Spontaneous Rupture of the Right Gastroepiploic Artery Immediately after Gastroscopy

Idiopathic spontaneous intraperitoneal hemorrhage is both rare and potentially fatal. The incidence of gastroepiploic artery rupture, especially a non-aneurysmal rupture, is extremely low. We report the case of an elderly woman who was mistakenly diagnosed with procedure-related bleeding after gastroscopy. A 0.3 cm polyp was identified and removed during the procedure. The patient later developed shock due to which gastroscopy was repeated; however, no unusual findings were observed. Therefore, abdominopelvic computerized tomography was performed and gastroepiploic artery rupture was detected. Transcatheter arterial embolization was immediately performed without laparotomy, without any complications. The bleeding was controlled, and the patient was discharged after embolization. It is important to acknowledge the possibility of spontaneous rupture of the visceral arteries in elderly individuals with hypertension or atherosclerosis, especially in the event of sudden abdominal pain or shock immediately after an endoscopic procedure. This is the first case report of idiopathic spontaneous rupture of the right gastroepiploic artery successfully managed by transcatheter arterial embolization in South Korea.

P–153 Comparison outcome of vitrified human embryos stored in vapor phase liquid nitrogen (LN2) and direct LN2

Study question

Is vapor cryopreserved LN2 storage beneficial for clinical outcomes of vitrified human embryos that are frozen compared to vitrified human embryos having direct contact with LN2.

Summary answer

There are no significant differences compared to clinical outcomes of human embryos stored in LN2 vapor and direct store in LN2.

What is known already

There has been concerned about potential cross-contamination and biohazard issues of embryos for long term storage using direct LN2. This study aimed to compare clinical outcomes of human embryos transfer between vapor phase and liquid LN2.

Study design, size, duration

The embryo has undergone vitrification for long term storage with vapor or direct contact in LN2. After the thawing of the embryo, we checked on the survival rates. We transferred only one or two embryos per patient and kept analyzing the implantation and pregnancy rates

Participants/materials, setting, methods

This retrospective study was carried out from January 2018 to December 2019 with 3272cycles 4713embryos; vitrified for long term storage in vapor phase or direct contact with LN2. We compared the clinical outcomes of frozen embryo transfer cycles using vitrified for long term storage in vapor phase and direct contact with LN2. Clinical outcomes monitored were embryo survival, subsequent implantation and pregnancy after single or double embryo transfer

Main results and the role of chance

A total of 4713 fertilized human embryos are vitrified and then stored in LN2 vapor (n = 2520 cycles) or direct contact LN2 (n = 752 cycles). The study showed that the blastocyst stored in vapor able to retain full development. Survival was 97.8% (vapor) and 97.6% (direct contact LN2), and the vapor storage of human embryos had no significant difference in survival rates after a long term storage. For single blastocyst transfer, pregnancy and implantation rates were 51.5%, 52.4% in vapor, 54.6%, 54.9% in direct LN2; respectively (p=NS). In double blastocyst transfer, the pregnancy and implantation rates were 61.8%, 42.0% in vapor and 64.7%, 44.5% in direct LN2; respectively (p=NS). There were also no significant differences between two groups.

Limitations, reasons for caution

The study showed that the blastocyst stored in vapor can retain full development. A vapor storage system thus is safe and effective for long term vapor storage of vitrified human embryos.Within the limits of this study, there was no detection of an adverse effect of vapor storage.

Wider implications of the findings: Vapor storage systems thus represent a useful alternative for safe and effective long-term storage of vitrified human embryos that can avoid cross contamination chances from having direct contact with LN2.

Trial registration number

Not applicable

Multiplexed targeting of miRNA-210 in stem cell-derived extracellular vesicles promotes selective regeneration in ischemic hearts

Extracellular vesicles (EVs) are cell derivatives containing diverse cellular molecules, have various physiological properties and are also present in stem cells used for regenerative therapy. We selected a "multiplexed target" that demonstrates multiple effects on various cardiovascular cells, while functioning as a cargo of EVs. We screened various microRNAs (miRs) and identified miR-210 as a candidate target for survival and angiogenic function. We confirmed the cellular and biological functions of EV-210 (EVs derived from ASC^miR-210) secreted from adipose-derived stem cells (ASCs) transfected with miR-210 (ASC^miR-210). Under hypoxic conditions, we observed that ASC^miR-210 inhibits apoptosis by modulating protein tyrosine phosphatase 1B (PTP1B) and death-associated protein kinase 1 (DAPK1). In hypoxic endothelial cells, EV-210 exerted its angiogenic capacity by inhibiting Ephrin A (EFNA3). Furthermore, EV-210 enhanced cell survival under the control of PTP1B and induced antiapoptotic effects in hypoxic H9c2 cells. In cardiac fibroblasts, the fibrotic ratio was reduced after exposure to EV-210, but EVs derived from ASC^miR-210 did not communicate with fibroblasts. Finally, we observed the functional restoration of the ischemia/reperfusion-injured heart by maintaining the intercommunication of EVs and cardiovascular cells derived from ASC^miR-210. These results suggest that the multiplexed target with ASC^miR-210 is a useful tool for cardiovascular regeneration.

The Effect of Additional Embryo Transfer on the Pregnancy Rate in Young Women Receiving in vitro Fertilization: A Natural Experiment Study

Purpose

To assess the impact of additional embryo transfer (ET) on pregnancy in young women, we used a natural-experiment approach.

Patients and Methods

The design was based on the national policy of South Korea limiting the number of embryos transferred in vitro fertilization (IVF):≦2 embryos on day 2–4 or one on day 5–6 for patients aged <35, with one extra embryo allowed for patients aged ≥35. Using the data from 1909 ET cycles of 1287 women aged ≥34 and ≤35, we calculated adjusted risk ratios (RRs) for pregnancy.

Results

Half of cycles were undertaken by women aged 35, and additional ET was performed in 68.7% of them. Intrauterine pregnancy (45.2% vs 51.3%) and multiple gestation (30.5% vs 6.9%) were more common in women aged 35 than in those aged 34. The RR for intrauterine pregnancy was 1.34 (95% confidence interval: 1.12–1.59) when comparing double ET to single ET in frozen day 5–6 cycles.

Conclusion

We observed no evidence of a higher probability of pregnancy with additional ET in fresh or frozen day 3–4 ET, or in fresh day 5–6 ET of women aged 35. Additional ET may not increase the successful pregnancy rate in the 35-year-old group, unless it is a frozen day 5–6 ET cycle.

A12 PRE-TREATMENT HLADQA1-HLADRB1 TESTING FOR THE PREVENTION OF AZATHIOPRINE-INDUCED PANCREATITIS IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Azathioprine (AZA) therapy has a long history of use in IBD. The need to promote its safe use in this population is ensured by governmental health policy requiring IBD patients to fail low cost drugs, such as AZA, prior to approving funding for more potent biologic therapies. AZA-induced pancreatitis is an idiosyncratic and unpredictable response, occurring in up to 7% of AZA-exposed patients that can lead to patient morbidity, hospitalization, delay in effective IBD management, as well as result in substantial additional health-related costs. There are no tools in clinical practice to identify individuals at risk of AZA-induced pancreatitis. Genetic variation in the HLADQA1-HLADRB1*07:01 haplotype is strongly associated with azathioprine (AZA)-induced pancreatitis in inflammatory bowel disease (IBD).

Aims

To evaluate whether HLA DQA1-HLADRB1*07:01A&gt;C pre-treatment genotype testing in an adult IBD population prior to AZA therapy to guide AZA selection would result in a lower incidence of AZA-induced pancreatitis.

Methods

Participants with IBD (n=599) were screened for HLADQA1-HLADRB1*07:01A&gt;C and participants with a variant genotype were excluded from azathioprine treatment (n=271). Wildtype participants (n=328) were started on azathioprine and followed for 3 months. The incidence of pancreatitis was compared to unscreened historical controls (n=373).

Results

The minor allele frequency of HLADQA1-HLADRB1*07:01 was 30.4% and 30.0% in the screened and unscreened populations respectively. Up to 45.2% of participants were excluded from AZA therapy based on genotype in the HLADQA1-HLADRB1*07:01A&gt;C screened cohort. HLADQA1-HLADRB1*07:01A&gt;C screening resulted in an 11-fold reduction in the odds of azathioprine-induced pancreatitis (0.30% versus 3.4%, OR=0.085, 95%CI=0.011–0.651, p=0.002).

Conclusions

HLA DQA1-HLADRB1*07:01A&gt;C screening substantially reduced the risk of pancreatitis during AZA treatment in patients with IBD. However, using this strategy as a tool for guiding the use of AZA therapy in IBD may eliminate a large proportion of patients from being eligible for treatment with AZA. In regions, where there is access to other IBD therapies, and given the short and long term toxicities associated with AZA, HLA DQA1-HLADRB1*07:01A&gt;C screening may be a clinically-relevant strategy for enhancing the safe use of AZA in IBD. Additionally, cost-effectiveness analyses are needed to further solidify the utility of HLA DQA1-HLADRB1*07:01A&gt;C-screening in IBD populations.

Funding Agencies

Academic Medical Organization of Southwestern Ontario Innovation Fund

Percutaneous radiologic gastrostomy with single gastropexy: outcomes in 636 patients

OBJECTIVES

This study aimed to assess the technical success and overall complication rate of percutaneous radiologic gastrostomy (PRG) with single gastropexy using a separate tract from that used for tube placement.

METHODS

From January 2014 to December 2018, 636 patients (469 men, 167 women; mean age 66.8 years; age range, 22-98 years) underwent PRG using single gastropexy at a tertiary center. Preprocedural computed tomography (CT) was recommended if there were no data on the location of the stomach on previous CT. After a single anchor was applied, the PRG tube was inserted through a separate tract from that used for tube placement. The technical success rate and major and minor complications were retrospectively reviewed. The number of patients and percentages were used as descriptive statistics for evaluating the complication rate.

RESULTS

The technical success rate of PRG with single gastropexy was 99.2% (631/636). There were 32 complications among the 631 procedures. There were 19 (3.0%) major complications, including peritonitis (n = 7), migration (n = 5), infection (n=4), malposition (n = 2), and bleeding (n = 1). There were 13 (2.1%) minor complications, including local infection (n = 11), malfunction (n = 1), and pneumoperitoneum (n = 1). The overall complication rate within 30 days of PRG placement was 4.1% (26/631).

CONCLUSIONS

PRG with single gastropexy using a separate tract from that used for tube placement is technically feasible with a low complication rate.

KEY POINTS

• Percutaneous radiologic gastrostomy with single gastropexy using a separate tract from that used for tube placement is technically feasible. • Complications including peritonitis and bleeding were comparatively low with the conventional technique.

Endovascular Treatment for Lower Extremity Deep Vein Thrombosis: An Overview

Lower extremity deep vein thrombosis (DVT) is a serious medical condition that can result in local pain and gait disturbance. DVT progression can also lead to death or major disability as a result of pulmonary embolism, postthrombotic syndrome, or limb amputation. However, early thrombus removal can rapidly relieve symptoms and prevent disease progression. Various endovascular procedures have been developed in the recent years to treat DVT, and endovascular treatment has been established as one of the major therapeutic methods to treat lower extremity DVT. However, the treatment of lower extremity DVT varies according to the disease duration, location of affected vessels, and the presence of symptoms. This article reviews and discusses effective endovascular treatment methods for lower extremity DVT.

How to Treat Peripheral Arteriovenous Malformations

Arteriovenous malformations (AVMs) are direct communications between primitive reticular networks of dysplastic vessels that have failed to mature into capillary vessels. Based on angiographic findings, peripheral AVMs can be classified into six types: type I, type IIa, type IIb, type IIc, type IIIa, and type IIIb. Treatment strategies vary with the types. Type I is treated by embolizing the fistula between the artery and the vein with coils. Type II (IIa, IIb, and IIc) AVM is treated as follows: first, reduce the blood flow velocity in the venous segment of the AVM with coils; second, perform ethanol embolotherapy of the residual shunts. Type IIIa is treated by transarterial catheterization of the feeding arteries and injection of diluted ethanol. Type IIIb is treated by transarterial or direct puncture approaches. A high concentration of ethanol is injected through the transarterial catheter or direct puncture needle. When the fistula is large, coil insertion is required to reduce the amount of ethanol. Type I and type II AVMs showed the best clinical results; type IIIb showed a satisfactory response rate. However, type IIIa showed the poorest response rate, either alone or in combination with other types. Clinical success can be achieved by using different treatment strategies for different angiographic AVM types.

Therapeutic outcomes of embolotherapy of extremity bone intraosseous arteriovenous malformation with ethanol, coils, and n-butyl cyanoacrylate

OBJECTIVE

We evaluated the therapeutic outcomes of embolotherapy for bone arteriovenous malformations (AVMs) affecting the extremities using ethanol, coils, and n-butyl cyanoacrylate (NBCA).

METHODS

We reviewed the data from 36 patients (18 males, 18 females; mean age 25 years; age range, 1-64 years) with bone AVMs affecting their extremities who had undergone embolotherapy using ethanol, coils, and NBCA from December 1996 to July 2019. Of the 36 patients, 19 had had pure bone AVMs and 17 mixed bone and soft tissue (MBS) AVMs. Embolotherapy was performed using direct puncture or a transvenous or an intra-arterial approach (range, 1-18 procedures; mean, 5 procedures). During the 178 embolotherapy procedures, ethanol was used in all 36 patients, except for 1. Coils were used in 14 patients, and NBCA and a lipiodol mixture in 9 patients. The therapeutic outcomes were evaluated by the clinical symptom response and the degree of devascularization on follow-up angiography or computed tomography. The major and minor complications were also evaluated.

RESULTS

The clinical success (cure or markedly improvement) rate of embolotherapy for pure bone AVMs was significantly better than that for the MBS AVMs (88% vs 18%; P < .001). The complete devascularization rate of the bone AVM component of the MBS AVMs was 71%; however, the cure rate of the MBS AVMs was 0% owing to the remaining soft tissue AVMs. Of the 36 patients, 12 experienced complications, including 11 minor (2 skin bullae formation and 10 transient peripheral nerve injury) and 1 major (longstanding nerve palsy).

CONCLUSIONS

Embolotherapy for bone AVMs affecting the extremities using ethanol, coils, and an NBCA mixture is effective and safe for the resolution or improvement of symptoms, especially in those with pure bone AVMs.

Regulation of alternative macrophage activation by MSCs derived hypoxic conditioned medium, via the TGF-β1/Smad3 pathway

Macrophages are re-educated and polarized in response to myocardial infarction (MI). The M2 anti-inflammatory phenotype is a known dominator of late stage MI. Mesenchymal stem cells (MSCs) represent a promising tool for cell therapy, particularly heart related diseases. In general, MSCs induce alteration of the macrophage subtype from M1 to M2, both in vitro and in vivo. We conjectured that hypoxic conditions can promote secretome productivity of MSCs. Hypoxia induces TGF-β1 expression, and TGF-β1 mediates M2 macrophage polarization for anti-inflammation and angiogenesis in infarcted areas. We hypothesized that macrophages undergo advanced M2 polarization after exposure to MSCs in hypoxia. Treatment of MSCs derived hypoxic conditioned medium (hypo-CM) promoted M2 phenotype and neovascularization through the TGF-β1/Smad3 pathway. In addition, hypo-CM derived from MSCs improved restoration of ischemic heart, such as attenuating cell apoptosis and fibrosis, and ameliorating microvessel density. Based on our results, we propose a new therapeutic method for effective MI treatment using regulation of macrophage polarization. 

Right ventricular longitudinal strain measured using feature-tracking cardiac magnetic resonance is an independent predictor of all cause mortality in patients with severe tricuspid regurgitation

Introduction

Tricuspid regurgitation imposes a volume overload on the right ventricle (RV) that can lead to progressive RV dilation and dysfunction. Overt RV dysfunction is associated with poor prognosis and increased operative risk. Abnormalities of myocardial strain may provide the earliest evidence of ventricular dysfunction. CMR feature-tracking techniques now allow assessment of strain from routine cine-images, without specialized pulse sequences. Whether abnormalities of RV strain measured using CMR feature-tracking have prognostic value in patients with tricuspid regurgitation is unknown

Purpose

To evaluate the prognostic value of CMR feature-tracking derived RV free wall longitudinal strain (RVFWLS) in a large multicenter population of patients with severe tricuspid regurgitation.

Methods

Consecutive patients with severe tricuspid regurgitation undergoing CMR at four US medical centers were included in this study. Feature-tracking RVFWLS was calculated from 4 chamber cine-views (Figure-left panel). The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between RVFWLS and death. The incremental prognostic value of RVFWLS was assessed in nested models.

Results

Of the 406 patients in this study,115 died during a median follow-up of 8.8 years. By Kaplan-Meier-analysis, patients with RVFWLS ≥median (−16%) had significantly reduced event free survival compared to those with RVFWLS &lt; median (log-rank p&lt;0.001) (Figure-right panel). By Cox multivariable regression modeling, each 1% worsening in RVFWLS was associated with a 13% increased risk-of-death after adjustement for clinical and imaging risk factors (HR=1.13 per %; p&lt;0.001). Addition of RVFWLS in this model resulted in significant-improvement in the global-chi-square (26 to 65; p&lt;0.0001).

Conclusions

CMR feature-tracking derived RVFWLS is an independent predictor of mortality in patients with severe tricuspid regurgitation, incremental to common clinical and imaging risk factors.

Funding Acknowledgement

Type of funding source: None

Clinical experience with distal transradial access for endovascular treatment of various noncoronary interventions in a multicenter study

Background

Transradial access is a well-known alternative to conventional transfemoral access for interventional procedures. Recently, transradial access through the “snuffbox”, which lies in the radial dorsal aspect of the hand, has been introduced as a new technique with positional versatility. In this study, we aimed to evaluate the clinical feasibility and safety of distal transradial access for interventional procedures in a retrospective, multicenter study.

Material & methods

Distal transradial access was attempted in 46 patients (36 men and 10 women; mean age, 64 years) who underwent 47 consecutive procedures from January 2018 to December 2019. Procedures included chemoembolization (19/47, 40.4%), bronchial artery embolization (7/47, 14.9%), renal intervention (3/47, 6.4%), arteriovenous fistula angioplasty (7/47, 14.9%), subclavian artery stenting (5/47, 10.6%), other embolization (5/47, 10.6%), and uterine artery embolization (1/47, 2.1%). We recorded the success rate of the procedures, complications, and postprocedural hemostasis time during the follow-up period.

Results

The technical success of distal transradial access without major complications was 97.9% (46/47). Of the 46 patients, one patient (2.2%) had a minor complication, which was a thrombotic segmental occlusion of the distal radial artery. Of the enrolled patients, only one patient did not complete the transradial access procedure via the snuffbox because the left proximal subclavian artery was occluded and a crossover to conventional transfemoral access was performed. The mean postprocedural hemostasis time was 131.7 minutes (range, 120–360 minutes).

Conclusion

Distal transradial access can be a valid option for the endovascular treatment of various noncoronary interventions with technical feasibility and safety.

Peroxisome Proliferator-Activated Receptor Gamma Modulator Promotes Neonatal Mouse Primordial Follicle Activation In Vitro

Peroxisome proliferator-activated receptor gamma (PPARγ) is known as a regulator of cellular functions, including adipogenesis and immune cell activation. The objectives of this study were to investigate the expression of PPARγ and identify the mechanism of primordial follicle activation via PPARγ modulators in mouse ovaries. We first measured the gene expression of PPARγ and determined its relationship with phosphatase and tensin homolog (PTEN), protein kinase B (AKT1), and forkhead box O3a (FOXO3a) expression in neonatal mouse ovaries. We then incubated neonatal mouse ovaries with PPARγ modulators, including rosiglitazone (a synthetic agonist of PPARγ), GW9662 (a synthetic antagonist of PPARγ), and cyclic phosphatidic acid (cPA, a physiological inhibitor of PPARγ), followed by transplantation into adult ovariectomized mice. After the maturation of the transplanted ovaries, primordial follicle growth activation, follicle growth, and embryonic development were evaluated. Finally, the delivery of live pups after embryo transfer into recipient mice was assessed. While PPARγ was expressed in ovaries from mice of all ages, its levels were significantly increased in ovaries from 20-day-old mice. In GW9662-treated ovaries in vitro, PTEN levels were decreased, AKT was activated, and FOXO3a was excluded from the nuclei of primordial follicles. After 1 month, cPA-pretreated, transplanted ovaries produced the highest numbers of oocytes and polar bodies, exhibited the most advanced embryonic development, and had the greatest blastocyst formation rate compared to the rosiglitazone- and GW9662-pretreated groups. Additionally, the successful delivery of live pups after embryo transfer into the recipient mice transplanted with cPA-pretreated ovaries was confirmed. Our study demonstrates that PPARγ participates in primordial follicle activation and development, possibly mediated in part by the PI3K/AKT signaling pathway. Although more studies are required, adapting these findings for the activation of human primordial follicles may lead to treatments for infertility that originates from poor ovarian reserves.

A214 GENETIC VARIATION IN THE FARNESOID X RECEPTOR PREDICTS CROHN’S DISEASE SEVERITY IN FEMALE PATIENTS

Background

Crohn’s disease (CD) is an immune-mediated inflammatory bowel disease defined by episodes of intestinal inflammation. There is now an increasing appreciation of the bile acid-sensing nuclear receptor, FXR, as an important regulator of intestinal inflammation, intestinal permeability and response to bacterial overgrowth. Many of these processes are dysregulated in CD. It is unclear how genetic variation in FXR impacts on CD severity. FXR deficiency is rare. Loss of function mutations in FXR as contributors to CD are unlikely; however, partial loss of function of FXR may contribute to CD progression or severity. Our group demonstrated that FXR-1G&gt;T, a SNV adjacent to the ATG start codon, is linked to reduced transactivation of FXR gene targets. We hypothesized that changes in the intestinal barrier as a result of reduced FXR expression among those who harbor the FXR-1T allele are more likely to exhibit a severe CD phenotype compared to G (reference) allele carriers, and thereby experience a more rapid progression to surgery. Alterations in FXR activity may in part be secondary to genetic variation in the FXR gene.

Aims

To evaluate FXR-1G&gt;T as a genomic biomarker of severity in CD and propose a plausible molecular mechanism.

Methods

A retrospective study (n=542) was conducted in a Canadian cohort of CD patients. Blood samples were obtained for genotypic analysis (FXR-1G&gt;T), as well as determination of the FXR downstream product, fibroblast growth factor (FGF) 19. Primary outcomes included risk and time to first CD-related surgery. To better elucidate a potential molecular basis for the observed effect of FXR-1G&gt;T genotype on CD prognosis (more frequent and early surgery) in female CD patients, we explored a connection between the estrogen receptor (ER)-mediated pathway and genetic variation in FXR using a cell-based model. .

Results

The FXR-1GT genotype was associated with the risk of (odds ratio, OR=3.34, 95%CI=1.58–7.05, p=0.002) and early progression to surgery (hazard ratio, HR=3.00, 95%CI=1.86–4.83, p&lt;0.0001) in CD. Female carriers of the FXR-1GT genotype had the greatest risk of surgery (OR=14.87 95%CI=4.22–52.38, p&lt;0.0001) and early progression to surgery (HR=6.28, 95%CI=3.62–10.90, p&lt;0.0001). Furthermore, women carriers of FXR-1GT polymorphism had a nearly three-fold lower FGF19 plasma concentration compared to women with wildtype FXR-1GG genotype (p&lt;0.0001). In HepG2 cells cotransfected with estrogen receptors (ERα and β) and FXR, presence of estradiol further attenuated variant FXR activity.

Conclusions

FXR-1GT is deleterious to women with CD through ER-mediated attenuation of FXR activation. Female CD FXR-1GT carriers should be considered for more aggressive medical management.

Funding Agencies

CAG, CCC, CIHR

A208 HLA-DQA1*05 GENOTYPE PREDICTS ANTI-DRUG ANTIBODY FORMATION AND LOSS OF RESPONSE DURING INFLIXIMAB THERAPY FOR INFLAMMATORY BOWEL DISEASE

Background

The underlying mechanism for immunogenicity in anti-TNFa-exposed patients with inflammatory bowel disease is poorly understood. Anti-drug antibodies are a leading contributor to infliximab loss of response and adverse drug events. Currently, it is not feasible to identify patients at risk of antibody formation prior to initiating infliximab. The genetic variation HLADQA1*05(rs2097432) has been linked to infliximab antibody formation in a cohort of patients with Crohn’s disease.

Aims

Due to the wide variation in the frequency of HLADQA1* 05 across ethnic groups, we aim to independently evaluate the association between HLADQA1*05and infliximab antibody formation, infliximab loss of response, treatment discontinuation and adverse drug events, in a Canadian inflammatory bowel disease cohort.

Methods

In a retrospective cohort study, infliximab-exposed patients with inflammatory bowel disease (n=262) were screened for the genetic variation, HLADQA1*05A&gt;G(rs2097432). The risk of infliximab anti-drug antibody formation, infliximab loss of response, adverse events, and discontinuation were assessed in wild type (GG) and variant-carrying (AG or AA) individuals.

Results

Forty percent of all participants were HLADQA1*05A&gt;Gvariant carriers, with 79% of participants with infliximab antibodies carrying at least one variant allele. The risk of infliximab antibody formation was higher in HLADQA1*05A&gt;Gvariant carriers in an IBD population (adjusted HR=7.29, 95%CI=2.97–17.191, p=1.46x10-5) independent of age, sex, weight, dose and co-immunosuppression with an immunomodulator. Variant carrier status was associated with an increased risk of infliximab loss of response (adjusted HR=2.34, 95%CI=1.41–3.88, p=0.001) and discontinuation (adjusted HR=2.27, 95%CI=1.46–3.43, p=2.53x10-4) though not with infliximab-associated adverse drug events.

Conclusions

HLADQA1*05 is independently associated with a high risk of infliximab antibody formation in addition to infliximab loss of response and treatment discontinuation. As a result, we propose that pre-emptive genetic screening for the HLADQA1* 05A&gt;Gvariant would be useful in order to predict individuals at risk of developing immunogenicity. There may be a role for genotype-guided application of combination therapy in inflammatory bowel disease.

Funding Agencies

NoneWolfe Medical Research Chair in Pharmacogenomics (MOP-89753 to RBK), the Academic Medical Organization of Southwestern Ontario (INN18-005 to RBK and AW; S17-004 to AW), and Lawson Health Research Institute (IRF-05-19 to AW)