Clinical Case Summary

Introduction: Autoimmune enteropathy (AIE) is a rare disorder characterized by chronic diarrhea and villous atrophy. The diagnostic criteria include malabsorption, chronic diarrhea, anti-enterocyte antibodies (AEA), villous blunting/atrophy, and exclusion of other causes of villous atrophy (1).
Case report: A 69-year-old female affected by autoimmune hypothyroidism was admitted for watery diarrhea, severe hypokalemia, and acute kidney injury. An infectious, neuroendocrine, or iatrogenic etiology of diarrhea was excluded. Anterograde enteroscopy detected diffuse enteropathy; HLA-DQ8 typing was positive, but celiac antibodies resulted negative. Duodenal biopsies revealed villous blunting, normal CD3+ infiltration. Anti-enterocyte antibodies were negative. Any other causes of seronegative duodenal atrophy were excluded, including Giardia infection, immune deficiency, HIV, and Olmesartan therapy. Prednisone was started, and a gluten-free diet was initiated with clinical benefit. She was discharged with 40 mg prednisolone tapered to 5 mg every week. The patient required long-term therapy with open-capsule budesonide. Progressive histological improvement was observed with relapse after budesonide withdrawal, although clinical remission persisted. Recently, a diagnosis of autoimmune hepatitis has been made based on a liver biopsy finding. According to the Parigi consensus (1), the patient has been diagnosed with an idiopathic villous atrophy, although autoimmune origin seems more evident.
Conclusion: Autoimmune enteropathy is a rare cause of chronic diarrhea. The diagnostic criteria are still under debate because AEA are not always present. We believe that the presence of these antibodies should not be mandatory for the diagnosis.

References

Schiepatti A, Sanders DS, Baiardi P, Caio G, Ciacci C, Kaukinen K, Lebwohl B, Leffler D, Malamut G, Murray JA, Rostami K, Rubio-Tapia A, Volta U, Biagi F. Nomenclature and diagnosis of seronegative coeliac disease and chronic non-coeliac enteropathies in adults: the Paris consensus. Gut. 2022 Nov;71(11):2218-2225. doi: 10.1136/gutjnl-2021-326645. Epub 2022 Jun 8. PMID: 35676085; PMCID: PMC9554081.

Clinical Case Summary

Seronegative enteropathies pose a complex diagnostic challenge, as their histology mimics celiac disease (CeD) (1). We report a 51-year-old patient with hypertension and osteoporosis, referred for abdominal pain, weight loss, and constipation. Blood tests showed no anemia; anti-transglutaminase and anti-endomysium antibodies were negative, but HLA typing was compatible with CeD. Ileocolonoscopy excluded IBD and microscopic colitis, while OEGD revealed villous atrophy (MARSH 3c). Negative anti-enterocyte antibodies, and exclusion of drugs and infections, led to a diagnosis of seronegative CeD. A gluten-free diet was started, but after 1 year, symptoms improved only partially despite good adherence. OEGD showed persistent duodenal damage with increased intraepithelial lymphocytes (IELs), CD3+ and CD8+ T-cells with monoclonal TCR expression (fig. 1), consistent with RCeD type 1, despite no overt malabsorption. The patient began prednisone 50 mg/day, then switched to open-capsule budesonide, with some clinical benefit but persistent atrophy.
A year later, his daughter was diagnosed with CVID and a heterozygous STAT3 variant (c.1252T>C, p.Cys418Arg), somatically acquired in NK-cell leukemia. A luciferase assay confirmed its gain-of-function (GOF) effect (fig. 2). Family studies revealed the same germline variant in the patient. His diagnosis was revised to STAT3 GOF-associated enteropathy. Further investigations revealed hypogammaglobulinemia, splenomegaly, bronchiectasis, and emphysema. Treatment with Ruxolitinib (a JAK1/2 inhibitor) was started, resulting in clinical and histological remission (fig. 3).
STAT3 GOF enteropathy is a very rare condition (2,3) that should be considered in the differential diagnosis of seronegative villous atrophy. Anti-JAK therapy may be effective (4).

References

References of the images:
Figure 1: Histologic aspects at diagnosis
Figure 2: Luciferase assay of STAT3
Figure 3: Histologic aspects after 1 year of therapy

1. Schiepatti A, Sanders DS, Baiardi P, Caio G, Ciacci C, Kaukinen K, et al. Nomenclature and diagnosis of seronegative coeliac disease and chronic non-coeliac enteropathies in adults: the Paris consensus. Gut. 2022 Jun 8;71(11):2218–25.
2. Vogel TP, Leiding JW, Cooper MA, Forbes Satter LR. STAT3 gain-of-function syndrome. Vol. 10, Frontiers in Pediatrics. Frontiers Media SA; 2023.
3. Flanagan SE, Haapaniemi E, Russell MA, Caswell R, Allen HL, De Franco E, et al. Activating germline mutations in STAT3 cause early-onset multi-organ autoimmune disease. Nat Genet. 2014;46(8):812–4.
4. Kaneko S, Sakura F, Tanita K, Shimbo A, Nambu R, Yoshida M, et al. Janus kinase inhibitors ameliorate clinical symptoms in patients with STAT3 gain-of-function. Immunotherapy Advances. 2023;3(1).

Introduction

Anti-tissue transglutaminase IgA antibodies (tTG) are used in the follow-up of celiac disease (CD) to assess adherence to a gluten-free diet (GFD). Persistent positivity may indicate the need for histological reassessment. There is limited information about the rate of complete normalization of tTG and associated factors. Our objective was to evaluate the percentage, kinetics, and factors related to tTG normalization.

Aims & Methods

This was a retrospective observational study including patients with tTG testing at diagnosis and follow-up monitoring of these antibodies from 1991 to 2023 in a specialized unit dedicated to patients with CD. Inclusion criteria were: patients over 16 years of age at diagnosis, initially elevated tTG titres, and at least one serological follow-up after starting a GFD. Time to tTG normalization was estimated using the Kaplan-Meier method. Comparisons between groups were performed using the log-rank test. The association between demographic and clinicopathological characteristics at diagnosis and time to tTG normalization was assessed using Cox regression analysis.

Results

A total of 179 patients were included (75% female, mean age 40 ± 16 years). Duodenal atrophy was present in 81%, and 79% had symptoms. 83% strictly adhered to a GFD. Median follow-up was 3 years. The incidence rate of tTG normalization was 35% per patient-year. The cumulative tTG normalization rate was 38% (95% CI: 30-45) at 1 year, 61% (53-69) at 2 years, 70% (63-77) at 3 years, 80% (73-87) at 4 years, 81% (74-89) at 5 years, and 95% (88-100) at 10 years. The median time to tTG normalization was 24 months (95% CI: 20–28). Table 1 shows Kaplan–Meier estimates expressed as percentages of tTG normalization by adherece to GFD and baseline tTG. In the multivariable analysis, two factors were found to be significantly associated with the normalization of tTG: lower baseline tTG and good adherence to a GFD. Regarding baseline tTG level, patients with titres ≤ 286 U/ml (median) had 2.46 times higher likelihood of antibody normalization compared to those with higher titres (HR: 2.46; 95% CI: 1.69–3.56; p < 0.001). Regarding adherence to a GFD, patients who followed a strict GFD had 5.38 times higher likelihood of tTG normalization (HR: 5.38; 95% CI: 2.79–10.36; p < 0.001).

Table 1. Kaplan–Meier estimates expressed as percentages of normalization (with 95% CIs) after CD diagnosis, by adherece to GFD and baseline tGA titres.

Conclusion

1. The incidence rate of tTG normalization in CD patients after initiating a GFD was 35% per patient-year of follow-up.
2. In the long-term (10 years), 95% of CD patients achieved tTG normalization.
3. Lower tTG titres at diagnosis and good adherence to the GFD were predictive factors for tTG normalization.
4. Understanding the kinetics of tTG normalization according to various factors is essential before considering histological reassessment for suspected poor disease progression.

Clinical Case Summary

A 75-year-old woman was admitted to our department for weight loss (25 kg in 10 months) and chronic diarrhea (> 6 months). In history: hypertension in olmesartan 20 mg/day, multinodular goiter. The patient was already tested for anti-transglutaminase antibodies (negative, IgA in normal range) but EGDS showed severe duodenal villous atrophy. On suspicion of ARBsII-associated enteropathy olmesartan was suspended with partial but not complete benefit on clinical. During hospitalization, the patient presented asthenic, occasionally soporific, severely malnourished (Table1) and with a picture of pan-cytopenia (Table1). We excluded neurological (brain CT scan), infectious (blood cultures and co-cultures) and hematologic (bone marrow biopsy) causes. Ultrasound of the intestinal loops and ileo-colonoscopy were normal. Video capsule endoscopy showed marked scalloping of DII and jejunum with extensive ulcers (Figure1). Later, she performed at referral center anterograde double-balloon enteroscopy (DBE). DBE confirmed marked atrophy and map ulcers primarily suggestive of refractory celiac disease type II/EATL with ulcerative jejunum-ileitis. Histologic examination described findings referable to chronic exacerbated, erosive enteritis, not diagnostic for celiac disease. HLA search for celiac disease was negative therefore celiac disease was excluded. Hemotransfusions and nutritional supplementation were administered in consideration of anemia and nutritional deficiency. Empiric/ex-juvantibus therapy with steroid was also set up with marked improvement in symptomatology.
Following hospitalization, she was re-evaluated on an outpatient basis at enteropathy referral center. Here she was first imposed high-dose steroid therapy with marked improvement and weight gain, then Azathioprine in maintenance. She was therefore discharged with a diagnosis of autoimmune enteropathy with likely previous overlap with sartane enteropathy.

References

1. Schiepatti A, et al.. Nomenclature and diagnosis of seronegative coeliac disease and chronic non-coeliac enteropathies in adults: the Paris consensus. Gut. 2022 Nov;71(11):2218-2225. doi: 10.1136/gutjnl-2021-326645. Epub 2022 Jun 8. PMID: 35676085; PMCID: PMC9554081.
2. van Wanrooij RLJ, et al. Adult-Onset Autoimmune Enteropathy in an European Tertiary Referral Center. Clin Transl Gastroenterol. 2021 Aug 1;12(8):e00387. doi: 10.14309/ctg.0000000000000387. PMID: 34333499; PMCID: PMC8323799.
3. Schiepatti A, et al. Systematic review: Clinical phenotypes, histopathological features and prognosis of enteropathy due to angiotensin II receptor blockers. APT. 2024 Feb;59(4):432-444. doi: 10.1111/apt.17855. Epub 2024 Jan 7. PMID: 38185985.

Introduction

The intestinal microbiota is defined as the community of microorganisms inhabiting the gastrointestinal tract, which confer benefits to the organism and play a role in immune system regulation. It has been suggested that the microbiota may play a role in the pathogenesis of gut diseases, including Celiac Disease (CeD), and the response to a gluten free diet (GFD). (1) Intestinal dysbiosis may be a contributing factor to the inflammatory state, thereby hindering resolution of symptoms and complete mucosal healing, particularly in patients who show a lack of clinical and histological improvement despite following a GFD. (2,3).

Aims & Methods

We aimed to provide a preliminary evaluation of the gut microbiota profile from diagnosis to follow-up, classifying patients who respond and do not respond to diet in order to establish a first baseline of the microbial composition and its relationship to the dietary response.
We collected fecal samples from patients enrolled at the Gastroenterology Unit of Azienda Ospedale- Università of Padova, from March to November 2024. All patients needed to be off antibiotics, probiotics and proton-pump inhibitors for at least one month before enrolment. Stool samples were collected and transferred in a buffer solution, and stored at -20°C.
Fecal samples were analyzed by BMR Genomic s.r.l. (Padua, Italy) that sequenced the V3-V4 hypervariable 16S ribosomal RNA region using the Illumina MiSeq. The results were compared to an internal population of healthy subjects (provided by BMR genomics) using Qiime2 tools. Statistical analysis was conducted using STATA 18 software. Categorical variables were compared using the Chi-square test, while non-parametric continuous variables were analysed using the Mann-Whitney test.

Results

We enrolled 71 CeD patients with mean age at diagnosis of 35.76 ± 16.29 years old (50 out of 71 were female). Of the 71 patients, 9 were newly diagnosed with CeD, while 62 were in follow-up. Among follow-up groups, 44 of 62 patients (71%) were classified as responders to diet and 18 (29%) were classified as non- responders, exhibiting classical symptoms, positive serology and histology. We compared the relative abundance of the main bacterial phyla in each sample: a significant decrease in beneficial phyla such as Actinobacteria (p = 0.04) and a decrease close to the significant threshold in Firmicutes (p = 0.06) was observed after the follow-up. This factor could be ascribed to a long-term dietary regime rather than to the disease itself. (4) Proteobacteria were more abundant in follow-up, especially in non-responders. This phylum includes many potentially pathogenic microorganisms belonging to Escherichia, Klebsiella and Shigella genera. Comparing diagnosis and follow-up patients, Clostridium perfringens was significantly more present in patients during follow-up (p=0.02), while Escherichia coli showed greater presence in patients at diagnosis (p=0.035) and in non-responders, consistently with his role in the inflammatory phase of the disease. (5)

Conclusion

Our preliminary data suggest that a long-term GFD does not always restore completely the intestinal dysbiosis present at the diagnosis and could be associated with specific alterations in beneficial bacteria. The presence of abundant Proteobacteria at diagnosis and in non-responder patients may be considered as biomarkers of active state of CeD. Future studies on various biological samples, as well as a more extensive investigation into the impact of long-term GFD, are required to highlight microbiota-immunity relationships involved in development of CeD.

References

1. Zafeiropoulou K, Nichols B, Mackinder M, et al. Alterations in intestinal microbiota of children with celiac disease at the time of diagnosis and on a gluten-free diet. Gastroenterology. 2020;159(6):2039–2051.e20.

2. Freire R, Ferreira R, Almeida LM, et al. Human gut-derived organoids provide model to study gluten response and effects of microbiota-derived molecules in celiac disease. Sci Rep. 2019;9(1):1–12

3. Schiepatti A, Montagnani M, D'Argenio V, et al. Relationship between duodenal microbiota composition, clinical features at diagnosis, and persistent symptoms in adult celiac disease. Front Microbiol. 2021;12:1–12

4. Wacklin P, Nikkilä J, Tuovinen E, et al. Altered duodenal microbiota composition in celiac disease patients suffering from persistent symptoms on a long-term gluten-free diet. Am J Gastroenterol. 2014;109(10):1587–1594

5. Olshan KL, Leonard MM, Serena G, Zomorrodi AR, Fasano A. Gut microbiota in celiac disease: microbes, metabolites, pathways and therapeutics. Expert Rev Clin Immunol. 2020 Nov;16(11):1075-1092.

Introduction

Several studies have proposed a non-biopsy serological diagnosis of celiac disease (CeD) based on the sequential detection of anti-tissue transglutaminase (tTG) IgA and follow-up with anti-endomysial IgA as a confirmatory test or, more recently, using one test, the tTG IgA at cut-off values ≥10 UNL in both children and adults. However, while the non-biopsy strategy was well received by pediatricians, gastroenterologists still raise concerns about adopting such a strategy for diagnosing CeD in adults, especially in a non-expert setting.

Aims & Methods

The study aimed to assess the performance and clinical utility of the concurrent detection of two autoantibodies targeting two independent antigens, tTG and deamidated gliadin peptides (DGP), as an effective alternative approach for a non-biopsy diagnosis of CeD in adults with high pre-test probability.
This prospective, multicenter, binational study collected consecutive patients with a high pre-test probability for CeD. Between 2018 and 2020, adults were enrolled at four Italian and one Argentinian centers. Patients underwent evaluation for serology and duodenal biopsy at local centers. Serology was also blindly analyzed by a central laboratory (Werfen, San Diego, USA) for tTG IgA and DGP IgG by Aptiva Particle Multi-Analyte Technology (PMAT) assays. CeD diagnosis required histological confirmation of Marsh 3 damage.

Results

181 adult patients with suspected CeD were enrolled (134 with histological diagnosis of CeD and 47 not histologically confirmed as CeD). The sensitivities of tTG IgA and DGP IgG were 98.5 and 93.3%, respectively. Patients positive for both tTG IgA and DGP IgG (double positive) were predictive of CeD in 92.5% of patients at >1x upper limit of normal (ULN). Double positivity for tTG IgA and DGP IgG, both at >10x ULN, had a 100% positive predictive value for the presence of Marsh 3 histology.

Conclusion

The presence of both tTG IgA and DGP IgG at concentrations >10x ULN was 100% predictive of CeD. Incorporating DGP IgG alongside tTG IgA in a single-step approach can be considered a valid confirmatory strategy for definitive non-biopsy diagnosis of CeD, particularly for patients with high pretest probability, even in non-expert settings.

References

Ciacci C et al Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study. Lancet Gastroenterol Hepatol. 2023 Nov;8(11):1005-1014.

Disclosure

FZ served as a speaker for Werfen and a consultant for Takeda. CC served as a speaker for Werfen and Takeda. GLN was employee of Werfen at time of study. JB JCB was consultant for Takeda. All other authors declared no conflict of interest.

Introduction

Celiac disease (CD) is an autoimmune enteropathy triggered by gluten in genetically predisposed individuals. Both hereditary and acquired factors may increase thrombotic risk in CD. Anti-phospholipid antibodies (aPL), including anti-cardiolipin (aCL) and anti-β2 glycoprotein I (β2GPI), are known markers of thrombophilia.

Aims & Methods

This study aimed to evaluate the frequency of these antibodies in CD patients and investigate any correlation with gluten-free diet (GFD) adherence.
This prospective, descriptive study was conducted over four years and included 42 patients diagnosed with CD based on clinical, serological, and histological criteria. Anti-cardiolipin IgG (aCL) and anti-β2GPI IgG antibodies were tested by ELISA, and lupus anticoagulant (LA) was assessed via coagulation assay.

Results

Among 42 CD patients, aPL results were available for 9 (22%). The mean age was 35.5 years (range 18–58), with a female-to-male ratio of 2. All patients were prescribed a GFD with regular follow-up.
aCL IgG antibodies were positive in 3/9 patients (15.2%), β2GPI IgG antibodies were positive in 1/9 (5%), and LA was negative in all patients. No correlation was found between the presence of aPL and disease activity or adherence to GFD. Additionally, aPL presence was not associated with disease duration or thrombotic events.

Conclusion

In our cohort, we did not observe a high prevalence of anti-phospholipid antibodies among CD patients. aCL IgG was the most frequently detected antibody (15.2%) under strict GFD. The clinical significance and pathogenic role of these antibodies in CD remain unclear and warrant further large-scale prospective studies.