Practical Approach to the Flattened Duodenal Biopsy

Diagnosis of Seronegative and Ultrashort Celiac Disease

In its conventional form, celiac disease (CeD) is characterized by both positive serology and flat villi in the duodenum, and is well known by gastroenterologists and general practitioners. The aim of this review was to shed light on 2 neglected and not yet well-defined celiac phenotypes, that is, seronegative and ultrashort CeD. Seronegative CeD can be suspected in the presence of flat villi, positive HLA-DQ2 and/or HLA-DQ8, and the absence of CeD antibodies. After ruling out other seronegative enteropathies, the diagnosis can be confirmed by both clinical and histologic improvements after 1 year of a gluten-free diet. Ultrashort CeD is characterized by the finding of flat villi in the duodenal bulb in the absence of mucosal damage in the distal duodenum and with serologic positivity. Data on the prevalence, clinical manifestations, histologic lesions, genetic features, and outcome of seronegative and ultrashort CeD are inconclusive due to the few studies available and the small number of patients diagnosed. Some additional diagnostic tools have been developed recently, such as assessing intestinal transglutaminase 2 deposits, flow cytometry technique, microRNA detection, or proteomic analysis, and they seem to be useful in the identification of complex cases. Further cooperative studies are highly desirable to improve the knowledge of these 2 still-obscure variants of CeD.

Histologic evaluation in the diagnosis and management of celiac disease: practical challenges, current best practice recommendations and beyond

Celiac disease (CD) is an immunoallergic enteropathy affecting genetically susceptible individuals upon dietary exposure to gluten. In current clinical practice, the diagnosis of CD is based on a combination of clinical, serologic, and histologic factors with the possible exception of pediatric patients. Histopathologic evaluation of small intestinal tissue plays a critical role in the disease diagnosis and management, despite many practical challenges. Recently published best practice guidelines help to standardize biopsy sample procurement, tissue preparation, histology interpretation, and reporting, to optimize patient care. In addition, an increasing demand for monitoring the disease course, particularly demonstrating the efficacy of dietary and nondietary interventions for disease management, calls for the use of quantitative histology. With the advent of a gradual transition toward digital pathology in routine diagnostic practice, quantitative histopathologic evaluation in CD shows a promising future.

Diagnostic and therapeutic challenge of unclassifiable enteropathies with increased intraepithelial CD103+ CD8+ T lymphocytes: a single center case series

OBJECTIVES

Chronic diarrhea, villous atrophy and/or increased intraepithelial T-lymphocytes (IEL) occur in many inflammatory disorders including celiac disease (CD). However, a definite diagnosis is difficult to make in some patients despite an extensive diagnostic work-up. Clinical outcomes and histological phenotypes of such patients we refer to as unclassifiable enteropathy (UEP) remain unclear.

MATERIAL AND METHODS

We performed a retrospective single-center analysis of patients with chronic diarrhea, weight loss and increased IEL. Patients with defined etiologies including infections, CD, drugs, immunodeficiencies or neoplasms were excluded. Clinical and histologic/immunophenotypic parameters were analyzed.

RESULTS

Nine patients with UEP were identified. Small intestinal damage ranged from minor villous abnormalities to complete atrophy while all patients displayed high numbers of CD103⁺ CD8⁺ IELs. In contrast to CD, these CD8⁺ T cells were not confined to the surface epithelium, but also infiltrated the crypts. Additional histological features included apoptotic crypt epithelial cells and mixed inflammatory infiltrates in the tunica propria. Involvement of other segments of the gastrointestinal tract was observed in 7/9 patients. A clonal intestinal T-cell lymphoproliferative disorder developed in 2 patients, one of which had a fatal disease course. The majority of patients responded to corticosteroids, while response to immunosuppressive medications yielded heterogeneous results.

CONCLUSIONS

We report a patient population with 'difficult-to-classify' enteropathies characterized by various degrees of villous atrophy and strongly increased intraepithelial CD103⁺ CD8⁺ T cells in the small intestine which harbor an increased risk for T-cell lymphoproliferative disorders. Clinical course, histology, and response to immunosuppressive therapy all suggest an autoimmune pathogenesis.

Minimal Lesions of the Small Intestinal Mucosa: More than Morphology

Minimal lesions of the small bowel are mucosal changes characterized by an increased number of intraepithelial lymphocytes (with or without crypt hyperplasia) and normal villous architecture. Such changes are associated with a wide spectrum of conditions, ranging from food intolerances to infections, and from drugs to immune diseases, with different clinical profiles and manifestations, which complicates the formulation of a differential diagnosis. Patient history, symptom evaluation, and histopathology are the diagnostic features needed to establish a correct diagnosis. Physicians should assist pathologists in formulating a precise morphological evaluation by taking well-oriented small intestinal biopsies and collecting informative clinical findings that inform histopathology. In this current clinical controversy, the authors provide the reader with an appraisal of the small intestine minimal lesions through a careful analysis of the major conditions (e.g., celiac disease and other non-celiac disorders) responsible for such changes and their differential diagnosis. Also, we acknowledge that some of the diseases detailed in this article may progress from an early minimal lesion to overt mucosal atrophy. Thus, the timing of the diagnosis is of paramount importance.

Educational Case: Immune-Related Disorders of the Bowel: Celiac Disease

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.

Capsule endoscopy for patients with coeliac disease

Coeliac disease is an autoimmune mediated condition in response to gluten. A combination of innate and adaptive immune responses results in villous shortening in the small bowel (SB) that can be morphologically picked up on capsule endoscopy. It is the only imaging modality that can provide mucosal views of the entire SB, while histology is generally limited to the proximal SB. Radiological modalities are not designed to pick up changes in villous morphology. Areas covered: In this review, we provide a comprehensive analysis on the justified use of small bowel capsule endoscopy (SBCE) in the assessment of patients with coeliac disease; compare SBCE to histology, serology, and symptomatology; and provide an overview on automated quantitative analysis for the detection of coeliac disease. We also provide insight into future work on SBCE in relation to coeliac disease. Expert commentary: SBCE has opened up new avenues for the diagnosis and monitoring of patients with coeliac disease. However, larger studies with new and established coeliac disease patients and with greater emphasis on morphological features on SBCE are required to better define the role of SBCE in the setting of coeliac disease.