Antibody response to the COVID-19 ChAdOx1nCov-19 and BNT162b vaccines after temporary suspension of DMARD therapy in immune-mediated inflammatory disease: an extension study (RESCUE 2)

The persistence of immunogenicity in patients with immune-mediated inflammatory diseases (IMID) on disease-modifying antirheumatic therapy (DMARD) has been less well studied. This extension study evaluates the SARS-CoV2 antibody decay kinetics 6 months following two doses of ChAdO1nCov-19 (AZ) and BNT162b (Pfizer) and subsequent response following an mRNA booster. RESULTS: 175 participants were included. Six months after initial AZ vaccination, 87.5%, 85.4% and 79.2% (p=0.756) in the withhold, continue and control groups remained seropositive compared with 91.4%, 100% and 100% (p=0.226), respectively, in the Pfizer group. Both vaccine groups developed robust humoral immune responses following a booster with seroconversion rates being 100% for all three intervention categories. The mean SARS-CoV-2 antibody levels were significantly lower in the targeted synthetic DMARD (tsDMARD) group that continued therapy compared with the control (2.2 vs 4.8 U/mL, p=0.010). The mean time interval until loss of protective antibodies in the IMID group was 61 days for the AZ and 137.5 days for the Pfizer vaccine. Within each DMARD class the interval until loss of protective antibody titres in the csDMARD, bDMARD and tsDMARD groups were 68.3, 71.8 and 64.0 days in the AZ group and 185.5, 137.5 and 116.0 days in the Pfizer group, respectively. CONCLUSION: Antibody persistence was longer in the Pfizer group due to a higher peak antibody level following second vaccination with levels of protection in IMID on DMARD therapy similar to controls except in those on tsDMARDs where it was lower. A third mRNA vaccine booster can restore immunity in all groups.

Two-step aggregation of gold nanoparticles based on charge neutralization for detection of melamine by colorimetric and surface-enhanced Raman spectroscopy platform

A colorimetric and surface-enhanced Raman scattering (SERS) signal amplification platform based on 2-step aggregation of gold nanoparticles (AuNP) was constructed for the sensitive detection of melamine. In this study, the positively charged SYBR Green I was used for the first step of aggregation of AuNP, via charge neutralization, to obtain small-sized AuNP aggregates. The positively charged SYBR Green I decreased the negative charges of the surface of AuNP, which was beneficial to the aggregation of AuNP. In addition, the melamine could aggregate AuNP by decreasing the negative charges of the surface of AuNP and self-assemble with each other on the surface of AuNP by hydrogen bonds. Therefore, the second efficient aggregation of small-sized AuNP aggregates could be achieved with melamine at low concentration, resulting in significant signal changes of color and SERS. The sensitivity of a colorimetric (0.60 mg/L) and SERS (0.089 mg/L) platform, based on 2-step aggregation of AuNP, was 15 and 2.2 times higher than that based on 1-step aggregation of AuNP for detecting melamine.

Metabonomics and the Gut Microbiome Associated With Primary Response to Anti-TNF Therapy in Crohn's Disease

BACKGROUND AND AIMS

Anti-tumour necrosis factor [anti-TNF] therapy is indicated for treatment of moderate to severe inflammatory bowel disease [IBD], but has a primary non-response rate of around 30%. We aim to use metabonomic and metataxonomic profiling to identify predictive biomarkers of anti-TNF response in Crohn's disease.

METHODS

Patients with luminal Crohn's disease, commencing anti-TNF therapy, were recruited with urine, faeces, and serum samples being collected at baseline and 3-monthly. Primary response was defined according to a combination of clinical and objective markers of inflammation. Samples were measured using three UPLC-MS assays: lipid, bile acid, and Hydrophillic Interaction Liquid Chromatography [HILIC] profiling with 16S rRNA gene sequencing of faeces.

RESULTS

Samples were collected from 76 Crohn's disease patients who were anti-TNF naïve and from 13 healthy controls. There were 11 responders, 37 non-responders, and 28 partial responders in anti-TNF-treated Crohn's patients. Histidine and cysteine were identified as biomarkers of response from polar metabolite profiling [HILIC] of serum and urine. Lipid profiling of serum and faeces found phosphocholines, ceramides, sphingomyelins, and triglycerides, and bile acid profiling identified primary bile acids to be associated with non-response to anti-TNF therapy, with higher levels of phase 2 conjugates in non-responders. Receiver operating curves for treatment response demonstrated 0.94 +/ -0.10 [faecal lipid], 0.81 +/- 0.17 [faecal bile acid], and 0.74 +/- 0.15 [serum bile acid] predictive ability for anti-TNF response in Crohn's disease.

CONCLUSIONS

This prospective, longitudinal cohort study of metabonomic and 16S rRNA gene sequencing analysis demonstrates that a range of metabolic biomarkers involving lipid, bile acid, and amino acid pathways may contribute to prediction of response to anti-TNF therapy in Crohn's disease.

PODCAST

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The body composition profile is associated with response to anti-TNF therapy in Crohn's disease and may offer an alternative dosing paradigm

BACKGROUND

Anti-tumour necrosis factor (TNF)s form a major part of therapy in Crohn's disease and have a primary nonresponse rate of 10%-30% and a secondary loss of response rate of 5% per year. Myopenia is prevalent in Crohn's disease and is measured using body composition analysis tools.

AIM

To test the hypothesis that body composition can predict outcomes of anti-TNF primary nonresponse and secondary loss of response.

METHODS

Between January 2007 and June 2012, 106 anti-TNF naïve patients underwent anti-TNF therapy for Crohn's disease with body composition parameters analysed using CT scans to estimate body fat-free mass. The outcome measures were primary nonresponse and secondary loss of response. COX-regression analysis was used with 3 year follow-up data.

RESULTS

A total of 106 patients were included for analysis with 26 (24.5%) primary nonresponders and 29 (27.4%) with secondary loss of response to anti-TNF therapy. Sex-specific cut-offs for muscle and fat were ascertained by stratification analysis. On univariate analysis, primary nonresponse was associated with low albumin (OR 0.94; 0.88-0.99, P = .04) and presence of myopenia (OR 4.69; 1.83-12.01, P = .001) when taking into account patient's medical therapy, severity of disease and body composition. On multivariate analysis, presence of myopenia was associated with primary nonresponse (OR 2.93; 1.28-6.71, P = .01). Immunomodulator therapy was associated with decreased secondary loss of response (OR 0.48; 0.23-0.98, P = .04). BMI was poorly correlated with lean body mass (r² = 0.15, P = .54).

CONCLUSIONS

In this cohort study, body composition profiles did not correlate well with BMI. Myopenia was associated with primary nonresponse with potential implications for dosing and serves as an explanation for pharmacokinetic failure.

Systematic review with meta-analysis: the management of chronic refractory pouchitis with an evidence-based treatment algorithm

BACKGROUND

Restorative proctocolectomy with ileal pouch anal anastomosis (IPAA) is considered the procedure of choice in patients with ulcerative colitis (UC) refractory to medical therapy. The incidence of pouchitis is 40% at 5 years. Ten to 15% of patients with pouchitis experience chronic pouchitis.

AIM

To determine the efficacy of medical therapies for the treatment of chronic refractory pouchitis in patients undergoing IPAA for UC.

METHODS

A systematic computer-assisted search of the on-line bibliographic database MEDLINE and EMBASE was performed between 1966 and February 2016. All original studies reporting remission rates following medical treatment for chronic pouchitis were included. All study designs were considered. Remission was defined according to the individual study. Remission endpoints ranged from 15 days to 10 weeks. Chronic pouchitis was defined by each study.

RESULTS

Twenty-one papers were considered eligible. Results from all studies combined suggested that overall remission was obtained in 59% of patients (95% CI: 44-73%). Antibiotics significantly induced remission in patients with chronic pouchitis with 74% remission rate (95% CI:56-93%), (P < 0.001). Biologics significantly induced remission in patients with chronic pouchitis with 53% remission rate (95% CI:30-76%), (P < 0.001). Steroids, bismuth, elemental diet and tacrolimus all can induce remission but failed to achieve significance. Faecal microbiota transplantation in a single study was not found to achieve remission.

CONCLUSIONS

Treatment of chronic refractory pouchitis remains difficult and is largely empirical. Larger randomised controlled trials will help aid the management of chronic pouchitis.

Infliximab vs. adalimumab in Crohn's disease: results from 327 patients in an Australian and New Zealand observational cohort study

BACKGROUND

Maintenance anti-tumour necrosis factor-α (anti-TNFα) treatment for Crohn's disease is the standard of care for patients with an inadequate response to corticosteroids and immunomodulators.

AIM

To compare the efficacy and safety of infliximab and adalimumab in clinical practice and assess the value of concomitant immunomodulator therapy.

METHODS

We performed an observational cohort study in consecutive patients with Crohn's disease qualifying for anti-TNFα treatment in Australia and New Zealand between 2007 and 2011. Demographic and clinical data were prospectively recorded to identify independent factors associated with induction and maintenance of response to infliximab or adalimumab, or to either anti-TNFα therapy.

RESULTS

Three hundred and twenty-seven patients (183 infliximab, 144 adalimumab) successfully applied for treatment. Eighty-nine percent responded in all groups and median maintenance of response was similar for the two agents. Concomitant immunomodulator with infliximab, but not adalimumab, demonstrated a significantly longer response overall (P = 0.002), and significantly fewer disease and treatment-related complications (P = 0.017). Corticosteroids at baseline, and/or in the preceding 12 months, were associated with a 9-13 times greater risk of disease flare during maintenance treatment as compared to no corticosteroids (P < 0.0001). Maintenance of response was similar in the anti-TNF naïve and anti-TNF experienced subgroups.

CONCLUSIONS

In this large, real-life study, we demonstrate infliximab and adalimumab to have similar response characteristics. However, infliximab requires concomitant immunomodulator to achieve optimal maintenance of response comparable to adalimumab monotherapy. The results of this study will assist clinicians in further optimising patient care in their day-to-day clinical practice.

Identification of new single nucleotide polymorphisms affecting total number born and candidate genes related to ovulation rate in Chinese Erhualian pigs

The Chinese Erhualian pig has the highest record for litter size in the world. However, the genetic mechanism of its high prolificacy remains poorly understood. In our study, large phenotypic variations in litter size were found among Erhualian sows. Significant differences in total number born (TNB) and corpora lutea numbers were observed between sows with high and low estimated breeding values (EBVs) for TNB. To identify single nucleotide polymorphisms (SNPs) associated with TNB, a selective genomic scan was conducted on 18 sows representing the top 10% and 18 sows representing the bottom 10% of EBVs of 177 sows using Illumina Porcine SNP60 genotype data. Genome-wide fixation coefficient (F_ST ) values were calculated for each SNP between the high- and low-EBV groups. A total of 154 SNPs were significantly differentiated loci between the two groups. Of the top 10 highest F_ST SNPs, rs81399474, rs81400131 and rs81405013 on SSC8 and rs81434499 and rs81434489 on SSC 12 corresponded to previously reported QTL for litter size. The other five SNPs, rs81367039 on SSC2, rs80891106 on SSC7, rs81477883 on SSC12 and rs80938898 and rs80971725 on SSC14, appeared to be novel QTL for TNB. Significant associations between rs81399474 on SSC8 and TNB were confirmed in 313 Erhualian sows. Forty genes were identified around the top 10 highest F_ST SNPs, of which UCHL1, adjacent to rs81399474, and RPS6KB1 and CLTC, adjacent to rs81434499, have been reported to affect the ovulation rate in pig. The findings can advance understanding of the genetic variations in litter size of pigs.

Relapse after withdrawal from anti-TNF therapy for inflammatory bowel disease: an observational study, plus systematic review and meta-analysis

BACKGROUND

Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation.

AIM

To establish outcomes following anti-TNF withdrawal for sustained remission using new data from a large UK cohort, and assimilation of all available literature for systematic review and meta-analysis.

METHODS

A retrospective observational study was performed on 166 patients with IBD (146 with Crohn's disease (CD) and 20 with ulcerative colitis [UC) and IBD unclassified (IBDU)] withdrawn from anti-TNF for sustained remission. Meta-analysis was undertaken of all published studies incorporating 11 further cohorts totalling 746 patients (624 CD, 122 UC).

RESULTS

Relapse rates in the UK cohort were 36% by 1 year and 56% by 2 years for CD, and 42% by 1 year and 47% by 2 years for UC/IBDU. Increased relapse risk in CD was associated with age at diagnosis [hazard ratio (HR) 2.78 for age <22 years], white cell count (HR 3.22 for >5.25 × 10⁹ /L) and faecal calprotectin (HR 2.95 for >50 μg/g) at drug withdrawal. Neither continued immunomodulators nor endoscopic remission were predictors. In the meta-analysis, estimated 1-year relapse rates were 39% and 35% for CD and UC/IBDU respectively. Retreatment with anti-TNF was successful in 88% for CD and 76% UC/IBDU.

CONCLUSIONS

Assimilation of all available data reveals remarkable homogeneity. Approximately one-third of patients with IBD flare within 12 months of withdrawal of anti-TNF therapy for sustained remission.

Systematic review: predicting and optimising response to anti-TNF therapy in Crohn's disease - algorithm for practical management

BACKGROUND

Nonresponse and loss of response to anti-TNF therapies in Crohn's disease represent significant clinical problems for which clear management guidelines are lacking.

AIM

To review the incidence, mechanisms and predictors of primary nonresponse and secondary loss of response to formulate practical clinical algorithms to guide management.

METHODS

Through a systematic literature review, 503 articles were identified which fit the inclusion criteria.

RESULTS

Primary nonresponse to anti-TNF treatment affects 13-40% of patients. Secondary loss of response to anti-TNF occurs in 23-46% of patients when determined according to dose intensification, and 5-13% of patients when gauged by drug discontinuation rates. Recent evidence suggests that the mechanisms underlying primary nonresponse and secondary loss of response are multifactorial and include disease characteristics (phenotype, location, severity); drug (pharmacokinetic, pharmacodynamic or immunogenicity) and treatment strategy (dosing regimen) related factors. Clinical algorithms that employ therapeutic drug monitoring (using anti-TNF tough levels and anti-drug antibody levels) may be used to determine the underlying cause of primary nonresponse and secondary loss of response respectively and guide clinicians as to which patients are most likely to respond to anti-TNF therapy and help optimise drug therapy for those who are losing response to anti-TNF therapy.

CONCLUSIONS

Nonresponse or loss of response to anti-TNF occurs commonly in Crohn's disease. Clinical algorithms utilising therapeutic drug monitoring may establish the mechanisms for treatment failure and help guide the subsequent therapeutic approach.

SUSCEPTIBILITY LOCI FOR UMBILICAL HERNIA IN SWINE DETECTED BY GENOME-WIDE ASSOCIATION

Umbilical hernia (UH) is a complex disorder caused by both genetic and environmental factors. UH brings animal welfare problems and severe economic loss to the pig industry. Until now, the genetic basis of UH is poorly understood. The high-density 60K porcine SNP array enables the rapid application of genome-wide association study (GWAS) to identify genetic loci for phenotypic traits at genome wide scale in pigs. The objective of this research was to identify susceptibility loci for swine umbilical hernia using the GWAS approach. We genotyped 478 piglets from 142 families representing three Western commercial breeds with the Illumina PorcineSNP60 BeadChip. Then significant SNPs were detected by GWAS using ROADTRIPS (Robust Association-Detection Test for Related Individuals with Population Substructure) software base on a Bonferroni corrected threshold (P = 1.67E-06) or suggestive threshold (P = 3.34E-05) and false discovery rate (FDR = 0.05). After quality control, 29,924 qualified SNPs and 472 piglets were used for GWAS. Two suggestive loci predisposing to pig UH were identified at 44.25MB on SSC2 (rs81358018, P = 3.34E-06, FDR = 0.049933) and at 45.90MB on SSC17 (rs81479278, P = 3.30E-06, FDR = 0.049933) in Duroc population, respectively. And no SNP was detected to be associated with pig UH at significant level in neither Landrace nor Large White population. Furthermore, we carried out a meta-analysis in the combined pure-breed population containing all the 472 piglets. rs81479278 (P = 1.16E-06, FDR = 0.022475) was identified to associate with pig UH at genome-wide significant level. SRC was characterized as plausible candidate gene for susceptibility to pig UH according to its genomic position and biological functions. To our knowledge, this study gives the first description of GWAS identifying susceptibility loci for umbilical hernia in pigs. Our findings provide deeper insights to the genetic architecture of umbilical hernia in pigs.

Genome-wide association study identifies QTLs for EBV of backfat thickness and average daily gain in Duroc pigs

Backfat thickness (BFT) and average daily gain (ADG) are two important economic traits in commercial swine production. Identifying QTLs and uncovering the molecular mechanism for BFT and ADG would greatly help to speed up the breeding progress. In current breeding program, EBV for these two traits are calculated and formulated a comprehensive breeding index, which then be used to improve pig performance. Using Illumina PorcineSNP60 BeadChip, a pilot genomewide association studies (GWAS) for BFT and ADG in 83 Duroc pigs were performed. A total of 31 genome-wise significant SN Ps were detected to be associated with BFT on SSC 4, 9, 11, 12 and 14, ten of which were coincident with previously reported QTL regions. There are two genome-wise loci prominently associated with ADG on SSC2 and SSC13, respectively. The two loci on SSC2 are well overlapped with the QTL regions previously reported. All the 31 significant SNPs associated with BFT are verified on 219 outbreed pigs, six SN Ps reach an extreme significant level and seven SNP reaches a significant level, CACNA1E and ACBD6 are chosen as positional candidate genes. Our findings not only confirmed previously findings, but also revealed a number of novel SNPs associated with BFT and ADG. Two positional candidate genes CACNA1E and ACBD6 were identified for further study. These results would facilitate the identification of causative genes for BFT and ADG.

A genome-wide scan reveals candidate susceptibility loci for pig hernias in an intercross between White Duroc and Erhualian

Pig scrotal/inguinal and umbilical hernias are the most prevalent congenital disorders in pigs and often cause animal welfare problems and economic loss. To identify susceptibility loci for these traits, a genome-wide scan with 194 microsatellite markers covering the pig genome was performed in a White Duroc x Erhualian resource population with 23 scrotal/inguinal F(2) animals, 50 umbilical F(2) animals, and their unaffected siblings. A sex-average linkage map with a total length of 2,350.3 cM and an average marker interval of 12.84 cM was constructed. Both nonparametric genome-wide linkage (NPL) analysis and transmission disequilibrium test (TDT) were implemented to detect closely linked markers. The NPL analysis revealed 11 chromosomal regions on SSC1, 2, 3, 6, 7, 8, 10, and 11 for umbilical hernia and 5 regions on SSC2, 4, 8, 13, and 16 for scrotal/inguinal hernia, whereas the TDT test identified susceptibility loci for umbilical hernia on SSC1, 2, 4, 7, 10, 13, 14, and 15 and for scrotal/inguinal hernias on SSC2, 8, 10, and 18. The most promising loci were SWR1928 on SSC7 and SW830 on SSC10 for umbilical hernia, and SW933 on SSC8 for scrotal hernia, which were consistently detected by both NPL and TDT. Several previously reported chromosomal regions for scrotal/inguinal hernia were confirmed, and new evidence for linkage with this pig defect was found. Moreover, susceptibility loci for pig umbilical hernia were detected for the first time.