Pediatric-onset Chronic Nonspecific Multiple Ulcers of Small Intestine: A Nationwide Survey and Genetic Study in Japan

Chronic enteropathy associated with SLCO2A1 gene and hereditary fructose intolerance: A coincidence of two rare diseases

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a rare disorder characterized by multiple small intestine ulcers. Patients with CEAS typically present with chronic anemia and gastrointestinal bleeding. Besides CEAS, SLCO2A1 mutations cause primary hypertrophic osteoarthropathy (PHO) which is considered as an extraintestinal manifestation in CEAS patients. Since CEAS and Crohn's disease are clinically indistinguishable, patients are often misdiagnosed with Crohn's disease. Herein, we describe a 4-year-old Turkish girl with CEAS due to homozygous pathogenic variant (c.656C > T) in SLCO2A1 with concomitant hereditary fructose intolerance (HFI) caused by homozygous pathogenic variant (c.1005C > G) in ALDOB. Prompt restriction of fructose, sucrose and sorbitol resulted in hepatomegaly regression and mild amelioration of patient's symptoms. Despite budesonide and azathioprine treatments, patient's protein losing enteropathy and chronic anemia did not improve. Although previous CEAS cases were reported from East Asian countries, it is likely to occur in people from other geographic areas. CEAS seems to be underdiagnosed and high index of suspicion is required for the diagnosis of this rare entity. Patients with prior diagnosis of Crohn's disease with no response to immunosuppressive treatment or anti-TNF therapy should be re-evaluated for possible CEAS diagnosis.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Obscure gastrointestinal bleeding caused by congenital enteropathy in a Chinese young child-a case report

Background

SLCO2A1 was recently reported to cause nonspecific ulcers at small bowel, it was named as chronic enteropathy associated with SLCO2A1 (CEAS). It was rarely reported beyond the Japanese population.

Case presentation

A 4-year-5-month old girl presented with intractable anemia since 1-year-3-month. Her stool occult blood test was positive and the result of esophagogastroduodenoscopy and colonoscopy were normal. She was considered as obscure gastrointestinal bleeding. The magnetic resonance enterography and ultrasound of small intestinal revealed segmental thickening of small bowel. The capsule endoscopy detected ulcers, erosion and slightly stenosis near the site of junction of jejunum and ileum. She was considered chronic non-specific multiple ulcers of the small intestine and was advised to have whole exon sequencing. She was treated with exclusive enteral nutrition and iron supplement for two months. However, she was not responsive to this treatment, then she had three doses of infliximab. At the same time, the next-generation sequencing of this patient revealed two novel compound heterozygous mutations in SLCO2A1. She was diagnosed with CEAS and was treated with oral mercaptopurine. Her hemoglobin level was stable and the serum albumin level was slightly decreased during the follow up.

Conclusion

CEAS may present as nonspecific small bowel ulcers, and misinterpret as small bowel Crohn’s disease. Genetic tests may help with the precise diagnosis of small bowel ulcers.

Very Early Onset Inflammatory Bowel Disease: A Clinical Approach With a Focus on the Role of Genetics and Underlying Immune Deficiencies

Very early onset inflammatory bowel disease (VEO-IBD) is defined as IBD presenting before 6 years of age. When compared with IBD diagnosed in older children, VEO-IBD has some distinct characteristics such as a higher likelihood of an underlying monogenic etiology or primary immune deficiency. In addition, patients with VEO-IBD have a higher incidence of inflammatory bowel disease unclassified (IBD-U) as compared with older-onset IBD. In some populations, VEO-IBD represents the age group with the fastest growing incidence of IBD. There are contradicting reports on whether VEO-IBD is more resistant to conventional medical interventions. There is a strong need for ongoing research in the field of VEO-IBD to provide optimized management of these complex patients. Here, we provide an approach to diagnosis and management of patients with VEO-IBD. These recommendations are based on expert opinion from members of the VEO-IBD Consortium (www.VEOIBD.org). We highlight the importance of monogenic etiologies, underlying immune deficiencies, and provide a comprehensive description of monogenic etiologies identified to date that are responsible for VEO-IBD.

Characteristic Facial Appearance Was the Key to Diagnosing Chronic Enteropathy Associated with SLCO2A1-associated Primary Hypertrophic Osteoarthropathy

Patients with chronic enteropathy associated with SLCO2A1 (CEAS) develop multiple circular, longitudinal, or eccentric ulcers in the ileum. It is sometimes difficult to distinguish CEAS from Crohn's disease. CEAS and primary hypertrophic osteoarthropathy (PHO) are together known to be caused by a mutation of SLCO2A1 gene. The case of a 65-year-old man whose characteristic appearance due to pachydermia of the forehead folds led to the diagnosis of CEAS with PHO is presented.

Chronic Enteropathy Associated with SLCO2A1 with Pachydermoperiostosis

A 49-year-old man complained of chronic palpitation and shortness of breath, which had recently become exacerbated. A blood examination indicated severe refractory anemia and hypoproteinemia. Physical examinations revealed anemia, a systolic murmur, and spoon nails. Multiple nonspecific ileal ulcers were observed. A pathological examination indicated a small granuloma with CD68-positive histiocytes. He had a deeply wrinkled forehead, chiseled face, and clubbed fingers. Radiography revealed periostosis of the fingers and long bones in the limb. He was diagnosed with pachydermoperiostosis. SLCO2A1 demonstrated a c.1807C>T homo-mutation. He was also diagnosed with SLCO2A1-associated chronic enteropathy and thus was treated with 5-aminosalicylic acid, which temporarily improved the ileal ulcers, anemia, and hypoalbuminemia.

Cryptogenic Multifocal Ulcerating Stenosing Enteropathy(CMUSE) and/or Chronic Non-specific Multiple Ulcers of the Small Intestine(CNSU) and Non-granulomatous Ulcerating Jejunoileitis (NGUJI)

PURPOSE OF REVIEW

The purpose is to make aware of the existence of the rare and exclusive small intestine (SI) diseases, namely cryptogenic multifocal ulcerating stenosing enteropathy (CMUSE) or chronic non-specific multiple ulcers of the small intestine (CNSU) and non-granulomatous ulcerating jejunoileitis (NGUJI). The article will elucidate their epidemiology, pathogenesis, clinical features, diagnosis, differentiating features and management.

RECENT FINDINGS

Recent papers have published the clinical features and diagnostic criteria of CMUSE/CNSU and NGUJI. CNSU/CMUSE is caused by gene mutations involved in the prostaglandin pathways. Although capsule endoscopy can detect these lesions, it carries a risk of retention. TNF antagonists and azathioprine have shown response in few cases. CMUSE/CNSU and NGUJI are uncommon diseases that cause relapsing SI obstruction and bleed due to short-segment strictures and multiple shallow ulcers. This article focuses on current knowledge and novel insights regarding their pathogenesis, genetics, clinical features, diagnostic criteria and management. Multicentric clinical and genetic studies are the need of the hour.

Distinction between Chronic Enteropathy Associated with the SLCO2A1 Gene and Crohn's Disease

Background/Aims

We recently identified recessive mutations in the solute carrier organic anion transporter family member 2A1 gene (SLCO2A1) as causative variants of chronic nonspecific multiple ulcers of the small intestine (chronic enteropathy associated with SLCO2A1, CEAS). The aim of this study was to investigate the gastroduodenal expression of the SLCO2A1 protein in patients with CEAS and Crohn’s disease (CD).

Methods

Immunohistochemical staining for SLCO2A1 was performed with a polyclonal antibody, HPA013742, on gastroduodenal tissues obtained by endoscopic biopsy from four patients with CEAS and 29 patients with CD.

Results

The expression of SLCO2A1 was observed in one of four patients (25%) with CEAS and in all 29 patients (100%) with CD (p<0.001). The three patients with CEAS without SLCO2A1 expression had a homozygous splice-site mutation in SLCO2A1, c.1461+1G>C (exon 7) or c.940+1G>A (exon 10). The remaining one CEAS patient with positive expression of SLCO2A1 had compound heterozygous c.664G>A and c.1807C>T mutations.

Conclusions

Immunohistochemical staining for SLCO2A1 in gastroduodenal tissues obtained by endoscopic biopsy is considered useful for the distinction of CEAS from CD.

Early-onset inflammatory bowel disease as a model disease to identify key regulators of immune homeostasis mechanisms

Rare, monogenetic diseases present unique models to dissect gene functions and biological pathways, concomitantly enhancing our understanding of the etiology of complex (and often more common) traits. Although inflammatory bowel disease (IBD) is a generally prototypic complex disease, it can also manifest in an early-onset, monogenic fashion, often following Mendelian modes of inheritance. Recent advances in genomic technologies have spurred the identification of genetic defects underlying rare, very early-onset IBD (VEO-IBD) as a disease subgroup driven by strong genetic influence, pinpointing key players in the delicate homeostasis of the immune system in the gut and illustrating the intimate relationships between bowel inflammation, systemic immune dysregulation, and primary immunodeficiency with increased susceptibility to infections. As for other human diseases, it is likely that adult-onset diseases may represent complex diseases integrating the effects of host genetic susceptibility and environmental triggers. Comparison of adult-onset IBD and VEO-IBD thus provides beautiful models to investigate the relationship between monogenic and multifactorial/polygenic diseases. This review discusses the present and novel findings regarding monogenic IBD as well as key questions and future directions of IBD research.

Successful azathioprine treatment in an adolescent with chronic enteropathy associated with SLCO2A1 gene: A case report

INTRODUCTION

Chronic nonspecific multiple ulcers of the small intestine (CNSU), an entity with female preponderance and manifestations including anemia and hypoproteinemia reflecting persistent gastrointestinal bleeding and intestinal protein loss, has been considered idiopathic. Umeno et al recently reported that CNSU is caused by loss-of-function mutations in the solute carrier organic anion transporter family member 2A1 gene (SLCO2A1) encoding a prostaglandin transporter, renaming the disorder "chronic enteropathy associated with SLCO2A1 gene mutation" (CEAS). Treatments for chronic enteropathies such as inflammatory bowel disease, including 5-aminosalicylic acid, corticosteroids, azathioprine, and anti-tumor necrosis factor-α antibody, often are ineffective in CEAS, which frequently requires surgery.

CASE PRESENTATION

A 14-year-old girl had refractory anemia and hypoproteinemia for more than 2 years. Video capsule endoscopy showed nonspecific jejunal and ileal ulcers with varied sizes and shapes. She was diagnosed with CEAS resulting from compound heterozygous mutation of the SLCO2A1 gene. After corticosteroid treatment without improvement, azathioprine treatment improved her anemia and edema as hemoglobin and serum protein increased. Video capsule endoscopy 1 year after initiation of azathioprine showed improvement of small intestinal ulcers.

CONCLUSION

Physicians should consider CEAS in patients with refractory anemia, hypoproteinemia, and multiple small intestinal ulcers. Why our patient responded to azathioprine but not to corticosteroids is unclear, but azathioprine might benefit some other patients with CEAS.

A rare cause of multiple small bowel ulcers and strictures in a 10-year-old child

Enteritis and small bowel ulcers can be caused by inflammatory bowel disease, drug-induced enteritis, cytomegalovirus, tuberculosis, or intestinal lymphoma. Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE) is an uncommon idiopathic cause of ulceration and stricture of the small bowel. CMUSE can occur in adults, but only few pediatric cases have been reported. Inflammatory bowel disease and other causes should be carefully sought first before the diagnosis of CMUSE can be made. Previous reports demonstrated that surgical intervention may be necessary for both diagnostic and therapeutic purposes. With regard to the management, systemic corticosteroids may help, and surgery plays a role in patients present with signs of intestinal obstruction. We report a young girl who presented with a prolonged history of refractory iron deficiency anemia with protein-losing enteropathy without other obvious gastrointestinal symptoms. She underwent several laboratory and endoscopic investigations as well as histopathology of the resected full-thickness small bowel area before a proposed diagnosis of CMUSE was made. A trial of immunosuppression (both prednisolone and azathioprine) was initiated that provided a relatively satisfactory result.

Clinical features of chronic enteropathy associated with SLCO2A1 gene: a new entity clinically distinct from Crohn's disease

BACKGROUND

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a hereditary disease caused by mutations in the SLCO2A1 gene and characterized by multiple small intestinal ulcers of nonspecific histology. SLCO2A1 is also a causal gene of primary hypertrophic osteoarthropathy (PHO). However, little is known about the clinical features of CEAS or PHO.

METHODS

Sixty-five Japanese patients recruited by a nationwide survey of CEAS during 2012-2016 were enrolled in this present study. We reviewed the clinical information of the genetically confirmed CEAS patients.

RESULTS

We identified recessive SLCO2A1 mutations at 11 sites in 46 patients. Among the 46 patients genetically confirmed as CEAS, 13 were men and 33 were women. The median age at disease onset was 16.5 years, and parental consanguinity was present in 13 patients (28%). Anemia was present in 45 patients (98%), while a single patient experienced gross hematochezia. All patients showed relatively low inflammatory markers in blood tests (median CRP 0.20 mg/dl). The most frequently involved gastrointestinal site was the ileum (98%), although no patient had mucosal injuries in the terminal ileum. Mild digital clubbing or periostosis was found in 13 patients (28%), with five male patients fulfilling the major diagnostic criteria of PHO.

CONCLUSIONS

The clinical features of CEAS are distinct from those of Crohn's disease. Genetic analysis of the SLCO2A1 gene is therefore recommended in patients clinically suspected of having CEAS.

Clinical Genomics in Inflammatory Bowel Disease

Genomic technologies inform the complex genetic basis of polygenic inflammatory bowel disease (IBD) as well as Mendelian disease-associated IBD. Aiming to diagnose patients that present with extreme phenotypes due to monogenic forms of IBD, genomics has progressed from 'orphan disease' research towards an integrated standard of clinical care. Advances in diagnostic clinical genomics are increasingly complemented by pathway-specific therapies that aim to correct the consequences of genetic defects. This highlights the exceptional potential for personalized precision medicine. IBD is nevertheless a challenging example for genomic medicine because the overall fraction of patients with Mendelian defects is low, the number of potential candidate genes is high, and interventional evidence is still emerging. We discuss requirements and prospects of explanatory and predictive clinical genomics in IBD.