Recognising and Managing Refractory Coeliac Disease: A Tertiary Centre Experience

Advances in Nonresponsive and Refractory Celiac Disease

Nonresponsive celiac disease (CeD) is relatively common. It is generally attributed to persistent gluten exposure and resolves after correction of diet errors. However, other complications of CeD and disorders clinically mimicking CeD need to be excluded. Novel therapies are being evaluated to facilitate mucosal recovery, which might benefit patients with nonresponsive CeD. Refractory CeD (RCeD) is rare and is divided into 2 types. The etiology of type I RCeD is unclear. A switch to gluten-independent autoimmunity is suspected in some patients. In contrast, type II RCeD represents a low-grade intraepithelial lymphoma. Type I RCeD remains a diagnosis of exclusion, requiring ruling out gluten intake and other nonmalignant causes of villous atrophy. Diagnosis of type II RCeD relies on the demonstration of a clonal population of neoplastic intraepithelial lymphocytes with an atypical immunophenotype. Type I RCeD and type II RCeD generally respond to open-capsule budesonide, but the latter has a dismal prognosis due to severe malnutrition and frequent progression to enteropathy-associated T-cell lymphoma; more efficient therapy is needed.

Immunosuppressants and immune modulators in luminal gastroenterology

Heritage small molecule immunosuppressants and the immune-acting biologics have a major place in the management of luminal gastrointestinal disease and especially so in inflammatory bowel disease. This narrative review considers their current use, concentrating on issues not already well addressed in the literature. An evidence-based approach is taken, supplemented by advice based on observations from clinical practice when data are missing. There is a general trend towards earlier use of the biologics for perceived greater safety and impact on disease modification, despite their substantially greater cost and systemic administration. Early semi-prophylactic treatment is now considered for patients with high-risk Crohn's disease. In other conditions the immune active agents remain a back-up for those failing to respond to simpler options. There are few and mostly unimportant differences between the different antibodies to TNFα, but it is beginning to be possible to identify patients who could be preferentially treated with an anti-integrin approach or by addressing other cytokines.

Cellular and molecular bases of refractory celiac disease

Refractory celiac disease (RCD) encompasses biologically heterogeneous disorders that develop in a small proportion (0.3%) of individuals with celiac disease that are associated with high morbidity. Two broad categories are currently recognized, type I (RCD I) and type II (RCD II), based on immunophenotypic and molecular features of the intraepithelial lymphocytes (IELs). RCD I is characterized by a polyclonal expansion of IELs displaying a normal immunophenotype, while RCD II represents a clonal proliferation of immunophenotypically "aberrant" IELs, and is considered a low-grade lymphoproliferative disorder. The pathogenesis of RCD I has not been clarified, but limited studies suggest multifactorial etiology. On the other hand, recent immunologic, molecular and immunophenotypic analyses have proposed lineage-negative innate IELs to be the cell of origin of a proportion of RCD II cases. Furthermore, sequencing studies have identified frequent, recurrent, activating mutations in members of the JAK-STAT pathway in RCD II. This finding, in conjunction with prior in vitro experimental observations, suggests roles of deregulated cytokine signaling in disease pathogenesis. In this review, we describe current understanding of environmental, immune and genetic factors associated with the development of RCD and briefly discuss diagnostic and therapeutic considerations.

Immunophenotypic Spectrum and Genomic Landscape of Refractory Celiac Disease Type II

Refractory celiac disease type II (RCD II), also referred to as "cryptic" enteropathy-associated T-cell lymphoma (EATL) or "intraepithelial T-cell lymphoma," is a rare clonal lymphoproliferative disorder that arises from innate intraepithelial lymphocytes. RCD II has a poor prognosis and frequently evolves to EATL. The pathogenesis of RCD II is not well understood and data regarding the immunophenotypic spectrum of this disease and underlying genetic alterations are limited. To gain further biological insights, we performed comprehensive immunophenotypic, targeted next-generation sequencing, and chromosome microarray analyses of 11 RCD II cases: CD4-/CD8- (n=6), CD8+ (n=4), and CD4+ (n=1), and 2 of 3 ensuing EATLs. Genetic alterations were identified in 9/11 (82%) of the RCD II cases. All 9 displayed mutations in members of the JAK-STAT signaling pathway, including frequent, recurrent STAT3 (7/9, 78%) and JAK1 (4/9, 44%) mutations, and 9/10 evaluable cases expressed phospho-STAT3. The mutated cases also harbored recurrent alterations in epigenetic regulators (TET2, n=5 and KMT2D, n=5), nuclear factor-κB (TNFAIP3, n=4), DNA damage repair (POT1, n=3), and immune evasion (CD58, n=2) pathway genes. The CD4-/CD8- and other immunophenotypic subtypes of RCD II exhibited similar molecular features. Longitudinal genetic analyses of 4 RCD II cases revealed stable mutation profiles, however, additional mutations were detected in the EATLs, which occurred at extraintestinal sites and were clonally related to antecedent RCD II. Chromosome microarray analysis demonstrated copy number changes in 3/6 RCD II cases, and 1 transformed EATL with sufficient neoplastic burden for informative analysis. Our findings provide novel information about the immunophenotypic and genomic characteristics of RCD II, elucidate early genetic events in EATL pathogenesis, and reveal potential therapeutic targets.

Refractory coeliac disease: what should we be doing different?

PURPOSE OF REVIEW

The aim of this review is to provide insight into the diagnosis and management of patients with refractory coeliac disease (RCD) and highlight recent advances in this field.

RECENT FINDINGS

The diagnosis of RCD can be more accurately confirmed with flow cytometry in addition to immunohistochemistry. Dietary input and excretion of gluten immunogenic peptides can help rule out gluten contamination, and therefore, substantiate a diagnosis of RCD type I. Small bowel capsule endoscopy (SBCE) is important at diagnosis and follow-up in addition to duodenal histology. Apart from ruling out complications, it can give information on extent of disease in the small bowel, and therefore, help assess response to therapy. Those patients with a poor response can have earlier intensification of therapy, which may result in an improved outcome. RCD also occurs in patients with serology negative coeliac disease but with an increased mortality compared with patients with serology-positive coeliac disease.

SUMMARY

Patients with RCD can present with persistent symptoms of malnutrition but can also be completely asymptomatic. Serology is not a reliable marker to detect refractory disease. Immunostaining and flow cytometry are necessary for a diagnosis of RCD. Small bowel endoscopy enables disease extent to be assessed and allows for small bowel biopsies to be taken in case of suspicious lesions. Small bowel radiology can be complementary to small bowel endoscopy.

Refractory celiac disease type II: An atypical case highlighting limitations of the current classification system

Refractory celiac disease (RCD) is a rare condition associated with high morbidity that develops in individuals with celiac disease. It is known to be biologically heterogeneous, and currently two types are recognized based on immunophenotypic and molecular features, type I (RCD I) and type II (RCD II). Differentiating between RCD I and RCD II is critical, as patients with RCD II have substantially worse outcomes and a high risk of developing enteropathy-associated T-cell lymphoma. However, the current RCD classification is limited in scope, and atypical presentations and immunophenotypes are not recognized at present. Herein, we describe a unique case of RCD II with atypical clinical (primarily neurologic manifestations and lack of significant gastrointestinal symptoms), histopathologic (no villous atrophy), immunophenotypic (virtual absence of cytoplasmic CD3 expression), and molecular features (absence of clonal TR rearrangement and identification of pathogenic STAT3 and KMT2D mutations). This case highlights limitations of the current RCD classification system and the utility of next generation sequencing (NGS) studies in the diagnostic workup of RCD. Future algorithms need to recognize extraintestinal manifestations and incorporate atypical histopathologic and immunophenotypic features, as well as results of NGS analysis for RCD II classification.

How to manage adult coeliac disease: perspective from the NHS England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease

Adult coeliac disease (CD) affects approximately 1% of the population. Most patients diagnosed will respond to a gluten-free diet; however, up to 30% may have persisting symptoms. Such patients may have ongoing issues associated with adherence, non-responsive CD or refractory CD. This article provides a clinical overview of how to manage this group of patients with persisting symptoms, including an investigational algorithm and details of how to contact the National Health Service England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease. We hope this will be a valuable source of contemporary information for all UK gastroenterologists and internationally.

Diagnosis and Treatment Patterns in Celiac Disease

Celiac disease (CD) is an immune-mediated gastrointestinal (GI) disorder driven by innate and adaptive immune responses to gluten. Presentation of CD has changed over time, with non-GI symptoms, such as anemia and osteoporosis, presenting more commonly. With improved screening and diagnostic methods, the reported prevalence of CD has increased globally, and there is considerable global variation in diagnostic and treatment practices. The objective of this study was to describe the current state of CD diagnosis and treatment patterns. A targeted review of literature from MEDLINE, Embase, the Cochrane Library, and screening of relevant conference abstracts was performed. The generally recommended diagnostic approach is GI endoscopy with small bowel biopsy; however, in selected patients, biopsy may be avoided and diagnosis based on positive serology and clinical symptoms. Diagnosis often is delayed; the average diagnostic delay after symptom onset is highly variable and can last up to 12 years. Barriers to accurate and timely diagnosis include atypical presentation, lack of physician awareness about current diagnostic criteria, misdiagnosis, and limited access to specialists. Currently, strict adherence to a gluten-free diet (GFD) is the only recommended treatment, which is not successful in all patients. Only one-third of patients are monitored regularly following diagnosis. Unmet needs for CD include improvements in the accuracy and timeliness of diagnosis, and the development of treatments for both refractory CD and GFD nonresponsive CD. Further research should investigate the impact of education about gluten-free eating and the availability of gluten-free foods support adherence and improve outcomes in patients with CD.

Celiac disease: a comprehensive current review

BACKGROUND

Celiac disease remains a challenging condition because of a steady increase in knowledge tackling its pathophysiology, diagnosis, management, and possible therapeutic options.

MAIN BODY

A major milestone in the history of celiac disease was the identification of tissue transglutaminase as the autoantigen, thereby confirming the autoimmune nature of this disorder. A genetic background (HLA-DQ2/DQ8 positivity and non-HLA genes) is a mandatory determinant of the development of the disease, which occurs with the contribution of environmental factors (e.g., viral infections and dysbiosis of gut microbiota). Its prevalence in the general population is of approximately 1%, with female predominance. The disease can occur at any age, with a variety of symptoms/manifestations. This multifaceted clinical presentation leads to several phenotypes, i.e., gastrointestinal, extraintestinal, subclinical, potential, seronegative, non-responsive, and refractory. Although small intestinal biopsy remains the diagnostic 'gold standard', highly sensitive and specific serological tests, such as tissue transglutaminase, endomysial and deamidated gliadin peptide antibodies, have become gradually more important in the diagnostic work-up of celiac disease. Currently, the only treatment for celiac disease is a life-long, strict gluten-free diet leading to improvement in quality of life, ameliorating symptoms, and preventing the occurrence of refractory celiac disease, ulcerative jejunoileitis, and small intestinal adenocarcinoma and lymphoma.

CONCLUSIONS

The present review is timely and provides a thorough appraisal of various aspects characterizing celiac disease. Remaining challenges include obtaining a better understanding of still-unclear phenotypes such as slow-responsive, potential (minimal lesions) and seronegative celiac disease. The identification of alternative or complementary treatments to the gluten-free diet brings hope for patients unavoidably burdened by diet restrictions.

Approach to patients with refractory coeliac disease

Refractory coeliac disease (RCD) is a recognised complication, albeit very rare, of coeliac disease (CD). This condition is described when individuals with CD continue to experience enteropathy and subsequent or ongoing malabsorption despite strict adherence to a diet devoid of gluten for at least 12 months and when all other causes mimicking this condition are excluded. Depending on the T-cell morphology and T-cell receptor (TCR) clonality at the β/γ loci, RCD can be subdivided into type 1 (normal intra-epithelial lymphocyte morphology, polyclonal TCR population) and type 2 (aberrant IELs with clonal TCR). It is important to differentiate between the two types as type 1 has an 80% survival rate and is managed with strict nutritional and pharmacological management. RCD type 2 on the other hand has a 5-year mortality of 50% and can be complicated by ulcerative jejunitis or enteropathy-associated T-cell lymphoma (EATL). Management of RCD type 2 has challenged many experts, and different treatment approaches have been adopted with variable results. Some of these treatments include immunomodulation with azathioprine and steroids, methotrexate, cyclosporine, alemtuzumab (an anti CD-52 monoclonal antibody), and cladribine or fludarabine sometimes with autologous stem cell transplantation. In this article, we summarise the management approach to patients with RCD type 2.

Improving outcomes of refractory celiac disease - current and emerging treatment strategies

Intestinal inflammation and symptoms of celiac disease (CD) usually respond well to gluten withdrawal, but rare cases are refractory to diet. Two types of refractory CD are discriminated on the basis of the presence or absence of an atypical population of mucosal lymphocytes that may progress to enteropathy-associated T-cell lymphoma. Challenges remain in the secure diagnosis of both types of refractory disease, and evidence on which to base treatment recommendations is flawed by the small numbers of reported patients and the use of different diagnostic strategies. Recent advances in our understanding of the mechanisms of the condition in conjunction with the development of immunomodulatory agents for managing other inflammatory diseases are helping to shape future approaches to targeted therapy. Progression will depend on collaboration and recruitment to trials. In the meantime, there is evidence to suggest that earlier diagnosis and better follow-up and management of CD may prevent the development of refractoriness.