Relationship between clostridium difficile infection and gastrointestinal graft versus host disease in recipients of allogeneic stem cell transplantation

Reduction of product composition variability using pooled microbiome ecosystem therapy and consequence in two infectious murine models

Growing evidence demonstrates the key role of the gut microbiota in human health and disease. The recent success of microbiotherapy products to treat recurrent Clostridioides difficile infection has shed light on its potential in conditions associated with gut dysbiosis, such as acute graft-versus-host disease, intestinal bowel diseases, neurodegenerative diseases, or even cancer. However, the difficulty in defining a "good" donor as well as the intrinsic variability of donor-derived products' taxonomic composition limits the translatability and reproducibility of these studies. Thus, the pooling of donors' feces has been proposed to homogenize product composition and achieve higher taxonomic richness and diversity. In this study, we compared the metagenomic profile of pooled products to corresponding single donor-derived products. We demonstrated that pooled products are more homogeneous, diverse, and enriched in beneficial bacteria known to produce anti-inflammatory short chain fatty acids compared to single donor-derived products. We then evaluated pooled products' efficacy compared to corresponding single donor-derived products in Salmonella and C. difficile infectious mouse models. We were able to demonstrate that pooled products decreased pathogenicity by inducing a structural change in the intestinal microbiota composition. Single donor-derived product efficacy was variable, with some products failing to control disease progression. We further performed in vitro growth inhibition assays of two extremely drug-resistant bacteria, Enterococcus faecium vanA and Klebsiella pneumoniae oxa48, supporting the use of pooled microbiotherapies. Altogether, these results demonstrate that the heterogeneity of donor-derived products is corrected by pooled fecal microbiotherapies in several infectious preclinical models.IMPORTANCEGrowing evidence demonstrates the key role of the gut microbiota in human health and disease. Recent Food and Drug Administration approval of fecal microbiotherapy products to treat recurrent Clostridioides difficile infection has shed light on their potential to treat pathological conditions associated with gut dysbiosis. In this study, we combined metagenomic analysis with in vitro and in vivo studies to compare the efficacy of pooled microbiotherapy products to corresponding single donor-derived products. We demonstrate that pooled products are more homogeneous, diverse, and enriched in beneficial bacteria compared to single donor-derived products. We further reveal that pooled products decreased Salmonella and Clostridioides difficile pathogenicity in mice, while single donor-derived product efficacy was variable, with some products failing to control disease progression. Altogether, these findings support the development of pooled microbiotherapies to overcome donor-dependent treatment efficacy.

Effective treatment of Clostridioides difficile infection improves survival and affects graft-versus-host disease: a multicenter study by the Polish Adult Leukemia Group

Clostridioides difficile infection (CDI) is the most common cause of infectious diarrhea after allogeneic hematopoietic cell transplantation (allo-HCT). The impact of CDI and its treatment on allo-HCT outcomes and graft-versus-host disease (GVHD), including gastrointestinal GVHD (GI-GVHD) is not well established. This multicenter study assessed real-life data on the first-line treatment of CDI and its impact on allo-HCT outcomes. Retrospective and prospective data of patients with CDI after allo-HCT were assessed. We noted statistically significant increase in the incidence of acute GVHD and acute GI-GVHD after CDI (P = 0.005 and P = 0.016, respectively). The first-line treatment for CDI included metronidazole in 34 patients, vancomycin in 64, and combination therapy in 10. Treatment failure was more common with metronidazole than vancomycin (38.2% vs. 6.2%; P < 0.001). The need to administer second-line treatment was associated with the occurrence or exacerbation of GVHD (P < 0.05) and GI-GVHD (P < 0.001) and reduced overall survival (P < 0.05). In the multivariate analysis, the risk of death was associated with acute GVHD presence before CDI (hazard ratio [HR], 3.19; P = 0.009) and the need to switch to second-line treatment (HR, 4.83; P < 0.001). The efficacy of the initial CDI treatment affects survival and occurrence of immune-mediated GI-GVHD after allo-HCT. Therefore, agents with higher efficacy than metronidazole (vancomycin or fidaxomicin) should be administered as the first-line treatment.

Non-viral pathogens of infectious diarrhoea post-allogeneic stem cell transplantation are associated with graft-versus-host disease

Infectious diarrhoea is common post-allogeneic haematopoietic stem-cell transplantation (alloHSCT). While the epidemiology of Clostridioides difficile infection (CDI) post-alloHSCT has been described, the impact of other diarrhoeal pathogens is uncertain. We reviewed all alloHSCT between 2017 and 2022 at a single large transplant centre; 374 patients were identified and included. The 1-year incidence of infectious diarrhoea was 23%, divided into viral (13/374, 3%), CDI (65/374, 17%) and other bacterial infections (16/374, 4%). There was a significant association between infectious diarrhoea within 1 year post-transplant and the occurrence of severe acute lower gastrointestinal graft-versus-host disease (GVHD, OR = 4.64, 95% CI 2.57-8.38, p < 0.001) and inferior GVHD-free, relapse-free survival on analysis adjusted for age, donor type, stem cell source and T-cell depletion (aHR = 1.64, 95% CI = 1.18-2.27, p = 0.003). When the classes of infectious diarrhoea were compared to no infection, bacterial (OR = 6.38, 95% CI 1.90-21.40, p = 0.003), CDI (OR = 3.80, 95% CI 1.91-7.53, p < 0.001) and multiple infections (OR = 11.16, 95% CI 2.84-43.92, p < 0.001) were all independently associated with a higher risk of severe GI GVHD. Conversely, viral infections were not (OR = 2.98, 95% CI 0.57-15.43, p = 0.20). Non-viral infectious diarrhoea is significantly associated with the development of GVHD. Research to examine whether the prevention of infectious diarrhoea via infection control measures or modulation of the microbiome reduces the incidence of GVHD is needed.

An Algorithm Addressing the Problem of Overdiagnoses of Clostridioides difficile Infections in Hematopoietic Stem-Cell Transplant Recipients: Effects on CDI Rates and Patient Outcomes

BACKGROUND

Diarrhea of other causes and Clostridioides difficile colonization are common in patients hospitalized for hematopoietic stem-cell transplants (HSCT). It has been well recognized that these issues tend to decrease the specificity of stool testing for C. difficile infection (CDI). The best way to address this problem is uncertain.

OBJECTIVE

In September 2018, we initiated a project with the goal of addressing the apparent problem of overdiagnosis of CDIs in our HSCT population. Using the quality improvement tool Model for Improvement we introduced a C. difficile stool testing and CDI diagnosis algorithm with the aim of decreasing unnecessary inpatient CDI diagnoses and treatments. In this study we examine the effects of the algorithm.

STUDY DESIGN

We reviewed all HSCT admissions for the 2 years before the algorithm introduction and the 3 years following recording all stool submissions for C. difficile determination and CDI. At the close of the study, we recruited our advanced practice providers (APPs) to review all CDI following algorithm initiation and provide feedback on the ease of use of the algorithm and potential improvements to the overall process.

RESULTS

Stool submissions for C. difficile determination decreased from 38.0 to 20.6/1000 inpatient days (p=<0.001) and CDI from 5.5 to 2.4/1000 days (p=0.007). Patients admitted for a first allogeneic-HSCT, a first autologous-HSCT, or an HSCT readmission showed similar proportionate reductions. No detrimental effects on length of stay, overall survival, progression free survival, rates of readmission following transplant, incidence of acute graft vs. host disease, or incidence of recurrent CDI were noted following algorithm introduction. A strategy of education, monitoring/feedback, and ease of algorithm access proved effective in inducing provider compliance. APPs rated the algorithm high on ease of use.

CONCLUSIONS

Use of an algorithm defining criteria for C. difficile testing, diagnosis, and treatment was associated with significantly decreased CDI diagnoses on a HSCT inpatient unit without apparent adverse effects.

The incidence and impact of clostridioides difficile infection on transplant outcomes in acute leukemia and MDS after allogeneic hematopoietic cell transplant-a CIBMTR study

Clostridioides difficile infection (CDI) is common after allogeneic hematopoietic cell transplantation (alloHCT). The determination of incidence, risk factors, and impact of CDI on alloHCT outcomes is an unmet need. The study examines all patients aged 2 years and older who received first alloHCT for acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), or myelodysplastic syndrome (MDS) between 2013 and 2018 at US centers and reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) data registry. In total, 826 patients with CDI and 6723 controls from 127 centers were analyzed. The cumulative incidence of CDI by day 100 was 18.7% (99% CI: 15-22.7%) and 10.2% (99% CI: 9.2-11.1%) in pediatric and adult patients, respectively, with a median time to diagnosis at day +13. CDI was associated with inferior overall survival (OS) (p = 0.0018) and a 2.58-fold [99% CI: 1.43-4.66; p < 0.001] increase in infection-related mortality (IRM). There was a significant overlap in the onset of acute graft versus host disease (aGVHD) and CDI. IRM increased to >4 fold when CDI + aGVHD was considered. Despite advances in the management of CDI, increased IRM and decreased OS still results from CDI.

American Society for Transplantation and Cellular Therapy Series: #5-Management of Clostridioides difficile Infection in Hematopoietic Cell Transplant Recipients

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious disease guidelines for hematopoietic cell transplantation (HCT). A completely new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and then answered FAQs and finalized topics with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. This fifth guideline in the series focuses on Clostridioides difficile infection with FAQs that address the prevalence, incidence, clinical features, colonization versus infection, clinical complications, diagnostic considerations, pharmacological therapies for episodic or recurrent infection, and the roles of prophylactic antibiotics, probiotics, and fecal microbiota transplantation.

Prevalence of Clostridium difficile Infection in the Hematopoietic Transplantation Setting: Update of Systematic Review and Meta-Analysis

Hematopoietic stem cell transplant (HSCT) recipients are vulnerable to Clostridium difficile infection (CDI) due to risk factors such as immunosuppression, antimicrobial use, and frequent hospitalization. We systematically searched PubMed and Embase to screen relevant studies from April 2014 to November 2021. A meta-analysis was performed to identify the association between CDI and hematopoietic transplantation based on the standard mean difference and 95% confidence intervals (CIs). Among the 431 retrieved citations, we obtained 43 eligible articles, which included 15,911 HSCT patients at risk. The overall estimated prevalence of CDI was 13.2%. The prevalence of CDI among the 10,685 allogeneic transplantation patients (15.3%) was significantly higher than that among the 3,840 autologous HSCT recipients (9.2%). Different incidence rates of CDI diagnosis over the last 7 years were found worldwide, of which North America (14.1%) was significantly higher than Europe (10.7%) but not significantly different from the prevalence among Asia (11.6%). Notably, we found that the estimated prevalence of CDI diagnosed by polymerase chain reaction (PCR) (17.7%) was significantly higher than that diagnosed by enzyme immunoassay (11.5%), indicating a significant discrepancy in the incidence rate of CDI owing to differences in the sensibility and specificity of the detection methods. Recurrence of CDI was found in approximately 15% of the initial patients with CDI. Furthermore, 20.3% of CDI cases were severe. CDI was found to be a common complication among HSCT recipients, displaying an evident increase in the morbidity of infection.

Clostridioides difficile infection in solid organ and hematopoietic stem cell transplant recipients: A prospective multinational study

BACKGROUND

Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality in recipients of solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). In retrospective single center analyses, severe disease and relapse are common. We undertook an international, prospective cohort study to estimate the response to physician determined antibiotic treatment for CDI in patients with SOT and HSCT.

METHODS

Adults with a first episode of CDI within the first 2 years of SOT or HSCT were enrolled. Demographics, comorbidities, and medication history were collected, and over 90 days of follow-up clinical cure, recurrences, and complications were assessed. Logistic regression was used to study associations of baseline predictors of clinical cure and recurrence. Odds ratios (ORs) and 95% confidence intervals (CIs) are cited.

RESULTS

A total of 132 patients, 81 SOT and 51 HSCT (32 allogeneic), were enrolled with a median age of 56 years; 82 (62%) were males and 128 (97%) were hospitalized at enrollment. One hundred and six (80.3%) were diagnosed by DNA assay. CDI occurred at a median of 20 days post-transplant (interquartile range, IQR: 6-133). One hundred and eight patients (81.8%) were on proton pump inhibitors; 126 patients (95.5%) received antibiotics within the 6 weeks before CDI. The most common initial CDI treatments prescribed, on or shortly before enrollment, were oral vancomycin alone (50%) and metronidazole alone (36%). Eighty-three percent (95% CI: 76, 89) of patients had clinical cure; 18% (95% CI: 12, 27) of patients had recurrent CDI; global clinical cure occurred in 65.2%. Of the 11 patients who died, two (1.5% of total) were related to CDI. In multivariable logistic regression analyses, the type of initial treatment was associated with clinical cure (p = .009) and recurrence (p = .014). A history of cytomegalovirus (CMV) after transplant was associated with increased risk of recurrence (44% with versus 13% without CMV history; OR: 5.7, 95% CI: 1.5, 21.3; p = .01).

CONCLUSIONS

Among adults who develop CDI after SOT or HSCT, despite their immunosuppressed state, the percentage with clinical cure was high and the percentage with recurrence was low. Clinical cure and recurrence varied by type of initial treatment, and CMV viremia/disease was associated with an increased risk of recurrence.

An investigation of the potential association between gastrointestinal viral and bacterial infection and development of intestinal acute graft versus host disease following allogeneic hematopoietic stem cell transplantation

It is uncertain whether gastrointestinal (GI) infection caused by viral and bacterial pathogens may predispose to gastrointestinal acute Graft-versus-host disease (aGvHD-GI) in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). We investigated the potential association between detection of enteropathogenic viruses or bacteria in stools and subsequent occurrence of aGvHD-GI in a cohort of 121 allo-HSCT patients. Eighty-six out of 121 patients (71%) had acute diarrhea and underwent screening for primary GI pathogens by molecular diagnostic methods. One or more GI pathogens were detected in 27 out of the 86 patients with diarrhea (31.3%). Specifically, Clostridioides difficile was found in 16 patients (18.6%), enteropathogenic viruses in 11 patients (12.7%) (Astrovirus, n = 4; Norovirus, n = 2; Sapovirus, n = 2; Adenovirus, n = 2; and Rotavirus, n = 1), and Campylobacter spp. in two patients (2.3%). Thirty patients were diagnosed with all grade aGvHD-GI by histopathology. Detection of primary GI pathogens was achieved in 12 out of 30 patients (Clostridium difficile, n = 5; enteric viruses, n = 8; Campylobacter spp., n = 1) who either subsequently developed (n = 9) or previously had (n = 3) grade I-IV IaGvHD (n = 9). Neither the detection of these microorganisms (all combined), enteric viruses, nor C. difficile was significantly associated with subsequent aGvHD-GI development in Cox models (hazard ratio [HR] = 1.11, p = .80; HR = 1.64, p = .62; HR = 0.75, p = .64, respectively). Analogous results were obtained when grade II-IV aGvHD-GI was selected as the clinical outcome. In summary, data in the current study did not support an association between GI infection and subsequent occurrence of aGvHD-GI in an unselected cohort of allo-HSCT recipients.

Clostridioides difficile Infection and Risk of Acute Graft-versus-Host Disease among Allogeneic Hematopoietic Stem Cell Transplantation Recipients

Clostridioides difficile infection (CDI) is a major cause of infectious diarrhea among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. The relationship between CDI and acute graft-versus-host disease (aGVHD) has been a topic of interest, as these 2 conditions may influence each other. We studied the temporal relationship of CDI to aGVHD in the first 100 days post-transplantation in a large cohort of allo-HSCT recipients. We performed a retrospective cohort study of adult patients undergoing their first allo-HSCT at our tertiary care medical center between January 1, 2010, and December 31, 2016. Patients were followed for CDI diagnosis, development of aGVHD, and vital status up to day +100 post-transplantation. Descriptive statistics and multivariate Cox models with CDI as a time-varying covariate and aGVHD and high-grade aGVHD as outcomes were used for data analyses. A total of 656 allo-HSCT recipients were included in the analysis. Of these, 419 (64%) developed aGVHD, and 111 (17%) were diagnosed with CDI within the first 100 days post-transplantation. CDI developed before the onset of aGVHD in 72 of the 84 allo-HSCT recipients (85%) with both CDI and aGVHD. Fidaxomicin was used in the treatment of 57 of the 111 CDI cases (50%), whereas vancomycin was used in 52 (47%). Most of the CDI cases (88%) were diagnosed in the peritransplantation period (between day -10 and day +10). The median time to the development of CDI and aGVHD was 3.5 days (range, -7 to 95 days) and 33 days (range, 9 to 98 days) post-transplantation, respectively. Using multivariate Cox model, the following predictors were significantly associated with the development of aGVHD: CDI (adjusted hazard ratio [aHR], 1.52; 95% confidence interval [CI], 1.17 to 1.97; P = .0018), transplantation from a matched related donor (MRD) compared with a matched unrelated donor (aHR, 0.68; 95% CI, 0.54 to 0.85; P = .0003), and myeloablative versus nonmyeloablative conditioning (aHR, 2.45; 95% CI, 1.80 to 3.34; P < .0001), adjusting for age, sex, race, underlying disease, cytomegalovirus CMV serostatus, transplant source, and receipt of antithymocyte globulin (ATG). There was no association between CDI and high-grade aGVHD after adjustment for age, underlying disease, transplant type, intensity of conditioning, and receipt of ATG (aHR, 1.59; 95% CI, 0.95 to 2.66; P = .0755). CDI after allo-HSCT is associated with increased risk of GVHD when no CDI prophylaxis was used. Further studies examining CDI preventive measures, including prophylaxis, as well as the preservation or reconstitution of the gastrointestinal microbiome in the setting of HSCT are warranted.

Impact of a Clostridioides Difficile Testing Computerized Clinical Decision Support Tool on an Adult Stem Cell Transplantation and Hematologic Malignancies Unit

Clostridioides difficile infection rates are higher in hospitalized hematopoietic stem cell transplantation (HSCT) recipients and patients with hematologic malignancy (HM) compared with the general population. This is related both to extensive exposure to antibiotics as well as to frequent and often prolonged hospitalization. In this population, with numerous potential causes of diarrhea, a subset of C difficile detected is presumed to represent colonization rather than clinical infection. The use of decision support tools to guide ordering in hospitalized patients has been reported to decrease both C difficile testing and detection rates. Following implementation of a computerized decision support tool on our HSCT/HM unit, we observed a >2-fold decrease in C difficile testing volume and National Healthcare Safety Network-defined laboratory identifications of C difficile. Furthermore, the rate of oral vancomycin use, as well as the incidence of vancomycin-resistant enterococci colonization and bloodstream infection, decreased in the postintervention period.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.