Introduction

The use of a gluten-free diet (GFD) in healthy people has been steadily increasing worldwide based upon the unproven belief that avoiding gluten enhances overall wellness. In contrast, evidence indicates that voluntary GFD has an impact on living costs, psychosocial profile and may cause malnutrition in the long-term^1,2. Since dietary changes may significantly affect gut microbiota composition³, we tested whether a 30-day unnecessary GFD in healthy subjects has an impact on diversity and richness of gut microbiota.

Aims & Methods

116 fecal samples were collected from 30 thoroughly examined healthy subjects (21 females, 9 males; 34±14 years) recruited at St. Anna University Hospital in Ferrara, Italy. All subjects had no demonstrable metabolic, cardiovascular, respiratory, rheumatic and neurological illnesses and were asymptomatic for gastrointestinal symptom (established by Gastrointestinal Symptom Rating Scale, GSRS). Stool samples, collected at day 0, and 3, 7, 30 days from GFD were sequenced via shotgun metagenomic and computationally profiled (bioBAkery 3). Data were analyzed on MetaPhlAn 4.0 and HUMAnN 3.0 for taxonomic and functional profiling, respectively and relative abundance transformed via arcsin-sqrt. Only species present at any time point in at least 5 subjects were considered (600 species). Statistical analysis was performed using a linear mixed model and Friedman’s ANOVA. P values were combined and corrected for multiple hypothesis testing (q value).

Results

Species alpha-diversity did not significantly change during 30 days of GFD (p >0.05). However, during the GFD, 14 species significantly decreased (q < 0.05) in relative abundance. Most of the decreased bacteria belonged to Bifidobacterium genus (e.g. Bifidobacterium longum p=0.000000003; q=0.000001) or those involved in complex carbohydrate metabolism.

Conclusion

In healthy subjects, a 30-day GFD did not significantly affect gut eubiosis. However, consistent changes in the relative abundance of gut microbiota species showed a reduction of Bifidobacterium genus thus potentially affecting intestinal and immunological homeostasis and health status⁴.

References

1. Cardo, A. et al. Nutritional Imbalances in Adult Celiac Patients Following a Gluten-Free Diet. Nutrients 13, 2877 (2021).
2. Dennis, M., Lee, A. R. & McCarthy, T. Nutritional Considerations of the Gluten-Free Diet. Gastroenterology Clinics of North America 48, 53–72 (2019).
3. Caio, G. et al. Effect of Gluten-Free Diet on Gut Microbiota Composition in Patients with Celiac Disease and Non-Celiac Gluten/Wheat Sensitivity. Nutrients 12, 1832 (2020).
4. Tojo, R. et al. Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis. World J Gastroenterol 20, 15163–15176 (2014).

Clinical Case Summary

A 70-year-old patient with diabetes mellitus and cholecystectomy performed six months earlier was admitted to the emergency department for generalized abdominal pain, hyporexia and weight loss.
An abdominal CT scan showed a solid-cystic pancreatic lesion suggestive of mucinous neoplasia, together with peritoneal nodules in the right paracolic gout. In view of the suspicion of malignancy, an echoendoscopy with fine needle aspiration puncture (EUS-FNA) was performed, identifying an irregular lesion with heterogeneous and hypovascular ultrastructure in the pancreatic neck-body and a discrete dilatation of the main pancreatic duct. Finally, the histological study didn´t show neoplastic cells.
Suddenly the patient experienced a clinical worsening with severe pain and high fever. Laboratory tests showed a progressive increase in C-reactive protein and leukocytosis with left shift. In a control CT scan, a reduction in the size of the pancreatic lesion is observed, together with an increase in the peritoneal lesions which present a polyglobulated contour, hypercapillary margins and rarefaction of the surrounding fat. These finding suggesting the presence of peritoneal abscesses secondary to dropped gallstones. After broad-spectrum antibiotic therapy, the intra-abdominal abscesses improved radiologically, but the collection persisted in the right posterior pararenal space which was drained under ultrasound control with subsequent disappearance of fever and normalization of analytical parameters.
Dropped gallstones occur in approximately 7% of cholecystectomies. The secondary granulomatous reaction in paucisymptomatic patients can simulate peritoneal tumor processes in imaging tests, being one of the adverse effects described in relation to this pathology. In our case, the concomitant presence of peritoneal lesions together the pancreatic lesion oriented the initial case as a malignant process; however, the patient's evolution were key to the final diagnosis.

Introduction

Immuno-mediated colitis is one of the most common gastrointestinal side effects associated with immune checkpoint inhibitors (ICIs). ICIs-colitis shares with inflammatory bowel disease (IBD), including both Crohn’s Disease (CD) and Ulcerative Colitis (UC), the clinical presentation, macroscopic, microscopic, and serological findings, making challenging the differentiation between the two conditions. The gut microbiota has been suggested as an important driver in the pathogenesis of ICIs-colitis as well as in the pathogenesis of IBD. We aimed to assess whether a specific microbiota profile, as measured by a machine learning approach, can be associated with ICIs-colitis and whether it differs from the one assessed in patients with IBD and in healthy controls (HCs).

Aims & Methods

In this prospective pilot study, consecutive patients with ICIs-colitis, patients with IBD and HCs were enrolled. Stool samples were collected for fecal microbiota assessment analysis by 16S rRNA gene sequencing approach. The raw reads underwent a filtering procedure performed within QIIME2 analysis framework (version 2022.8). Alpha diversity was evaluated on rarefied counts (Richness, Shannon, and Pielou indices; rarefaction level: 31,556), while beta diversity was calculated on normalized counts (Bray-Curtis, Jaccard, Canberra, Weighted and Unweighted Unifrac; counts normalized with GMPR). The diversity analysis was conducted in R (version 4.1.0). A permutational analysis of variance (PERMANOVA) test on Bay-Curtis dissimilarity was used to test for differences in the microbiota composition between disease status groups (vegan and ecole packages). The MaAsLin2 package was then used to perform differential abundance analysis at all taxonomic levels. Supervised and unsupervised machine learning algorithms were applied.

Results

Nineteen patients with ICIs-colitis, 40 patients with UC (20 active and 20 inactive), 34 with CD (14 active and 20 inactive) and 36 HC were enrolled. Alpha diversity was not significantly different between ICIs-colitis and HCs (p=0.94), while it was statistically significant between IBD and HCs (p=0.02) and between IBD and ICIs-colitis (p=0.03). At phylum levels, we found high levels of Tenericutes in HCs and high levels of Proteobacteria in ICIs-colitis. Moreover, we found high levels of Actinobacteria in IBD compared to the other group. Interestingly, at genus levels, we found very high levels of Enhydrobacters in ICIs-colitis compared to patients with IBD. While at species levels, high levels of Bifidobacterium longum in patients with UC were observed. A specific microbiota profile was found for each group (IBD, ICIs, HC) and was confirmed with sparse partial least squares discriminant analysis, a machine learning-supervised approach. The latter allowed us to observe a perfect class prediction and group separation using the complete information (full Operational Taxonomic Unit table), with a minimal loss in performance when using only 5% of features.

Conclusion

A machine learning approach to 16S rRNA data identifies a bacterial signature characterizing ICIs-colitis from IBD and HCs. Future research will clarify whether such microbiota profiling is useful for prediction, early diagnosis and management of patients with ICIs-colitis.

Disclosure

None

Clinical Case Summary

The authors present a case of a 22-year-old male with no previous medical history, apart from COVID-19 in January 2022, which had a mild course. He was referred to a medical appointment in our department after routine blood tests, from March 2022, that revealed abnormal liver biochemistry elevation (ALT 476U/L, AST 139U/L, GGT 135U/L, normal ALP and total bilirubin), which was normal in the previous year. He reported no symptoms and physical examination was unremarkable. There was no chronic medication, recent introduction of drugs, herbal products or epidemiology for zoonoses.
Abdominal ultrasound and CT scan with IV contrast showed discrete hepatomegaly with homogeneous steatosis, without focal lesions, and splenomegaly.
An extensive work-up excluded hepatotropic agents, metabolic causes, autoimmune aetiologies and haematological or lymphoproliferative disorders. The serum protein electrophoresis and immunofixation, immunoglobulins count, tumour markers and celiac disease serology were also normal. During this period, the patient maintained the same liver elevation pattern with stable values, without any alteration in total bilirubin, albumin, coagulation and hemogram, except for the appearance of discrete thrombocytopenia. We remained asymptomatic, with no signs of hepatic decompensation or haemorrhagic diathesis.
The percutaneous liver biopsy documented septal fibrosis and regenerative nodules, interface hepatitis, focal hepatocellular necrosis and, notably, the presence of numerous multinucleated giant hepatocytes, allowing the diagnosis of post-infantile giant cell hepatitis (PIGCH), in cirrhotic phase.
We present a case of PIGCH, with rapid progression to cirrhosis, whose aetiology remains unknow. Viral aetiologies account for 20% of the cases. Given the temporal association between SARS-CoV-2 infection and liver enzymes’ elevation, we cannot exclude this agent as a possible culprit. To our knowledge, this is the first case reporting this possible trigger.

References

Xiao, Y., Gao, Z. H., & Deschenes, M. (2021). Autoimmune post-infantile giant cell hepatitis: a case report and review of the literature. Canadian liver journal, 4(2), 104–109. https://doi.org/10.3138/canlivj-2020-0024;
Jiao, J., & Zhang, X. (2022). Post-infantile Giant Cell Hepatitis: A Literature Review and Meta-analysis. Journal of clinical and translational pathology, 2(3), 100–107. https://doi.org/10.14218/jctp.2022.00016.

Introduction

Hypertriglyceridemia is a well-established cause of acute pancreatitis, representing up to 35% of all etiologies. The risk of developing acute pancreatitis increases progressively with serum triglyceride (TG) levels over 500 mg/dL. The degree of TG elevation is also associated to the severity of hypertriglyceridemia-induced pancreatitis (HTGP). Besides general measures, it has been suggested from observation studies that, in selected patients, insulin and plasmapheresis may have a role in the management of this condition.

Aims & Methods

We present an observational retrospective study of patients diagnosed with severe HTGP treated with plasmapheresis (PX) in an Intensive Care Unit (ICU) between January 2013 and March 2023.

Results

Of the 19 patients included in this study, 89% were men (n=17) and the mean age of presentation was 41 ± 7 years. Around 90% of patients were obese with a mean body mass index (BMI) of 29 ± 3 kg/m². The average APACHE II score was 9±7 and most patients did not require organ support (n=16, 84%). All the selected patients had severe hypertriglyceridemia at admission (1225 to 4700 mg/dL) and underwent PX within 48h of ICU admission. Levels of TG were measured before and after each plasmapheresis. 68% of patients needed only one treatment to reduce TG to a value below 500 mg/dL (n=13), 26% needed two treatments (n=5) and 5% needed four (n=1). A total of 27 PX were conducted. The average decrease in TG levels per treatment was 67% and 74% with the first treatment. The mean volume exchanged was 3683 mL ± 859 mL, and the most used replacement solutions were albumin/crystalloid (n=12, 44%) and albumin alone (n=11, 41%). The technique was interrupted mainly due to elevated transmembrane pressure (n=11, 40%). There were no PX interruptions due to complications related to the patient. Although heparin was used in all patients for anticoagulation, no hemorrhagic complications were associated to the technique. Hypotension occurred in 7% of plasmapheresis and was solved with crystalloid administration . The mean ICU length of stay was 7+11 days and the mean hospital length of stay was 17+21 days. The hospital mortality was 5% (n=1).

Conclusion

PX proved to be successful in lowering TG levels in HTGP. One to two plasma exchanges effectively reduced the serum TG level. There was a low rate of procedure-related complications. However, having no comparison with standard treatments, the impact of this technique on the patients’ clinical outcomes is still uncertain. Further prospective randomized clinical studies are needed to outline an efficient treatment for the management of HTGP.

References

Padmanabhan, A et al, “Guidelines on the Use of Therapeutic Apheresis in Clinical Practice”, J Clin Apher. 2019;34:171–354.
Banks PA, “Practice guidelines in acute pancreatitis.”, Am J Gastroenterol. 2006;101(10):2379)
Rawla, P. “Hypertriglyceridemia-induced pancreatitis: updated review of current treatment and preventive strategies”, Clin J Gastroenterol. 2018 Dec;11(6):441-448.
Faria, R. et al, “Therapeutic Plasmapheresis: Seven Year Experience of an Intensive Care Unit in Portugal”, Acta Med Port 2022 Mar;35(3):176-183
Stefanutti, C. et al, “Severe Hypertriglyceridemia-Related Acute Pancreatitis”, Therapeutic Apheresis and Dialysis 2013; 17(2):130–137

Clinical Case Summary

A 77-year-old man underwent liver transplantation in 2008 due to alcoholic cirrhosis associated with hemochromatosis, and was taking tacrolimus and mycophenolate mofetil since that.
He was admitted in the Emergency Department in February 2023 with right upper quadrant abdominal pain and diarrhea for one week. Abdominal computed tomography(CT) showed ileal thickening. Laboratory tests revealed leukocytosis(19,000 leukocytes/mm3) and elevated C-reactive protein(16 mg/dL). Acute gastroenteritis was assumed and he was discharged on metronidazole with clinical improvement. One month later, he returned to the Emergency Department with abdominal pain for two days. CT revealed concentric wall thickening of the last ileal loop and a probable enteromesenteric fistula. He was admitted for further evaluation. Colonoscopy revealed deep mucosal ulceration of the terminal ileum. After colonoscopy, his abdominal pain worsened, so he repeated the abdominal CT, which showed a new organized collection in the right flank measuring 63 mm and small gas bubbles of pneumoperitoneum in the right upper quadrant. He underwent ileocecal resection with terminal ileostomy, and the histopathological evaluation revealed a neoplasm composed of atypical lymphoid proliferation, with positive immunohistochemistry for CD45, CD20, CD79a, BCL2, and BCL6, compatible with diffuse large B-cell lymphoma. After staging and exclusion of distant disease, the patient was proposed for chemotherapy following reduction of immunosuppression.
The clinical presentation of Inflammatory Bowel Disease can be quite heterogeneous and several pathologies can mimic its clinical, endoscopic, and/or histological findings. This case illustrates the importance of considering the diagnosis of small bowel lymphoma as a differential diagnosis of Crohn's disease, especially in elderly patients with risk factors, such as chronic immunosuppression.