Are Complicated Forms of Celiac Disease Cryptic T-Cell Lymphomas?

Immunophenotyping of intraepithelial lymphocytes in canine chronic enteropathy and intestinal T-cell lymphoma using endoscopic samples

Human enteropathy-associated T-cell lymphoma (EATL) is considered to be derived from intraepithelial lymphocytes (IELs); however, the origin of canine intestinal T-cell lymphoma (ITCL) remains unclear. Histological, immunohistochemical, and clonality examinations were performed using endoscopically collected canine duodenum samples of mucosal lesions of chronic enteropathy (CE; 73 cases) and ITCL without transmural neoplastic mass lesions (64 cases). Histopathological examinations revealed the intraepithelial accumulation of lymphocytes (called "intraepithelial lymphocytosis") in 54/73 CE cases (74%) and the epitheliotropism of neoplastic lymphocytes in 63/64 ITCL cases (98%). Immunohistochemically, IELs in CE with intraepithelial lymphocytosis (IEL⁺CE) were diffusely immunopositive for CD3, with scattered immunopositivity for CD5, CD8, CD20, and granzyme B (GRB). The percentage of CD8⁺ in CD3⁺ IELs was significantly lower in IEL⁺CE than in CE without intraepithelial lymphocytosis (IEL^-CE). Double-labeling immunohistochemistry revealed a high percentage of GRB expression in CD8^- IEL among IEL⁺CE. Among 64 ITCL cases, CD3 was immunopositive in 64 (100%), CD5 in 22 (34%), CD8 in 8 (13%), CD20 in 12 (19%), CD30 in 13 (20%), and GRB in 49 (77%). In CD3⁺ cells, Ki67 immunopositivity was highest in ITCL, intermediate in IEL⁺CE, and lower in IEL^-CE. A clonal TCR gene rearrangement was detected in 1/19 IEL^-CE cases (5%), 15/54 IEL⁺CE (28%), and 38/58 ITCL (66%). These results indicate that the immunophenotype of canine ITCL (CD8^-GRB⁺) is similar to that of the increased IELs in CE. The high proliferative activity and clonality of T cells in IEL⁺CE suggest that canine ITCL originates from these IELs, similar to human EATL.

Immune-mediated enteropathies: From bench to bedside

Immune-mediated enteropathies are caused by excessive reactions of the intestinal immune system towards non-pathogenic molecules. Enteropathy leads to malabsorption-related symptoms and include (severe) chronic diarrhea, weight loss and vitamin deficiencies. Parenteral feeding and immunosuppressive therapy are needed in severe cases. Celiac disease has long been recognized as the most common immune-mediated enteropathy in adults, but the spectrum of immune-mediated enteropathies has been expanding. Histological and clinical features are sometimes shared among these enteropathies, and therefore it may be challenging to differentiate between them. Here, we provide an overview of immune-mediated enteropathies focused on clinical presentation, establishing diagnosis, immunopathogenesis, and treatment options.

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.

T- and NK-cell lymphoproliferative disorders of the gastrointestinal tract: review and update

T- and NK-cell lymphoproliferative disorders of the gastrointestinal (GI) tract are uncommon, but are important to recognise as there may be morphological and immunophenotypic overlap between lymphoid lesions with vastly different clinical outcomes. Recent data have led to the reclassification of some lymphomas and inclusion of new entities in the 2016 revision of World Health Organization (WHO) classification of lymphoid neoplasms. It has become clear that enteropathy associated T-cell lymphoma (EATL), formerly thought to be composed of two subtypes known as type I and type II, are distinct entities. Type I EATL is now simply classified as EATL; it is strongly associated with coeliac disease and occurs mainly in Western populations. Type II EATL has been renamed monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL); it shows no definite association with coeliac disease and occurs worldwide with a predominance in Asian populations. There is also a group of aggressive intestinal T-cell lymphomas which do not meet criteria for EATL, MEITL, extranodal NK/T-cell lymphoma of nasal type or anaplastic large cell lymphoma. These neoplasms are now designated intestinal T-cell lymphoma, not otherwise specified. Indolent T-cell lymphoproliferative disorder of the GI tract has been included as a provisional entity in the most recent WHO classification. It is a clonal T-cell lymphoproliferative disorder (CD4+ or CD8+) with an indolent clinical course. Finally, benign NK-cell proliferations of the GI tract, variably designated 'NK-cell enteropathy' and 'lymphomatoid gastropathy' have also been recognised in the last two decades but have not been included in the WHO classification as their neoplastic nature is not established. This review covers the aforementioned lymphoid proliferations, emphasising their salient clinicopathological features and genetic abnormalities. It also provides practical insights into resolving difficult differential diagnoses in daily surgical pathology practice.

Celiac Disease: Updates on Pathology and Differential Diagnosis

Celiac disease is a gluten-triggered immune-mediated disorder, characterized by inflammation of the enteric mucosa following lymphocytic infiltration and eventually resulting in villous blunting. There have been many developments in refining diagnostic laboratory tests for celiac disease in the last decade. Biopsy-sparing diagnostic guidelines have been proposed and validated in a few recent prospective studies. However, despite these developments, histologic evaluation of duodenal mucosa remains one of the most essential diagnostic tools as it helps in the diagnosis of celiac disease in individuals who do not fulfill the biopsy-sparing diagnostic criteria and in those not responding to a gluten-free diet. Histologic evaluation also allows for the assessment of mucosal recovery after treatment and in the identification of concurrent intestinal diseases. Therefore, pathologists should be familiar with the histologic spectrum of celiac disease and need to be aware of other disorders with similar symptoms and histopathology that may mimic celiac disease. This review aims to provide pathologists with updates on celiac laboratory testing, biopsy-sparing diagnostic criteria, histopathology, complications, and differential diagnoses of celiac disease.

New/Revised Entities in Gastrointestinal Lymphoproliferative Disorders

The gastrointestinal tract is a common extranodal site of involvement by lymphomas. These may be diagnostically challenging because they can mimic a variety of benign conditions and may be difficult to subclassify when malignant. The classification of gastrointestinal lymphomas is an evolving area with some recent changes. Although some of these entities are rare, they are important to recognize because of the variable clinical presentations, comorbidities, and treatment implications. This article explores new and revised entities in gastrointestinal lymphoproliferative disorders.

Pathogenesis of Enteropathy-Associated T Cell Lymphoma

PURPOSE OF REVIEW

To provide an update on the pathogenesis of enteropathy-associated T cell lymphoma (EATL) and its relationship with refractory celiac disease (RCD), in light of current knowledge of immune, genetic, and environmental factors that promote neoplastic transformation of intraepithelial lymphocytes (IELs).

RECENT FINDINGS

EATL frequently evolves from RCD type II (RCD II) but can occur "de novo" in individuals with celiac disease. Recurrent activating mutations in members of the JAK/STAT pathway have been recently described in EATL and RCD II, which suggests deregulation of cytokine signaling to be an early event in lymphomagenesis. Intraepithelial T cells are presumed to be the cell of origin of EATL (and RCD II). Recent in vitro molecular and phenotypic analyses and in vivo murine studies, however, suggest an origin of RCD II from innate IELs (NK/T cell precursors), which could also be the cell of origin of RCD II-derived EATL. The immune microenvironment of the small intestinal mucosa in celiac disease fosters the development of EATL, often in a multistep pathway.

T-cell repertoires in refractory coeliac disease

OBJECTIVE

Refractory coeliac disease (RCD) is a potentially hazardous complication of coeliac disease (CD). In contrast to RCD type I, RCD type II is a precursor entity of enteropathy-associated T-cell lymphoma (EATL), which is associated with clonally expanding T-cells that are also found in the sequentially developing EATL. Using high-throughput sequencing (HTS), we aimed to establish the small-intestinal T-cell repertoire (TCR) in CD and RCD to unravel the role of distinct T-cell clonotypes in RCD pathogenesis.

DESIGN

DNA extracted from duodenal mucosa specimens of controls (n=9), active coeliacs (n=10), coeliacs on a gluten-free diet (n=9), RCD type I (n=8), RCD type II (n=8) and unclassified Marsh I cases (n=3) collected from 2002 to 2013 was examined by TCRβ-complementarity-determining regions 3 (CDR3) multiplex PCR followed by HTS of the amplicons.

RESULTS

On average, 10⁶ sequence reads per sample were generated consisting of up to 900 individual TCRβ rearrangements. In RCD type II, the most frequent clonotypes (ie, sequence reads with identical CDR3) represent in average 42.6% of all TCRβ rearrangements, which was significantly higher than in controls (6.8%; p<0.01) or RCD type I (6.7%; p<0.01). Repeat endoscopies in individual patients revealed stability of clonotypes for up to several years without clinical symptoms of EATL. Dominant clonotypes identified in individual patients with RCD type II were unique and not related between patients. CD-associated, gliadin-dependent CDR3 motifs were only detectable at low frequencies.

CONCLUSIONS

TCRβ-HTS analysis unravels the TCR in CD and allows detailed analysis of individual TCRβ rearrangements. Dominant TCRβ sequences identified in patients with RCD type II are unique and not homologous to known gliadin-specific TCR sequences, supporting the assumption that these clonal T-cells expand independent of gluten stimulation.

Detection of monoclonality in intestinal lymphoma with polymerase chain reaction for antigen receptor gene rearrangement analysis to differentiate from enteritis in dogs

The diagnosis of canine intestinal lymphoma by morphological examination is challenging, especially when endoscopic tissue specimens are used. The utility of detection of antigen receptor gene rearrangement by polymerase chain reaction (PARR) in canine lymphoma has been well established, but its usefulness to distinguish enteritis and intestinal lymphoma remains unclear. In this retrospective study we assessed clonality of 29 primary canine intestinal lymphoma, 14 enteritis and 15 healthy control cases by PARR analysis, using formalin-fixed, paraffin-embedded full-thickness tissue specimens. We could detect monoclonal rearrangements in 22 of 29 canine intestinal lymphomas [76%; 95% confidence interval (CI) 56-90%] and polyclonal rearrangements in all of the enteritis and healthy control cases (100%; CI 88-100%). We revealed a predominance of T-cell phenotype compared to B-cell phenotype (85%; CI 65-96% and 15%; CI 4-35%, respectively). We showed that PARR analysis contributes to differentiation of canine intestinal lymphoma from enteritis and to phenotyping of lymphomas.

CD103+ γδ T cell large granular lymphocytosis in a patient with refractory celiac disease: a diagnostic enigma

Indolent γδ T cell lymphomas/leukemias are rare and overlap with the morphological spectrum of large granular lymphocyte (LGL) leukemia. We report an extremely rare case of CD103(+) γδ T LGL leukemia in a patient with celiac disease who presented with refractory diarrhea. Whether the refractory diarrhea in our patient was a manifestation of LGL leukemia itself or whether the clonal LGL expansion is a manifestation of refractory celiac disease (RCD) remains an enigma. This report highlights the diagnostic difficulties and the need of consensus in categorizing clonal CD103(+) lymphocytosis in patients with RCD.

Enteropathy-associated T cell lymphoma as a complication of silent celiac disease

Celiac disease is an autoimmune disorder in which a genetic predisposition and the ingestion of wheat gluten triggers a deleterious immune response. This response is complex and may lead to manifestations other than enteropathyha: hepatitis, dermatitis and neuropathy. There is higher risk for neoplasia. We observed an atypical case, corresponding to a 69-year old female presenting with complicated celiac disease. The patient was referred following the histological examination of an enterectomy specimen, which unexpectedly revealed an enteropathy-associated T cell lymphoma in a background of celiac disease. Patient’s previous medical history comprised several abdominal surgical procedures, without other prior symptoms suggestive of celiac disease. Indeed, the patient was obese and no signs of malabsortion were apparent. This case draws our attention to clinically silent celiac disease, which represents a diagnostic challenge. Thus, this should be kept in mind whenever a patient presents with abdominal relapsing complications, otherwise unexplained.

Olmesartan-associated enteropathy: results of a national survey

BACKGROUND

Recently, a new enteropathy has been described: olmesartan-associated enteropathy. However, the association has been questioned: a phase 3 trial and a cohort study found no association between gastrointestinal events and olmesartan.

AIM

To collect French cases of sartan-associated enteropathy to describe further this entity, confirm or refute causality, and determine if the association exists with other sartans.

METHODS

French gastroenterologists were invited to report cases of sartan-associated enteropathy and collect clinical, biological and histological data. Patients with diarrhoea and histological duodenal abnormalities were included.

RESULTS

Thirty-six patients with olmesartan-associated enteropathy were reported, including 32 with villous atrophy and four without. There was only one patient with irbesartan-associated enteropathy. None of the patients died. Patients with villous atrophy had diarrhoea, vomiting, renal failure, hypokalaemia, body weight loss and hypoalbuminaemia. Thirty-one patients were hospitalised; four required intensive care. Anti-transglutaminase and anti-enterocyte antibodies were negative; anti-nuclear antibodies were positive (9/11). Endoscopic duodenal biopsies showed villous atrophy (32/32) and polyclonal intra-epithelial CD3+CD8+ lymphocytosis (11/11). Exactly, 14/15 patients responded to steroids and/or immunosuppressants, prescribed because of suspected autoimmune enteropathy. Ten olmesartan interruptions were followed by reintroductions before steroids or immunosuppressants. Interruptions were followed by remissions (9/10), but reintroductions were followed by relapses (9/9). Twenty-nine patients were in remission since olmesartan interruption, including 26 without immunosuppressants. Patients with normal villi had similar clinical characteristics, but mild histological abnormalities (intra-epithelial lymphocytosis and lamina propria lymphocytic infiltration).

CONCLUSIONS

Olmesartan causes a severe and immune-mediated enteropathy, with or without villous atrophy. Enteropathy associated with other sartans seems to be very rare.

T-cell receptor diversity prevents T-cell lymphoma development

Mature T-cell lymphomas (MTCLs) have an extremely poor prognosis and are much less frequent than immature T-cell leukemias. This suggests that malignant outgrowth of mature T lymphocytes is well controlled. Indeed, in a previous study we found that mature T cells are resistant to transformation with known T-cell oncogenes. Here, however, we observed that T-cell receptor (TCR) mono-/oligoclonal mature T cells from TCR transgenic (tg) mice (OT-I, P14) expressing the oncogenes NPM/ALK or ΔTrkA readily developed MTCLs in T-cell-deficient recipients. Analysis of cell surface markers largely ruled out that TCR tg lymphomas were derived from T-cell precursors. Furthermore, cotransplanted non-modified TCR polyclonal T cells suppressed malignant outgrowth of oncogene expressing TCR tg T lymphocytes. A dominant role of an anti-leukemic immune response or Tregs in the control of MTCLs seems unlikely as naïve T cells derived from oncogene expressing stem cells, which should be tolerant to leukemic antigens, as well as purified CD4 and CD8 were resistant to transformation. However, our results are in line with a model in which homeostatic mechanisms that stabilize the diversity of the normal T-cell repertoire, for example, clonal competition, also control the outgrowth of potentially malignant T-cell clones. This study introduces a new innate mechanism of lymphoma control.

Lymphoproliferative disorders of the gastrointestinal tract: a review and pragmatic guide to diagnosis

CONTEXT

The gastrointestinal tract is the most common site of extranodal lymphomas. Although all histologic categories of malignant lymphoma develop in the gastrointestinal tract, large B-cell lymphomas predominate, followed by extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) type; the latter is especially prevalent in stomach. The acceptance of extranodal marginal zone lymphoma of MALT type as a clinicopathologic entity has reduced the number of cases that formerly were interpreted as florid lymphoid hyperplasia ("pseudolymphoma"). Nonetheless, the distinction of lymphoid hyperplasia from a lymphoma of MALT type in small biopsy specimens remains problematic.

OBJECTIVE

To assess the relevant morphologic, immunologic, molecular, and genetic properties of gastrointestinal lymphomas and to present a feasible tactic for diagnosis, expressly for small biopsy specimens.

DATA SOURCES

Case-derived material and literature review using PubMed (National Library of Medicine).

CONCLUSIONS

Most gastrointestinal lymphomas are readily amenable to an unqualified diagnosis, primarily those cases consisting of monomorphic large cells whether of B- or T-cell lineage, including cases associated with enteropathy. Diagnosis for infiltrates dominated by small lymphocytes remains taxing, as the differential diagnosis embraces not only MALT lymphoma and lymphoid hyperplasia but also mantle cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma. Adherence to strict morphologic criteria is the standard for diagnosis, but these criteria should be augmented by immunologic studies together with judicious use of molecular techniques to determine clonality. In establishing a diagnosis of gastric marginal zone lymphoma of MALT type, determination of t(11;18)(q21;q21) status may be required since this translocation has clinical ramifications.

[Complications of celiac disease]

Numerous complications can occur in celiac disease, nutritional (growth failure in children, malnutrition, vitamin deficiencies), hematologic (anaemia), bone disease (osteoporosis, fracture), gynaecologic (hypo fertility), cardiovascular (coronaropathy, venous thrombosis), neurological (peripheral neuropathy), hepatic (cytolysis, cirrhosis). Celiac disease is associated with an increased risk of autoimmune diseases (type 1 diabetes, thyroiditis), and cancer (upper digestive tract, hepatocellular carcinoma, lymphoma). The main digestive complications are microscopic colitis and refractory sprue, which are resistant to gluten-free diet. It can be associated with a monoclonal proliferation of intraepithelial lymphocytes (type 2 refractory sprue), which may be considered as a cryptic lymphoma and can lead to invasive T lymphoma, which occurs in one celiac patient in 1000. Gluten-free diet protects from the occurrence of most complications and correct the over-mortality related to these complications.

[Histopathology of coeliac disease]

Coeliac disease is a common disease, affecting 1% of the population. Clinical manifestations are multiple. The diagnosis requires serologic testing and a duodenal biopsy that shows the characteristic findings of intraepithelial lymphocytosis, crypt hyperplasia and villous atrophy, and a positive response to a gluten-free diet. In most patients, the histological diagnosis is easily established. Pitfalls in the pathological diagnosis include a poorly orientated biopsy specimen, either an inadequate biopsy sampling in patients with patchy villous atrophy and the other causes of villous atrophy. A non-response to the gluten-free diet needs to reassess first, the initial diagnosis, second to be sure of the gluten-free diet adherence, and third, to exclude malignant complications such as refractory celiac disease or enteropathy-associated T-cell lymphoma.

The incidence and clinical spectrum of refractory celiac disease in a north american referral center

OBJECTIVES

Refractory celiac disease (RCD) is one of the most serious causes of persistent symptoms in patients with celiac disease (CD). Published reports suggest that approximately half of patients in Europe are RCD type II, which carries a poor prognosis with a 5-year survival rate of ~50% compared with ~90% for RCD type I. However, disease patterns may be different in North America. The aim of this study was to explore the clinical spectrum of RCD in a North American population.

METHODS

Medical records of patients with biopsy-proven CD presenting to our institution were reviewed for a diagnosis of RCD. Demographic data, clinical characteristics, and mortality were evaluated and compared with our general CD population.

RESULTS

In all, 34 out of 844 (4.0%) CD patients had RCD. The cumulative incidence of RCD for patients diagnosed with CD at our center was 1.5%. Unintentional weight loss at diagnosis of RCD was found in 76.5% (n=26) compared with 16.7% (n=141) at diagnosis of CD (P<0.0001) and diarrhea at diagnosis of RCD was found in 79.4% (n=27) compared with 40.5% (342) at diagnosis of CD (P<0.0001). Five patients (14.7%) were diagnosed with RCD type II and of these, two died of enteropathy-associated lymphoma within 24 months of diagnosis of CD (observed mortality rate 5.9%).

CONCLUSIONS

Although RCD is a serious condition with significant morbidity; the observed mortality rates are low in our population. This study suggests that RCD may be less severe in North American vs. European populations.

Enteropathy-associated T-cell lymphoma: a review on clinical presentation, diagnosis, therapeutic strategies and perspectives

INTRODUCTION

Enteropathy-associated T-cell lymphoma (EATL) is a rare complication of celiac disease (<1% of lymphomas) and has a poor prognosis.

METHODS

International literature review with PubMed search (up to January 2009) of pathophysiological, clinical and therapeutic data.

RESULTS

EATL is found in patients with a mean age of 59 years, often with a complication that signals its diagnosis. Refractory celiac disease (RCD), equivalent to low-grade intraepithelial T-cell lymphoma, could be an intermediary between celiac disease and high-grade invasive T-cell lymphoma. The median survival is 7 months, with no significant difference between stages; the cumulative 5-year survival is less than 20%. The poor prognosis is determined by disease that has often spread before it is diagnosed (50%), multifocal involvement of the small bowel (50%), poor general health status and undernutrition, and recurrence of complications (infections, perforations, gastrointestinal haemorrhages, occlusions), thus delaying the chemotherapy and contributing to frequent chemotherapy resistance. There is currently no effective and consensual treatment: preventive surgery for complications is controversial, and the results of chemotherapy are disappointing. The classic CHOP protocol (combination of doxorubicin-cyclophosphamide-vincristine-prednisone) does not have satisfactory results and survival remains poor, especially in patients with underlying RCD. High-dose chemotherapy with autotransplantion seems to only improve the prognosis in localised forms. Allogeneic bone marrow transplantation was not evaluated. In all, 1/3 of patients, being unfit for treatment, die before 3 months and half of treated patients stop chemotherapy prematurely due to inefficacy, intolerance and/or complications.

CONCLUSION

Improvement of the prognosis requires collaboration in order to compose a national cohort, to evaluate new diagnostic and therapeutic strategies and to define prognostic factors.

Flow cytometry of intestinal intraepithelial lymphocytes in celiac disease

This article reviews the multiple uses of flow cytometry in the diagnosis, monitoring and research of celiac disease, the most prevalent chronic autoimmune gastrointestinal disease. The phenotyping of intraepithelial lymphocytes (IELs) is of clinical relevance in the diagnosis of the disease given the characteristic features of elevated CD3+ IELs (αβ and γδ TcR) and the decrease in CD3- IELs. IEL biomarkers are also useful in the assessment of the response to the gluten-free diet and, importantly, in the diagnosis of the severe complications of celiac disease: refractory celiac disease and enteropathy-associated T-cell lymphoma. Novel applications of flow cytometry for the detection of anti-transglutaminase antibodies (a validated biomarker of celiac disease) and of gluten (the triggering antigen of the autoimmune process) are also discussed. The assessment of diagnostic and prognostic biomarkers by flow cytometry in celiac disease is performed routinely in a growing number of centers and it is an example of the versatility of this technique and its applicability to the research and clinical study of solid tissues.

Enteropathy associated T-cell lymphoma and its precursor lesions

Enteropathy Associated T-cell Lymphoma (EATL) is an intestinal tumour of intra-epithelial lymphocytes. Based on morphology, immunohistochemistry and genetic profile EATL can be divided into two groups. EATL type I is a large cell lymphoma which is highly associated with Coeliac Disease (CD) and mostly presents with malabsorption, weight loss and CD-related symptoms. EATL type II consists of small to medium-sized cells and presents often with obstruction or perforation of the small bowel. This type of EATL has no known association with CD. When EATL has been diagnosed a thorough diagnostic work-up is needed. This work-up preferably includes video capsule enteroscopy (VCE), double-balloon enteroscopy (DBE), computed tomography (CT) combined with 18F-fluorodeoxyglucose positron emission tomography scan (18F-FDG-PET scan) if possible and magnetic resonance enteroclysis (MRE). Nowadays, most EATL patients are treated with chemotherapy mostly preceded by resection of the tumour and followed by stem cell transplantation. Despite these therapies outcome of EATL remains very poor with a 5-year survival of 8-20%. In order to improve survival prospective multicentre trials, studying new therapies are needed. The combination of chemotherapy, monoclonal antibodies and/or apoptosis inducing small molecules might be a potential treatment for EATL in the (nearby) future.

Aberrant T-lymphocytes in refractory coeliac disease are not strictly confined to a small intestinal intraepithelial localization

BACKGROUND

Refractory coeliac disease (RCD) is characterized by persisting mucosal pathology in spite of a strict gluten free diet (GFD). In RCD type II, phenotypically aberrant (CD7+CD3-CD4/8-cytoplasmicCD3+) T-lymphocytes are present within the intraepitelial lymphocyte (IEL) population in the small intestine, and 50-60% of these patients develops an enteropathy associated T-cell lymphoma (EATL).

AIM

To investigate whether aberrant T-lymphocytes in RCD II can be detected in other parts of the small intestinal mucosa besides the intraepithelial compartment. Additionally, the presence of aberrant T-lymphocytes was analyzed in two RCD II patients that developed atypical skin lesions.

METHODS

Multiparameter flow cytometric immunophenotyping was performed on both IEL and lamina propria lymphocyte (LPL) cell suspensions, isolated from small bowel biopsy specimens of RCD II patients (n = 14), and on cutaneous lymphocytes isolated from skin-lesion biopsy specimens of RCD II patients (n = 2). In addition, immunofluorescence analysis of frozen RCD II derived small intestinal biopsies was performed.

RESULTS

Our results clearly show that aberrant T-lymphocytes may be present in both the IEL and the LPL compartments of RCD II derived small intestinal biopsies. Although the highest percentages are always present in the IEL compartment, aberrant LPL can exceed 20% of total LPL in half the RCD II patients. Interestingly, cutaneous lymphocytes isolated from atypical skin lesions that developed in some RCD II patients showed a similar aberrant immunophenotype as found in the intestinal mucosa.

CONCLUSIONS

In RCD II, the aberrant T-lymphocytes may also reside in the subepithelial layer of the small intestinal mucosa, in the lamina propria, and even in extraintestinal localizations including the skin. Whether this phenomenon represents a passive overflow from the intestinal epithelium or active trafficking towards other anatomical localizations remains to be elucidated. RCD II appears to be a disseminated disease, which may impose the risk of EATL development outside the intestine.

Presentation and long-term follow-up of refractory celiac disease: comparison of type I with type II

BACKGROUND & AIMS

Refractory celiac disease (RCD) was recently subdivided into 2 subtypes (RCD I and II) based on a normal or abnormal phenotype of intraepithelial lymphocytes (IELs), respectively. It is not clear, however, if these 2 entities differ in their presentation at diagnosis or long-term outcome. We compared the clinical and biological characteristics of RCD I and RCD II at diagnosis, the risk of developing an overt lymphoma, and the predictive factors of survival.

METHODS

Medical files of 14 patients with RCD I and 43 with RCD II were analyzed retrospectively. Predictive factors of overt lymphoma and survival were studied in univariate and multivariate analyses.

RESULTS

At diagnosis, malnutrition, ulcerative jejunitis, and lymphocytic gastritis were more common in patients with RCD II than RCD I (P< .05). Overt lymphomas occurred in 2 patients with RCD I and 16 with RCD II. In the univariate analysis, abnormal IEL phenotype and increased age at diagnosis of RCD were predictive factors for overt lymphoma. Abnormal IEL phenotype (P< .01), clonality (P= .01), and overt lymphoma (P= .001) predicted short survival time. Only abnormal IEL phenotype (P= .03) and overt lymphoma (P= .04) were predictive in the multivariate analysis. The 5-year survival rate was 93% in patients with RCD I and 44% with RCD II.

CONCLUSIONS

RCD II has a much more severe presentation and prognosis than patients with RCD I; <44% of patients with RCD II survive 5 years after diagnosis. Abnormal IEL phenotype is a predictive factor but not a necessary condition for the development of overt lymphoma.

[Refractory sprue--precursor lesion of enteropathy type T-cell lymphoma--a clinicopathological case report]

INTRODUCTION

Refractory sprue is characterised by distinctive morphologic alterations and the emergence of clonal intraepithelial lymphocytes.

AIM

In this case report the authors emphasize the importance of histopathology in the diagnosis of refractory sprue.

METHODS

The sequential biopsies from this patient have been investigated with routine histology, immunohistochemistry and molecular genetics for T-cell clonality analysis.

RESULTS

The severely cachectic patient presenting with malabsorption syndrome has been diagnosed with celiac disease through a duodenal biopsy, and the CD8 negativity of the intraepithelial lymphocytes suggested the possible diagnosis of refractory sprue. Azathioprine and glucocorticoid therapy was administered due to the failed jejunal feeding and gluten-free diet, resulting in clinically complete, morphologically partial remission. Intestinal T-cell lymphoma developed in the ileocecal region within two years after the first clinical presentation.

DISCUSSION

Refractory sprue and the enteropathy-type T-cell lymphoma constitute a disease spectrum. The reported case shows how a simple method can provide crucial information in the diagnosis of refractory sprue.

Mucosal intraepithelial T-lymphocytes in refractory celiac disease: a neoplastic population with a variable CD8 phenotype

Celiac disease (CD) is characterized by villous atrophy and an increase in intraepithelial lymphocytes (IEL). The IEL usually exhibit a suppressor/cytotoxic phenotype (CD3 and CD8) and display a polyclonal profile for T-cell receptor (TCR) rearrangement as opposed to the monoclonality of refractory CD (RCD) with CD8 IEL. A complication of CD is the loss of response to a gluten-free diet called RCD that may progress to an enteropathy-associated T-cell lymphoma. We reviewed 20 uncomplicated CD and 23 complicated CD (19 RCD and 4 diagnosed at the same time as enteropathy-associated T-cell lymphoma). In complicated CD, the IEL phenotype was CD8 in 9 cases and CD8 in 14 cases. In 100% of cases, IEL showed a monoclonal TCR rearrangement. All the 9 CD8 complicated CD exhibited a monoclonal TCR rearrangement and 3 of them were associated with a T-cell lymphoma (2 at the same time as CD and 1 after 43-mo follow-up) and bore the same monoclonal rearrangement in IEL and in lymphoma. Interestingly, the 13 cases (100%) of CD with a CD8 phenotype were also found monoclonal and 2 of them were associated with a T-cell lymphoma diagnosed at the same time as CD and exhibiting the same rearrangement in IEL and in lymphoma. An aberrant CD3 CD8 IEL phenotype is a good criterion for RCD diagnosis. However, cases with a normal CD3 CD8 IEL phenotype may correspond to RCD. In such cases, we suggest that molecular analysis of TCR-gamma genes is a useful method for identifying cases with RCD.

Flow cytometric analysis of intestinal intraepithelial lymphocytes in the diagnosis of refractory celiac sprue

The etiology of refractory celiac sprue (RCS) is unclear. In a high proportion of cases, the clonal nature of intestinal intraepithelial lymphocytes (IEL) can be demonstrated and a pathogenetic implication of intestinal IEL has been postulated. The prognosis of this subgroup of RCS is poor, with a high risk to develop an overt lymphoma and uncontrolled malabsorption despite steroid/immunosuppressive therapy. Cases with a relatively indolent clinical course, however, exist and their early diagnosis may be difficult. To gain insight into the pathogenic implication of intestinal IEL in refractory celiac sprue, we have performed an extensive phenotypic and functional characterization of clonal intestinal IEL in a patient with an indolent form of refractory celiac sprue, using multiparametric flow cytometry. The abnormal lymphocyte infiltrate lacked surface membrane expression of CD3/T-cell receptor (TCR) complexes (TCR(-), CD4(-), CD8(-), sCD3(-)), but contained intracellular CD3(epsilon) (CyCD3(+)) and surface CD103(+) and CD7(+). In particular, these cells showed a unique spontaneous ex-vivo cytokine secretion profile with an increased percentage of CD3(-) IEL containing TNF-alpha and IL-10, in the absence of IL-2, IL-4 and IFN-gamma. Altogether our results suggest that flow cytometry immunophenotyping of intestinal IEL, in cases suspected of celiac disease and their complicated forms, could be of great help in the correct diagnosis of RCS and the understanding of the immunopathogenic mechanisms of the disease and their clinical and/or therapeutical implications.

Extranodal lymphoma

Lymphomas arising in extranodal sites are intriguing. The types of lymphomas encountered vary widely from one extranodal site to another. For many types of extranodal lymphomas, there are distinctive clinicopathologic features, sometimes including association with an underlying immunodeficiency syndrome, autoimmune disease, infection, or other immunologic disorder, or a predilection to affect patients of certain ethnic origins. Presented below is a review of lymphomas that are encountered most often in extranodal sites.

Refractory celiac disease

Celiac disease (CD) is a small intestinal inflammatory disorder characterized by an immune-mediated enteropathy triggered by the ingestion of wheat gluten or related rye and barley proteins in genetically predisposed individuals carrying the human leukocyte antigens (HLA)-DQ2 or -DQ8. Nonresponsive CD (NRCD) is a clinical diagnosis defined by the persistence of signs, symptoms, and/or laboratory abnormalities typical of CD despite adherence to a gluten-free diet for at least 6 months. One cause for NRCD is refractory CD (RCD), defined as the persistence of severe villous atrophy on small intestinal biopsy despite strict gluten withdrawal for at least 6 months with no evidence of other pathology. Although rare, RCD should be suspected in individuals with an established diagnosis of CD who fail to respond primarily or secondarily to a strict gluten-free diet, particularly if they manifest significant weight loss. A thorough evaluation must be performed to distinguish RCD from other causes of NRCD. RCD may be categorized into type I or type II. Type I RCD has a more favorable prognosis compared with type II and can often be managed with nutritional supplementation and possibly low level immunosuppressive therapy. Type II RCD carries a poor prognosis and is more likely to progress to life-threatening malnutrition or intestinal T-cell lymphoma. Immunosuppressive agents and, more recently, autologous stem cell transplant have been used to treat type II RCD.

Flow cytometric determination of aberrant intra-epithelial lymphocytes predicts T-cell lymphoma development more accurately than T-cell clonality analysis in Refractory Celiac Disease

BACKGROUND

Refractory celiac disease (RCD) patients with aberrant, often clonal, intraepithelial T-cells are at high risk for development of enteropathy associated T-cell lymphoma (EATL). Early detection of those patients that actually develop EATL is of utmost importance for curative intervention.

AIM

First, to establish an optimal cut-off value for the percentage of aberrant lymphocytes, previously determined based on clinical observations, via reference ranges for aberrant T-cells in the duodenal mucosa of celiac disease patient and control groups. Secondly, to compare aberrancy with intestinal T-cell clonality as a prognostic parameter for EATL development in RCD.

METHODS

Immunophenotyping using flow cytometry was performed on small intestinal biopsy-derived lymphocytes, obtained from distinct celiac disease (CD) patient and control groups (N=167 in total). T-cell clonality in duodenal biopsy specimens was assessed by PCR in RCD, ulcerative jejunitis and EATL patients (N=31 in total).

RESULTS

In 95% of non-refractory CD patients, the highest percentage aberrant T-cells was 20%. Using this cut-off value, EATL development was exclusively seen in RCD with more than 20% aberrant T-cells (median 52% aberrant T-cells, range 27-94%). When compared with T-cell clonality analysis, >20% aberrancy showed a much higher negative predictive value and sensitivity (both 100%) for EATL development in RCD patients than T-cell clonality analysis (respectively 75% and 78%).

CONCLUSIONS

Quantification of aberrant T-cells by flow cytometry is preferable to T-cell clonality analysis for identification of RCD patients at risk for EATL development. A cut-off value of 20% is of use in risk stratification, therapeutic options and subsequent follow-up of RCD patients.

Disappointing outcome of autologous stem cell transplantation for enteropathy-associated T-cell lymphoma

BACKGROUND

Despite treatment, enteropathy-associated T-cell lymphoma has a very poor outcome. Chemotherapy can be complicated by small bowel perforation, gastrointestinal bleeding and development of enterocolic fistulae. Here we report on the feasibility, safety and efficacy of high-dose chemotherapy followed by autologous stem cell transplantation in patients with enteropathy-associated T-cell lymphoma (three upfront and one at relapse), with or without prior partial small bowel resection.

METHODS

Four patients [two males, two females, mean age 65 years (range 60-69 years)] received high-dose chemotherapy followed by autologous stem cell transplantation. Partial small bowel resection has been performed in three patients.

RESULTS

All four patients completed the mobilization and leucopheresis procedures successfully and subsequently received conditioning chemotherapy and transplantation. Engraftment occurred in all patients. No major non-haematological toxicity or transplantation-related mortality was observed. One patient has ongoing complete remission 32 months after transplantation. Three patients died from relapse within few months after autologous stem cell transplantation.

CONCLUSIONS

Autologous stem cell transplantation seems unsatisfactory for patients with enteropathy-associated T-cell lymphoma. More intensive conditioning and aggressive chemotherapy with/or without targeted immunotherapy as well as allogenous stem cell transplantation needs to be explored.

Cladribine therapy in refractory celiac disease with aberrant T cells

BACKGROUND & AIMS

Refractory celiac disease (RCD) may be subdivided into RCD types I and II with phenotypically normal and aberrant intraepithelial T-cell populations, respectively. In RCD II, transition into enteropathy-associated T-cell lymphoma (EATL) is seen frequently. We have evaluated the effect of cladribine (2-CDA), a purine analogue inducing T-cell depletion, on clinical, histopathologic, and immunologic parameters, as well as the toxicity and side effects in a group of RCD II patients.

METHODS

Between 2000 and 2005, 17 patients were included (8 men, 9 women). All patients had a clonal rearrangement of the T-cell receptor gamma gene and immunophenotyping showed an aberrant T-cell population lacking surface expression of CD3, CD8, and T-cell receptor alphabeta, in the presence of expression of surface CD103 and intracytoplasmic CD3. Treatment consisted of 2-CDA (0.1 mg/kg/day) intravenously for 5 days, given in 1-3 courses every 6 months depending on the response.

RESULTS

All patients tolerated 2-CDA without serious side effects. Six patients (35.8%) showed a clinical improvement (weight gain, improvement of diarrhea, and hypoalbuminemia). In 10 patients (58.8%) a significant histologic improvement and in 6 patients (35.2%) a significant decrease in aberrant T cells was seen. Seven patients (41.1%) developed EATL and died subsequently. One patient died of progressive refractory state with emaciation.

CONCLUSIONS

Treatment with 2-CDA in RCD II is feasible, well tolerated, and can induce clinical and histologic improvement as well as a significant decrease of aberrant T cells in a subgroup of patients, albeit it does not prevent EATL development. However, the earlier reported potential risk of precipitating an overt lymphoma should be taken into consideration.

Gluten sensitive enteropathy and other causes of small intestinal lymphocytosis

Recent studies on gluten sensitive enteropathy (GSE) have heightened the pathologist's awareness of intraepithelial lymphocytes in duodenal biopsies. Mild histologic forms of GSE are now recognized with increased IELs as the only histologic change. In this review, both the classic morphology and "minimal deviation" GSE are discussed in detail, with special emphasis on the differential diagnosis and how to avoid overdiagnosing this condition. The Marsh-Oberhuber classification is described and contrasted with a more practical diagnostic terminology that is recommended for use in pathology reports. Other important conditions associated with duodenal lymphocytosis, such as refractory sprue, autoimmune enteropathy, and Helicobacter pylori-associated duodenitis, are also presented.

Immunohistochemical Diagnosis of Alimentary Lymphomas and Severe Intestinal Inflammation in Cats

Intestinal tissue samples were examined from 32 cats in which a histopathological diagnosis of alimentary lymphoma or multicentric lymphoma affecting the gastrointestinal tract had been made. These samples were re-evaluated histopathologically and serial sections were examined immunohistochemically with antisera specific for the lymphoid markers CD3, CD79a and BLA-36 and for class II molecules of the major histocompatability complex. The cats ranged in age from 4-16 years (median 10.5 years). The main presenting clinical signs were vomiting, diarrhoea and weight loss. The majority of alimentary lymphomas were of the B-cell type (n=15), whereas cases of T-cell lymphoma were fewer in number (n=8). Four cats had lymphoma of a mixed T-and B-cell phenotype. In five of the cats, immunohistochemistry suggested an inflammatory process, in contradiction to the original histopathological diagnosis of lymphoma. Immunolabelling would appear to be a useful adjunct to histopathology in classifying cases of feline alimentary lymphoma, and may help in distinguishing lymphoma from severe intestinal inflammation.

Innate and adaptive immunity: the yin and yang of celiac disease

Celiac disease is a multigenetic complex inflammatory disorder with an autoimmune component, induced by gluten, a protein found in wheat. It is a unique human disease model to dissect the innate and adaptive immune mechanisms underlying T-cell-mediated tissue destruction and the development of T-cell lymphoma in conditions of chronic T-cell activation.

Fatal CNS vasculopathy in a patient with refractory celiac disease and lymph node cavitation

Celiac disease is an enteropathy occurring in genetically predisposed individuals due to a dietary intolerance to gluten. Patients with celiac disease may develop a neurological disorder of unknown cause, although autoimmune mechanisms are suspected. We report on a 56-year-old man with celiac disease, who became refractory to a gluten-free diet and died of a rapidly progressive encephalopathy. Magnetic resonance imaging indicated focal lesions of the cerebellum and brainstem, and electrodiagnostic studies suggested an axonal neuropathy. Autopsy revealed a flattened small-bowel mucosa with intraepithelial lymphocytosis, a spectrum of degenerative changes of the intra-abdominal and mediastinal lymph nodes, including cavitary degeneration, and splenomegaly. Histologically, the lymph nodes showed pseudocyst formation and lymphocytic vasculitis with fibrinoid necrosis, and sections of the brain exhibited fibrinoid degeneration of small blood vessels, sparse perivascular lymphocytic infiltrates, and perivascular ischemic lesions. Identical T-cell clones were identified in the duodenum, stomach, lymph nodes, and spleen. This patient had an unusual neurological disorder related to a vasculopathy, probably mediated by a circulating neoplastic clone of activated T cells.

Coeliac disease: changing views

A continuing flow of new scientific developments concerning coeliac disease in the last decade asks for the formulation of new concepts of pathophysiology and clinical considerations. Immunogenetic studies have shown a correlation of the disease to the HLA region on the short arm of chromosome 6, immunological research has led to the concept of a T-cell driven immunologic response of the small intestine, with the identification of highly sensitive and specific antibodies. The understanding of the histopathology of coeliac disease has changed dramatically, initiated by the proposition of a spectrum of gluten sensitive enteropathy by Marsh in 1992. Clinical studies report a significant change in patient characteristics and epidemiology. The incidence of the disease has shifted to a majority of adult coeliacs, the disease may present with less severe symptoms of malabsorption and the screening studies suggest an overall prevalence of up to 1 in 200-300. Histopathology has been standardized; lymphocytic enteritis (Marsh I), lymphocytic enteritis with crypthyperplasia (Marsh II), and villous atrophy, subdivided in partial, subtotal and total (Marsh IIIABC). Special attention is given to a subgroup of 'refractory coeliacs', including the identification of pre-malignant T-cells in the intestinal mucosa. The management of coeliacs primarely consists of monitoring for compliance and complications. Dietetic and medical associations need to establish protocols and offer additional training to undergraduetes, internships, general practitioners and other allied health professionals. It might be relevant to have a low threshold for intestinal biopsies. However, screening asymptomatics may be harmful for individuals. Research is needed to assess the benefits of mass-screening in the future. HLA analysis can contribute towards recognising populations at increased risk.

Refractory coeliac disease

A small proportion of coeliac disease (CD) patients fail to improve after a gluten-free diet (GFD) and may be considered as atypical regarding their outcome (refractory coeliac disease). The aim of this study is to diagnose and manage patients with CD who fail to improve after a GFD. Refractory coeliac disease (RCD) is a malabsorption syndrome defined by persisting villous atrophy with, usually, an increase of intraepithelial lymphocytes (IELs) in the small bowel in spite of a strict GFD and comprises a heterogenous group of diseases. Some of these diseases have to be excluded and can be treated by specific therapies like antibiotics in tropical sprue and giardiasis and immune globulin substitution in common variable immunodeficiency, while other malabsorption syndromes are less well defined and may require immunosuppressive therapy. Standardized treatment, however, has not been evaluated in such patients so far. In a subgroup of patients with RCD, an abnormal intraepithelial lymphocyte (IEL) population may be observed with the lack of surface expression of usual T-cell markers (CD3-CD8 and/or the T-cell receptor (TCR)) on IELs associated with T-cell clonality pattern suggest the presence of an early enteropathy-associated T-cell lymphoma (EATL) in a subgroup of patients with RCD. This hypothesis has been supported by studies, which revealed progression into overt intestinal T-cell lymphomas in a subgroup of RCD. Steroid treatment has been reported effective even in patients with underlying early EATL. However, long-term results are unsatisfactory in most of these patients with RCD and parenteral nutrition has to be applied in some of these cases. First results with more aggressive chemotherapies and use of cytokines are under way. Due to the difficulty of diagnostic and therapeutic regimens patients should be referred to tertiary centres for coeliac disease.

Malignant complications of coeliac disease

Patients with coeliac disease (CD), particularly those who are undiagnosed or do not adhere to a strict gluten free diet (GFD), are prone to develop complications. Malignant complications are the most serious and should be suspected when expected responses to GFD are not achieved or sustained. Lymphomas, mostly T-cell type, and other malignant tumours, particularly carcinoma of the small bowel, less frequently of stomach and oesophagus, are associated with CD. Loss of response to a gluten free diet (refractory coeliac disease) and ulcerative jejunitis are two recently described complications of CD that may progress to an Enteropathy-Associated T-cell Lymphoma (EATL). Coeliac disease-related lymphoma most often appears at extra-nodal sites, essentially the small bowel, although one have to realise that T-cell lymphomas arising in sites outside the small bowel could be related to coeliac disease. Workup of an EATL must include immunehistology and if necessary T-cell flow cytometry and T-cell rearrangement. Adequate imaging with CT and PET-scanning is mandatory.