Chronic enteropathy associated with SLCO2A1 gene: A case report and literature review

Characteristics of chronic enteropathy associated with SLCO2A1 gene (CEAS) in children, a unique type of monogenic very early-onset inflammatory bowel disease

BACKGROUND

 Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a unique type of inflammatory bowel disease. CEAS is monogenic disease and is thought to develop from childhood, but studies on pediatric CEAS are scarce. We analyzed characteristics of pediatric CEAS.

METHODS

Eleven patients diagnosed with CEAS at Seoul National University Children's Hospital were identified and analyzed. Clinical data of patients were collected. Sanger sequencing of SLCO2A1 was performed on all patients.

RESULTS

Patients were diagnosed at a median age of 16.0 years (IQR 11.0 ~ 20.0), and the median age at symptoms onset was only 4.0 years (IQR 2.5 ~ 6.0). Growth delay was observed at the time of diagnosis. Patients showed multiple ulcers or strictures in the small intestine, while the esophagus and colon were unaffected in any patients. Almost half of the patients underwent small intestine resection. The major laboratory features of pediatric CEAS include iron deficiency anemia (IDA), hypoalbuminemia, and near-normal levels of C-reactive protein (CRP). Two novel mutations of SLCO2A1 were identified. The most prevalent symptoms were abdominal pain and pale face. None of the immunomodulatory drugs showed a significant effect on CEAS.

CONCLUSIONS

Pediatric CEAS typically develop from very young age, suggesting it as one type of monogenic very early onset inflammatory bowel disease. CEAS can cause growth delay in children but there is no effective treatment currently. We recommend screening for SLCO2A1 mutations to pediatric patients with chronic IDA from a young age and small intestine ulcers without elevation of CRP levels.

A novel variant in the SLCO2A1 gene in a Chinese patient with chronic gastroenteropathy and primary hypertrophic osteoarthropathy

BACKGROUND

Chronic enteropathy associated with SLCO2A1 gene (CEAS) results from loss-of-function variants in SLCO2A1, which encodes the prostaglandin transporter (PGT). CEAS follows an autosomal recessive inheritance pattern. To date, approximate 30 pathogenic variants have been reported in CEAS.

METHODS

We performed whole exome sequencing (WES) to screen for potential pathogenic variants in a patient suspected of having CEAS, and confirmed a variant in SLCO2A1 using Sanger sequencing. We established an in vitro minigene model to compare splicing between wild type (WT) and mutant transcripts. Quantitative polymerase chain reaction (qPCR) was used to evaluate SLCO2A1 transcription in the stomach and colon tissues from the patient and a healthy control (HC). The transcripts were further cloned and sequenced.

RESULTS

The patient had a novel, homozygous, recessive c.929A > G variant in exon 7 of SLCO2A1, which has not been previously reported in CEAS or PHO. This variant altered splicing, resulting in an exon 7-truncated transcript lacking 16 bases. No normal transcript was detected in the patient's stomach or colon tissue. qPCR also showed significantly decreased SLCO2A1 transcription compared to HC.

CONCLUSION

A previously unreported variant caused defective SLCO2A1 splicing and reduced mRNA levels in a patient with CEAS and PHO. This research enhances understanding of CEAS and PHO pathophysiology and aids genetic counseling and diagnosis.

Updates on the diagnosis and management of cryptogenic multifocal ulcerative stenosing enteropathy (CMUSE) and non-steroidal enteropathy

Crohn's disease and coeliac disease are well-known to induce ulcerations in the small-bowel. However, there is a group of very rare chronic ulcerative conditions of the small intestine that has emerged from the intestinal black box nearly 70 years ago, and that has gained interest with the advent of small-bowel capsule endoscopy and device-assisted enteroscopy. These distinct ulcerative enteropathies have come to our attention, and continue to reveal their aetiology and treatment options. Two distinct entities, called cryptogenic multifocal ulcerative stenosing enteritis/enteropathy (CMUSE) and chronic nonspecific multiple ulcers of the small intestine (CNSU) are gaining more clinical attention. CMUSE was first reported in Europe, whereas CNSU was exclusively diagnosed in Japanese patients. With the identification of susceptibility genes impacting prostaglandin metabolism, CMUSE and CNSU have become two distinct pathologies within the group of prostaglandin-associated enteropathies, to be differentiated from medication-induced enteropathies, especially non-steroidal anti-inflammatory drugs (NSAID)-induced enteropathy with similar intestinal ulcerations due to interference with prostaglandin metabolism. The current review provides an historical overview of CMUSE and CNSU publications, in addition to the currently available diagnostic and treatment options, and how to differentiate these rare enteropathies from NSAID-induced enteropathy.

A Novel Chronic Enteropathy Associated with SLCO2A1 Gene Mutation: Enterography Findings in a Multicenter Korean Registry

OBJECTIVE

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a recently recognized disease. We aimed to evaluate the enterographic findings of CEAS.

MATERIALS AND METHODS

Altogether, 14 patients with CEAS were confirmed based on known SLCO2A1 mutations. They were registered in a multicenter Korean registry between July 2018 and July 2021. Nine of the patients (37.2 ± 13 years; all female) who underwent surgery-naïve-state computed tomography enterography (CTE) or magnetic resonance enterography (MRE) were identified. Two experienced radiologists reviewed 25 and 2 sets of CTE and MRE examinations, respectively, regarding the small bowel findings.

RESULTS

In initial evaluation, eight patients showed a total of 37 areas with mural abnormalities in the ileum on CTE, including 1-4 segments in six and > 10 segments in two patients. One patient showed unremarkable CTE. The involved segments were 10-85 mm (median, 20 mm) in length, 3-14 mm (median, 7 mm) in mural thickness, circumferential in 86.5% (32/37), and showed stratified enhancement in the enteric and portal phases in 91.9% (34/37) and 81.8% (9/11), respectively. Perienteric infiltration and prominent vasa recta were noted in 2.7% (1/37) and 13.5% (5/37), respectively. Bowel strictures were identified in six patients (66.7%), with a maximum upstream diameter of 31-48 mm. Two patients underwent surgery for strictures immediately after the initial enterography. Follow-up CTE and MRE in the remaining patients showed minimal-to-mild changes in the extent and thickness of the mural involvement for 17-138 months (median, 47.5 months) after initial enterography. Two patients required surgery for bowel stricture at 19 and 38 months of follow-up, respectively.

CONCLUSION

CEAS of the small bowel typically manifested on enterography in varying numbers and lengths of abnormal ileal segments that showed circumferential mural thickening with layered enhancement without perienteric abnormalities. The lesions caused bowel strictures that required surgery in some patients.

Crohn-like disease affecting small bowel due to monogenic SLCO2A1 mutations: First cases of Chronic Enteropathy Associated with SLCO2A1 gene (CEAS) in France

INTRODUCTION

Multiple chronic ulcers of small intestine are mainly ascribed to Crohn's disease. Among possible differential diagnoses are chronic ulcers of small bowel caused by abnormal activation of the prostaglandin pathway either in the archetypal but uncommon non-steroidal anti-inflammatory drug (NSAID)-induced enteropathy, or in rare monogenic disorders due to PLA2G4A and SLCO2A1 mutations. SLCO2A1 variants are responsible for CEAS (Chronic enteropathy associated with SLCO2A1), a syndrome which was exclusively reported in patients of Asian origin. Herein, we report the case of two French female siblings with CEAS.

CASE REPORT

P1 underwent iterative bowel resections (removing 1 meter of small bowel in total) for recurrent strictures and perforations. Her sister P2 had a tight duodenal stricture which required partial duodenectomy. Next-generation sequencing was performed on P1's DNA and identified 2 compound heterozygous variants in exon 12 in SLCO2A1, which were also present in P2.

CONCLUSION

CEAS can be detected within the European population and raise the question of its incidence and recognition outside Asia. Presence of intractable recurrent ulcerations of the small intestine mimicking Crohn's disease with concentric stricture should motivate a genetic search for SLCO2A1 mutations, particularly in the context of family history or consanguinity.

Chronic Enteropathy Associated with Solute Carrier Organic Anion Transporter Family, Member 2A1 (SLCO2A1) with Positive Immunohistochemistry for SLCO2A1 Protein

Chronic enteropathy associated with solute carrier organic anion transporter family, member 2A1 (SLCO2A1) (CEAS) is a rare autosomal recessive hereditary disease characterized by chronic persistent anemia and hypoproteinemia. Its diagnosis typically requires a genetic analysis. The efficacy of immunohistochemical staining with SLCO2A1 polyclonal antibody as a pre-diagnostic tool for CEAS has been previously reported. We herein report a patient with CEAS in whom immunohistochemical staining confirmed SLCO2A1 protein expression. The immunopositive results may have been due to nonsense-mediated RNA decay. As immunohistochemical staining of SLCO2A1 protein may show immunopositive results, a genetic analysis should also be performed when CEAS is strongly clinically suspected.

Four Variants of SLCO2A1 Identified in Three Chinese Patients with Chronic Enteropathy Associated with the SLCO2A1 Gene

BACKGROUND

Chronic enteropathy associated with the SLCO2A1 gene (CEAS) is an enteropathy characterized by multiple small intestinal ulcers of nonspecific histology, also known as chronic nonspecific multiple ulcers of the small intestine. The SLCO2A1 gene encodes a prostaglandin transporter (PGT).

AIMS

The aim of this study was to investigate the clinical characteristics of ten Chinese patients with intestinal ulcers of unknown origin, screen them for variants of SLCO2A1, and to investigate the expression of PGT in the small intestinal mucosa of patients with CEAS.

METHODS

Ten Chinese patients with intestinal ulcers of unknown origin were included in this study. Blood samples were collected for whole-exome sequencing and Sanger sequencing of candidate gene variants. Immunohistochemical staining was used to investigate the expression of PGT.

RESULTS

These ten patients were clinically diagnosed with intestinal ulcers of unknown origin based on criteria established according to earlier publications. Three of them were genetically diagnosed as having CEAS and four candidate variants of the SLCO2A1 gene were identified, among which c.941-1G>A, c.178G>A and c.1681C>T were detected in patients with CEAS for the first time. The terminal ileum was involved in all three patients with CEAS in our study, which was different from the results of Japanese patients. The expression of PGT in the vascular endothelial cells of the intestinal mucosa tissues of patients with CEAS was negative or intermediate.

CONCLUSION

We summarized the clinical data of ten Chinese patients with intestinal ulcers of unknown origin and identified three novel SLCO2A1 variants from three patients with CEAS. This study improves our understanding of CEAS and broadens the spectrum of SLCO2A1 variants known to cause CEAS.

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.