Pathogenesis, diagnosis and treatment of anaemia in immune-mediated gastrointestinal disorders

A systematic review of gastritis as an immune-related adverse event in clinical interventions

Immune checkpoint inhibitors (ICIs) are crucial in cancer treatment, and the associated immune-related adverse events (irAEs) have garnered significant attention, yet reports on associated immune related gastritis are limited. The diagnosis of immune related gastritis remains predominantly exclusionary, meanwhile its management diverges significantly from that of conventional gastritis. Current guidelines lack standardized grading criteria, and substantial data from large-scale, tertiary clinical studies are absent, therefore we conducted a systematic review of Medline, Web of Science, and Embase databases, identifying 31 articles from 2017 to December 31, 2023, involving 258 patients. Clinical manifestations included epigastric pain (53.1%), mucosal erythema (56.1%), and lymphocyte infiltration (48.6%). Corticosteroid therapy was common (94.7%), with 86.7% experiencing post-treatment improvement. 80% of patients can be diagnosed through endoscopy and pathology, while the remaining 20% may require PET-CT. Hormonal therapy is favored but diverges from standard management. Accurate diagnosis is crucial in managing immune related gastritis effectively.

Update understanding on diagnosis and histopathological examination of atrophic gastritis: A review

Chronic atrophic gastritis (CAG) is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa, reducing the stomach's ability to secrete gastric juice and pepsin, and interfering with its normal physiological function. Multiple pathogenic factors contribute to CAG incidence, the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity. Furthermore, CAG has a broad spectrum of clinical manifestations, including gastroenterology and extra-intestinal symptoms and signs, such as hematology, neurology, and oncology. Therefore, the initial CAG evaluation should involve the examination of clinical and serological indicators, as well as diagnosis confirmation via gastroscopy and histopathology if necessary. Depending on the severity and scope of atrophy affecting the gastric mucosa, a histologic staging system (Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia) could also be employed. Moreover, chronic gastritis has a higher risk of progressing to gastric cancer (GC). In this regard, early diagnosis, treatment, and regular testing could reduce the risk of GC in CAG patients. However, the optimal interval for endoscopic monitoring in CAG patients remains uncertain, and it should ideally be tailored based on individual risk evaluations and shared decision-making processes. Although there have been many reports on CAG, the precise etiology and histopathological features of the disease, as well as the diagnosis of CAG patients, are yet to be fully elucidated. Consequently, this review offers a detailed account of CAG, including its key clinical aspects, aiming to enhance the overall understanding of the disease.

Nutritional Consequences of Celiac Disease and Gluten-Free Diet

Celiac disease is an immune-mediated condition triggered by gluten ingestion in genetically predisposed individuals. The global prevalence of celiac disease is significant, affecting approximately 1.4% of women and 0.7% of men, with incidence rates of 17.4 and 7.8 per 100,000 person-years, respectively. The clinical presentation of celiac disease may range from overt diarrhea and malabsorption to more subtle features such as nutritional deficiencies and extraintestinal manifestations. It is the most common cause of global malabsorption in Western countries. A life-long gluten-free diet is the only available treatment for celiac disease. Moreover, a gluten-free diet is often adopted by individuals without celiac disease, either to address non-celiac gluten sensitivity or for other reasons. This review aims to explore the current understandings of the nutritional consequences of untreated celiac disease and the impact of the gluten-free diet itself. Physicians and dietitians specializing in celiac disease should focus on providing a well-rounded nutritional scheme to address deficiencies caused by the disease and prevent the instauration of new nutritional imbalances.

Follow-up evaluation and management of anemia in inflammatory bowel disease: A study by the Italian Group for Inflammatory Bowel Diseases (IG-IBD)

BACKGROUND

The RIDART I study found a 13.6% prevalence of anemia in Italian patients with inflammatory bowel disease (IBD); most cases were due to iron-deficiency anemia (IDA).

AIMS

To evaluate changes in hemoglobin concentration during a 24-week follow-up of anemic patients with IBD.

METHODS

Follow-up laboratory and clinical data were obtained from RIDART I study patients with anemia. Factors affecting hemoglobin concentration, the impact of anemia on fatigue and quality of life (QoL), and its relationship with treatment, disease activity and disease complications were investigated.

RESULTS

Hemoglobin was 108 g/L at baseline, increased to 121 g/L at follow-up week 12 (p < 0.001) and then stabilized until week 24, but most patients remained anemic, with IDA, throughout the study. Hemoglobin improvement was greater in patients receiving either oral or parenteral iron supplementation. Following hemoglobin normalization, anemia relapse rate during follow-up was 30%. Oral iron did not cause disease reactivation. Lower follow-up hemoglobin was associated with a higher probability of having active disease, clinical complications, increased fatigue and reduced QoL.

CONCLUSIONS

In anemic patients with IBD, anemia represents a long-lasting problem, in most cases persisting for up to 24 weeks, with high relapse rate and a negative impact on fatigue and QoL.

Prevalence, Pathogenesis and Management of Anemia in Inflammatory Bowel Disease: An IG-IBD Multicenter, Prospective, and Observational Study

BACKGROUND

Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD), with a 6% to 74% prevalence and a negative impact on patient survival and quality of life, although the prevalence is apparently declining due to improved disease treatment. We aimed to investigate the prevalence, pathogenesis, and clinical correlates of anemia in Italian patients with IBD.

METHODS

A multicenter, prospective, observational study, involving 28 Italian gastroenterology centers, was conducted to investigate the epidemiology and consequences of IBD-associated anemia. Clinical and laboratory data of anemic patients were obtained at study enrolment.

RESULTS

Anemia was diagnosed in 737 of 5416 adult IBD outpatients (prevalence 13.6%); females were more commonly affected than males (odds ratio, 1.5; 95% confidence interval [CI], 1.2-1.7) and had more severe anemia. In the majority of cases, anemia was due to iron deficiency (62.5% of cases; 95% CI, 58.3%-66.6%), either isolated or in association with inflammation and/or vitamin deficiencies; anemia of inflammation accounted for only 8.3% of cases. More severe anemia was associated with increasing fatigue and worse quality of life. Only 68.9% of anemic patients with iron deficiency (95% CI, 63.4%-73.8%) and 34.6% of those with vitamin deficiencies (95% CI, 26.2%-44.2%) were properly treated with supplementation therapy.

CONCLUSIONS

In Italy, the prevalence of IBD-associated anemia is lower than previously reported. Anemia of IBD is most commonly due to iron deficiency and contributes to fatigue and poor quality of life, but remains untreated in a large proportion of patients with iron and/or vitamin deficiencies. This study is registered at clinicaltrials.gov as NCT02872376.

Autoimmune atrophic gastritis and coeliac disease: A case-control study

BACKGROUND

Autoimmune atrophic gastritis (AAG) is rarely associated with coeliac disease (CD).

AIMS

To assess the frequency of AAG-CD association and to compare clinical, biochemical, and histological features of adults affected by both diseases (cases) with AAG controls.

METHODS

This case-control study included 9 cases (F55%, median age 47, range 23-59yrs) matched (1:3) by age (±4 yrs) and gender to 27 controls randomly selected from our AAG cohort (2009-2021). The AAG and CD diagnosis was based on internationally agreed criteria.

RESULTS

Of 434 AAG patients (median age:62.5yrs, range18-92yrs, F:M ratio=2.2:1),9 had a concomitant diagnosis of CD. The occurrence of AAG-CD association was 2% and 1.65% among AAG/CD cohorts, respectively. Cases were significantly younger than AAG cohort (n = 425, p = 0.002). In 4/9cases, AAG was diagnosed by proactive screening for autoimmune disorders. Autoimmune thyroid disorders were present in 5/9 cases. Cases had a significant higher prevalence of normocytic anaemia than controls (p = 0.004). No significant differences were found between cases and controls concerning clinical and histological features.

CONCLUSIONS

AAG-CD association is rare. Gastric and duodenal biopsies might be advisable in young people with normocytic anaemia and associated autoimmune disorders to timely diagnose clinically silent conditions.

Pathophysiology and therapeutic management of anemia in gastrointestinal disorders

INTRODUCTION

Anemia is a common complication of gastrointestinal (GI) disorders, with a prevalence up to 60% in celiac disease (CeD) and inflammatory bowel disease (IBD). Iron deficiency anemia (IDA) is the most prevalent form of anemia in these conditions, but chronic inflammation and vitamin B12 deficiency represent other common contributing mechanisms, especially in IBD.

AREAS COVERED

We discuss the pathogenesis of anemia in various medical GI disorders, the sometime problematic distinction between IDA, anemia of inflammation (AI) and the association of the two, and therapeutic and preventive measures that can be useful for the management of anemia in GI disorders. Unfortunately, with the exception of IDA and AI in IBD, large RCT concerning the treatment of anemia in GI disorders are lacking.

EXPERT OPINION

Anemia management strategies in GI disorders are outlined, with a focus on the main prevention, diagnostic, and therapeutic measures. Specific problems and situations such as the role of gluten-free diet for IDA treatment in CeD, the choice between oral and parenteral supplementation of iron or vitamin B12 in carential anemias, the use of endoscopic procedures to stop bleeding in intestinal angiodysplasia and preventive/treatment strategies for NSAID-associated GI bleeding are discussed.

Impact of in-hospital intravenous iron supplementation on red blood cell transfusions: experience from an Internal Medicine Unit

BACKGROUND

Pharmacological treatment of iron deficiency anaemia can reduce red blood cell (RBC) transfusions. Intravenous iron provides a more effective and quicker correction of iron deficiency anaemia than oral iron, and third-generation high-dose intravenous iron formulations allow the complete correction of iron deficiency with just one or two drug infusions, thus facilitating iron supplementation therapy and reducing transfusion requirement.

MATERIAL AND METHODS

In an observational, retrospective study we compared RBC transfusion requirement during hospitalisation and within 3 months of hospital discharge in 88 patients with iron deficiency anaemia treated with high-dose ferric carboxymaltose and in 85 patients treated with ferric gluconate while hospitalised in the Internal Medicine unit of our Institution.

RESULTS

Ferric carboxymaltose reduced the number of RBC units given to each transfused patient during hospitalisation (1.81±0.84 vs 2.39±1.49, p=0.011). At hospital discharge, fewer ferric carboxymaltose patients were prescribed home therapy with iron. No differences between treatment groups were observed in the proportion of patients or the number of RBC units transfused within 3 months of discharge. At one month from discharge, however, only 2 ferric carboxymaltose patients had been transfused compared with 7 ferric gluconate patients (p=0.078). Patients transfused post-discharge were more likely to have an underlying malignancy and/or higher serum creatinine concentrations.

DISCUSSION

Treatment with ferric carboxymaltose reduced the number of RBC units per transfused patient. Larger studies are required to define risk factors associated with post-discharge transfusion requirement and to establish if home therapy with iron will reduce subsequent transfusions in patients treated with ferric carboxymaltose.

Acquired Refractory Iron Deficiency Anemia

Anemia is a global health problem affecting one-third of the world population, and half of the cases are due to iron deficiency (ID). Iron deficiency anemia (IDA) is the leading cause of disability in several countries. Although multiple mechanisms may coexist, ID and IDA causes can be classified as i) insufficient iron intake for the body requirement, ii) reduced absorption, and iii) blood losses. Oral iron represents the mainstay of IDA treatment. IDA is defined as "refractory" when the hematologic response after 4 to 6 weeks of treatment with oral iron (an increase of >=1 g/dL of Hb) is absent. The cause of iron-refractory anemia is usually acquired and frequently related to gastrointestinal pathologies, although a rare genetic form called iron-refractory iron deficiency anemia (IRIDA) exists. In some pathological circumstances, either genetic or acquired, hepcidin increases, limiting the absorption in the gut, remobilization, and recycling of iron, thereby reducing iron plasma levels. Indeed, conditions with high hepcidin levels are often under-recognized as iron refractory, leading to inappropriate and unsuccessful treatments. This review provides an overview of the iron refractory anemia underlying conditions, from gastrointestinal pathologies to hepcidin dysregulation and iatrogenic or provoked conditions, and the specific diagnostic and treatment approach.

Cellular therapies for the treatment of immune-mediated GI and liver disease

INTRODUCTION

Immune-mediated liver and gastrointestinal diseases are chronic conditions that lack curative treatments. Despite advances in the understanding and treatment of these conditions, they frequently remain refractory to treatment and represent a significant unmet need. Cellular therapies are an emerging option and hold the potential to have a major impact.

DATA SOURCES

A literature review was carried out using Pubmed. Keywords used for search were 'ATMP', 'immune mediated', 'autoimmune liver disease' and 'immune mediated gastrointestinal conditions', 'cell therapy', 'MSC', 'HSCT', 'Regulatory T cells', 'GVHD', 'Coeliac disease' 'IBD', 'PSC', 'AIH', 'PBC'. No new data were generated or analysed in support of this review.

AREAS OF AGREEMENT

There is substantial evidence from clinical trials to support the use of cell therapies as a treatment for immune-mediated liver and gastrointestinal conditions. Cellular therapy products have the ability to 'reset' the dysregulated immune system and this in turn can offer a longer term remission. There are ongoing clinical trials with mesenchymal stromal cells (MSCs) and other cells to evidence their efficacy profile and fill the gaps in current knowledge. Insights gained will inform future trial designs and subsequent therapeutic applications.

AREAS OF CONTROVERSY

There remains some uncertainty around the extrapolation of results from animal studies to clinical trials. Longevity of the therapeutic effects seen after the use of cell therapy needs to be scrutinized further. Heterogeneity in the selection of cells, source, methods of productions and cell administration pose challenges to the interpretation of the data.

GROWING POINTS

MSCs are emerging as a key therapeutic cells in immune-mediated liver and gastrointestinal conditions. Ongoing trials with these cells will provide new insights and a better understanding thus informing future larger scale studies.

AREAS TIMELY FOR DEVELOPING RESEARCH

Larger scale clinical trials to build on the evidence from small studies regarding safety and efficacy of cellular therapy are still needed before cellular therapies can become off the shelf treatments. Alignment of academia and industry to standardize the processes involved in cell selection, manipulation and expansion and subsequent use in clinical trials is an important avenue to explore further.

Persistent Iron Deficiency Anemia in Patients with Celiac Disease Despite a Gluten-Free Diet

Celiac disease (CD) is an autoimmune disorder characterized by intolerance to dietary gluten in genetically predisposed subjects. Iron deficiency anemia (IDA) is a common sign in CD, being the only abnormality in approximately 40% of celiac patients. A multifactorial etiology leads to IDA in CD. The two main causes are the villous atrophy of the mucosa at the site of iron absorption (the duodenum) and the resulting inflammation, which triggers the mechanism that leads to the anemia of chronic disease. Until now, it has been unclear why some patients with CD continue to have IDA despite a careful gluten-free diet (GFD) and the normalization of villous atrophy. Furthermore, some celiac patients are refractory to oral iron supplementation despite the healing of the mucosa, and they thus require periodic intravenous iron administration. The Marsh classification evaluates the degree of inflammation and villous atrophy, but it does not assess the possible persistence of ultrastructural and molecular alterations in enterocytes. The latter was found in CD in remission after adopting a GFD and could be responsible for the persistently reduced absorption of iron and IDA. Even in non-celiac gluten sensitivity, anemia is present in 18.5-22% of patients and appears to be related to ultrastructural and molecular alterations in intestinal microvilli. It is possible that a genetic component may also play a role in IDA. In this review, we evaluate and discuss the main mechanisms of IDA in CD and the possible causes of its persistence after adopting a GFD, as well as their therapeutic implications.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Iron Absorption in Celiac Disease and Nutraceutical Effect of 7-Hydroxymatairesinol. Mini-Review

Anemia is the main extra-gastrointestinal symptom in inflammatory bowel diseases (IBDs). Interleukin-6 (IL-6) and other cytokines are secreted and act in the microenvironment of the small intestine mucous membrane of IBD patients. Iron is essential for multiple cell functions and its homeostasis is regulated by the hepcidin–ferroportin axis. Hepcidin (HEPC) is mainly produced by the liver in response to iron needs but is also an acute phase protein. During inflammation, hepcidin is upregulated by IL-6 and is responsible for iron compartmentalization within cells, in turn causing anemia of inflammation. Tissues other than liver can produce hepcidin in response to inflammatory stimuli, in order to decrease iron efflux at a local level, then acting in an autocrine–paracrine manner. In IBDs and, in particular, in celiac disease (CeD), IL-6 might trigger the expression, upregulation and secretion of hepcidin in the small intestine, reducing iron efflux and exacerbating defective iron absorption. 7-Hydroxymatairesinol (7-HMR) belongs to the family of lignans, polyphenolic compounds produced by plants, and has nutraceutical antioxidant, anti-inflammatory and estrogenic properties. In this mini-review we revise the role of inflammation in IBDs and in particular in CeD, focusing our attention on the close link among inflammation, anemia and iron metabolism. We also briefly describe the anti-inflammatory and estrogenic activity of 7-HMR contained in foods that are often consumed by CeD patients. Finally, considering that HEPC expression is regulated by iron needs, inflammation and estrogens, we explored the hypothesis that 7-HMR consumption could ameliorate anemia in CeD using Caco-2 cells as bowel model. Further studies are needed to verify the regulation pathway through which 7-HMR may interfere with the local production of HEPC in bowel.

Thyro-entero-gastric autoimmunity: Pathophysiology and implications for patient management

The association between autoimmune atrophic gastritis and thyroid disorders has been observed since the early 1960s and the expression "thyrogastric syndrome" was coined to indicate the presence of thyroid autoantibodies or autoimmune thyroid disease in patients with pernicious anemia, a late clinical stage of autoimmune atrophic gastritis. More recently, it was confirmed that autoimmune thyroid disorders, in particular Hashimoto's thyroiditis, may be frequently associated with other organ-specific, immune-mediated disorders, such as autoimmune atrophic gastritis or celiac disease. The association of Hashimoto's thyroiditis with autoimmune atrophic gastritis or celiac disease in adult patients is currently considered part of the polyglandular autoimmune syndromes which include several autoimmune disorders associated with an autoaggressive impairment of endocrine glands. From a clinical point of view, the thyro-entero-gastric autoimmunity may lead to potentially serious consequences like anemia, micronutrients deficiencies, and drugs malabsorption, as well as to an increased risk for malignancies. These alterations may frequently present in an underhand manner, with consequent diagnostic and treatment delays. Many aspects of the association between thyroid, gastric and intestinal autoimmune diseases still await clarification. The present review focuses on the embryological, genetic and pathophysiological aspects of thyro-entero-gastric autoimmunity. In particular, the current diagnostic criteria of autoimmune thyroid disease, autoimmune atrophic gastritis, and celiac disease are reviewed, along with the evidences for their association in poly-autoimmunity syndromes. The benefits of proactive screening of autoimmune thyroid disorders in patients with autoimmune gastritis or enteropathy and viceversa are also discussed.

Chronic atrophic gastritis: Natural history, diagnosis and therapeutic management. A position paper by the Italian Society of Hospital Gastroenterologists and Digestive Endoscopists [AIGO], the Italian Society of Digestive Endoscopy [SIED], the Italian Society of Gastroenterology [SIGE], and the Italian Society of Internal Medicine [SIMI]

Chronic atrophic gastritis (CAG) is an underdiagnosed condition characterised by translational features going beyond the strict field of gastroenterology as it may manifest itself by a variable spectrum of gastric and extra-gastric symptoms and signs. It is relatively common among older adults in different parts of the world, but large variations exist. Helicobacter pylori-related CAG [multifocal] and autoimmune CAG (corpus-restricted) are apparently two different diseases, but they display overlapping features. Patients with cobalamin and/or iron deficiency anaemia or autoimmune disorders, including autoimmune thyroiditis and type 1 diabetes mellitus, should be offered screening for CAG. Pepsinogens, gastrin-17, and anti-H. pylori antibodies serum assays seem to be reliable non-invasive screening tools for the presence of CAG, helpful to identify individuals to refer to gastroscopy with five standard gastric biopsies in order to obtain histological confirmation of diagnosis. Patients with CAG are at increased risk of developing gastric cancer, and they should be estimated with histological staging systems (OLGA or OLGIM). H. pylori eradication may be beneficial by modifying the natural history of atrophy, but not that of intestinal metaplasia. Patients with advanced stages of CAG (Stage III/IV OLGA or OLGIM) should undergo endoscopic surveillance every three years, those with autoimmune CAG every three-five years. In patients with CAG, a screening for autoimmune thyroid disease and micronutrient deficiencies, including iron and vitamin B₁₂, should be performed. The optimal treatment for dyspeptic symptoms in patients with CAG remains to be defined. Proton pump inhibitors are not indicated in hypochlorhydric CAG patients.

Cell Blood Count Alterations and Patterns of Anaemia in Autoimmune Atrophic Gastritis at Diagnosis: A Multicentre Study

BACKGROUND

Autoimmune atrophic gastritis (AAG) leads to iron and/or vitamin B12 malabsorption, with subsequent haematological alterations which could represent the sole clinical manifestation. We aimed to assess patterns of anaemia and micronutrient deficiencies in patients with AAG at the time of diagnosis.

METHODS

Observational, multicentre, cross-sectional study including consecutive adult patients diagnosed with AAG within the last ten years. Cell blood count, red cell distribution width, serum vitamin B12, and ferritin were collected. Multivariate analysis for predictive factors of anaemia was computed.

RESULTS

654 AAG patients (mean age 59.2 ± 13.8 years, female (F): male (M) ratio = 2.3:1) were included. Anaemia was present in 316 patients (48.3%; mean age 60.1 ± 15.8 years, F:M ratio = 2.3:1). Pernicious anaemia (132/316 cases, 41.7%) was more common in males (27.1% versus 12.4%; p = 0.001) and in older patients (63.0 ± 14.6 versus 58.9 ± 14.9 years; p = 0.014), while iron deficiency anaemia (112/316 cases, 35.4%) was more common in females (16.9% versus 10.0%; p = 0.039) and in younger patients (56.8 ± 16.6 versus 60.2 ± 14.6 years; p = 0.043). The prevalence of iron deficiency was equally distributed between anaemic and non-anaemic patients (p = 0.9). Anisocytosis (odds ratio: 10.65, 95% confidence interval: 6.13-18.50, p < 0.0001) was independently associated with anaemia.

CONCLUSIONS

Anaemia is a common manifestation in AAG patients, mostly due to micronutrient deficiencies. Scant haematologic alterations and micronutrient deficiencies may precede overt anaemia.

Determinants of diagnostic delay in autoimmune atrophic gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is characterised by a wide clinical spectrum that could delay its diagnosis.

AIMS

To quantify the diagnostic delay in patients suffering from AAG and to explore possible risk factors for longer diagnostic delay.

METHODS

Consecutive patients with AAG evaluated at our gastroenterological outpatient clinic between 2009 and 2018 were included. Diagnostic delay was estimated as the time lapse occurring between the appearance of the first likely symptoms, laboratory alterations, and other clues indicative of AAG and the final diagnosis. Patient-dependent and physician-dependent diagnostic delays were also assessed. Multivariable regression models were fitted.

RESULTS

291 patients with AAG (mean age at diagnosis 61 ± 15 years; F:M ratio = 2.3:1) were included. The median overall diagnostic delay was 14 months (interquartile range [IQR] 4-41). Factors associated with longer median overall diagnostic delay were female sex (17 months, IQR 5-48), having a previous misdiagnosis (36 months, IQR 17-125) and a history of infertility/miscarriages (33 months, IQR 8-120), whereas a higher level of education was associated with longer patient-dependent diagnostic delay (4 months, IQR 1-12). First evaluation by a gastroenterologist was associated with a median longer diagnostic delay (6 months, IQR 2-15) compared to an internist (3 months, IQR 3-31) and a haematologist (1 month, IQR 0-2). Age, socioeconomic or marital status did not affect the diagnostic delay.

CONCLUSIONS

AAG is burdened by substantial diagnostic delay, especially in female patients, and due to lack of awareness, particularly among gastroenterologists. Uncommon vitamin B12 deficiency-related manifestations are overlooked and may prolong the diagnostic delay.

Small Bowel Carcinomas Associated with Immune-Mediated Intestinal Disorders: The Current Knowledge

Small bowel carcinomas (SBC) are uncommon neoplasms, whose predisposing conditions include hereditary syndromes and immune-mediated intestinal disorders including coeliac disease (CD) and Crohn's disease (CrD). Although both CD-associated SBC (CD-SBC) and CrD-associated SBC (CrD-SBC) arise from an inflammatory background, they differ substantially in tumour cell phenotype, frequency of microsatellite instability and nuclear β-catenin expression, as well as in prognosis. For these patients, high tumour-infiltrating lymphocyte density and glandular/medullary histotype represent independent positive prognostic factors. Dysplasia adjacent to SBC is rare and characterized by intestinal phenotype and nuclear β-catenin in CD, while it is frequent and typified by gastro-pancreatobiliary marker expression and preserved membranous β-catenin in CrD. Recent evidence suggests that Epstein-Barr virus-positive dysplasia and SBC, albeit exceptional, do exist and are associated with CrD. In this review, we summarize the novel pathological and molecular insights of clinical and therapeutic interest to guide the care of CD-SBC and CrD-SBC.

Anemia of inflammation

Anemia of inflammation (AI), also known as anemia of chronic disease (ACD), is regarded as the most frequent anemia in hospitalized and chronically ill patients. It is prevalent in patients with diseases that cause prolonged immune activation, including infection, autoimmune diseases, and cancer. More recently, the list has grown to include chronic kidney disease, congestive heart failure, chronic pulmonary diseases, and obesity. Inflammation-inducible cytokines and the master regulator of iron homeostasis, hepcidin, block intestinal iron absorption and cause iron retention in reticuloendothelial cells, resulting in iron-restricted erythropoiesis. In addition, shortened erythrocyte half-life, suppressed erythropoietin response to anemia, and inhibition of erythroid cell differentiation by inflammatory mediators further contribute to AI in a disease-specific pattern. Although the diagnosis of AI is a diagnosis of exclusion and is supported by characteristic alterations in iron homeostasis, hypoferremia, and hyperferritinemia, the diagnosis of AI patients with coexisting iron deficiency is more difficult. In addition to treatment of the disease underlying AI, the combination of iron therapy and erythropoiesis-stimulating agents can improve anemia in many patients. In the future, emerging therapeutics that antagonize hepcidin function and redistribute endogenous iron for erythropoiesis may offer additional options. However, based on experience with anemia treatment in chronic kidney disease, critical illness, and cancer, finding the appropriate indications for the specific treatment of AI will require improved understanding and a balanced consideration of the contribution of anemia to each patient's morbidity and the impact of anemia treatment on the patient's prognosis in a variety of disease settings.