Increased Prevalence of Clostridioides difficile Infection Among Pediatric Oncology Patients: Risk Factors for Infection and Complications

BACKGROUND

Pediatric oncology patients, who are typically immunosuppressed, exposed to medications associated with increased Clostridioides difficile infection (CDI) risk and hospitalized, are expected to be at substantial risk for infection and complications. Although certain C. difficile ribotypes have been associated with more severe infection in adults, such an association has not been described in children.

METHODS

To characterize CDI epidemiology, including risk factors and complications among pediatric oncology patients, we retrospectively reviewed charts of patients 1-18 years old treated at a designated cancer center during 2000-2017. We used fluorescence-based polymerase chain reaction to identify ribotypes causing disease at our institution.

RESULTS

In 11,366 total patients, we identified 207 CDI cases during the study period. CDI prevalence in our pediatric oncology population was 18 cases per 1000 patients. CDI was highest among patients with acute myeloid leukemia, neuroblastoma, and desmoplastic small round cell tumor (105, 66 and 111 cases per 1000 patients, respectively; P < 0.01). Fever, leukocytosis, elevated creatinine and abdominal radiation and fluoroquinolone exposure concurrent with treatment of CDI were associated with complications. Patients with severe CDI experienced increased mortality. Ribotypes previously associated with severe infection were observed infrequently and were not associated with mortality.

CONCLUSIONS

This is the largest study of CDI in pediatric oncology patients to date. The study identifies specific oncologic diagnoses with increased CDI risk and factors predictive of poor outcomes. As CDI treatment guidelines are developed for this population, these data will be useful for risk stratification of patients in need of early, aggressive treatment.

Metagenomes of rectal swabs in larger, advanced stage cervical cancers have enhanced mucus degrading functionalities and distinct taxonomic structure

Background

Gut microbiome community composition differs between cervical cancer (CC) patients and healthy controls, and increased gut diversity is associated with improved outcomes after treatment. We proposed that functions of specific microbial species adjoining the mucus layer may directly impact the biology of CC.

Method

Metagenomes of rectal swabs in 41 CC patients were examined by whole-genome shotgun sequencing to link taxonomic structures, molecular functions, and metabolic pathway to patient’s clinical characteristics.

Results

Significant association of molecular functions encoded by the metagenomes was found with initial tumor size and stage. Profiling of the molecular function abundances and their distributions identified 2 microbial communities co-existing in each metagenome but having distinct metabolism and taxonomic structures. Community A (Clostridia and Proteobacteria predominant) was characterized by high activity of pathways involved in stress response, mucus glycan degradation and utilization of degradation byproducts. This community was prevalent in patients with larger, advanced stage tumors. Conversely, community B (Bacteroidia predominant) was characterized by fast growth, active oxidative phosphorylation, and production of vitamins. This community was prevalent in patients with smaller, early-stage tumors.

Conclusions

In this study, enrichment of mucus degrading microbial communities in rectal metagenomes of CC patients was associated with larger, more advanced stage tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09997-0.

Safety and efficacy of fecal microbiota transplantation to treat and prevent recurrent Clostridioides difficile in cancer patients

Background: Cancer patients are at increased risk of recurrent Clostridioides difficile infection (rCDI) due to malignancy itself, cancer therapy, and frequent antibiotic use and have a lower response rate to standard oral antibiotics. There are limited data on the safety and efficacy of fecal microbiota transplantation (FMT) for treating rCDI in cancer patients. We aim to describe our experience of using FMT to treat rCDI at a tertiary cancer center.

Methods: We conducted a retrospective study of cancer patients who underwent FMT for rCDI at The University of Texas MD Anderson Cancer Center from June 2017 through January 2020. Baseline clinical data and risk factors related to rCDI and FMT were evaluated and compared between cancer types and between cases with remission and recurrence.

Results: A total of 19 patients were studied: 12 with solid malignancies and 7 with hematologic malignancies. Most patients had stage IV cancer, and 21% of patients were in cancer remission. On average, patients had 2 episodes of CDI and received 3 courses of antibiotics within 1 year before FMT. 84% of patients with rCDI responded to FMT. Compared with patients who had CDI remission following FMT, non-remission cases were more likely to have received antibiotics following FMT. There were no serious adverse events or mortality within 30 days associated with FMT.

Conclusions: FMT is safe, well-tolerated, and efficacious in treating rCDI in selected cancer patients. However, additional antibiotic use for complications from chemotherapy or immunosuppression negatively affected the efficacy of FMT in this population with advanced cancer.

Human herpesvirus 6 and central nervous system disease in oncology patients: A retrospective case series and literature review

BACKGROUND

Human herpesvirus 6 (HHV-6) can reactivate with immunosuppression and cause central nervous system (CNS) dysfunction. Much of the literature describes cases after hematopoietic stem cell transplantation (HSCT), ranging from encephalitis to a post-transplant acute limbic encephalitis syndrome (PALE). Outside of HSCT, studies of HHV-6 encephalitis are limited to case reports.

OBJECTIVES

This study was designed to review HHV-6 CNS infection, and evaluate all patients admitted to MD Anderson Cancer Center between March 2016 and December 2018 with detectable HHV-6 DNA in the cerebrospinal fluid (CSF).

STUDY DESIGN

Patients with HHV-6 DNA detected in the CSF using the Viracor or Biofire® Meningitis Encephalitis Panel platforms and no other identified etiology were identified and demographic features, known risk factors, imaging findings, CSF analysis, treatments and patient outcomes were extracted from medical records.

RESULTS

725 patients underwent HHV-6 testing during the study timeframe, with 19 cases (2.6 %) of HHV-6 mediated CNS disease identified. Most patients, 13/19 (68 %), had undergone HSCT with median time to presentation of 31 days after transplant. Survival at 240 days after transplant was 62 %. CSF had lymphocyte predominance and nearly all patients had peripheral lymphopenia. Other at risk populations identified included patients who received chimeric antigen receptor (CAR) T-cell therapy and biologic immunotherapy. Notable discordance among testing platforms was found in 5/9 (55 %) instances.

CONCLUSIONS

In addition to HSCT patients, HHV-6 reactivation leading to CNS disease also occurs in settings such as following adoptive T cell therapy or biologic immunotherapy. Significant diagnostic discordance exists between testing platforms.

Telomere dysfunction activates YAP1 to drive tissue inflammation

Germline telomere maintenance defects are associated with an increased incidence of inflammatory diseases in humans, yet whether and how telomere dysfunction causes inflammation are not known. Here, we show that telomere dysfunction drives pATM/c-ABL-mediated activation of the YAP1 transcription factor, up-regulating the major pro-inflammatory factor, pro-IL-18. The colonic microbiome stimulates cytosolic receptors activating caspase-1 which cleaves pro-IL-18 into mature IL-18, leading to recruitment of interferon (IFN)-γ-secreting T cells and intestinal inflammation. Correspondingly, patients with germline telomere maintenance defects exhibit DNA damage (γH2AX) signaling together with elevated YAP1 and IL-18 expression. In mice with telomere dysfunction, telomerase reactivation in the intestinal epithelium or pharmacological inhibition of ATM, YAP1, or caspase-1 as well as antibiotic treatment, dramatically reduces IL-18 and intestinal inflammation. Thus, telomere dysfunction-induced activation of the ATM-YAP1-pro-IL-18 pathway in epithelium is a key instigator of tissue inflammation.

Safety and efficacy of fecal microbiota transplantation (FMT) in the management of recurrent clostridioides difficile infection (rCDI) in cancer patients

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Background: Cancer patients are at a significantly increased risk of rCDI by virtue of a compromised immune function from underlying malignancy, anti-cancer therapy and frequent antibiotic use for opportunistic infections. Furthermore, cancer patients have shown to have a lower response rate to standard oral antibiotics for CDI. Data is limited in regards to the safety and efficacy of FMT in managing rCDI in cancer patients. We aim to describe our experience of the same at a tertiary care cancer center. Methods: We conducted a retrospective study of cancer patients who underwent FMT for rCDI at the MD Anderson Cancer Center 06/2017-01/2020. FMT was performed through colonoscopy with universal donors’ stool. Baseline clinical data were collected and analyzed. Results: Our sample comprises 19 patients of whom 12 had solid tumors and 7 hematological malignancies, most of which were stage 4 at the time of FMT. The mean age was 66.5 years. Most patients received proton pump inhibitor, antibiotics and cancer therapy within 3-6 months of FMT. On average, each patient had 3 episodes of CDI, received 4 courses of antibiotic treatments, and required 4 CDI related hospitalizations within 1 year prior to FMT. Majority of the CDI episodes were managed with a combination of antibiotics. Bezlotoxumab was used in 4 cases. 18 patients received FMT once, while one patient was treated with FMT thrice. Clinical response was seen in 74% patients with a median time of 1 day. 5 patients had refractory CDI including 3 recurrent rCDI, and 2 persistent symptoms. Compared to patients with good response, these refractory cases received more frequent antibiotics following FMT (100% vs 43%, p=0.033). Side effects were mostly mild GI complaints in 15.8% patients with no serious adverse events or mortality related to FMT. Conclusions: Our study shows that FMT is a safe and effective treatment for rCDI in cancer patients and provides rapid resolution of symptoms; Subsequent antibiotic use for the management of cancer related complications can negatively affect the efficacy of FMT. [Table: see text]

Outcome of immune checkpoint inhibitor (ICI) related diarrhea/colitis (IMDC) in cancer patients with superimposed GI infections

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Background: ICI therapies have revolutionized the landscape of cancer treatment. However, their increased use has also contributed to adverse events, e.g. IMDC. Clinically it is difficult to distinguish between infectious etiology or IMDC. It is unclear whether antimicrobial treatment substantially impacts the disease course. Here, we evaluated the characteristics and outcome of IMDC in cancer patients with superimposed diarrheagenic GI infections. Methods: We retrospectively evaluated cancer patients who received ICI with clinical symptoms of IMDC and confirmed stool microbiology of E. coli or non-CMV viral infections either at the time of IMDC, or within 60 days after IMDC diagnosis at MD Anderson Cancer Center 01/2011-08/2019. We described the disease course and outcome of IMDC based on their status of GI infection and antimicrobial treatment. Results: Total 72 patients were included, among them, 50 control patients with IMDC and no GI infection, 22 had diarrheagenic infections, composed of 17 E coli pathogens: Enteropathogenic, Enterotoxigenic, Enteroaggregative, and E coli 0157:H7 serotype; and 5 viral etiologies: Adenovirus, Norovirus, and Sapovirus. Patients in the infection group had higher grade of colitis (42.9% vs 18.4%, P = 0.041), and more frequent hospitalization (86.4% vs 62%, P = 0.052). 68.2% patients in the infection group received infliximab/vedolizumab add-on treatment compared to 40% in the no infection group (P = 0.078). Patients with GI infection and antimicrobial treatment had much higher IMDC recurrence rate than no antimicrobial treatment (50% vs 0, P = 0.015). GI infection was not associated with higher IMDC recurrence or worse overall survival of these patients. Conclusions: IMDC can occasionally be complicated by infection from common GI pathogens. Antimicrobial treatment was mostly used in severe IMDC cases and did not circumvent the need for immunosuppressant or improve the clinical outcomes. GI infection was not associated with higher IMDC recurrence or worse overall survival of these patients. [Table: see text]

Microbial Diversity and Composition Is Associated with Patient-Reported Toxicity during Chemoradiation Therapy for Cervical Cancer

PURPOSE

Patients receiving pelvic radiation for cervical cancer experience high rates of acute gastrointestinal (GI) toxicity. The association of changes in the gut microbiome with bowel toxicity from radiation is not well characterized.

METHODS AND MATERIALS

Thirty-five patients undergoing definitive chemoradiation therapy (CRT) underwent longitudinal sampling (baseline and weeks 1, 3, and 5) of the gut microbiome and prospective assessment of patient-reported GI toxicity. DNA was isolated from stool obtained at rectal examination and analyzed with 16S rRNA sequencing. GI toxicity was assessed with the Expanded Prostate Cancer Index Composite instrument to evaluate frequency, urgency, and discomfort associated with bowel function. Shannon diversity index was used to characterize alpha (within sample) diversity. Weighted UniFrac principle coordinates analysis was used to compare beta (between sample) diversity between samples using permutational multivariate analysis of variance. Linear discriminant analysis effect size highlighted microbial features that best distinguish categorized patient samples.

RESULTS

Gut microbiome diversity continuously decreased over the course of CRT, with the largest decrease at week 5. Expanded Prostate Cancer Index Composite bowel function scores also declined over the course of treatment, reflecting increased symptom burden. At all individual time points, higher diversity of the gut microbiome was linearly correlated with better patient-reported GI function, but baseline diversity was not predictive of eventual outcome. Patients with high toxicity demonstrated different compositional changes during CRT in addition to compositional differences in Clostridia species.

CONCLUSIONS

Over time, increased radiation toxicity is associated with decreased gut microbiome diversity. Baseline diversity is not predictive of end-of-treatment bowel toxicity, but composition may identify patients at risk for developing high toxicity.

1539. Diagnosis of Yersinia enterocolitica in Cancer Patients With Diarrhea in the Era of Molecular Diagnostics for Gastrointestinal Infections

Background

Methods

Results

Conclusion

Disclosures

1100. Characterization of Enteropathogenic Escherichia coli (EPEC) in Cancer Patients With Diarrhea

Background

Methods

Results

Conclusion

Disclosures

Association of changes in vaginal microbiome with oligoclonal T-cell expansion and early response to chemoradiation for cervical cancer

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Background: The composition of the vaginal microbiome has been shown to affect clearance of HPV virus and transformation to invasive cancer. Clinical studies correlating the vaginal microbiome with immune activation and response to cancer treatment are lacking. We profiled intratumoral T-cell clonality during radiation therapy and correlated it with the diversity of the vaginal flora. Methods: Thirty patients with newly diagnosed locally advanced cervical cancer were enrolled on a prospective study to characterize changes in the cervical microbiome during chemoradiation. Cervical samples were obtained before radiation therapy and during the 1st, 3rd, and 5th week of radiation therapy. The vaginal microbiome was characterized using 16 sRNA gene sequencing to produce operational taxonomic units (OTU’s) representing individual bacterial species. Disease response was categorized as early response (ER), late response (LR), or nonresponse (NR) on the basis of clinical examination at brachytherapy and 3-month PET/CT. Twenty patients had T-cell receptor β sequencing of DNA performed using the ImmunoSEQ platform. The maximum productive frequency of the top three clones (MP3) was used to assess T-cell clonality. Results: Early response was associated with clonal T-cell expansion with an increase of MP3 of 11.1% during treatment as compared to a decline of 6.1% in patients with LR/NR (p = 0.05). Early response was also associated with lower quantity of observed OTU’s of vaginal microbiota (25.0 [SD 12.68]) vs patients with LR/NR (41.15 [SD = 23.3]) (p = 0·03). Increased MP3 was associated with increased abundance of Corynebacteriales (R = 0.90; p < .0001) , Actinomycetales (R = 0.83; p < .0001) and Bifidobacteriales (R = 0.82; p < .0001) . Decreased MP3 was associated with increased abundance of lactobacillus (R = -0.61; p < .0001). Conclusions: Increased diversity of the vaginal microbiome is negatively associated with outcome, supporting previous clinical studies in non-cancer settings. Specific vaginal bacterial species are associated with increased or decreased T-cell clonality at completion of radiation.

Line of Service-Specific Performance and Antibiotic Prescribing Habits Following Introduction of a Two-Step Diagnostic Approach Using NAAT Followed by Enzyme Immunoassay in Cancer Patients with Suspected Clostridium difficile Infection

Background

Patients with cancer are at an increased risk for C. difficile infection (CDI). A two-step approach with a Nucleic Acid Amplification Test (NAAT) followed by enzyme immunoassay (EIA) increases diagnostic sensitivity and specificity and can be used to guide antibiotic therapy. We retrospectively investigated the relative performance of the two-step approach in cancer patients with solid tumors (ST), hematologic malignancies (HS), and hematopoietic stem cell transplant recipients (HSCT).

Methods

We identified 204 patients with a positive NAAT test for CDI as determined by GI multiplex (Biofire) or by Illumigene (Meridian, Bioscience) in whom a reflex EIA was performed for C. difficile A/B toxins between November 2015 and February 2017. Patients were stratified into ST, HM, HSCT groups. We compared the proportion of discordant NAAT+, EIA- results among the three groups. We then compared the clinical presentation and antibiotic use for patients in the NAAT+/EIA- to those with NAAT+/EIA+ results.

Results

Overall an EIA+ result was found in 53 (26%) patients. The proportion of patients with NAAT+/EIA+ results was significantly different between the three lines of service; ST 31/86 (36%), HM 16/62 (26%), and HSCT 6/56 (11%) P < 0.01. A trend towards a higher proportion of positive results was observed for ST compared with the HM group (P = 0.06). Results were similar between the HM and HSCT group. However, patients in the ST were more likely to have a positive EIA when compared with HSCT patients (36% vs. 11% P < 0.01). Clinical presentation and healthcare-association were similar in all three groups regardless of the EIA result. Despite the low proportion of EIA+ confirmatory results, the majority of patients (196/204 96%) received antibiotic therapy targeting CDI. Discontinuation of CDI antibiotics prior to 10 days of therapy was similar in the EIA+ (12%) vs. EIA- (10%).

Conclusion

The relevance of discordant results needs to be interpreted in the context of the line of service/patient care unit. The presence of CDI as determined by NAAT/EIA is low in patients with other potential causes of diarrhea such as in HSCT recipients. A substantial proportion of cancer patients are treated unnecessarily for CDI.

Disclosures

All authors: No reported disclosures.

Characterization of gp120 hydrolysis by IgA antibodies from humans without HIV infection

Antibody hydrolysis of the superantigenic gp120 site and HIV-1 neutralization was studied as a potential anti-HIV mechanism in uninfected humans. gp120 hydrolysis by purified serum and salivary antibodies was determined by electrophoresis and peptide sequencing, the proteolytic mechanism was analyzed using electrophilic peptide analogs, and viral neutralization was studied using peripheral blood mononuclear cells as hosts. Polyclonal and monoclonal IgA but not IgG preparations selectively catalyzed the cleavage of HIV gp120 at rates sufficient to predict biologically relevant protection against the virus. The IgA hydrolytic reaction proceeded by noncovalent recognition of gp120 residues 421-433, a component of the superantigenic site of gp120, coordinated with peptide bond cleavage via a serine protease-like mechanism. The Lys-432-Ala-433 bond was one of the cleavage sites. Infection of peripheral blood mononuclear cells by a primary isolate of HIV was neutralized by the IgA but not IgG fractions. The neutralizing activity was specifically inhibited by an electrophilic inhibitor of the catalytic activity. The existence of catalytic IgAs to gp120 in uninfected humans suggests their role in resistance to HIV.

Association of interleukin-8 polymorphism and immunoglobulin G anti-toxin A in patients with Clostridium difficile-associated diarrhea

BACKGROUND & AIMS

Previous studies have shown that failure to produce serum antibodies to C. difficile (CD) toxin A is associated with more severe and recurrent C. difficile-associated diarrhea (CDAD); and that presence of AA genotype in the interleukin (IL)-8 gene promoter -251 position is associated with increased susceptibility to CDAD. This study examined the relationship between serum immunoglobulin G antibodies to CD toxin A and the presence of IL-8 AA genotype in hospitalized patients with CDAD.

METHODS

At enrollment, blood for host IL-8 genotype, serum for CD anti-toxin A antibody, and stool for IL-8 by enzyme-linked immunosorbent assay were obtained in CDAD patients and in CD-toxin-negative asymptomatic controls.

RESULTS

Nine of 24 (37.5%) CDAD and 3 of 20 (15%) controls were CD anti-toxin A positive (P = .095). Eleven of 24 (45.8%) CDAD subjects were positive for AA genotype compared with 5 of 20 (25.0%) controls (P = .0019). One of 11 (9.1%) CDAD with AA genotype were positive for anti-toxin A antibodies compared with 8 of 13 (61.5%) non-AA genotype CDAD (P < .0001). Fecal IL-8 concentration for the single antibody-positive CDAD subject with AA genotype was lower than the median level of 822 microg/mL seen in 10 anti-toxin A antibody-negative subjects with CDAD.

CONCLUSIONS

This study provided evidence that host susceptibility to C. difficile diarrhea is related both to a defective humoral immune response to CD toxin A and host IL-8 AA genotype.

A common polymorphism in the interleukin 8 gene promoter is associated with Clostridium difficile diarrhea

OBJECTIVE

Mucosal interleukin 8 (IL-8) and neutrophil recruitment are central to the pathogenesis of Clostridium difficile (CD) toxin-induced diarrhea (CDD). We hypothesized that like other inflammatory mucosal infections, susceptibility to CDD would relate to genetically determined variations in the production of IL-8.

METHODS

Fecal IL-8 production and single nucleotide polymorphism (SNP) frequency in the -251 region of the IL-8 gene were determined in hospitalized patients: 42 with CDD, 42 with CD-negative diarrhea, and 41 without diarrhea. Cases and controls were matched by age, length of hospital stay, comorbidity, and receipt of antibiotics.

RESULTS

An association was found between the IL-8 -251 A/A allele and occurrence of CDD, 39%versus 16% (OR = 3.26, 95% CI 1.09-9.17) and 17% (OR = 5.50, 95% CI 1.22-24.8) for the two control groups. Comparing results by IL-8 genotype for the CDD cases, median and mean fecal IL-8 levels were significantly higher for the -251 A/A genotype (p = 0.03 for median and 0.001 for mean).

CONCLUSIONS

These studies indicate a common SNP in the IL-8 gene is associated with increased susceptibility to CDD and with increased fecal IL-8 in diarrheal stools.