Clinicopathological comparison between acute gastrointestinal-graft-versus-host disease and infectious colitis in patients after hematopoietic stem cell transplantation

Endoscopic findings in the evaluation of gastrointestinal symptoms in pediatric patients post hematopoietic stem cell transplantation

OBJECTIVES

Endoscopy plays a pivotal role in diagnosing gastrointestinal (GI) symptoms of pediatric patients post hematopoietic stem cell transplantation (HSCT). There is very little data on whether endoscopic findings can predict pathological diagnosis and treatment outcomes in the pediatric population. The primary objective was to determine the association between macroscopic and microscopic findings of endoscopies in pediatric patients post-HSCT. A secondary objective was to evaluate whether macroscopic findings can predict treatment outcomes or differentiate between causes of GI symptoms.

METHODS

This single-center prospective study analyzed the results of endoscopic evaluation in patients aged 18 years or younger, who developed GI symptoms during and after HSCT and required an endoscopy for diagnosis. Macroscopic and microscopic findings of upper and lower endoscopies were reviewed and compared, thus evaluating the correlation between the two. Predetermined sites throughout the GI tract were examined for their macroscopic and microscopic findings, to examine whether their results suggest graft-versus-host disease (GVHD), infection, or both. Patients' change in treatment and clinical response were also assessed.

RESULTS

In 22 patients, 249 tissue samples were macroscopically and microscopically evaluated. When abnormal macroscopic findings were present, microscopic findings were present in 86.2% of the cases. In 72.1% of the endoscopic sites with normal macroscopic results, abnormal microscopic findings were present (p value = 0.004, Fisher-Freeman-Halton exact test).

CONCLUSION

This study provides further evidence supporting the correlation between macroscopic and microscopic evaluation in the diagnosis of GVHD post-HSCT, however, normal macroscopic findings do not rule out the presence of GVHD.

Multiplexed Gastrointestinal PCR Panels for the Evaluation of Diarrhea in Hematopoietic Stem Cell Transplantation Recipients

Multiplexed gastrointestinal PCR panels (MGPPs) are frequently used to aid the diagnosis and management of diarrhea in hematopoietic stem cell transplantation (HCT) recipients. Many issues related to the optimal use of MGPPs in HCT patients remain to be clarified. We aimed to better define MGPP diagnostic and therapeutic stewardship in HCT recipients, including indications for and benefits of testing, optimal timing of tests, and interpretation of results. We retrieved 463 consecutive MGPPs ordered on 651 consecutive first HCT (312 allogeneic, 339 autologous) performed at our institution between June 2015 and June 2023. One hundred and sixteen of the 463 MGPPs (25%) identified at least 1 diarrheagenic pathogen, and 12 (3%) identified more than 1 diarrheagenic pathogen. A positive result was more likely if the test was ordered within 48 hours of a hospital admission (41%; 32 of 78) or as an outpatient (41%; 46 of 111) compared with evaluation of hospital-onset diarrhea (14%; 38 of 274). Among the positive results, the most frequent pathogens identified included Clostridioides difficile (64%), diarrheagenic Escherichia coli (20%), norovirus (9%), and adenovirus 40/41 (5%). Thirty-eight percent of the positive C. difficile MGPP determinations were associated with a positive test for toxin. In our allogeneic HCT cohort, 3% of MGPPs for hospital-onset diarrhea yielded an organism other than C. difficile. Fifty-six percent of positive and 14% of all submitted tests resulted in a change in treatment. For organisms other than C. difficile, only 1% of all tests and 5% of positive tests resulted in initiation of therapy. For patients at risk for acute graft-versus-host disease (aGVHD), a positive or negative MGPP result was not predictive of a new diagnosis of aGVHD in proximity to diarrhea onset. These results suggest that MGPP testing is most useful when performed at hospital admission or on an outpatient basis. Because MGPPs are sensitive and do not distinguish between colonization and causes of diarrhea, caution is needed when interpreting results, especially for toxin-negative C. difficile and diarrheagenic gram-negative organisms.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

A Winning New Combination? Toward Clinical Application in Oncology

Immunotherapy has substantial attention in oncology due to the success of CTLA-4 and PD-1 inhibitors in the treatment of melanoma, lung cancer, head and neck cancer, renal cell carcinoma, and Hodgkin's lymphoma. A deeper understanding of interaction of tumor with its environment and the immune system provides best guide for oncology research. Recent studies in oncology have explained how a tumor alters antigen presentation, avoids detection, and activation of the host immune system to live and develop. Understanding the connections between the tumor and the immune system has resulted in several innovative therapy options. The extensive field of gene therapy has provided a number of cutting-edge medicines that are expected to play an important role in lowering cancer-related mortality. This article explains the history, important breakthroughs, and future prospects for three separate gene therapy treatment modalities: immunotherapy, oncolytic virotherapy, and gene transfer. Immunotherapies have completely changed how cancer is treated, especially for individuals whose condition was previously thought to be incurable. Examples include ACT (adoptive cell therapy) and ICB (immune checkpoint blockade). This review article will discuss the relationship between the immune response to cancer and the mechanisms of immunotherapy resistance. It will cover combination drugs authorized by the US Food and Drug Administration and provide a thorough overview of how these drugs are doing clinically right now. Cytokines, vaccines, and other soluble immunoregulatory agents, innate immune modifiers, ACT, virotherapy, and other treatment modalities will all be covered in detail.

Evaluation of gastrointestinal symptoms in pediatric patients post hematopoietic stem cell transplantation: Ileo-colonoscopy versus sigmoidoscopy. A single-center experience and review of literature

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a curative therapy used to treat high-risk hematological malignant disorders and other life-threatening nonmalignant diseases. Gastrointestinal (GI) symptoms post-HSCT might be due to GI graft-versus-host disease (GVHD) or GI infections or both. GI endoscopy with biopsies is safe and beneficial in guiding the management of GI symptoms in children after HSCT, justifying the therapeutic management and contributing to improved outcomes.

METHODS

A retrospective cohort study including 16 children with malignant and nonmalignant diseases that underwent allogeneic HSCT who had 24 ileo-colonoscopies performed for GI symptoms. To facilitate an evidence-based approach to the endoscopic evaluation of GI symptoms in pediatric patients post HSCT, we examined whether a full ileo-colonoscopy, which includes right colon and terminal ileum (TI), as opposed to a limited sigmoidoscopy, was more accurate in the evaluation of GI symptoms in pediatric patients post HSCT.

RESULTS

Specific findings on the right colon/TI were found in nine out of 24 ileo-colonoscopies (38%, CI = 19%-59%). The macroscopic findings on ileo-colonoscopy were compared with the histopathologic findings. When macroscopic findings were present, there were matching histopathologic findings in 100% of cases. However, even in the absence of any macroscopic findings on ileo-colonoscopy, there were histopathological findings in 29% of the cases (p-value = .016).

CONCLUSIONS

This cohort favors ileo-colonoscopy over sigmoidoscopy, with systematic biopsy sampling, in evaluating GI symptoms in pediatric patients post HSCT.

[Management of patients developing acute gastro-intestinal graft-versus-host-disease: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Graft-versus-host disease (GVHD) is the most common complication after allogeneic hematopoietic cell transplantation (allo-HCT) with a frequency range of 30% to 50%. GVH is the leading cause of non-relapse-related deaths and a cause early mortality. Gastro-intestinal (GI) GVH results in digestive manifestations that involve the small intestine and the colon. The patient may then have diarrhea, intestinal bleeding, abdominal pain but also clinical signs such as nausea and vomiting may lead to anorexia. GI-GVHD promotes undernutrition as well as significant losses of vitamins and trace elements. In the case of post-transplant diarrhea, differential diagnosis can include GI-GVHD, infection and drug toxicity. Although, corticosteroids w/wo calcineurin inhibitors represent the standard of care in first line treatment, there is no consensus regarding salvage therapy in case of corticoresistant GI-GVH. In addition, assessment of early nutritional status would help combating undernutrition, which is an independent risk factor for mortality in patients with GI-GVHD. In this workshop of the Fancophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) we focused on the management of patients developing GI-GVHD following allo-HCT.