Peri-transplant clostridium difficile infections in patients undergoing allogeneic hematopoietic progenitor cell transplant

A Systematic Literature Review on Risk Factors for and Timing of Clostridioides difficile Infection in the United States

INTRODUCTION

Clostridioides difficile infection (CDI) is a major public health threat. Up to 40% of patients with CDI experience recurrent CDI (rCDI), which is associated with increased morbidity. This study aimed to define an at-risk population by obtaining a detailed understanding of the different factors leading to CDI, rCDI, and CDI-related morbidity and of time to CDI.

METHODS

We conducted a systematic literature review (SLR) of MEDLINE (using PubMed) and EMBASE for relevant articles published between January 1, 2016, and November 11, 2022, covering the US population.

RESULTS

Of the 1324 articles identified, 151 met prespecified inclusion criteria. Advanced patient age was a likely risk factor for primary CDI within a general population, with significant risk estimates identified in nine of 10 studies. Older age was less important in specific populations with comorbidities usually diagnosed at earlier age, such as bowel disease and cancer. In terms of comorbidities, the established factors of infection, kidney disease, liver disease, cardiovascular disease, and bowel disease along with several new factors (including anemia, fluid and electrolyte disorders, and coagulation disorders) were likely risk factors for primary CDI. Data on diabetes, cancer, and obesity were mixed. Other primary CDI risk factors were antibiotics, proton pump inhibitors, female sex, prior hospitalization, and the length of stay in hospital. Similar factors were identified for rCDI, but evidence was limited. Older age was a likely risk factor for mortality. Timing of primary CDI varied depending on the population: 2-3 weeks in patients receiving stem cell transplants, within 3 weeks for patients undergoing surgery, and generally more than 3 weeks following solid organ transplant.

CONCLUSION

This SLR uses recent evidence to define the most important factors associated with CDI, confirming those that are well established and highlighting new ones that could help to identify patient populations at high risk.

Clostridioides difficile infection in the allogeneic hematopoietic cell transplant recipient

Clostridioides difficile (CD) is one of the most important causes of diarrhea in hospitalized patients, in particular those who undergo an allogeneic hematopoietic cell transplant (allo-HCT) and who are more at risk of developing a CD infection (CDI) due to frequent hospitalizations, iatrogenic immunosuppression, and prolonged antibiotic cycles. CDI may represent a severe condition in allo-HCT patients, increasing the length of hospitalization, influencing the intestinal microbiome with a bidirectional association with graft-versus-host disease, and leading to unfavorable outcomes, including death. The diagnosis of CDI requires the exclusion of other probable causes of diarrhea in HCT patients and is based on highly sensitive and highly specific tests to distinguish colonization from infection. In adult patients, fidaxomicin is recommended as first-line, with oral vancomycin as an alternative agent. Bezlotoxumab may be used to reduce the risk of recurrence. In pediatric patients, vancomycin and metronidazole are still suggested as first-line therapy, but fidaxomicin will probably become standard in pediatrics in the near future. Because of insufficient safety data, fecal microbiota transplantation is not routinely recommended in HCT in spite of promising results for the management of recurrences in other populations.

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.

Fecal Microbiota Transplant for Hematologic and Oncologic Diseases: Principle and Practice

Understanding of the importance of the normal intestinal microbial community in regulating microbial homeostasis, host metabolism, adaptive immune responses, and gut barrier functions has opened up the possibility of manipulating the microbial composition to modulate the activity of various intestinal and systemic diseases using fecal microbiota transplant (FMT). It is therefore not surprising that use of FMT, especially for treating relapsed/refractory Clostridioides difficile infections (CDI), has increased over the last decade. Due to the complexity associated with and treatment for these diseases, patients with hematologic and oncologic diseases are particularly susceptible to complications related to altered intestinal microbial composition. Therefore, they are an ideal population for exploring FMT as a therapeutic approach. However, there are inherent factors presenting as obstacles for the use of FMT in these patients. In this review paper, we discussed the principles and biologic effects of FMT, examined the factors rendering patients with hematologic and oncologic conditions to increased risks for relapsed/refractory CDI, explored ongoing FMT studies, and proposed novel uses for FMT in these groups of patients. Finally, we also addressed the challenges of applying FMT to these groups of patients and proposed ways to overcome these challenges.

Antimicrobial therapy during cancer treatment: Beyond antibacterial effects

Cancer treatment options have evolved to include immunotherapy and targeted therapy, in addition to traditional chemoradiation. Chemoradiation places the patient at a higher risk of infection through a myelosuppressive effect. High clinical suspicion and early use of antimicrobials play a major role in decreasing any associated morbidity and mortality. This has led to a widespread use of antimicrobials in cancer patients. Antimicrobial use, however, does not come without its perils. Dysbiosis caused by antimicrobial use affects responses to chemotherapeutic agents and is prognostic in the development and severity of certain cancer treatment-related complications such as graft-versus-host disease and Clostridioides difficile infections. Studies have also demonstrated that an intact gut microbiota is essential in the anticancer immune response. Antimicrobial use can therefore modulate responses and outcomes with immunotherapy targeting immune checkpoints. In this review, we highlight the perils associated with antimicrobial use during cancer therapy and the importance of a more judicious approach. We discuss the nature of the pathologic changes in the gut microbiota resulting from antimicrobial use. We explore the effect these changes have on responses and outcomes to different cancer treatment modalities including chemotherapy and immunotherapy, as well as potential adverse clinical consequences in the setting of stem cell transplant.

A contemporary review of Clostridioides difficile infections in patients with haematologic diseases

Clostridioides (Clostridium) difficile (C. difficile) infection is one of the most common causes of increased morbidity and mortality. Approximately 500 000 C. difficile infections (CDIs) occur each year in the United States, and they result in more than 29 000 deaths. Patients with haematologic diseases are at a higher risk for this infection due to frequent hospitalization and exposure to treatment-associated risk factors. Whilst several currently available antimicrobial agents offer resolution, recurrence of infection remains a major concern. Recent advancement in deciphering C. difficile virulence mechanisms and identification of its allies in contributing to the infection has led to the development of alternative treatment strategies. Here, we will provide a contemporary discussion of how major risk factors in haematologic diseases, such as immunosuppression, chemoradiation, use of antibiotic, proton pump inhibitor and opioid, and deficiency in butyrate and antimicrobial peptides contribute to C. difficile infection. Next, we will highlight different approaches to control and mitigate this infection such as antibiotic stewardship and faecal microbiota transplantation. Finally, we will explore several emerging treatments such as use of pre- and probiotics, immunotherapy and microbiome-sparing agents.

Oral Vancomycin Prophylaxis Is Highly Effective in Preventing Clostridium difficile Infection in Allogeneic Hematopoietic Cell Transplant Recipients

BACKGROUND

Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients.

METHODS

We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse.

RESULTS

There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2-4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88-2.89; P = .12), acute, grades 3-4 GVHD (sHR 0.65; 95% CI 0.25-1.66; P = .36), or acute, grades 2-4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93-4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed.

CONCLUSIONS

Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

Incidence Rates and Risk Factors of Clostridioides difficile Infection in Solid Organ and Hematopoietic Stem Cell Transplant Recipients

Background

Transplant recipients are an immunologically vulnerable patient group and are at elevated risk of Clostridioides difficile infection (CDI) compared with other hospitalized populations. However, risk factors for CDI post-transplant are not fully understood.

Methods

Adults undergoing solid organ (SOT) and hematopoietic stem cell transplant (HSCT) from January 2010 to February 2017 at Rigshospitalet, University of Copenhagen, Denmark, were retrospectively included. Using nationwide data capture of all CDI cases, the incidence and risk factors of CDI were assessed.

Results

A total of 1687 patients underwent SOT or HSCT (1114 and 573, respectively), with a median follow-up time (interquartile range) of 1.95 (0.52–4.11) years. CDI was diagnosed in 15% (164) and 20% (114) of the SOT and HSCT recipients, respectively. CDI rates were highest in the 30 days post-transplant for both SOT and HSCT (adjusted incidence rate ratio [aIRR], 6.64; 95% confidence interval [CI], 4.37–10.10; and aIRR, 2.85; 95% CI, 1.83–4.43, respectively, compared with 31–180 days). For SOT recipients, pretransplant CDI and liver and lung transplant were associated with a higher risk of CDI in the first 30 days post-transplant, whereas age and liver transplant were risk factors in the later period. Among HSCT recipients, myeloablative conditioning and a higher Charlson Comorbidity Index were associated with a higher risk of CDI in the early period but not in the late period.

Conclusions

Using nationwide data, we show a high incidence of CDI among transplant recipients. Importantly, we also find that risk factors can vary relative to time post-transplant.

Design and analysis of longitudinal trials of antimicrobial use at the end of life: to give or not to give?

This perspective review considers analytic features of the design of a longitudinal trial regarding antimicrobial therapy in older terminal cancer patients receiving palliative care. We first overview antimicrobial use at the end of life; both the potential hazards and benefits. Antimicrobial prescribing should consider both initiation as well as cessation of medications when analyzing the burden of medications. Approaches to decision making regarding antimicrobial use are presented and the importance of health literacy in these decision processes. We next present aspects of both feasibility and comparative trial design with a health literacy intervention to reduce antimicrobial use in older terminal cancer patients receiving palliative care. Considerations to clustered randomization and given that infections can reoccur over a trial period, we share suggestions of longitudinal modeling of clustered randomized trial data.

Changes in intestinal microbiota and their effects on allogeneic stem cell transplantation

The human intestinal microbiota is essential for microbial homeostasis, regulation of metabolism, and intestinal immune tolerance. Rapidly evolving understanding of the importance of the microbiota implicates changes in the composition and function of intestinal microbial communities in an assortment of systemic conditions. Complications following allogeneic stem cell transplant now join the ever-expanding list of pathologic states regulated by intestinal microbiota. Dysbiosis, or disruption of the normal ecology of this microbiome, has been directly implicated in the pathogenesis of entities such as Clostridium difficile infections, graft-versus-host disease (GVHD), and most recently disease relapse, all of which are major causes of morbidity and mortality in patients undergoing allogeneic stem cell transplant. In this review, we elucidate the key origins of microbiotic alterations and discuss how dysbiosis influences complications following allogeneic stem cell transplant. Our emerging understanding of the importance of a balanced and diverse intestinal microbiota is prompting investigation into the appropriate treatment of dysbiosis, reliable and early detection of such, and ultimately its prevention in patients to improve the outcome following allogeneic hematopoietic stem cell transplant.

Poorer outcomes among cancer patients diagnosed with Clostridium difficile infections in United States community hospitals

Background

Cancer predisposes patients to Clostridium difficile infection (CDI) due to health care exposures and medications that disrupt the gut microbiota or reduce immune response. Despite this association, the national rate of CDI among cancer patients is unknown. Furthermore, it is unclear how CDI affects clinical outcomes in cancer. The objective of this study was to describe CDI incidence and health outcomes nationally among cancer patients in the United States (U.S.).

Methods

Data for this study were obtained from the U.S. National Hospital Discharge Surveys from 2001 to 2010. Eligible patients included those at least 18 years old with a discharge diagnosis of cancer (ICD-9-CM codes 140–165.X, 170–176.X, 179–189.X, 190–209.XX). CDI was identified using ICD-9-CM code 008.45. Data weights were applied to sampled patients to provide national estimates. CDI incidence was calculated as CDI discharges per 1000 total cancer discharges. The in-hospital mortality rate and hospital length of stay (LOS) were compared between cancer patients with and without CDI using bivariable analyses.

Results

A total of 30,244,426 cancer discharges were included for analysis. The overall incidence of CDI was 8.6 per 1000 cancer discharges. CDI incidence increased over the study period, peaking in 2008 (17.2 per 1000 cancer discharges). Compared to patients without CDI, patients with CDI had significantly higher mortality (9.4% vs. 7.5%, p < 0.0001) and longer median LOS (9 days vs. 4 days, p < 0.0001).

Conclusions

CDI incidence is increasing nationally among cancer patients admitted to U.S. community hospitals. CDI was associated with significantly increased mortality and hospital LOS.

Intestinal dysbiosis and allogeneic hematopoietic progenitor cell transplantation

The intestinal microbiota is a diverse and dynamic ecosystem that is increasingly understood to play a vital role in human health. Hematopoietic stem cell transplant recipients undergo prolonged exposure to antimicrobials, chemotherapeutic agents, and immunosuppressants, resulting in profound shifts in the gut microbiome. A growing body of research has revealed the ways in which these microbiologic shifts shape immune modulation, affecting susceptibility to infections and graft-versus-host disease, the two major post-transplant complications in this population. As transplant medicine becomes increasingly personalized, the potential for microbiome-modulating treatments holds immense potential. Strategies to preserve the intestinal microbiota, including targeted antibiotics, prebiotics and probiotics, and fecal microbiota transplant could mitigate some of the microbiologic shifts in stem cell transplant recipients, and reduce the incidence of peri-transplant morbidity and mortality.