Gastrointestinal pathology in patients with common variable immunodeficiency and X-linked agammaglobulinemia

Diarrhea in the immunocompromised patient

Diarrhea is a common problem in patients with immunocompromising conditions. The etiologic spectrum differs from patients with diarrhea who have a normal immune system. This article reviews the most important causes of diarrhea in immunocompromised patients, ranging from infectious causes to noninfectious causes of diarrhea in the setting of HIV infection as a model for other conditions of immunosuppression. It also deals with diarrhea in specific situations, eg, after hematopoietic stem cell or solid organ transplantation, diarrhea induced by immunosuppressive drugs, and diarrhea in congenital immunodeficiency syndromes.

Liver transplantation for severe hepatitis in patients with common variable immunodeficiency

CVID is a heterogeneous group of primary immunodeficiency diseases characterized by hypogammaglobulinemia, recurrent bacterial infections, and frequent autoimmune manifestations. The post-transplant course of liver transplant recipients with CVID is rarely described. We report two patients with CVID complicated by severe enteropathy who underwent living donor liver transplantation for liver failure because of severe hepatitis. The post-transplant course was complicated by recurrent acute rejection, leading to ductopenic rejection in one and recurrent hepatitis in the other. We reviewed the tissue samples histologically and immunohistochemically. Native livers showed submassive hepatocyte necrosis in one and cirrhotic liver with active hepatitis in the other, both with infiltration of CD8+ T cells accompanied by endothelialitis and bile duct damage; the intestine contained increased numbers of intraepithelial CD8+ T cells with apoptosis of epithelial cells. The liver allograft exhibited acute rejection, with prominent CD8+ T cells infiltrating the bile duct or endothelium. In the allograft following the diagnosis of post-transplant recurrent hepatitis, CD8+ T cells comprised the majority of infiltrating cells in portal areas spilling over into hepatic parenchyma. Our cases suggest that T cells contribute to the pathogenesis of CVID in native organs as well as allografts and may constitute evidence of T-cell deregulation in the pathogenesis of CVID.

The significance of duodenal mucosal atrophy in patients with common variable immunodeficiency: a clinical and histopathologic study

Gastrointestinal manifestations and villous atrophy can be seen in patients with common variable immunodeficiency (CVID). In some patients, infectious agents may be responsible, whereas in others, celiac disease (CD) may be the cause. In this study, we investigate the causes and the histopathologic features seen in patients with CVID. Eleven patients with CVID and villous atrophy underwent duodenal biopsies, human leukocyte antigen (HLA) typing, and testing for all celiac antibodies. Fifteen patients with CVID and normal villi and 6 patients with CD but without CVID served as controls. Histologic response to a gluten-free diet (GFD) allowed a diagnosis of CD in 3 of 11 patients. In the remaining 8, the lack of a histologic response to a GFD or HLA typing excluded CD. Celiac antibodies gave conflicting results and were of no help. Polymorphonuclear infiltrates and lesions like graft-versus-host disease are seen more often in flat mucosa unresponsive to a GFD. However, the specificity of these findings remains to be determined and response to a GFD remains the only diagnostic criteria for CD in these patients. Villous atrophy was gluten-sensitive in 3 of 11 patients with CVID. It was not related to gluten-responsive CD in most patients.

Clinical and pathologic features of nodular duodenum: An analysis of 17 cases

AIM: To investigate the incidence, clinical presentations, histopathological features, natural history, and response to therapy of nodular duodenum.

METHODS: The clinical data for 17 patients with nodular duodenum were analyzed retrospectively, including age, sex, disease type, symptoms, final diagnosis, histopathology, hemoglobin, SF, AL, IG, and OVA.

RESULTS: Of 17 patients with nodular duodenum, 9 were male and 8 were female. Their mean age was 28.1 years. Approximately 47% of patients had stomachache. Sinus tubercle was most frequently seen endoscopically. Histology of duodenal nodules revealed chronic inflammation in all cases, intraepithelial eosinophilic granulocyte proliferation in 70.5% of cases, and villous atrophy in 47% of cases. Six patients had flagellate. Clinical diagnostic features included diarrhea, giardiasis, secretory IgA deficiency, and Helicobacter pylori-associated gastritis.

CONCLUSION: Nodular duodenum is an endoscopically distinct entity that may respond clinically to antisecretory therapy but is difficult to eradicate.

The role of prolonged viral gastrointestinal infections in the development of immunodeficiency-related enteropathy

Patients with primary immunodeficiencies are prone to develop enteropathy of unknown pathogenesis. We hypothesize that ineffective clearance of gastrointestinal pathogens, particularly viruses, in combination with defective immune regulation may cause inflammatory enteropathy in certain immunodeficient hosts. We reviewed publications related to prolonged enteric viral infection, immunodeficiency, and the subsequent development of inflammatory enteropathy. Prolonged infection with especially enteroviral infections was reported more often in immunocompromised hosts than in healthy individuals. Protracted enteric viral shedding was not always associated with the presence or duration of gastrointestinal symptoms. The development of immunodeficiency-associated enteropathy after prolonged viral infections was described in sporadic cases. Clinical consequences of viral gut infections in immunocompromised hosts comprise isolation issues and supportive care. Prospective studies in cohorts of immunodeficient patients are required to study the impact of prolonged enteric viral replication with respect to the pathogenesis of non-infectious enteropathy.

Regulation of mucosal IgA responses: lessons from primary immunodeficiencies

Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal communities on mucosal surfaces. In spite of having available a wealth of immune-sensing and effector mechanisms capable of triggering inflammation in response to microbial intrusion, mucosal immune cells establish an intimate dialogue with microbes to generate a state of hyporesponsiveness against commensals and active readiness against pathogens. A key component of this homeostatic balance is IgA, a noninflammatory antibody isotype produced by mucosal B cells through class switching. This process involves activation of B cells by IgA-inducing signals originating from mucosal T cells, dendritic cells, and epithelial cells. Here, we review the mechanisms by which mucosal B cells undergo IgA diversification and production and discuss how the study of primary immunodeficiencies facilitates better understanding of mucosal IgA responses in humans.

Chronic diarrhea and malabsorption due to hypogammaglobulinemia: a report on twelve patients

Hypogammaglobulinemic sprue (HGS), which may predispose to infection, is uncommon. Twelve patients (all men; median age 29 years, 15-50) with HGS (4%) of 296 with chronic small bowel diarrhea and malabsorption syndrome (MAS) during a 10-year period were analyzed. Treatment of HGS was delayed due to misdiagnosis as intestinal tuberculosis (n = 7) and diarrhea-predominant irritable bowel syndrome (n = 1). All had diarrhea and weight loss (median loss 12 Kg). Associated conditions were clubbing, bronchiectasis, and seizure (2 patients each), and hypothyroidism (n = 1). Laboratory parameters were urinary D-xylose median 0.46 g/5 g/5 h (range 0.2-1.6; normal ≥ 1), fecal fat 11.9 g/day (3.8-16.7; normal ≤ 7 g), serum IgA, IgG, and IgM: 23.5 mg/dL (17-114; normal 90-450), 584 mg/dL (145-1051; normal 800-1800), and 23 (0-40.3; normal 60-280). IgA, IgG, and IgM were low in 10, 10, and 11, respectively. Duodenal biopsy was normal in 6 patients and showed partial villous atrophy in 6 and nodular lymphoid hyperplasia in two. Associated infections were giardiasis (n = 1), disseminated strongyloidiasis (1), small intestinal bacterial overgrowth (3), septicemia (2), and septic arthritis (1). Two patients died of sepsis, five are well on immunoglobulin and specific anti-infective treatment, and five are lost to follow up. Approximately 4% patients with MAS have hypogammaglobulinemia, which is often associated with infection and is diagnosed late.

Diffuse duodenal nodular lymphoid hyperplasia: a large cohort of patients etiologically related to Helicobacter pylori infection

BACKGROUND

Nodular lymphoid hyperplasia of gastrointestinal tract is a rare disorder, often associated with immunodeficiency syndromes. There are no published reports of its association with Helicobacter pylori infection.

METHODS

From March 2005 till February 2010, we prospectively followed all patients with diffuse duodenal nodular lymphoid hyperplasia (DDNLH). Patients underwent esophagogastroduodenoscopy with targeted biopsies, colonoscopy, and small bowel video capsule endoscopy. Duodenal nodular lesions were graded from 0 to 4 based on their size and density. Patients were screened for celiac sprue (IgA endomysial antibody), immunoglobulin abnormalities (immunoglobulin levels & serum protein electrophoresis), small intestine bacterial overgrowth (lactulose hydrogen breath test), and Helicobacter pylori infection (rapid urease test, and histological examination of gastric biopsies). Patients infected with Helicobacter pylori received sequential antibiotic therapy and eradication of infection was evaluated by 14C urea breath test. Follow up duodenoscopies with biopsies were performed to ascertain resolution of nodular lesions.

RESULTS

Forty patients (Males 23, females 17; mean age ± 1SD 35.6 ± 14.6 years) with DDNLH were studied. Patients presented with epigastric pain, vomiting, and weight loss. Esophagogastroduodenoscopy showed diffuse nodular lesions (size varying from 2 to 5 mm or more) of varying grades (mean score ± 1SD 2.70 ± 0.84) involving postbulbar duodenum. Video capsule endoscopies revealed nodular disease exclusively limited to duodenum. None of the patients had immunoglobulin deficiency or small intestine bacterial overgrowth or positive IgA endomysial antibodies. All patients were infected with Helicobacter pylori infection. Sequential antibiotic therapy eradicated Helicobacter pylori infection in 26 patients. Follow up duodenoscopies in these patients showed significant reduction of duodenal nodular lesions score (2.69 ± 0.79 to 1.50 ± 1.10; p < 0.001). Nodular lesions showed complete resolution in 5 patients and significant resolution in remaining 21 patients. Patients with resistant Helicobacter pylori infection showed no significant reduction of nodular lesions score (2.71 ± 0.96 to 2.64 ± 1.15; p = 0.58). Nodules partially regressed in score in 2 patients, showed no interval change in 10 patients and progressed in 2 patients.

CONCLUSIONS

We report on a large cohort of patients with DDNLH, etiologically related to Helicobacter pylori infection.

Coeliac disease: the histology report

To this day intestinal biopsy is justly considered the "gold standard" for the diagnosis of coeliac disease (CD). The aim of the authors in setting up these guidelines was to assist pathologists in formulating a more precise morphological evaluation of a duodenal biopsy in the light of clinical and laboratory data, to prepare histological samples with correctly oriented biopsies and in the differential diagnosis with other pathological entities and complications of the disease. A further intention was to promote the conviction for the need of a close collaborative relationship between different specialists namely the concept of a "multidisciplinary team".

Diagnosis and treatment of primary immunodeficiency disease in patients with gastrointestinal symptoms

An estimated 250,000 individuals in the Unites States have been diagnosed with a primary immunodeficiency disease (PIDD). Early diagnosis and treatment of PIDD are critical to minimizing morbidity and improving quality of life. Patients with certain subtypes of PIDD may present with gastrointestinal complaints such as chronic or acute diarrhea, malabsorption, gastrointestinal pain, and inflammatory bowel diseases. Therefore, gastroenterologists are well positioned to help identify patients with PIDD. The hallmarks of PIDD include recurrent or persistent infections, infections due to microorganisms that rarely cause significant disease in immunocompetent people, unusually severe or life-threatening infections, and either low or persistently high white blood cell counts. An assessment for PIDD involves detailed patient and family histories, a physical examination, and diagnostic screening tests. Immunoglobulin replacement therapy is the cornerstone of treatment for most subtypes of PIDD.

Characterization of immunologic defects in patients with common variable immunodeficiency (CVID) with intestinal disease

BACKGROUND

Common variable immunodeficiency (CVID) is a heterogeneous disorder commonly presenting with recurrent sinopulmonary infections. In all, 6%-10% of CVID patients develop an inflammatory bowel disease (IBD)-like disorder, making these patients a unique population to investigate immune-mediated gastrointestinal disease. This study examined whether defects in peripheral and/or intestinal lymphocytes are involved in disruption of the intestinal mucosa in CVID patients with inflammatory intestinal diseases.

METHODS

Peripheral blood (PB) T cells from healthy controls; CD or UC; CVID; and CVID with IBD were stimulated for 48 hours with anti-CD3+CD28 or phytohemagglutinin (PHA) + phorbol 12-myristate 13-acetate (PMA); cytokine production was measured by enzyme-linked immunosorbent assay (ELISA). Cytokine expression from unstimulated lamina propria lymphocytes (LPLs) was compared by real-time polymerase chain reaction (PCR). Immunohistochemistry of mucosal biopsies was performed. Cell populations were quantified by morphometry.

RESULTS

CVID/IBD PB T cells stimulated by anti-CD3+CD28 had trends for reduced IL-2, IL-10, IFN-γ, and TNF-α compared to controls. These differences were not apparent following stimulation by PHA/PMA. Constitutive production of inflammatory cytokines by LPLs was not detected. Histologically, CVID patients had reduced/absent plasma cells with reductions in intestinal IgM and IgA. CVID patients with and without gastrointestinal (GI) disease exhibited increased CD3+ T cells, specifically CD8+, in the colon compared to normal and IBD controls, suggesting immune dysregulation.

CONCLUSIONS

Intestinal inflammation in CVID patients with IBD-like disease may be mediated by abnormal cytokine production through a T-cell receptor-mediated pathway. However, the variability observed suggests multiple, rather than singular, mechanisms are involved. Histologic features such as reduced intestinal plasma cells and lack of intestinal immunoglobulins may be useful markers in diagnosing CVID in a patient with GI disease refractory to conventional therapies.

"A rose is a rose is a rose," but CVID is Not CVID common variable immune deficiency (CVID), what do we know in 2011?

Common variable immune deficiency (CVID) is the commonest symptomatic primary immunodeficiency and represents a heterogenous collection of disorders resulting mostly in antibody deficiency and recurrent infections. However, autoimmunity, granulomatous inflammation and malignancy frequently occur as part of the syndrome. The etiology of the condition has been poorly understood although in recent years, significant progress has been made in elucidating genetic mechanisms that can result in a CVID phenotype. In parallel to this, advances in treatment of the condition have also resulted in improved survival and quality of life for patients. There still remains significant work to be done in improving our understanding of the disease. In addition, recognition of the condition remains poor with significant diagnostic delays and avoidable morbidity. In this article, we review CVID with a particular focus on the areas of improving diagnosis and classification, recent developments in understanding the underlying etiology and genetics; and current treatment and monitoring recommendations for patients.

Inflammatory bowel diseases in patients with adaptive and complement immunodeficiency disorders

Crohn's disease and ulcerative colitis are idiopathic chronic inflammatory diseases that primarily affect the gastrointestinal tract. The underlying causes remain poorly understood, but there is a growing body of evidence advocating a likely primary pathogenic role for immunodeficiency in the development of Crohn's lesions. Concordantly, a number of congenital immunodeficiencies disrupting the cellular innate immune system strongly predispose to noninfectious, Crohn's-like inflammatory bowel disease. There are case reports and series suggesting that the same may be true for some of the congenital adaptive and complement immunodeficiencies. This review considers and critiques these potential associations.

Recognizing gastrointestinal and hepatic manifestations of primary immunodeficiency diseases

Given the complex immune function of the gastrointestinal (GI) tract, it is not surprising that many children with primary immunodeficiencies present with GI tract manifestations. Although many immunodeficiency disorders present with overt evidence of immune dysregulation, a few can present in older children with more subtle signs and symptoms. Such children may present first to a gastroenterologist with common symptoms, including malabsorption, diarrhea, hepatomegaly, or inflammatory bowel disease, which may actually be a manifestation of their underlying immune disorder. A thorough clinical history in combination with a careful review of histology from biopsies may reveal clues that one is dealing with a disease entity outside the norm and may prompt additional laboratory studies beyond the usual set of screening laboratory tests. Once the true underlying diagnosis is revealed, more appropriate therapy can be initiated. Additionally, more appropriate anticipatory guidance regarding the expected disease course, response to medications, and any additional risks that therapy may entail can be provided to the family.

The enteropathy associated with common variable immunodeficiency: the delineated frontiers with celiac disease

OBJECTIVES

The enteropathy associated with common variable immunodeficiency (CVID) is poorly characterized, and its possible relationships with well-defined causes of enteropathy, such as celiac sprue (CS), remain debated. We aimed to assess the clinical and histopathological features of the enteropathy associated with CVID.

METHODS

The medical files of 50 CVID patients with gastrointestinal symptoms were analyzed retrospectively. Histological, phenotypic, and molecular analysis of intestinal endoscopic specimens was centrally performed.

RESULTS

Chronic diarrhea was the most frequent gastrointestinal symptom (92%), and biological evidence of malabsorption was observed in 54% of patients. Chronic gastritis associated or not with pernicious anemia and microscopic colitis were the most frequently observed histopathological features in gastric and colonic mucosa, respectively. Small-bowel biopsies available in 41 patients showed moderate increase in intestinal intraepithelial lymphocytes in 31 patients (75.6%) and villous atrophy in 21 patients (51%). Distinctive features from CS were a profound depletion in plasma cells and follicular lymphoid hyperplasia. Presence of peripheral blood CD8+ hyperlymphocytosis was predictive of intestinal intraepithelial hyperlymphocytosis. Intravenous (i.v.) immunoglobulin (Ig) therapy had no effect on enteropathy-related symptoms. Gluten-free diet improved only two out of 12 patients with villous atrophy, whereas all patients (7/7) responded to steroid therapy.

CONCLUSIONS

Several distinctive features differentiate CVID enteropathy from other causes of enteropathy including CS. Replacement i.v. Ig therapy is insufficient to improve gastrointestinal symptoms. Steroids are effective in reducing inflammation and restoring mucosal architecture.

How I treat common variable immune deficiency

Common variable immunodeficiency is a rare immune deficiency, characterized by low levels of serum immunoglobulin G, A, and/or M with loss of antibody production. The diagnosis is most commonly made in adults between the ages of 20 and 40 years, but both children and older adults can be found to have this immune defect. The range of clinical manifestations is broad, including acute and chronic infections, inflammatory and autoimmune disease, and an increased incidence of cancer and lymphoma. For all these reasons, the disease phenotype is both heterogeneous and complex. Contributing to the complexity is that patient cohorts are generally small, criteria used for diagnosis vary, and the doses of replacement immune globulin differ. In addition, routines for monitoring patients over the years and protocols for the use of other biologic agents for complications have not been clarified or standardized. In the past few years, data from large patient registries have revealed that both selected laboratory markers and clinical phenotyping may aid in dissecting groups of subjects into biologically relevant categories. This review presents my approach to the diagnosis and treatment of patients with common variable immunodeficiency, with suggestions for the use of laboratory biomarkers and means of monitoring patients.

Common variable immunodeficiency: an update on therapeutic approaches

Common variable immunodeficiency (CVID) is not a homogeneous disease, as has become clear from recent scientific studies. This makes the interpretation of studies of clinical therapeutics difficult to assess and raises questions about historical case reports. The evidence for the optimum use of replacement immunoglobulin in CVID is reviewed. This therapy represents the current gold standard, despite attempts to use other immunostimulatory compounds. Questions of product properties, product selection, adverse events and infectious risks are addressed. Products are not interchangeable and have different physicochemical characteristics. Despite intravenous immunoglobulin being in use for 20 years, there are still unanswered questions over dose and target trough IgG levels, particularly with respect to patients with established lung disease. The management of organ-based complications of CVID is discussed. This includes the treatment of unusual infections such as mycoplasmas and enteroviruses, which are specific to antibody deficiency. The diagnosis and treatment of the granulomatous disease of CVID is discussed. The role of surgery, including lung transplantation, in the management of CVID complications is reviewed. There are few available data on optimum strategies for antibiotic usage for bacterial infective complications and it is clear that present regimens, at least in severe recurrent sinus disease, are not consistently effective. Better clinical trials are required to identify appropriate regimens and validate or disprove widely held assumptions about therapy in CVID. Despite advances in diagnosis and management, there is abundant evidence in the UK that patients do not yet receive rapid diagnosis and optimum therapy, even within the limited published data currently available. This leads to considerable avoidable morbidity and mortality.

A case of primary immune deficiency presenting with nephrotic syndrome

Common variable immunodeficiency (CVID) is the most common form of severe antibody deficiency. The disorder is associated with a broad spectrum of clinical manifestations, including infections and chronic lung, gastrointestinal and autoimmune diseases. A 29-year-old female patient has had frequent sinopulmonary infections and gastroenteritis for the last 20 years and had been given broad-spectrum antibiotics for treatment. Immunoglobulin (Ig) levels were at undetectable levels. Renal biopsy was consistent with AA amyloidosis. She is now under follow-up with periodic intravenous Ig treatment without any infection during the last 10 months. CVID must be kept in mind in patients with recurrent sinopulmonary infections.

Gastrointestinal and hepatic manifestations of primary immune deficiency diseases

Primary immune deficiency diseases (PIDs) are a heterogeneous group of inherited diseases characterized by variable genetic immune defects, conferring susceptibility to recurrent infections. They have a vast array of manifestations some of which involve the gastrointestinal and hepatobiliary systems. These complications can be the consequence of five different factors, namely, infection, autoimmune process, unregulated inflammation, malignancies and complications of therapeutic intervention. They may precede the PID diagnosis and, once developed, they pose high risk of morbidity. Untrained clinicians may treat these manifestations only at the level of their presentation, leaving the PIDs dangerously undiagnosed. In fact, early diagnosis of PIDs and accompanied gastrointestinal and hepatic complications clearly require appropriate treatment, and in-turn lead to an improved quality of life for the patient. To improve the awareness of gastroenterologists and related health care providers about these diseases, we have reviewed herein the complications of different PIDs focusing on gastrointestinal and hepatic manifestation.

Gastrointestinal manifestations in primary immune disorders

The gastrointestinal tract is the largest lymphoid organ in the body containing T and B lymphocytes, macrophages, and dendritic cells. Despite the fact that these cells are constantly confronted with antigen primarily in the form of food and bacteria, immune responses in the gut are tightly regulated to maintain homeostasis. Without this balance of active immunity and tolerance, mucosal inflammation may ensue, and manifest as Crohn's disease, ulcerative colitis, pernicious anemia, or celiac sprue. Therefore, it is not unreasonable that inflammatory diseases of the gut are commonly encountered in patients with primary immune deficiencies. The exact pathogenesis of gastrointestinal diseases in the setting of primary immunodeficiency remains unknown, however, both humoral and cell-mediated immunity appear to play a role in preventing intestinal inflammation. Patients presenting with atypical gastrointestinal disease and/or failure to respond to conventional therapy should be evaluated for an underlying primary immune disorder in order to initiate appropriate treatment, such as immunoglobulin or in more severe cases bone marrow transplantation, to prevent long term complications.

[Gastrointestinal manifestations in patients with primary immunodeficiencies causing antibody deficiency]

INTRODUCTION

Primary immunodeficiencies can lead to gastrointestinal manifestations that are still not well defined.

OBJECTIVE

To analyze gastrointestinal manifestations associated with primary immunodeficiencies.

MATERIAL AND METHODS

We performed a retrospective study that included patients diagnosed with primary antibody deficiencies in a third-level hospital. The patients were divided into two groups: isolated IgA deficiency and common variable immunodeficiency syndrome (CVIS). The timing of presentation and type of gastrointestinal symptoms were analyzed.

RESULTS

There were 57 patients: 20 with CVIS (35%) and 37 with isolated IgA deficiency (65%). Diagnosis was made in the pediatric age in 17 patients, of whom 13 had isolated IgA deficiency. In 84% of the patients, diagnosis of immunodeficiency was made before the development of gastrointestinal manifestations. Digestive symptoms were found in 74% of the patients, the most frequent being diarrhea. In 46% of the patients, digestive disease was confirmed, mainly through endoscopy. Celiac-like lesions, chronic atrophic gastritis, ulcerative colitis-like disease and Crohn's disease were more common in CVIS. In isolated IgA deficiency, Helicobacter pylori-positive chronic gastritis predominated. Mean age was significantly higher (36 vs. 24 years, p=0.02) and IgA titer significantly lower (17 vs. 34UI/ml; p=0.008) in patients with associated gastrointestinal disease.

CONCLUSIONS

Gastrointestinal symptoms are frequent and lead to endoscopic diagnosis in half of patients with primary immunodeficiencies. Ulcerative colitis, and celiac- and Crohn's-like disease are atypical entities that occur in CVIS.

Pathology of non-Helicobacter pylori gastritis: extending the histopathologic horizons

The development of modern endoscopic techniques, easier and greater access to healthcare, and interest in Helicobacter pylori infection and its implications have all led to a significant increase in upper endoscopies. In turn, gastroenterologists and pathologists have been recognizing an ever-increasing number of patterns of mucosal injury. Consequently, there is now an interest in a wider aspect of non-neoplastic gastric pathology, namely, non-HP (H. pylori) gastritis. In this review, we present major clinico-pathological entities, based on either the salient morphological features or the underlying etiologies.

GI-lymphomas in immunosuppressed patients (organ transplantation; HIV)

Gastrointestinal lymphoma plays a major role complicating different diseases presenting with immunosuppression, both primary and acquired immunodeficiency (incl. HIV, transplantation, immunosuppression following chemotherapy, or inflammatory bowel disease). Lymphoma in diseases with immunosuppression are clinically and pathologically heterogeneous, but share some features such as frequent involvement of extranodal sites, diffuse aggressive histology, B-cell lineage derivation, viral association with EBV and clinically aggressive courses. While gastrointestinal lymphoma in congenital immunodeficiency disorders seems to be a rare event inspite of higher prevalences, in post-transplant lymphoproliferative disorders (PTLD) the gastrointestinal tract is one of the most important organs of lymphoma. In HIV-associated non-Hodgkin's lymphoma, gastrointestinal lesions as the most frequent extranodal localisation occur in 30-50% of lymphoma patients, are late events of HIV infection with severe immunosuppression and are mainly diagnosed with advanced disease stages Ann Arbour III or IV. They are characterised by unusual, often multifocal localisation in the gastrontestinal tract, high rates of life-threatening complications (bleeding, perforation or obstruction) and high-grade B-cell histology. With the introduction of highly active antiretroviral therapy (HAART) in the therapeutic concept in AIDS, a decrease of AIDS-related GI lymphoma was noted with improved survival rates and prognosis of lymphoma. Therapy strategies including chemotherapy, immunotherapy and HAART will show promising results in response and survival rates.

Common variable immunodeficiency associated with inflammatory bowel disease and type I diabetes

Common variable immunodeficiency (CVID) is a heterogeneous group of primary immunodeficiency disorders characterized by defective antibody production, low levels of serum immunoglobulins and increased susceptibility to infection. The patient was a 39-year-old male who was admitted to the gastroenterology department with a two week history of diarrhea, blunt abdominal pain below the umbilicus, prolonged febrile state, loss of appetite and loss of body weight of 18 kg during the previous six months. Screening tests of serum immunoglobulins showed decreased concentrations of three types of immunoglobulins: IgA < 0.24 g/L, IgM < 0.18 g/L and IgG < 1.55 g/L. Lymphocytes immunophenotypisation revealed inversed CD4⁺/8⁺ T cells ratio, 0.31 and absence of plasma cells (CD138 negative). Colonoscopy showed a rectal mucosa like cobblestones with multiple longitudinal and serpentinous ulceration, without involvement of other segments of the colon and the small intestine. Histopathology revealed aphtous ulcerative lesions, transmural inflammation with multiple lymphoid aggregates and benign lymphoid nodular hyperplasia of the small intestine. Plasma cells were absent from the lamina propria. Magnetic resonance imaging of a perianal fistula demonstrated a trans-sphicteric type. This case is specific because of the three illnesses associated and only one case of an association of diabetes mellitus type I and immunodeficiency reported thus far.

Pathogenesis and treatment of gastrointestinal disease in antibody deficiency syndromes

Primary humoral immune deficiencies are characterized by limited antibody responses secondary to either impaired B-lymphocyte development or B-cell responses to T-lymphocyte signals. Given that the gastrointestinal tract is the largest lymphoid organ in the body, it is not surprising that intestinal diseases are common in immunodeficiency. These gastrointestinal diseases can be classified into one of 4 groups, infection, malignancy, inflammatory, and autoimmune, and can mimic other known disease processes, such as inflammatory bowel disease and celiac sprue. The exact pathogenesis of these gastrointestinal disorders in the setting of systemic immunodeficiency is still under investigation. However, studies suggest that defects in antibody deficiency alone do not result in gastrointestinal disease but rather that defects in cellular immunity are also involved. Treatment is difficult given an already immunocompromised state, and often therapy with immunomodulators is required for more severe processes.

Juvenile onset psoriatic arthritis in a patient with X‐linked agammaglobulinemia (Bruton's disease)

We describe a 47-year-old male patient suffering from X-linked (or Bruton's) agammaglobulinemia with severe psoriatic arthritis (PsA), which started in childhood. PsA has been previously described in T-cell defective disorders, such as HIV infection, but our observation demonstrates that this rheumatic disease can also occur in subjects with B-lymphocyte cell functional impairment. Chronic inflammatory (bacterial?) involvement of the bowel could represent a pathogenetic connection between X-linked agammaglobulinemia and PsA.

Pathology of graft-versus-host disease in the gastrointestinal tract

Graft-versus-host disease (GVHD), a common complication of hematopoietic stem cell transplantation, is a clinical syndrome that requires synthesis of clinical, laboratory, and histopathologic findings for diagnosis. The gastrointestinal (GI) tract is commonly affected, and pathologists must recognize subtle morphologic alterations in GI mucosal biopsies to make the diagnosis and to rule out other causes of GI dysfunction such as cytomegalovirus infection and drug effects. This review summarizes the histopathologic features of GVHD in the GI tract and outlines recent recommendations for reporting of GI biopsies with suspected GVHD.

Nodular lymphoid hyperplasia and histologic changes mimicking celiac disease, collagenous sprue, and lymphocytic colitis in a patient with selective IgA deficiency

Selective IgA deficiency is the most common primary immunoglobulin deficiency. The clinical manifestations of selective IgA deficiency, including gastrointestinal (GI) complications, are rare and typically milder than those seen with common variable immunodeficiency or X-linked agammaglobulinemia. We present a rare case of selective IgA deficiency that shows a number of interesting histological features in the GI tract, including diffuse nodular lymphoid hyperplasia involving the entire small and large intestine, celiac disease-like and collagenous sprue-like changes in the small intestine, as well as lymphocytic colitis pattern. However, this patient had no particular GI symptoms suggestive of celiac sprue or microscopic colitis. These findings suggest that the GI tract in patients with selective IgA deficiency can show peculiar histologic changes that mimic celiac disease, collagenous sprue, or lymphocytic colitis, which may be a pattern of injury related to infection or immunoglobulin immunodeficiency-associated autoimmune phenomena.

Diagnostic value of esophagogastroduodenoscopy in patients with ileal pouch-anal anastomosis

BACKGROUND

Inflammatory and noninflammatory complications of ileal pouch-anal anastomosis (IPAA) are common after restorative proctocolectomy of ulcerative colitis (UC). Some of the patients can have upper gastrointestinal pathology. The diagnostic role of esophagogastroduodenoscopy (EGD) in these patients has not been evaluated. The aim was to estimate the prevalence of upper gastrointestinal (GI) diseases detected by EGD and to assess factors associated with the abnormal EGD findings.

METHODS

IPAA patients with underlying inflammatory bowel disease undergoing diagnostic EGD were recruited from a subspecialty pouchitis clinic. Diagnostic yield and incidental findings of EGD were evaluated. Twenty-three variables were evaluated including age, gender, UC duration, IPAA duration, the Pouchitis Disease Activity Index scores, pouch type, pre-IPAA diagnosis, and disease category of the pouch. Univariate and multivariate analyses were performed; stepwise selection with 0.35 and 0.10 as entry and exit criteria.

RESULTS

Sixty-six patients undergoing EGD were enrolled in the study, of whom 64 (97%) patients had a concomitant pouch endoscopy. Indications for EGD include anemia, upper abdominal pain, weight loss, nausea and vomiting, and persistent diarrhea refractory to antibiotic therapy. Seventeen patients (25.8%) had a conclusive diagnosis and 14 (21.2%) had incidental findings, on EGD. The most common abnormal findings on EGD were Crohn's disease 12%), peptic ulcer disease (3%), gastritis/duodenitis on histology (11%), Candida esophagitis (3%), and arteriovenous malformations (3%). In multivariate analysis, factors associated with a conclusive EGD diagnosis were a high Pouchitis Disease Activity Index endoscopy score of the afferent limb (odds ratio [OR] = 1.8; 95% confidence interval [CI]: 1.09, 2.9; P = 0.02) and pouch types other than original J pouch (OR = 5.9; 95% CI: 1.08, 32.2; P = 0.041).

CONCLUSIONS

EGD evaluation can yield valuable diagnostic information in selected symptomatic patients with IPAA.

Primary antibody deficiency syndromes

The primary antibody deficiency syndromes are a group of rare disorders characterized by an inability to produce clinically effective immunoglobulin responses. Some of these disorders result from genetic mutations in genes involved in B cell development, whereas others appear to be complex polygenic disorders. They most commonly present with recurrent infections due to encapsulated bacteria, although in the most common antibody deficiency, Common Variable Immunodeficiency, systemic and organ-specific autoimmunity can be a presenting feature. Diagnostic delay in this group of disorders remains a problem, and the laboratory has a vital role in the detection of abnormalities in immunoglobulin concentration and function. It is critical to distinguish this group of disorders from secondary causes of hypogammaglobulinaemia, in particular lymphoid malignancy, and appropriate laboratory investigations are of critical importance. Treatment of primary antibody deficiencies involves immunoglobulin replacement therapy, either via the intravenous or subcutaneous route. Patients remain at risk of a wide variety of complications, not all linked to diagnostic delay and inadequate therapy. In common variable immunodeficiency (CVID) in particular, patients remain at significantly increased risk of lymphoid malignancy, and regular clinical and laboratory monitoring is required. This review aims to give an overview of these conditions for the general reader, covering pathogenesis, clinical presentation, laboratory investigation, therapy and clinical management.

Chronic active gastritis in X-linked lymphoproliferative disease

Gastric lesions in primary constitutive immune deficiencies include multifocal atrophic gastritis, erosive pangastritis, and a pattern of gastric lesions reminiscent of graft-versus-host disease. We describe the genetic anomalies in 2 monozygotic twins with an X-linked lymphoproliferative disease (XLP; MIM 308240), a rare familial setting of high susceptibility to Epstein-Barr virus (EBV). Since early childhood, both twin brothers exhibited a severe chronic active atrophic pangastritis. A germline screening of the SH2D1A (MIM 300490) and BIRC4 (MIM 300079) genes was performed, and also a high-resolution whole-genome SNP profiling (Infinium Sentrix Human-1 Genotyping BeadChip, Illumina). A 3 Megabase deletion in the Xq25 region, encompassing the SH2D1A gene, was defined by SNP array genotyping. Histologic analysis of yearly or twice yearly gastric biopsies in both children showed a Helicobacter pylori-negative, Epstein-Barr virus-negative chronic active atrophic pangastritis, with superficial ulcer formation, foveolar hyperplasia, glandular dilatation and ultimately pseudopyloric and intestinal metaplasia. No such chronic active inflammatory gastric lesions have been reported to date in XLP. The similarities between XLP and common variable immunodeficiency (MIM 240500) underscore the need for early recognition and close monitoring of these gastric lesions, with special regard to their neoplastic potential. No infectious cause was determined. We favor a dysimmune mechanism in the development of this chronic atrophic gastritis, presenting a striking similarity to the recently described atrophic autoimmune pangastritis.

Gastrointestinal tract pathology in patients with common variable immunodeficiency (CVID): a clinicopathologic study and review

BACKGROUND

Common variable immunodeficiency (CVID) is characterized by a host of gastrointestinal (GI) lesions that can mimic other conditions.

METHODS

We reviewed clinical documentation and samples from 132 separate GI biopsy or resection sites on 20 CVID patients obtained over a 26-year period, including biopsies from the colon (34), esophagus (19), small intestine (38), and stomach (35), a partial gastrectomy, small bowel resection, colectomy, 2 cholecystectomies, and 1 appendectomy.

RESULTS

There were 13 males and 7 females. Nine patients were children (10 y and younger) and 11 were adults. Age at diagnosis ranged from 6 months to 62 years (median, 35.5 y), and age at biopsy ranged from 10 months to 67 years (median, 38 y). Esophageal samples often showed intraepithelial neutrophils, accompanied by candida. Half of patients' esophageal biopsies had prominent intraepithelial lymphocytosis, one of which also had prominent apoptosis. The stomachs of 67% of patients lacked plasma cells. Most showed lymphoid aggregates. An increase in apoptosis was detected in biopsies from a third. About 20% had a lymphocytic gastritis pattern. Intraepithelial neutrophils were found in a subset, accompanied by various infections [cytomegalovirus (CMV), Helicobacter pylori, and Cryptosporidium]. Granulomas were found in 1 patient. Gastric adenocarcinoma was identified in one patient. There was a paucity of small bowel plasma cells in the majority of patients (68%). The small bowel showed prominent lymphoid aggregates in about half (47%). An increase in apoptosis was detected in specimens from about 20%. Increased intraepithelial lymphocytes (IELs) were found in samples from over half of patients (63%), most of whom (83%) also had villous blunting, mimicking celiac disease. Intraepithelial neutrophils were found in a subset (32%) and correlated with CMV and Cryptosporidium infections. Granulomas were seen in biopsies from 2 patients (11%). One patient had a collagenous enteritis pattern (accompanied by a collagenous colitis pattern). One patient had autoimmune enteritis; biopsies from this patient were initially relatively normal but later displayed prominent crypt apoptosis and loss of goblet cells. In colon samples, a paucity of plasma cells was seen in 10 patients (63%). The colon showed lymphoid aggregates in most patients (81%). Apoptosis was prominent in samples from half of the patients (50%). Biopsies from 6 patients had a lymphocytic colitis pattern (38%) and 2 patients had a collagenous colitis pattern. Intraepithelial neutrophils were found in samples from most patients (88%). Crypt distortion was seen in 6 of these patients (43%), thereby mimicking ulcerative or Crohn colitis. Granulomas were found in 3 patients (19%). CMV was detected in 1 patient. The appendix from 1 patient showed Cryptosporidium and acute serositis with a paucity of plasma cells and an increase in apoptosis. The gallbladder from 1 patient showed acute cholecystitis, and another patient's gallbladder lacked plasma cells.

CONCLUSIONS

GI tract CVID displays a wide spectrum of histologic patterns. Its features can mimic lymphocytic colitis, collagenous enterocolitis, celiac disease, lymphocytic gastritis, granulomatous disease, acute graft-versus-host disease, and inflammatory bowel disease. In fact, in our series, we found patients with a prior diagnosis of celiac disease (25%) and inflammatory bowel disease (35%), including Crohn disease (15%). The diagnosis of CVID may be suspected on the basis of the lack of plasma cells in a GI biopsy, but because this feature is only present in about two-thirds of patients, the diagnosis cannot always be suggested in isolation of other clinical and laboratory findings.

[Gastrointestinal diseases in primary immunodeficiency disorders]

Gastrointestinal symptoms are common and often reveal primary immunodeficiency. Although they mimic gastrointestinal diseases observed in immunocompetent patients, there have diagnostic and therapeutic specificities that should be known for optimal management of these patients. This review describes the gastrointestinal diseases found in primary immunodeficiency and proposes some diagnostic and therapeutic strategies.

Common variable immunodeficiency in children

PURPOSE OF REVIEW

Common variable immunodeficiency is the most common primary immunodeficiency that needs medical attention. Symptoms may occur at any time, with two major peaks of onset at 5-10 and 20-30 years. We present the different clinical phenotypes of common variable immunodeficiency, review recent genetic findings and point to current treatment strategies.

RECENT FINDINGS

Five genes, ICOS, CD19, TNFRSF13B, TNFRSF13C and MSH5, have been found to be mutated in patients with common variable immunodeficiency. Additional possible genetic loci for autosomal dominant forms were detected on chromosomes 4q and 16q. These findings illustrate the heterogeneous molecular basis of common variable immunodeficiency and indicate the value of genetic linkage studies, thereby improving the genetic diagnosis.

SUMMARY

In young patients with unusually frequent bacterial infections, common variable immunodeficiency should always be considered as a differential diagnosis. The compulsory individual work-up should comprise a family history in order to document siblings and additional family members suffering from common variable immunodeficiency and/or selective IgA deficiency. Since the recently found gene defects affect a minority of patients with common variable immunodeficiency only, future genetic research is required to identify further susceptibility genes involved in the pathogenesis of this condition.

Adult autoimmune enteropathy: Mayo Clinic Rochester experience

BACKGROUND & AIMS

Autoimmune enteropathy is a rare cause of intractable diarrhea associated with circulating gut autoantibodies and a predisposition to autoimmunity. It is rarely observed in adults, with only 11 cases reported to date.

METHODS

Fifteen adults with autoimmune enteropathy were identified at the Mayo Clinic, Rochester, from May 2001-June 2006. The demographic, clinical, and treatment data were abstracted from their records.

RESULTS

The study population was 87% white, 47% female, with median age of 55 years (interquartile range, 42-67 years). All patients had protracted diarrhea, weight loss, and malnutrition. Celiac disease was excluded by lack of response to gluten-free diet or absence of the celiac disease susceptibility HLA genotypes. Fourteen patients were tested for gut epithelial cell antibodies, and 93% were positive for anti-enterocyte and/or anti-goblet cell antibodies. Predisposition to autoimmune diseases was noted in 80%, as indicated by a variety of circulating autoantibodies. Small intestinal histopathologic findings included subtotal villous atrophy and lymphoplasmacytic infiltration in the lamina propria with relatively few surface intraepithelial lymphocytes. T-cell receptor gene rearrangement studies were negative in all cases. Immunosuppressive therapy was required in 93% of cases. Clinical improvement was noted in 60% after 1-8 weeks of steroid therapy.

CONCLUSIONS

Autoimmune enteropathy is a heterogeneous disease and should be considered in the differential diagnosis of malabsorption and small bowel villous atrophy. The presence of gut epithelial cell antibodies can help confirm the diagnosis. No single agent is unequivocally effective in inducing remission, and immunosuppressive therapy is required in most cases.

Gastrointestinal manifestations in patients with common variable immunodeficiency

This study focuses on endoscopic and pathologic alterations of gastrointestinal (GI) disorders of Iranian patients with common variable immunodeficiency (CVID). Nineteen of 39 CVID patients (48%) had GI complaints. The most common symptom was chronic diarrhea (28%). In endoscopic examination of small intestines, 15 patients had no abnormal finding. Duodenal biopsy revealed villous atrophy in eight and nodular lymphoid hyperplasia in three patients. There was no statistically significant difference between patients with and patients without duodenal villous atrophy regarding the presence of chronic diarrhea, anemia, and absolute CD4+T cells. In three patients, biopsies of the colon showed chronic noncrypt-destructive colitis. GI problems pose a high morbidity to CVID patients and are second only to respiratory complications. CVID patients are at increased risk of infectious and inflammatory conditions in the GI tract. Early diagnosis of these complications improves the quality of life and well-being of patients.

Anti-tumour necrosis factor-alpha therapy for severe enteropathy in patients with common variable immunodeficiency (CVID)

We present three common variable immunodeficiency (CVID) patients with severe inflammatory bowel disease of unknown aetiology, resistant to steroid treatment, treated with infliximab. After exclusion of any infection, infliximab was given at a dose of 5 mg/kg every 4 weeks for a 3 month induction followed by every 4-8 weeks depending on clinical response. Two of these patients had predominantly small bowel disease; they both showed clinical response to infliximab with weight gain and improvement of quality of life scores. The third patient had large bowel involvement with profuse watery diarrhea; this patient improved dramatically within 48 hours of having infliximab treatment. All three patients have been maintained on infliximab treatment for between 5 and 53 months (mean 37 months) with no evidence of increased susceptibility to infections in the patients with small bowel disease, although the third patient developed two urinary tract infections and a herpes zoster infection following therapy. This is the first small case series to show that infliximab is a useful addition to current therapy in this rare group of patients with potentially life threatening enteritis.

Recognition, clinical diagnosis and management of patients with primary antibody deficiencies: a systematic review

The primary purpose of this systematic review was to produce an evidence-based review of the literature as a means of informing current clinical practice in the recognition, diagnosis and management of patients with suspected primary antibody deficiency. Randomized controlled trials (RCTs) were identified from a search of MEDLINE, EMBASE, The Cochrane Library, DARE (CRD website) and CINAHL by combining the search strategies with The Cochrane Collaboration's validated RCT filter. In addition, other types of studies were identified in a separate search of MEDLINE and EMBASE. Patients at any age with recurrent infections, especially in the upper and lower respiratory tracts, should be investigated for possible antibody deficiency. Replacement therapy with immunoglobulin in primary antibody deficiencies increases life expectancy and reduces infection frequency and severity. Higher doses of immunoglobulin are associated with reduced infection frequency. Late diagnosis and delayed institution of immunoglobulin replacement therapy results in increased morbidity and mortality. A wide variety of organ-specific complications can occur in primary antibody deficiency syndromes, including respiratory, gastroenterological, hepatic, haematological, neurological, rheumatological and cutaneous. There is an increased risk of malignancy. Some of these complications appear to be related to diagnostic delay and inadequate therapy. High-quality controlled trial data on the therapy of these complications is generally lacking. The present study has identified a number of key areas for further research, but RCT data, while desirable, is not always obtained easily for rare conditions. Few data from registries or large case-series have been published in the past 5 years and a greater focus on international collaboration and pooling of data is needed.

Collagenous duodeno-ileo-colitis with transient IgG deficiency preceded by Yersinia enterocolitica intestinal infection: case report and review of literature

A case-report of a man with chronic diarrhoea is presented. After an unsuccessful treatment of an intestinal yersioniosis, the diagnosis of collagenous intestinal disease affecting duodenum, ileum and colon was made. In addition, a IgG transient deficiency was observed. The literature about gastrointestinal involvement, concomintant infection by Yersinia and IgG deficiency in collagenous colitis is reviewed.

Colonic lymphoid aggregates in slow transit constipation

Information available on colonic lymphoid aggregates, apart from data of patients with inflammatory conditions, is scarce in other pathologic conditions. We investigated colonic lymphoid aggregates in patients with severe slow transit constipation, unresponsive to conventional therapeutic measures, and undergoing surgery for relief of their symptoms. Tissues from 27 patients with intractable slow transit constipation were obtained and compared with 10 controls. The number, diameter, lymphocyte distribution, and proliferative index were calculated and compared in both groups. Constipated patients displayed a significantly increased number of colonic lymphoid aggregates compared with controls. No differences were found concerning the other variables. The increase of colonic lymphoid aggregates found in severely constipated patients may represent a protective mucosal mechanism toward the chronic fecal stasis.

Pathology of non-infective gastritis

The discovery of Helicobacter pylori and its intimate role in the development of the most common form of chronic gastritis has elicited a much-needed interest in non-neoplastic gastric pathology. This has been paralleled by an increase in upper endoscopic examinations, which allow recognition of novel patterns and distribution of mucosal injury. Numerous attempts at classification have been made, most based on the acuteness or chronicity of gastric mucosal injury. In this review, we will not offer a new classification but present a detailed description of the major clinicopathological entities, based either on the salient morphological features or the underlying aetiologies, i.e. iatrogenic, autoimmune, vascular or idiopathic.

Common variable immunodeficiency: The power of co-stimulation

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immune deficiency in adults. CVID is characterized by the sequelae of an antibody deficiency syndrome: an impaired terminal B cell differentiation results in hypogammaglobulinemia and susceptibility to recurrent infections by encapsulated bacteria. The clinical course of CVID is complicated by a plethora of systemic immunopathology, including autoimmunity, lymphoproliferation, malignancy and sarcoid-like granulomas. Phenotypic and functional studies in CVID patients revealed multiple abnormalities within the innate and adaptive immune system. The recent description of monogenic defects in ICOS, TACI and CD19 focussed our interest to an impaired T cell-B cell collaboration within the germinal center and intrinsic B cell defects as possible explanations for the etiology of CVID.

Excess IL-12 but not IL-23 accompanies the inflammatory bowel disease associated with common variable immunodeficiency

BACKGROUND & AIMS

Common variable immunodeficiency (CVID) patients can develop an idiopathic inflammatory bowel disease resulting in chronic diarrhea and life-threatening malabsorption. This study was designed to assess the status of the gastrointestinal tract and to define the mucosal immune abnormalities in patients with and without symptomatic gut inflammatory disease.

METHODS

CVID patients underwent tests of gut absorption, peripheral blood mononuclear cell phenotyping, and upper and lower endoscopy for histology and lamina propria mononuclear cell (LPMC) cytokine production.

RESULTS

CVID patients with gastrointestinal symptoms differed from asymptomatic CVID patients by having significantly longer duration of disease and lower body mass index, D-xylose absorption, serum albumin, CD4/CD45RA cells, CD3/CD25 cells, and natural killer cells. Symptomatic CVID patients showed diffuse histologic inflammatory changes in the duodenal and colonic mucosa including villus blunting, increased lamina propria and intraepithelial lymphocytes, and epithelial apoptosis, less frequently seen in asymptomatic patients. LPMCs from symptomatic CVID patients produced significantly higher T-helper (Th) 1 cytokines, interleukin-12, and interferon-gamma. Compared with the Th1 cytokines produced by LPMCs from Crohn's disease, CVID patients did not produce excess amounts of interleukin-23, interleukin-17, or tumor necrosis factor-alpha.

CONCLUSIONS

The idiopathic inflammatory bowel disease associated with gastrointestinal symptoms in CVID is a unique combination of diverse histologic findings accompanied by excessive Th1 cytokine production, distinct from that in Crohn's disease. These data show that human gut mucosal inflammatory disease can occur with excess interleukin-12 and interferon-gamma production alone and provide a rationale for developing targeted therapies for this complication of CVID.

Intraepithelial lymphocytosis in architecturally preserved proximal small intestinal mucosa: an increasing diagnostic problem with a wide differential diagnosis

CONTEXT

An increased intraepithelial lymphocyte density in an architecturally normal proximal small intestinal mucosal biopsy is a common finding facing surgical pathologists dealing with gastrointestinal biopsy specimens. Approximately 1% to 2% of all proximal small intestinal biopsies will show this change. It is increasingly recognized by surgical pathologists that gluten-sensitive enteropathy is an important cause of this pattern; however, gluten-sensitive enteropathy accounts for the minority of all cases. A wide variety of immunologic stimuli can raise intraepithelial lymphocyte numbers. Among the other common associations are enteric infection, autoimmune disease, drugs, and gastric Helicobacter infection.

OBJECTIVE

To outline the causes of intraepithelial lymphocytosis, to highlight the importance and the difficulties faced in establishing gluten-sensitive enteropathy as the cause, and to aid the surgical pathologist in the routine sign out of these cases.

DATA SOURCES

A review of the literature detailing the causes or associations of proximal small intestinal intraepithelial lymphocytosis is presented.

CONCLUSIONS

Increased lymphocyte numbers in the epithelium of architecturally preserved proximal small intestinal biopsies is a morphologic feature associated with a broad differential diagnosis.