005]), stratified for the onset of immunosuppression. Moreover, reoperation was far more common among patients who had a late start of immunosuppression (S36: 50% versus S0–6: 27% and S6–36: 25%, P < 0.001) and (I36: 16% versus I0–6: 5% and I6–36: 7%, P < 0.001). Conclusions: Although neither early surgery nor immunosuppression seem to be able to prevent global disabling disease, an early start of immunosuppression by itself is associated with fewer surgeries and should be considered in daily practice as a preventive strategy.

Accuracy of Faecal Calprotectin and Neutrophil Gelatinase B-associated Lipocalin in Evaluating Subclinical Inflammation in UlceRaTIVE Colitis-the ACERTIVE study.

Background and Aims Mucosal healing and histological remission are different targets for patients with ulcerative colitis, but both rely on an invasive endoscopic procedure. This study aimed to assess faecal calprotectin and neutrophil gelatinase B-associated lipocalin as biomarkers for disease activity in asymptomatic ulcerative colitis patients. Methods This was a multicentric cross-sectional study including 371 patients, who were classified according to their endoscopic and histological scores. These results were evaluated alongside the faecal levels of both biomarkers. Results Macroscopic lesions [i.e. endoscopic Mayo score ≥1] were present in 28% of the patients, and 9% had active disease according to fht Ulcerative Colitis Endoscopic Index of Severity. Moreover, 21% presented with histological inflammation according to the Geboes index, whereas 15% and 5% presented with focal and diffuse basal plasmacytosis, respectively. The faecal levels of calprotectin and neutrophil gelatinase B-associated lipocalin were statistically higher for patients with endoscopic lesions and histological activity. A receiver operating characteristic-based analysis revealed that both biomarkers were able to indicate mucosal healing and histological remission with an acceptable probability, and cut-off levels of 150-250 μg/g for faecal calprotectin and 12 μg/g for neutrophil gelatinase B-associated lipocalin were proposed. Conclusions Faecal calprotectin and neutrophil gelatinase B-associated lipocalin levels are a valuable addition for assessment of disease activity in asymptomatic ulcerative colitis patients. Biological levels of the analysed biomarkers below the proposed thresholds can rule out the presence of macroscopic and microscopic lesions with a probability of 75-93%. However, caution should be applied whenever interpreting positive results, as these biomarkers present consistently low positive predictive values.

Clinical performance of an infliximab rapid quantification assay

Background: Therapeutic drug monitoring (TDM)-based algorithms can be used to guide infliximab (IFX) adjustments in inflammatory bowel disease (IBD) patients. This study aimed to explore a rapid IFX-quantification test from a clinical perspective. Methods: This manuscript describes a prospective cohort study involving 110 ulcerative colitis (UC) patients on the maintenance phase of IFX. IFX trough levels were quantified using a rapid quantification assay and a commonly-used reference kit. Results: Irrespective of the assay used to measure IFX, its through levels were statistically different between patients with and without endoscopic remission (Mayo endoscopic score = 0), as well as between patients stratified by their faecal calprotectin (FC) levels. Despite the fact that the two methods correlated well with each other [Spearman’s rank correlation coefficient = 0.843, p < 0.001; intraclass correlation coefficients = 0.857, 95% confidence interval (CI): 0.791–0.903], there was a discernible systematic variation; values obtained with the reference kit were on average 2.62 units higher than those obtained with the rapid assay. Notwithstanding, 3 µg/ml was shown to be an acceptable cut-off to assess endoscopic status and inflammatory burden levels using both assays. The percentage of patients that had a positive outcome when the IFX concentration measured by the rapid assay ranked above 3 µg/ml was 88% both for a Mayo endoscopic score ⩽ 1 and for an FC concentration <250 µg/g. Conclusions: Based on this study, we concluded that using the rapid IFX assessment system with a 3 µg/ml threshold is a reliable alternative to the time-consuming enzyme-linked immunosorbent assays in patients on the maintenance phase of IFX.

Risk factors for severity and recurrence of colonic diverticular bleeding

BACKGROUND Colonic diverticular bleeding is the most common cause of lower gastrointestinal bleeding. Risk factors related to severity and repeated bleeding episodes are not completely clearly defined. OBJECTIVE To characterize a Portuguese population hospitalized due to colonic diverticular bleeding and to identify the clinical predictors related to bleeding severity and rebleeding. METHODS Retrospective analysis of all hospitalized patients diagnosed with colonic diverticular bleeding from January 2008 to December 2013 at our institution. The main outcomes evaluated were bleeding severity, defined as any transfusion support requirements and/or signs of hemodynamic shock, and 1-year recurrence rate. RESULTS Seventy-four patients were included, with a mean age of 75.7 ± 9.5 years; the majority were male (62.2%). Thirty-six patients (48.6%) met the criteria for severe bleeding; four independent risk factors for severe diverticular bleeding were identified: low hemoglobin level at admission (≤ 11 g/dL; OR 18.8), older age (≥ 75 years; OR 4.7), bilateral diverticular location (OR 14.2) and chronic kidney disease (OR 5.6). The 1-year recurrence rate was 12.9%. We did not identify any independent risk factor for bleeding recurrence in this population. CONCLUSION In this series, nearly half of the patients hospitalized with diverticular bleeding presented with severe bleeding. Patients with low hemoglobin levels, older age, bilateral diverticular location and chronic kidney disease had a significantly increased risk for severe diverticular bleeding. In addition, a small number of patients rebled within the first year after the index episode, although we could not identify independent risk factors associated with the recurrence of diverticular bleeding.