Comprehensive insights into pathogenesis, diagnosis, treatment, and prognosis in adult autoimmune enteropathy

Autoimmune enteropathy (AIE) constitutes a diverse array of disorders characterized by immune dysregulation and gastrointestinal manifestations, chiefly chronic diarrhea. Due to the small number of reported cohorts, the current knowledge and understanding of adult-onset AIE is rare compared with pediatric or syndromic AIE. Pathogenesis might involve genetic predisposition, aberrant immune homeostasis, comorbidities of autoimmune diseases and environmental trigger. Diagnosis relies on a comprehensive assessment encompassing clinical evaluation, laboratory tests, endoscopic findings and histopathological features, yet distinguishing AIE from other disorders with similar presentations poses diagnostic challenges. Treatment strategies predominantly center on immunosuppressive therapies, exhibiting varied efficacy among individuals. Supportive treatment and prevention and management of complications are also important for prognosis. The prospectives of future researches need to explore the genetic and immunological mechanism, the diagnostic modalities and the treatment strategies to improve patient outcomes.

Adult-Onset Autoimmune Enteropathy in an European Tertiary Referral Center

INTRODUCTION

Adult-onset autoimmune enteropathy (AIE) is a rare cause of severe chronic diarrhea because of small intestinal villous atrophy. We report on patients with adult-onset AIE in an European referral center.

METHODS

Retrospective study including patients diagnosed with AIE in the Amsterdam UMC, location VUmc, between January 2003 and December 2019. Clinical, serological, and histological features and response to treatment were reported. The specificity of antienterocyte antibodies (AEA) was evaluated by examining the prevalence of AEA in (i) controls (n = 30) and in patients with (ii) AIE (n = 13), (iii) celiac disease (CD, n = 52), (iv) refractory celiac disease type 2 (n = 18), and (v) enteropathy-associated T-cell lymphoma (EATL, n = 10).

RESULTS

Thirteen AIE patients were included, 8 women (62%), median age of 52 years (range 23-73), and 6 (46%) with an autoimmune disease. AEA were observed in 11 cases (85%), but were also found in CD (7.7%), refractory celiac disease type 2 (16.7%), and EATL (20%). Ten patients (77%) were human leukocyte antigen DQ2.5 heterozygous. Total parenteral nutrition was required in 8 cases (62%). Steroids induced clinical remission in 8 cases (62%). Step-up therapy with rituximab, cyclosporine, infliximab, and cladribine in steroid-refractory patients was only moderately effective. Four patients died (31%), but 4 (31%) others are in long-term drug-free remission after receiving immunosuppressive treatment, including 1 patient who underwent autologous stem cell transplantation.

DISCUSSION

Adult-onset AIE is a rare but severe enteropathy that occurs in patients susceptible for autoimmune disease. Four patients (31%) died secondary to therapy-refractory malabsorption, while immunosuppressive therapy leads to a long-lasting drug-free remission in one-third of patients.

Adult autoimmune enteropathy in autoimmune hepatitis patient. Case report and literature review

Autoimmune enteropathy (AIE) is a rare disease characterized by prolonged diarrhea, vomiting and weight loss; although it is mainly a rare pediatric disease, over the years a number of adults have also been found to be affected. In this study, we present a case report of a 73-year-old woman with a history of autoimmune hepatitis, antinuclear (ANA) and positive anti-enterocyte antibodies (AEA), who has suffered two months of intractable diarrhea, nausea, anorexia and severe weight loss. The histological examination of the endoscopic duodenal mucosa biopsies revealed severe shortening and flattening of the villi, resulting in mucosal atrophy. The immunohistochemical study revealed a polymorphic lymphoid population, exhibiting a B cell (CD20+) phenotype in follicles and a T cell phenotype (CD3+) in the diffuse component within the lamina propria. Our patient had a complete recovery after two weeks of taking prednisone and following a gluten-rich diet. To our knowledge this is the first case of autoimmune enteropathy in adults with ANA and AEA 7 years after a diagnosis of autoimmune hepatitis. To date, the patient is still in clinical remission on a low dose of orally administered predinisone without any additional immunosuppression.

Seronegative autoimmune enteropathy with duodenal sparing and colonic clues in an adult female

Autoimmune enteropathy (AIE) is a rare immune disorder of the gut seldom found in adults and characterized by uncontrollable diarrhea resulting in malabsorption. While AIE is known to be pan-enteric, virtually all cases have presented with altered duodenal histology following known patterns with or without macroscopic change. We describe a unique case of seronegative AIE lacking typical duodenal manifestations in a 43-year-old female. To our knowledge, this is the first report of AIE lacking usual duodenal histologic changes, which resulted in missed diagnosis for years. Ultimately, crypt epithelial apoptosis, mononuclear inflammation of the lamina propria, and goblet cell loss of intestinal mucosa besides the duodenum clinched the diagnosis of AIE. Colonic histologic abnormalities consistent with AIE in the setting of diarrhea with malnutrition despite duodenal sparing should prompt suspicion for AIE given the pan-enteric nature of this disease.