A Celiac Disease Phenotype After Checkpoint Inhibitor Exposure: An Example of Immune Dysregulation After Immunotherapy

Review article: Contemporary management of gastrointestinal, pancreatic and hepatic toxicities of immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are effective oncologic agents which frequently cause immune-related adverse events (irAEs) which can impact multiple organ systems. Onco-Gastroenterology is a novel and emerging subspecialty within gastroenterology focused on cancer treatment-related complications. Gastroenterologists must be prepared to identify and manage diverse immune-mediated toxicities including enterocolitis, hepatitis, pancreatitis and other ICI-induced toxicities.

AIM

To provide a narrative review of the epidemiology, diagnostic evaluation and management of checkpoint inhibitor-induced gastrointestinal and hepatic toxicities.

METHODS

We searched Cochrane and PubMed databases for articles published through August 2023.

RESULTS

Gastrointestinal and hepatic irAEs include most commonly enterocolitis and hepatitis, but also pancreatitis, oesophagitis, gastritis, motility disorders (gastroparesis) and other rarer toxicities. Guidelines from the National Comprehensive Cancer Network, American Society of Clinical Oncology and European Society for Medical Oncology, in combination with emerging cohort and clinical trial data, offer strategies for management of ICI toxicities. Evaluation of irAEs severity by formal classification and clinical stability, and a thorough workup for alternative etiologies which may clinically mimic irAEs underlie initial management. Treatments include corticosteroids, biologics and other immunosuppressive agents plus supportive care; decisions on dosing, timing and choice of steroid adjuncts and potential for subsequent checkpoint inhibitor dosing are nuanced and toxicity-specific.

CONCLUSIONS

Expanding clinical trial and cohort data have clarified the epidemiology and clinical characteristics of gastrointestinal, pancreatic and hepatic toxicities of ICIs. Guidelines, though valuable, remain based principally on retrospective cohort data. Quality prospective, controlled studies may refine algorithms for treatment and potential immunotherapy rechallenge.

Subclinical Celiac Disease Unmasked by Immune Checkpoint Inhibitor Therapy

Immune checkpoint inhibitors (ICI) are antibodies that block immune checkpoint proteins from binding with their partner proteins on cancer cells, subsequently allowing cytotoxic T-cell-associated enhancement of antitumor responses. Although ICIs have become the standard of care for various malignancies, their use is often limited by unique immune-related adverse events, including dermatologic, endocrine, inflammatory, hepatic, and gastrointestinal events. Diarrhea and colitis are common lower gastrointestinal tract immune-related adverse events, however, only a few cases have reported the association between celiac disease (CD) and ICIs. We report here a case of a 75-year-old man with new onset CD after exposure to the cytotoxic T-lymphocyte-associated antigen-4 ICI, ipilimumab. Although ICI-induced CD is relatively rare, it is essential to consider it in a genetically susceptible patient undergoing treatment with ICI. Patients with known high susceptibility to CD, such as a family history of CD, or with the ancestry of high celiac penetrance (eg, Northern Europe, North Africa, etc), dermatitis herpetiformis, or chronic bowel symptoms, we feel should have celiac panel testing before initiating ICI therapy.

Case Report: Fulminant Celiac Disease With Combination Immune Checkpoint Therapy

Since the first approval of immune checkpoint inhibitors (ICIs) in 2011, these agents have rapidly become an integral treatment option across tumor types. However, with the increased adoption of ICIs, the incidence of immune-related adverse events (irAEs) continues to rise, and rare toxicity continues to be reported. Here, we present a case of a 70-year-old male patient with widespread metastatic melanoma who developed rapid onset anasarca and transaminitis after initiation of dual anti-PD-1/CTLA-4 inhibition with nivolumab and ipilimumab. An extensive workup was performed with serologies returning positive for anti-tissue transglutaminase immunoglobulin (tTG-IgA) and endoscopy revealing duodenal mucosal atrophy with duodenal biopsies confirming celiac disease. All symptoms resolved after initiation of a gluten-free diet without the addition of immunosuppression. This case highlights the importance of considering celiac disease in patients with suspected protein-losing enteropathy on ICI, the fulminant nature this uncommon irAE can present with, and underscores the broad differential clinicians must maintain when managing presumed irAEs.

Checkpoint Inhibitors and Induction of Celiac Disease-like Condition

Immune checkpoint inhibitors herald a new era in oncological therapy-resistant cancer, thus bringing hope for better outcomes and quality of life for patients. However, as with other medications, they are not without serious side effects over time. Despite this, their advantages outweigh their disadvantages. Understanding the adverse effects will help therapists locate, apprehend, treat, and perhaps diminish them. The major ones are termed immune-related adverse events (irAEs), representing their auto-immunogenic capacity. This narrative review concentrates on the immune checkpoint inhibitors induced celiac disease (CD), highlighting the importance of the costimulatory inhibitors in CD evolvement and suggesting several mechanisms for CD induction. Unraveling those cross-talks and pathways might reveal some new therapeutic strategies.

Celiac Disease After Administration of Immune Checkpoint Inhibitors: A Case Report

Immune checkpoint inhibitors (ICI) reinvigorate the immune system to recognize and destroy tumor cells. Because of this biological mechanism, patients might develop autoimmune toxicities, notably in the digestive tract (most frequently, hepatitis or colitis). A 70-year-old man with relapsed mesothelioma was treated with nivolumab in 3rd line. He was hospitalized for watery and foul-smelling diarrhea. He underwent gastrointestinal endoscopy, showing duodenitis and villous atrophy and measurement of serum IgA antibodies to tissue transglutaminase (tTG-IgA+), leading to the diagnosis of ICI-induced celiac disease. He was treated with steroids, proton pump inhibitors, and a gluten-free diet. If ICI-induced celiac disease is rare in the literature, increasing reports suggest that celiac disease might represent an underestimated ICI toxicity. This case highlights the necessity of complementary investigation (including tTG-IgA and endoscopic biopsies) in patients with atypical digestive symptoms during immunotherapy.

Histological Features of Celiac-Disease-like Conditions Related to Immune Checkpoint Inhibitors Therapy: A Signal to Keep in Mind for Pathologists

Immune checkpoint inhibitors (ICIs) targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1), and its ligand PDL-1, are finding increasing application in the treatment of malignant neoplasms. The widespread clinical use of these drugs, however, resulted in the discovery of side effects. The occurrence of celiac disease (CD) after ICIs therapy has been reported in the literature, but its incidence remains unknown and the role of ICIs in its onset is not yet clear. In this review, we examine the published data on this topic in order to better understand and define this entity from a histological point of view. We performed an electronic literature search to identify original reports in which CD or pathological CD-like conditions were documented histologically in patients treated with ICIs. We identified ten papers. A total of twenty-five patients were included in these publications, eleven of them receiving a serologic and histological diagnosis of CD, and four a histological diagnosis of CD-like conditions, in which pathogenesis appears to be multifactorial. ICIs can cause a CD-like enteropathy and biopsies with clinical integration are crucial to diagnose this condition. CD rarely has been observed during treatment with ICIs and its morphological aspects are similar to ICIs-CD enteropathy. Moreover, the onset of ICIs-CD may have a distinct immune mechanism compared to classical CD. Thus, the pathologists must make a histological diagnosis of CD with caution and only in adequate clinical and serological context.

Immunotherapy-induced coeliac disease in curative lung cancer

The advent of immunotherapy has revolutionised the treatment of metastatic lung cancer and it has recently been established as the standard of care in the radical treatment of lung cancer. However, immune-related adverse events (IrAEs) frequently occur in patients treated with immunotherapy, and rare IrAEs continue to be identified. We report a case of immunotherapy-induced coeliac disease due to adjuvant durvalumab post-chemoradiotherapy in a patient receiving curative treatment for lung cancer. The patient had raised anti-tissue transglutaminase IgA and histological findings consistent with coeliac disease. This is the first published case report of probable immunotherapy-induced coeliac disease both with the immunotherapy drug durvalumab and in the curative lung cancer setting.

Immune checkpoint inhibitor-associated celiac disease

BACKGROUND

Rare cases of immune checkpoint inhibitor (ICI)-associated celiac disease (ICI-CeD) have been reported, suggesting that disruption of tolerance mechanisms by ICIs can unmask celiac disease (CeD). This study aims to characterize the clinicopathological and immunophenotypic features of ICI-CeD in comparison to ICI-associated duodenitis (ICI-Duo) and usual CeD.

METHODS

A medical and pathological records search between 2015 and 2019 identified eight cases of ICI-CeD, confirmed by tTG-IgA. Nine cases of ICI-Duo, 28 cases of moderate CeD, as well as 5 normal controls were used as comparison groups. Clinical information was collected from the electronic medical records. Immunohistochemistry for CD3, CD8, T-cell receptor gamma/delta (γδ), programmed death ligand 1 (PD-L1), and programmed death 1 (PD-1) were performed, with quantification of intraepithelial lymphocyte (IEL) subsets in three well-oriented villi. CD68, PD-L1, and PD-1 were assessed as a percentage of lamina propria surface area infiltrated by positive cells. Statistical significance was calculated by the Student's t-test and Fisher's exact test.

RESULTS

The eight patients with ICI-CeD (F:M=1:3) and nine patients with ICI-Duo (F:M=5:4) presented similarly with diarrhea (13/17) and abdominal pain (11/17) after a median of 1.6 months on ICI therapy. In patients with ICI-CeD, tTG-IgA ranged from 104 to >300 IU/mL. Histological findings in ICI-CeD and ICI-Duo were similar and included expansion of the lamina propria, active neutrophilic duodenitis, variably increased IELs, and villous blunting. Immunohistochemistry showed that the average number of IELs per 100 enterocytes is comparable between ICI-CeD and ICI-Duo, with increased CD3⁺ CD8⁺ T cells compared with normal duodenum but decreased γδ T cells compared with CeD. Average PD-L1 percentage was 9% in ICI-CeD and 18% in ICI-Duo, in comparison to <1% in CeD and normal duodenum; average PD-1 percentage was very low to absent in all cases (<3%). On follow-up, five patients with ICI-CeD improved on a gluten-free diet (GFD) as the sole therapeutic intervention (with down-trending tTG-IgA) while the other three required immunosuppression. All patients who developed ICI-Duo received immunosuppression with variable improvement in symptoms.

CONCLUSIONS

ICI-CeD resembles ICI-Duo clinically and histologically but shares the serological features and response to gluten withdrawal with classic CeD. Immunophenotyping of IELs in ICI-CeD and ICI-Duo also shows similar CD3, CD8, γδ T cell subsets, and PD-L1 populations, all of which differed quantitatively from usual CeD. We conclude that ICI-CeD is biologically similar to ICI-Duo and is likely a variant of ICI-Duo, but treatment strategies differ, with ICI-CeD often improving with GFD alone, whereas ICI-Duo requires systemic immunosuppression.

Innate and adaptive immunity in celiac disease

PURPOSE OF REVIEW

The current review is prompted by recent studies indicating that adaptive immunity could be sufficient to explain rapid onset symptoms as well as many chronic effects of gluten in celiac disease.

RECENT FINDINGS

Gluten re-exposure in treated celiac disease drives a coordinated systemic cytokine release response implicating T-cell activation within 2 h. Instead of direct effects of gluten on innate immunity, long lasting memory CD4+ T cells activated within 2 h of ingesting gluten or injecting purified gluten peptides now appear to be responsible for acute digestive symptoms. In addition, memory B cells and plasma cells specific for gluten and transglutaminase 2, rather than innate immune cells, are the preferred antigen-presenting cells for gluten in the gut. A variety of innate immune stimuli such as transient infections and local intestinal microbiome, not necessarily gluten itself, may contribute to disease initiation and transition to overt intestinal mucosal injury. Gluten-specific adaptive immunity in the gut and blood are now shown to be closely linked, and systemic cytokine release after gluten provides an additional explanation for extraintestinal manifestations of celiac disease.

SUMMARY

Clinical studies utilizing cytokines as new biomarkers for gluten immunity promise to improve understanding of clinical effects of gluten, accelerate therapeutics development, and augment diagnosis.

Emergency management of immune-related toxicity

PURPOSE OF REVIEW

Emergency presentations in patients treated with immune checkpoint inhibitors (ICIs) are a clinical challenge. Clinicians need to be vigilant in diagnosing and treating immune-mediated toxicities. In this review, we consider the approach to managing an acutely unwell patient being treated with ICIs presenting as an emergency.

RECENT FINDINGS

A minority of acutely unwell patients treated with ICIs will have an immune-mediated toxicity. Early recognition and intervention in those with immune-mediated toxicity can reduce the duration and severity of the complications. The use of early immunosuppressive agents along corticosteroid therapy may improve outcomes in patients with life-threatening immune-mediated toxicity.

SUMMARY

Individualized management of immune-mediated toxicities is a key challenge for emergency oncology services; this has become part of routine cancer care.