Clinical Case Summary

Introduction: Ulcerative colitis (UC) is a chronic inflammatory disease characterized by remitting and relapsing patterns, necessitating multifaceted therapeutic interventions, among which mesalazine, or 5-aminosalicylic acid (5-ASA), is prominently utilized. Despite its typically favorable tolerability profile, mesalazine may occasionally precipitate severe adverse events, such as myocarditis.
Case presentation: A 46-year-old male recently diagnosed with UC presented with a moderate UC flare-up and was initiated on 5-ASA therapy upon admission.
Within a span of two days following initiation of oral therapy, he developed acute chest pain, palpitations, dyspnea, and desaturation, necessitating intensive care due to cardiogenic shock.
Paraclinical assessments revealed elevated troponin levels, along with electrocardiographic and echocardiographic abnormalities, including left ventricular dysfunction and reduced ejection fraction.
Discontinuation of mesalazine resulted in symptom improvement and reduction of cardiac markers. Subsequent evaluations demonstrated a recovery in cardiac function, establishing a causal relationship between myocarditis and the administration of 5-ASA. Consequently, a therapeutic switch to mercaptopurine was instituted.
Conclusion: This case underscores the infrequent yet significant hazard of mesalazine-triggered myocarditis, emphasizing the critical necessity for vigilant patient monitoring during this therapy and prompt consideration of alternative therapeutic options in the presence of severe cardiac complications.

Clinical Case Summary

A 13-year-old boy presented with abdominal distention, recurrent hypoglycemia, and self-resolving jaundice. Clinical examination revealed growth retardation and hepatosplenomegaly. Blood work revealed anemia, thrombocytopenia, elevated aspartate and alanine transaminase levels, and raised plasma cholesterol and triglycerides. Ultrasound showed an enlarged liver with surface irregularity, splenomegaly, and a dilated portal vein. Etiological work-up for cirrhosis was positive for hepatitis B (HBV) surface antigen (HbsAg) and antibodies for HBV core and envelope antigens (anti Hbc, antiHbe) but an undetectable HBV DNA level. HBV was considered to be an unlikely cause of cirrhosis due to the young age of the patient, hence further metabolic and genetic work-up was done. Tests for Wilson’s and autoimmune liver disease were negative. Liver biopsy revealed a distorted lobular architecture with nodules, thin septae, and portal fibrosis. Hepatocytes showed marked swelling and pyknotic nuclei, and negative HbsAg immunostaining. Molecular analysis revealed a novel mutation in the exon 3 of the PHKG2 gene (c.98G>T, p.Gly33Val). The patient was diagnosed with cirrhosis due to GSD IXc with inactive chronic hepatitis B. His symptoms resolved with an optimized diet of corn starch, high-protein and vitamin supplementation. The importance of liver transplantation was also discussed with the family.

Introduction

Arsenic, a potent environmental toxin, has been widely reported to cause significant health problems, including liver damage and disturbances in the metabolic processes. One of the lesser-understood facets of arsenic toxicity is its impact on gut microbiota, the community of microorganisms living in the intestinal tract, which plays a crucial role in host metabolism and overall health. Previous studies have indicated that arsenic exposure can alter the composition of gut microbiota, potentially affecting the host’s metabolism of arsenic and exacerbating its toxic effects. Despite ongoing research, the mechanisms underlying the interaction between arsenic exposure, gut microbiota changes, and arsenic metabolism remain inadequately defined.

Aims & Methods

The primary objective of this study was to elucidate the dynamics of gut microbiota changes under varying levels of arsenic exposure and to understand how these changes affect arsenic metabolism and subsequent liver toxicity. We used C57BL/6 mice as a model system, exposing them to 0, 5, or 10 ppm sodium arsenite (NaAsO2) in their drinking water over a period of six months. We conducted a comprehensive analysis of the gut microbiota, focusing on folic acid (FA)/vitamin B12 (VB12)- and butyrate-synthesizing communities. Additionally, molecular interactions between arsenic and methionine synthase (MTR), an enzyme crucial for FA/VB12 utilization, were assessed using 3D molecular simulations and biochemical assays. The intervention model involved supplementation of FA and VB12 to evaluate their protective effects against arsenic-induced disturbances.

Results

Exposure to NaAsO2 significantly altered gut microbiota, with a notable increase in the abundance of FA/VB12- and butyrate-synthesizing microbiota. This shift was hypothesized to compensate for the disrupted utilization of these nutrients due to arsenic exposure. In higher arsenic exposure levels, however, the microbiota changes were inconsistent, suggesting a potential threshold beyond which the compensatory mechanism may be overwhelmed. Biochemical assays confirmed that arsenic binds to MTR, disrupting its function and further impacting FA/VB12 metabolism. The interaction was substantiated by SEC-UV-DAD and fluorescence-labeled arsenic studies, which demonstrated that arsenic directly interacts with MTR in both non-cellular and cellular systems. Our intervention model using FA and VB12 supplementation showed that it was possible to mitigate the disturbances in gut microbiota, restore MTR levels, enhance arsenic metabolism, and reduce liver injury.

Conclusion

This study provides significant insights into the interaction between arsenic exposure and gut microbiota. We demonstrated that changes in gut microbiota are not merely a consequence of arsenic exposure but are intricately linked to the metabolic processes affected by arsenic, particularly through the disruption of MTR function. The supplementation of FA and VB12 proved effective in blocking these disturbances, suggesting potential therapeutic strategies to combat arsenic toxicity. The findings emphasize the importance of considering gut microbiota in the management and treatment of arseniasis and underscore the complex interplay between environmental toxins, gut microbiota, and host metabolism. Future studies should focus on further delineating the specific pathways and mechanisms by which microbiota influence arsenic metabolism and exploring the potential for microbiota-targeted therapies in arsenic-related diseases.

Introduction

Crohn’s disease (CD), a variant of inflammatory bowel disease, is a complex, debilitating, chronic and relapsing disorder of the gastrointestinal tract. If poorly controlled, patients are at risk of intestinal obstruction and infection due to the formation of strictures, fistulae and narrowing of the intestinal lumen, often requiring surgical intervention. As the precise aetiology remains unclear, current treatments for CD are limited. An altered composition of native gut microbiota may play a role in CD pathogenesis, with recent faecal microbiota transplantation (FMT) studies revealing variable therapeutic efficacy in CD management. Orally administered Emu Oil, derived from Emu adipose tissue, has demonstrated anti-inflammatory and reparative properties in models of intestinal disease.

Aims & Methods

The current study aimed to determine whether Emu Oil-modulated FMT could reduce disease severity and modulate the gut microbiota in a mouse model of trinitrobenzene sulfonic acid (TNBS)-induced Crohn’s-like colitis. Female ARC(s) mice were assigned to FMT donor (n=5/group) and recipient (n=10/group) groups. Donor mice were orally administered either Water (80μl), Olive Oil (OO) or Emu Oil (160μl) daily (days -7 to 0); fresh faeces were collected (days -1 to 3) and pooled per group. Recipient mice were administered TNBS (3mg; day 0) and donor faecal supernatant (120μl; day 3) intrarectally and euthanised on day 6. Daily bodyweight and disease activity index (DAI), colonoscopically-assessed disease severity, organ weights, intestinal permeability (fluorescein isothiocyanate [FITC]-dextran uptake), histologically-assessed colonic damage (disease severity, crypt depth), intestinal barrier function (mucin-secreting cells), acute inflammation (myeloperoxidase [MPO]) and faecal microbiome (16S rRNA amplicon sequencing) were assessed. p<0.05 was considered statistically significant.

Results

TNBS induced bodyweight loss in all groups, which normalised to day 0 values on the final day of the experimental period. Daily DAI remained elevated throughout the trial in all groups; only Emu Oil FMT normalised DAI on day 6 compared with day 0 (p<0.05). TNBS increased colonoscopically-assessed disease severity scores (p<0.05), with no significant Emu Oil nor OO FMT effect. Emu Oil FMT decreased liver weights and increased small intestinal weights relative to bodyweight, reduced histologically assessed disease severity and increased colonic mucin counts compared with Water and OO FMT (p<0.05). The most abundant genera across all groups were Muribaculaceae, Eisenbergiella and Bacteroides; while alpha and beta diversity, taxonomic profiles, FITC-dextran, crypt depth and MPO activity remained unchanged in all treatment groups (p>0.05).

Conclusion

Emu Oil-modulated FMT improved histologically-assessed indicators of intestinal disease and barrier function, compared with Water FMT and OO FMT. Interestingly, Emu Oil-modulated FMT affected liver and small intestinal organs weights, suggesting a systemic effect in this setting of disease. Importantly, key genera across taxonomic profiles were identified, however, the microbiome and remaining disease indicators were largely unchanged between treatments. Overall, Emu Oil-modulated FMT demonstrates therapeutic potential in CD management. Future studies would benefit from a deeper assessment of the gastrointestinal microbiome through long-read whole genome sequencing to further determine the role of the microbiome in EO FMT efficacy compared with conventional FMT.

Introduction

Patients suffering from inflammatory bowel diseases (IBD) manifest an increased risk of developing colitis-associated colon cancer (CAC). Interleukin 22 (IL22) is a cytokine involved in the proliferation and survival of epithelial cells. However, it also correlates with the development of tumoral lesions. IL22 is secreted by different immune cell types, including iNKT cells, tissue resident cells possessing cytotoxic properties in colorectal cancer (CRC). In IBD patients, though, iNKT cells perform both pro-inflammatory or tolerogenic functions in a microbiota-dependent fashion, opening questions on their functional role in CAC development.

Aims & Methods

Immune cell composition and iNKT cell phenotype of inflamed, non-tumor and cancerous tissue lesions of CAC (n=49), IBD (n=20) and sporadic CRC (n=38) patients were analysed in samples obtained from Policlinico Hospital, Milan, and IOV-IRCCS, Padua. High-dimensional single-cell flow cytometry, metagenomics, RNAseq, spatial immunophenotyping and trascriptomic (Cosmx, Nanostring), ex vivo and in vitro experiments were performed to evaluate the phenotype and function of human iNKT cells. Metabolomics was performed to identify microbial-derived molecules involved in iNKT cells activation.Mechanisms were dissected in CAC murine models, either iNKT proficient or deficient.

Results

An increased expression of IL22 and a higher NKT22 infiltration was observed in CAC tissues, as well as an enrichment of Odoribacter, a gram-negative bacteria implicated in tryptophan metabolism. Stimulation of iNKT cells with Odoribacter-derived metabolites induced Ahr-dependent IL22 production by iNKT cells. Metabolomic analyses revealed an increased presence of tryptophan metabolites in the Odoribacter supernatant, promoting NKT22 differentiation both in vitro and in vivo models. Moreover, the administration of Odoribacter Supernatant or of the single purified metabolites were sufficient to increase tumorigenesis in CAC mouse models, but not in iNKT-deficient mice.
Spatial proteomics and trascriptomic analyses of human CAC tissues confirms the microbiota-dependent functional skewing of iNKT cells residing closely to cancer cells.

Conclusion

iNKT cells in CAC patients are the major IL22 producing cells and are induced by the recognition of microbiota-derived metabolites implicated in tryptophan metabolism and Aryl hydrocarbon receptor (AhR) stimulation. NKT22-microbiota interaction in CAC patients plays a potential crucial role in tumor development.

Introduction

Potential celiac disease (PCD) is a clinical condition characterized by the presence of a positive CD-specific serology and a normal intestinal architecture. Asymptomatic PCD patients are generally addressed to continue on a gluten containing diet (GCD), but long-term risks of this approach have never been explored.

Aims & Methods

In the present study we aim at investigating nutritional and autoimmune complications possibly developing overtime in a cohort of asymptomatic PCD children left on a GCD. We compared parameters of growth, nutritional status, and autoimmunity between time of diagnosis and in occasion of last medical check, after a long-term gluten containing diet.

Results

Altogether we collected data from 171 PCD children with a mean follow-up time of 3 years (range 0.35-15.3 years). During follow-up, despite patients did not reduce the amount of daily gluten intake , anti-tissue transglutaminase (anti-TG2) antibodies spontaneously and significantly decreased. Most of parameters analysed did not change over follow-up (height centile, ferritin, albumin., cholesterol, calcium, alkaline phosphatase , parathormone, vitamin D, p>0.05) or even improved (weight and BMI centile, haemoglobin, blood iron, HDL, glycaemia and HbA1C, p<0.05), always remaining in the limit of normality. Equally autoantibodies for other concomitant autoimmune disorders did not increase overtime. Similar results were obtained excluding from the analysis patients that stopped producing anti-TG2 and those with a follow up < 3 years.

Conclusion

Our pilot study provides reassuring results on the maintenance of a gluten containing diet in asymptomatic PCD children, even when a long term follow-up is considered.

Disclosure

no conflict of interest to declare

Introduction

Rectal cancer represent 30% of colorectal cancer with 46,220 new cases estimated in the United States in 2024. About 98% of rectal cancer patients have rectal adenocarcinoma. Gastrointestinal (GI) squamous cell neoplasm (SCN) is very rare with no enough studies to estimate its incidence and clinical features. Thus, our aim was to assess the risk of developing second primary GI SCN following chemo(radio)therapy after rectal adenocarcinoma.

Aims & Methods

We used the Surveillance Epidemiology and End Results (SEER) database to obtain the data of 145,789 patients with first primary rectal adenocarcinoma. We used MP-SIR session to calculate the standardized incidence ratios (SIR) ratio as (observed/Expected) with a latency exclusion period of 0 months, Excess risk (ER) was calculated per 10.000 and 95% Confidence Interval (CI). The results were significant if P> 0.05.

Results

Out of 145.789 patients with rectal adenocarcinoma, 4333 patients developed second primary SCN. Among who developed second primary GI SCN, 21.9% received chemotherapy with an O/E of 4.07 (P˂0.05, CI: 4.50 - 3.67, ER=74.53) while 3.25% received radiotherapy with an O/E of 2.23 (P ˂ 0.05, CI: 2.60- CI: 1.90, ER=42.59). The group who had no systemic therapy had an O/E of 2.83 (P˂ 0.05, 95%CI: 2.93–2.74, ER=57.27). The group who received combined chemoradiotherapy had a 2-fold increased risk of developing second primary GI SCN (O/E =2.34, P˂ 0.05, CI:2.44- 2.24, ER=34.88). There was a significant increase in the 0-11 months interval in the four groups. The group who received chemotherapy O/E was 11.73 (P ˂ 0.05, 95 % CI: 13.27– 10.32, ER=233.48) and the group who received radiotherapy had increased O/E to 5.16 (P˂0.05, ER=150.85, 95%CI: 6.51–4.03).

Conclusion

Chemotherapy increases the risk of multiple primary GI SCN after the first primary rectal adenocarcinoma, especially in the first year after diagnosis. Chemo(radio)therapy have a significantly high risk second primary GI SCN with different potential and variations across different intervals. Thus, more attention to be given for the screening of second primary GI malignancies after chemo(radio)therapy administration.