Genetic association between CD96 locus and immunogenicity to anti-TNF therapy in Crohn’s disease

Predictors of Immunogenicity and Loss of Response to ANTI-TNFα Therapy in Crohn Disease-A Systematic Review

BACKGROUND

As the use of anti-tumor necrosis factor-α (TNFα) therapies in Crohn disease (CD) is spread, the loss-of-response (LOR) to it is increasingly encountered. Discovering a pathological pathway and biomarkers that can predict LOR would assist in the management of patients with CD. In this article, we provide a comprehensive systematic review of studies assessing predictors of immunogenicity and loss-of-response to anti-TNFα drugs in patients with CD.

DATA SOURCES

We performed a systematic review of PubMed to identify citations pertaining to predictors of immunogenicity and loss-of-response to anti-TNFα drugs in patients with CD through April 27, 2024, using a predefined string of keywords. Data extraction and quality assessment were performed independently by 2 reviewers.

RESULTS

A total of 18 eligible studies were included in the review. Four major groups of studies were identified: genetic factors, factors linked with colonic inflammation, serum and anthropological markers, and prevention of LOR. Promising predictors of LOR to infliximab or adalimumab include the carriage of HLA-DQA1*05, visceral adiposity, intestinal abundant presence of CD96, IL-17, and IL-23. Substantial heterogeneity was observed, and none of the markers had undergone formal validation. Specific limitations to acceptance of these factors included failure to use a standardized definition of LOR to anti-TNFα treatment, lack of specificity, and insufficient relevance to the pathogenesis of LOR.

CONCLUSIONS

This review underlines the lack of well-defined studies and controlled trials investigating predictors of LOR to anti-TNFα therapies in CD. A research priority is the development of reliable and accurate biomarkers that can shed light on the pathogenesis of the implied LOR. These biomarkers, along with genetic factors, have the potential to enhance clinical management by aiding in patient stratification and monitoring.

Pharmacogenetics in Response to Biological Agents in Inflammatory Bowel Disease: A Systematic Review

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders influenced by microbial, environmental, genetic, and immune factors. The introduction of biological agents has transformed IBD therapy, improving symptoms, reducing complications, and enhancing patients' quality of life. However, approximately 30% of patients exhibit primary non-response, and 50% experience a loss of response over time. Genetic and non-genetic factors contribute to variability in treatment outcomes. This systematic review aims to thoroughly analyze and assess existing studies exploring the relationships between genetic variations and individual responses to biologic drugs, in order to identify genetic markers that are predictive of treatment efficacy, risk of adverse effects, or drug toxicity, thereby informing clinical practice and guiding future research. PubMed and EMBASE papers were reviewed by three independent reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses [PRISMA] guidelines. Of the 883 records screened, 99 met the inclusion criteria. The findings of this review represent an initial step toward personalized medicine in IBD, with the potential to improve clinical outcomes in biological therapy.

Therapeutic drug monitoring and immunogenetic factors associated with the use of adalimumab in Crohn's disease patients

Crohn's disease (CD) involves immune system interactions with intestinal tissue, driven by pro-inflammatory cytokines like Tumor Necrosis Factor (TNF-α). Adalimumab, targeting TNF-α, regulates associated inflammatory responses. Despite being humanized, it may induce immunogenic processes, affecting treatment effectiveness. Thus, monitoring serum adalimumab and anti-drug antibody (ADA) levels can optimize therapy. Understanding genetic factors influencing adalimumab response can enhance personalized treatment and improve patient quality of life. We aimed to quantify adalimumab serum levels, assess test interchangeability, detect ADA, examine immune complex formation, and investigate genetic phenotypes related to immunogenicity in CD patients. Seventy CD patients in the maintenance phase with adalimumab were classified into active (CDA) and remission (CDR) groups. Adalimumab concentration was determined via enzyme-linked immunosorbent assay (ELISA-Promonitor) and lateral flow assay (Quantum Blue), with assay interchangeability assessed statistically. ADA and immune complex formation were quantified using ELISA assays. DNA was genotyped for the genes ATG16L1, CD96, and CD155. No significant differences in adalimumab serum concentrations were observed between groups, regardless of the assay. However, a statistical difference between the tests indicated measurement disparity (P = 0.003), with moderate agreement (Lin's correlation of 0.247). ADA was detected in 4 of 27 of the patients with infratherapeutic levels, 3 in the CDA group and 1 in the CDR group. Analysis of immune complexes revealed significantly higher concentrations in the CDA group (P = 0.0125). The genotypic evaluation revealed significant associations for the CD96 CC (wild-type) genotype with higher CRP levels, colonic involvement, and infratherapeutic levels of adalimumab. ATG16L1 CC genotype was associated with higher CDEIS and fecal calprotectin values, while the variant (TT) genotype had lower platelet counts. The effectiveness of treatment with adalimumab was not directly related to higher medication levels in this cohort. The disparity between tests indicates the need to use only one test in patient follow-up to ensure accuracy in therapeutic monitoring. Genotypic differences highlight the correlation between the wild genotype for CD96 and ATG16L1 with unfavorable laboratory and endoscopic response to adalimumab. Finally, the more significant levels of immune complexes in the CDA group indicate an association with a worse response to adalimumab.

HLA-DQA1*05 correlates with increased risk of anti-drug antibody development and reduced response to infliximab in Chinese patients with Crohn's disease

Background

The efficacy of anti-TNF therapy in Crohn's disease (CD), such as infliximab, is often compromised by the development of anti-drug antibodies (ADAs). The genetic variation HLA-DQA1*05 has been linked to the immunogenicity of biologics, influencing ADA formation. This study investigates the correlation between HLA-DQA1*05 and ADA formation in CD patients treated with infliximab in a Chinese Han population and assesses clinical outcomes.

Methods

In this retrospective cohort study, 345 infliximab-exposed CD patients were genotyped for HLADQ A1*05A > G (rs2097432). We evaluated the risk of ADA development, loss of infliximab response, adverse events, and treatment discontinuation among variant and wild-type allele individuals.

Results

A higher percentage of patients with ADAs formation was observed in HLA-DQA1*05 G variant carriers compared with HLA-DQA1*05 wild-type carriers (58.5% vs 42.9%, P = 0.004). HLA-DQA1*05 carriage significantly increased the risk of ADAs development (adjusted hazard ratio = 1.65, 95% CI 1.18-2.30, P = 0.003) and was associated with a greater likelihood of infliximab response loss (adjusted HR = 2.55, 95% CI 1.78-3.68, P < 0.0001) and treatment discontinuation (adjusted HR = 2.21, 95% CI 1.59-3.06, P < 0.0001). Interestingly, combined therapy with immunomodulators increased the risk of response loss in HLA-DQA1*05 variant carriers.

Conclusions

HLA-DQA1*05 significantly predicts ADAs formation and impacts treatment outcomes in infliximab-treated CD patients. Pre-treatment screening for this genetic factor could therefore be instrumental in personalizing anti-TNF therapy strategies for these patients.

Single-Cell Transcriptomic and Targeted Genomic Profiling Adjusted for Inflammation and Therapy Bias Reveal CRTAM and PLCB1 as Novel Hub Genes for Anti-Tumor Necrosis Factor Alpha Therapy Response in Crohn's Disease

The lack of reliable biomarkers in response to anti-TNFα biologicals hinders personalized therapy for Crohn's disease (CD) patients. The motivation behind our study is to shift the paradigm of anti-TNFα biomarker discovery toward specific immune cell sub-populations using single-cell RNA sequencing and an innovative approach designed to uncover PBMCs gene expression signals, which may be masked due to the treatment or ongoing inflammation; Methods: The single-cell RNA sequencing was performed on PBMC samples from CD patients either naïve to biological therapy, in remission while on adalimumab, or while on ustekinumab but previously non-responsive to adalimumab. Sieves for stringent downstream gene selection consisted of gene ontology and independent cohort genomic profiling. Replication and meta-analyses were performed using publicly available raw RNA sequencing files of sorted immune cells and an association analysis summary. Machine learning, Mendelian randomization, and oligogenic risk score methods were deployed to validate DEGs highly relevant to anti-TNFα therapy response; Results: This study found PLCB1 in CD4+ T cells and CRTAM in double-negative T cells, which met the stringent statistical thresholds throughout the analyses. An additional assessment proved causal inference of both genes in response to anti-TNFα therapy; Conclusions: This study, jointly with an innovative design, uncovered novel candidate genes in the anti-TNFα response landscape of CD, potentially obscured by therapy or inflammation.

Nectin Family Ligands Trigger Immune Effector Functions in Health and Autoimmunity

The superfamily of immunoglobulin cell-adhesion molecules (IgCAMs) is a well-known family of cell-adhesion molecules used for immune-cell extravasation and cell-cell interaction. Amongst others, this family includes DNAX accessory molecule 1 (DNAM-1/CD226), class-I-restricted T-cell-associated molecule (CRTAM/CD355), T-cell-activated increased late expression (Tactile/CD96), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), Nectins and Nectin-like molecules (Necls). Besides using these molecules to migrate towards inflammatory sites, their interactions within the immune system can support the immunological synapse with antigen-presenting cells or target cells for cytotoxicity, and trigger diverse effector functions. Although their role is generally described in oncoimmunity, this review emphasizes recent advances in the (dys)function of Nectin-family ligands in health, chronic inflammatory conditions and autoimmune diseases. In addition, this review provides a detailed overview on the expression pattern of Nectins and Necls and their ligands on different immune-cell types by focusing on human cell systems.

CD96 Downregulation Promotes the Immune Response of CD4 T Cells and Associates with Ankylosing Spondylitis

Inhibitory receptors (IRs) play an indispensable role in regulating T cell activation and expansion. This study is aimed at exploring the correlation between IRs and ankylosing spondylitis (AS). Bioinformatics analysis of two datasets (GSE25101 and GSE73754), including 68 AS cases and 36 healthy controls, demonstrated that "T cell receptor signaling pathway" was significantly enriched, and two IRs (CD112R and CD96) were downregulated in AS cases. Real-time Quantitative PCR Detecting System (qPCR) analysis confirmed the decreased expression of CD112R and CD96 in the peripheral blood of AS patients. Flow cytometry demonstrated that the frequency of CD96-positive cells among CD4 T cells in AS patients was significantly reduced and that expressed on the cells was also significantly lower than the healthy controls. In addition, the expression of CD96 was altered on human primary CD4 T cells extracted from 3 healthy volunteers and cocultured with allogeneic dendritic cells (DCs). Also, low expression of CD96 elevated the phosphorylation of ERK in CD4 T cells and increased the level of TNF-α, IL-23, IL-17A, IL-6, and IFN-γ in the cell culture supernatant. These results suggested that CD96 is crucial for the pathogenesis of AS and may be a potential target in the treatment of the disease.

Pharmacogenetics of inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) show large variability in disease course, and also treatment response. The variability in treatment response has led to many initiatives in search of genetic markers to optimize treatment and avoid severe side effects. This has been very successful for thiopurines, one of the drugs used to induce and maintain remission in IBD. However, for the newer treatment options for IBD, like biologicals, the search for genetic predictors has not yielded any candidate biomarkers with clinical utility. In this review, a summary of recent advances in pharmacogenetics focusing on thiopurines and anti-TNF agents is given.