Endoscopic and Histological Findings Are Predicted by Fecal Calprotectin in Acute Intestinal Graft-Versus-Host-Disease

Cytomegalovirus Colitis in Immunocompetent and Immunocompromised Children: A 2-Center Study

BACKGROUND

Data about cytomegalovirus (CMV) colitis in children are scarce. We aimed to describe the characteristics of childhood CMV colitis in terms of risk factors, clinical symptoms, diagnosis, therapeutic approaches, and outcomes.

METHODS

Inflammatory bowel disease (IBD) and non-IBD patients with CMV colitis diagnosed by histology and tissue CMV PCR at 2 tertiary centers between January 2017 and November 2019 were studied. Clinical and laboratory data were retrieved from medical records. Underlying conditions, immune status, response to therapy and outcomes were described and followed up to 6 months after diagnosis.

RESULTS

A total of 16 children (8 non-IBD, 7 ulcerative colitis and 1 Crohn's disease) with CMV colitis were included. All patients had persistent diarrhea (bloody in 13 cases). There was a significant age difference between IBD and non-IBD children (P < 0.05). The final diagnosis in 1 patient was immunodeficiency with a mutation in JAK1 gene. Three children were categorized as apparently immunocompromised and 4 children as apparently immunocompetent. Ulcer was not visible in 2 children from the non-IBD group. The mean fecal calprotectin level of IBD children was significantly higher than that of non-IBD children (376.12 ± 231.21 µg/g vs. 160.96 ± 69.94 µg/g, P < 0.05). After follow-up, 1 patient died because of another reason. Ganciclovir was used in 14 of 16 children for 3 weeks and the treatment was continued with valganciclovir in selected 6 children.

CONCLUSIONS

CMV colitis is a rare but overlooked cause of prolonged diarrhea in immunocompetent and immunocompromised children. CMV colitis might present without any ulcer formation at colonoscopy in infants.

Immunopathology and biology-based treatment of steroid-refractory graft-versus-host disease

Acute graft-versus-host disease (GVHD) is 1 of the major life-threating complications after allogeneic cell transplantation. Although steroids remain first-line treatment, roughly one-half of patients will develop steroid-refractory GVHD (SR-GVHD), which portends an extremely poor prognosis. Many agents that have shown encouraging response rates in early phase 1/2 trials for prevention and treatment have been unsuccessful in demonstrating a survival advantage when applied in the setting of SR-GVHD. The discovery of novel treatments has been further complicated by the absence of clinically informative animal models that address what may reflect a distinct pathophysiology. Nonetheless, the combined knowledge of established bone marrow transplantation models and recent human trials in SR-GVHD patients are beginning to illuminate novel mechanisms for inhibiting T-cell signaling and promoting tissue tolerance that provide an increased understanding of the underlying biology of SR-GVHD. Here, we discuss recent findings of newly appreciated cellular and molecular mechanisms and provide novel translational opportunities for advancing the effectiveness of treatment in SR-GVHD.

Ileostomy for steroid-resistant acute graft-versus-host disease of the gastrointestinal tract

Steroid-resistant acute graft-versus-host disease (GVHD) of the gastrointestinal tract associates with important morbidity and mortality. While high-dose steroids are the established first-line therapy in GVHD, no second-line therapy is generally accepted. In this analysis of 65 consecutive patients with severe, steroid-resistant, intestinal GVHD (92% stage 4), additional ileostomy surgery significantly reduced overall mortality (hazard ratio 0.54; 95% confidence interval, 0.36-0.81; p = 0.003) compared to conventional GVHD therapy. Median overall survival was 16 months in the ileostomy cohort compared to 4 months in the conventional therapy cohort. In the ileostomy cohort, both infectious- and GVHD-associated mortality were reduced (40% versus 77%). Significantly declined fecal volumes (p = 0.001) after surgery provide evidence of intestinal adaptation following ileostomy. Correlative studies indicated ileostomy-induced immune-modulation with a > 50% decrease of activated T cells (p = 0.04) and an increase in regulatory T cells. The observed alterations of the patients' gut microbiota may also contribute to ileostomy's therapeutic effect. These data show that ileostomy induced significant clinical responses in patients with steroid-resistant GVHD along with a reduction of pro-inflammatory immune cells and changes of the intestinal microbiota. Ileostomy is a treatment option for steroid-resistant acute GVHD of the gastrointestinal tract that needs further validation in a prospective clinical trial.

Fecal Calprotectin as a Diagnostic and Prognostic Biomarker for Gastrointestinal Graft Versus Host Disease: A Systematic Review of Literature

The current practice for diagnosing graft versus host disease (GVHD) includes clinical or endoscopic evaluation of the patient. Clinical diagnosis is limited by an overlapping symptomatic spectrum with infectious causes, a common scenario in the post-transplant setting where an invasive procedure, such as endoscopy, is often impractical. We, therefore, evaluated the role of fecal calprotectin as a diagnostic as well as a prognostic biomarker for gastrointestinal GVHD (GI-GVHD) occurrence and severity in the post-hematopoietic transplant population. Following Prisma guidelines, we performed a systematic search of articles published after 2004 using the PubMed, Embase, Cochrane Library, and Web of Science databases. After a detailed screening, 10 studies involving a total of 494 patients were included. In the cohorts comparing median fecal calprotectin (mFC) level in GI-GVHD vs. non-GI-GVHD patients, the results indicated an increase in the mFC level in patients with GI-GVHD when compared to non-GI-GVHD patients. Similarly, an increase in the mFC level was seen in accordance with the severity of the disease. Moreover, corticosteroid-resistant patients had a higher mFC level as compared to corticosteroid-sensitive patients. Our study indicates that the mFC level can be used for diagnosing as well as predicting the treatment response to GI-GVHD. However, future randomized prospective trials involving larger populations are needed to further explore its significance.

Major microbiota dysbiosis in severe obesity: fate after bariatric surgery

OBJECTIVES

Decreased gut microbial gene richness (MGR) and compositional changes are associated with adverse metabolism in overweight or moderate obesity, but lack characterisation in severe obesity. Bariatric surgery (BS) improves metabolism and inflammation in severe obesity and is associated with gut microbiota modifications. Here, we characterised severe obesity-associated dysbiosis (ie, MGR, microbiota composition and functional characteristics) and assessed whether BS would rescue these changes.

DESIGN

Sixty-one severely obese subjects, candidates for adjustable gastric banding (AGB, n=20) or Roux-en-Y-gastric bypass (RYGB, n=41), were enrolled. Twenty-four subjects were followed at 1, 3 and 12 months post-BS. Gut microbiota and serum metabolome were analysed using shotgun metagenomics and liquid chromatography mass spectrometry (LC-MS). Confirmation groups were included.

RESULTS

Low gene richness (LGC) was present in 75% of patients and correlated with increased trunk-fat mass and comorbidities (type 2 diabetes, hypertension and severity). Seventy-eight metagenomic species were altered with LGC, among which 50% were associated with adverse body composition and metabolic phenotypes. Nine serum metabolites (including glutarate, 3-methoxyphenylacetic acid and L-histidine) and functional modules containing protein families involved in their metabolism were strongly associated with low MGR. BS increased MGR 1 year postsurgery, but most RYGB patients remained with low MGR 1 year post-BS, despite greater metabolic improvement than AGB patients.

CONCLUSIONS

We identified major gut microbiota alterations in severe obesity, which include decreased MGR and related functional pathways linked with metabolic deteriorations. The lack of full rescue post-BS calls for additional strategies to improve the gut microbiota ecosystem and microbiome-host interactions in severe obesity.

TRIAL REGISTRATION NUMBER

NCT01454232.

Acute graft-versus-host disease of the gut: considerations for the gastroenterologist

Haematopoietic stem cell transplantation (HSCT) is central to the management of many haematological disorders. A frequent complication of HSCT is acute graft-versus-host disease (GVHD), a condition in which immune cells from the donor attack healthy recipient tissues. The gastrointestinal system is among the most common sites affected by acute GVHD, and severe manifestations of acute GVHD of the gut portends a poor prognosis in patients after HSCT. Acute GVHD of the gastrointestinal tract presents both diagnostic and therapeutic challenges. Although the clinical manifestations are nonspecific and overlap with those of infection and drug toxicity, diagnosis is ultimately based on clinical criteria. As reliable serum biomarkers have not yet been validated outside of clinical trials, endoscopic and histopathological evaluation continue to be utilized in diagnosis. Once a diagnosis of gastrointestinal acute GVHD is established, therapy with systemic corticosteroids is typically initiated, and non-responders can be treated with a wide range of second-line therapies. In addition to treating the underlying disease, the management of complications including profuse diarrhoea, severe malnutrition and gastrointestinal bleeding is paramount. In this Review, we discuss strategies for the diagnosis and management of acute GVHD of the gastrointestinal tract as they pertain to the practising gastroenterologist.

Fecal but not serum calprotectin is a potential marker of GVHD after stem cell transplantation

Gastrointestinal graft-versus-host disease (GvHD) represents a life-threatening complication after stem cell transplantation. Differential diagnosis between gut GvHD and other causes of diarrhea after HSCT is still subjected to endoscopy and histological findings. The research for a reliable biomarker for gut GvHD might allow an early diagnosis of this condition and a consequent prompt treatment that could reduce unfavorable outcomes. Recently, fecal calprotectin was reported as reliable marker of gut involvement. We would evaluate if serum instead of fecal calprotectin could be considered a possible biomarker of gut GvHD. Serum calprotectin was measured in a cohort of 54 patients submitted to allogeneic stem cell transplantation using ELISA assay. For a subset of 21 patients, calprotectin serum levels were compared with fecal calprotectin detection. Contrary to fecal calprotectin, we found only a trend to high level of serum calprotectin for GvHD development and gut involvement, but statistical difference was not reached. Fecal but not serum calprotectin could be considered as possible biomarker for gut GvHD.