Role of the leukocyte response in normal and immunocompromised host after Clostridium difficile infection

Derivation and internal validation of the multivariate toxigenic C. difficile diarrhea model and risk score for emergency room and hospitalized patients with diarrhea

Background

Many factors have been associated with the risk of toxigenic C. difficile diarrhea (TCdD). This study derived and internally validated a multivariate model for estimating the risk of TCdD in patients with diarrhea using readily available clinical factors.

Methods

A random sample of 3,050 symptomatic emergency department or hospitalized patients undergoing testing for toxigenic C. difficile at a single teaching hospital between 2014 and 2018 was created. Unformed stool samples positive for both glutamate dehydrogenase antigen by enzyme immunoassay and tcdB gene by polymerase chain reaction were classified as TCdD positive. The TCdD Model was created using logistic regression and was modified to the TCdD Risk Score to facilitate its use.

Results

8.1% of patients were TCdD positive. TCdD risk increased with abdominal pain (adjusted odds ratio 1.3; 95% CI, 1.0-1.8), previous C. difficile diarrhea (2.5, 1.1-6.1), and prior antibiotic exposure, especially when sampled in the emergency department (4.2, 2.5-7.0) versus the hospital (1.7, 1.3-2.3). TCdD risk also increased when testing occurred earlier during the hospitalization encounter, when age and white cell count increased concurrently, and with decreased eosinophil count. In internal validation, the TCdD Model had moderate discrimination (optimism-corrected C-statistic 0.65, 0.62-0.68) and good calibration (optimism-corrected Integrated Calibration Index [ICI] 0.017, 0.001-0.022). Performance decreased slightly for the TCdD Risk Score (C-statistic 0.63, 0.62-0.63; ICI 0.038, 0.004-0.038).

Conclusions

TCdD risk can be predicted using readily available clinical risk factors with modest accuracy.

Prevention and treatment of C. difficile in cancer patients

PURPOSE OF REVIEW

We provide an update on the recent literature on Clostridioides difficile infection (CDI) in cancer patients.

RECENT FINDINGS

Distinguishing between colonization and infection remains challenging in cancer patients. Many patients with negative toxin analysis are still treated for CDI, and some meet criteria for severe cases. The incidence of CDI is high in cancer patients, especially those with haematological malignancies. Disruption of the gut microbiome due to antibiotic consumption, chemotherapy and radiotherapy is the primary factor contributing to CDI development. The severity of CDI in cancer patients is often unclear due to the absence of well-defined severity criteria. Certain microbiome species predominance and specific ribotypes have been associated with worse outcomes. Whole genome sequencing could be helpful for differentiating recurrence from reinfection and exploring potential nosocomial transmission. While certain new drugs such as fidaxomicin or bezlotoxumab show promise, the optimal treatment and prevention strategies for CDI in cancer patients remain uncertain. Faecal microbiota transplantation (FMT) holds potential for reducing CDI recurrence rates.

SUMMARY

Further studies are needed to provide robust recommendations for diagnosis, grading severity, and therapeutic management of CDI in cancer patients. Recurrences are particularly concerning due to subsequent exposition to CDI risk factors.

Performance of Clostridioides difficile infection severity scores and risk factors related to 30-day all-cause mortality in patients with cancer

PURPOSE

There are currently no standard definitions for assessing the severity of Clostridioides difficile infection (CDI) in cancer patients. We evaluated the performance of scoring systems for severity and analyzed risk factors for mortality in a cancer cohort.

METHODS

We conducted an observational study in patients with cancer and CDI. We calculated the incidence of hospital-onset (HO-CDI) and community-onset health-care facility associated (CO-HCFA-CDI) episodes. We classified severity using five prognostic scales and calculated sensitivity, specificity, positive (PPV), and negative predictive values (NPV) for mortality and intensive care unit (ICU) admission. In addition, multivariate regression was performed to assess variables associated with mortality.

RESULTS

The HO-CDI and CO-HCFA-CDI incidence rates were 3.7 cases/10,000 patient-days and 1.9 cases/1,000 admissions, respectively. ESCMID criteria showed the higher sensitivity (97%, 95% CI; 85-100%) and NPV (98%, 95% CI; 85-100%), while ATLAS (≥ 6 points) had the highest specificity (95%, 95% CI; 90-98%) for 30-day all-cause mortality; similar performance was observed for ICU admission. Characteristics associated with fatal outcome were neutropenia (≤ 100 cells/ml) (aOR; 3.03, 95% CI; 1.05-8.74, p = 0.040), male gender (aOR; 2.90, 95% CI; 1.08-7.80, p = 0.034), high serum creatinine (aOR; 1.71, 95% CI; 1.09-2.70, p = 0.020), and albumin (aOR; 0.17, 95% CI; 0.07-0.42, p < 0.001).

CONCLUSIONS

Some of the current scales may not be appropriate to discriminate severity in patients with cancer. The variables in this study associated with unfavorable outcomes could be evaluated in prospective studies to develop prognostic scores that identify susceptible patients, especially in immunocompromised populations.

Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases

Clostridioides difficile (C. difficile) is progressively colonizing humans and animals living with humans. During this process, hypervirulent strains and mutated toxin A and B of C. difficile (TcdA and TcdB) are originating and developing. While in healthy subjects colonization by C. difficile becomes a risk after the use of antibiotics that alter the microbiome, other categories of people are more susceptible to infection and at risk of relapse, such as those with inflammatory bowel disease (IBD). Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma (CKs). Therefore, in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C. difficile infection and its progression and relapses. TcdB is internalized in the cell via three receptors: chondroitin sulphate proteoglycan 4; poliovirus receptor-like 3; and Wnt receptor frizzled family. Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types, while poliovirus receptor-like 3 induces only necrosis. It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis. Therefore, in subjects with IBD there are the conditions: (1) For greater susceptibility to C. difficile infection, such as the inflammatory state, and abnormalities of the microbiome and of the immune system; (2) for the enhancement of the cytotoxic activity of TcdB +Cks; and (3) for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis. The only therapeutic approach currently possible in IBD patients is monitoring of C. difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins. The future perspective is to generate bacteriophages against C. difficile for targeted therapy.

Risk Factors Associated with Severe Clostridioides difficile Infection in Patients with Cancer

INTRODUCTION

Antibiotic use is a risk factor for Clostridioides difficile infection (CDI). Few studies have correlated use of prior antibiotic classes with CDI, microbiome composition, and disease severity in patients with cancer. We hypothesized that previous antibiotic exposure and fecal microbiome composition at time of presentation are risk factors for severe CDI in patients with cancer.

METHODS

This non-interventional, prospective, cohort study examined 200 patients with cancer who had their first episode or first recurrence of CDI. C. difficile was identified using nucleic acid amplification testing. Univariate analysis was used to determine significant risk factors for severe CDI. Fecal microbiome composition was determined by sequencing the V3/V4 region of 16 s rDNA encoding gene. Differential abundance analyses were used to single out significant microbial features which differed across severity levels.

RESULTS

On univariate analysis, factors associated with severe CDI included the presence of toxin A/B in stools (odds ratio [OR] 2.14 [1.05-4.36] p = 0.04 and prior 90-day metronidazole use (OR 2.66 [1.09-6.50] p = 0.03). Although alpha and beta diversity was similar between disease severity groups and toxin A/B in stools, increased abundance of Bacteroides uniformis, Ruminococcaceae, and Citrobacter koseri were associated with protection from severe CDI (p < 0.05) and depletion of anaerobes was higher in patients with prior metronidazole exposure.

CONCLUSION

Use of metronidazole for non-CDI indications within 90 days prior to diagnosis and presence of toxin A/B in stools were associated with severe CDI. Findings provide valuable insights into risk factors for severe CDI in an underserved population with cancer that warrants further exploration.

Fecal Microbiota Transplantation in Patients Co-Infected with SARS-CoV2 and Clostridioides difficile

Background: The COVID-19 pandemic has challenged the treatment of Clostridioides Difficile (CD)-infected patients given the increasing number of co-infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, fecal microbiota transplantation (FMT) shows promise in modulating the immune system’s function and alleviating the burdens associated with this condition. Methods: To achieve this goal, we performed a comparative, retrospective, single-center study on 86 patients (admitted between January 2020 and March 2022). We based our approach on specific inclusion criteria: 1. The study group included 46 co-infected patients (COVID-19 and CD) receiving antibiotics and FMT; 2. In the control group, 40 co-infected patients received antibiotics only. Our results showed no significant group differences in terms of gender, age, risk factors such as cardiovascular and neurological diseases, type 2 diabetes, and obesity (p > 0.05), or in pre-treatment inflammatory status, evaluated by white blood cell (WBC) count and C-reactive protein (CRP) levels. We report a significant decrease in inflammatory syndrome (CRP, WBC) in coinfected patients receiving FMT in addition to antibiotics (p < 0.05), with a lower relapse rate and mitigation of cramping and abdominal pain (91.3%). In addition, a higher level of fibrinogen, persistent moderate abdominal pain (82.5%), and a significantly higher CD infection relapse rate (42.5%) were recorded in co-infected patients treated only with antibiotics (p < 0.05). Conclusion: Our study provides new data to support the multiple benefits of FMT in the case of COVID-19 and CD co-infection by improving patients’ quality of life and inflammatory syndrome.

Risk factors and clinical outcomes for Clostridioides difficile infections in a case control study at a large cancer referral center in Mexico

INTRODUCTION

Clostridioides difficile infection (CDI) is recognized as the leading cause of nosocomial diarrhea. This study describes CDI's clinical characteristics, risk factors, and outcomes in the cancer population.

METHODS

We conducted a case-control study on cancer patients from 2015-2018 at the Instituto Nacional de Cancerologia in Mexico. CDI case was defined as diarrhea episode and positive polymerase chain reaction (PCR) for toxigenic strains. Controls were cancer diagnosis-matched patients with diarrhea and negative PCR. Healthcare Facility-Onset (HO-CDI) and Community-Onset, Healthcare Facility-Associated (CO-HCFA-CDI) rates were calculated. For assessing associations, univariate and multivariate logistic regression analyses were conducted.

RESULTS

We included 148 CDI cases and 148 controls. The CDI rate was 4.1 per 10,000 patient-days and 2.1 per 1,000 patient admissions for HO-CDI and CO-HCFA-CDI episodes, respectively. Clinical characteristics associated with CDI were fever, abdominal pain, and ≥4 episodes of diarrhea/24h. Previous use of proton pump inhibitors (P=.003), fluoroquinolones (P=.016), and cephalosporins (P=.026) increased the risk for CDI acquisition, while higher age (P=.022) and male gender (P=.015) were related to severe episodes. Thirty-day all-cause mortality was higher among CDI patients (18%) than controls (9%).

CONCLUSION

The CDI rate was lower compared to other series. The incidence of CO-HCFA-CDI episodes increased, and HO-CDI cases decreased from 2016 to 2018. Risk factors for acquisition and severe infection were similar to those reported in non-cancer populations.

Risk Factors for Recurrence of Clostridioides difficile in Hospitalized Patients

BACKGROUND

Diarrhea and pseudomembranous colitis associated with Clostridioides difficile - a spore-forming anaerobic Gram-positive bacillus - is a major infection in hospitalized patients with a profound impact on clinical and economic outcomes. Recurrence (rCDI) is common and predisposes to further episodes with poor outcomes.

METHOD

We aimed to identify a wide range of risk factors for recurrence to guide stewardship initiatives. After ethical approval, we commenced collecting demographic and clinical data of patients older than 18 years with clinically and microbiologically confirmed C. difficile infection. Data were statistically analyzed using R software.

RESULTS

Of 204 patients included in the analysis, 36 (18%) suffered 90-day recurrence, rCDI was higher among females (23%) compared to males (13%), overall age median (IQR) was 66 (51-77), and for rCDI cases 81 (69-86) years. Among 26 variables analyzed to evaluate their association with rCDI, prior clindamycin exposure, concurrent use of aztreonam, patients >76 years, total hospital length of stay, and LOS before diagnosis ≤7 days, WBC ≤ 9.85 × 10³ at discharge were more likely to experience rCDI.

CONCLUSION

As identified in this analysis, patients with risk factors for rCDI could be candidates for close monitoring, a high index of suspicion, and risk mitigation interventions to avoid rCDI and improve clinical outcomes.

Invisible steps for a global endemy: molecular strategies adopted by Clostridioides difficile

Clostridioides difficile infection (CDI) is on the rise worldwide and is associated with an increase in deaths and socio-health burden. C. difficile has become ubiquitous in anthropized environments because of the extreme resistance of its spores. Based on the epidemiological data and knowledge of molecular pathogenesis of C. difficile, it is possible to predict its progressive colonization of the human population for the following reasons: first, its global spread is unstoppable; second, the toxins (Tcds) produced by C. difficile, TcdA and TcdB, mainly cause cell death by apoptosis, but the surviving cells acquire a senescence state that favours persistence of C. difficile in the intestine; third, proinflammatory cytokines, tumour necrosis factor-α and interferon-γ, induced during CDI, enhance the cytotoxicity of Tcds and can increase the survival of senescent cells; fourth, Tcds block mobility and induce apoptosis in immune cells recruited at the infection site; and finally, after remission from primary infection or relapse, C. difficile causes functional abnormalities in the enteric glial cell (EGC) network that can result in irritable bowel syndrome, characterized by a latent inflammatory response that contributes to C. difficile survival and enhances the cytotoxic activity of low doses of TcdB, thus favouring further relapses. Since a 'global endemy' of C. difficile seems inevitable, it is necessary to develop an effective vaccine against Tcds for at-risk individuals, and to perform a prophylaxis/selective therapy with bacteriophages highly specific for C. difficile. We must be aware that CDI will become a global health problem in the forthcoming years, and we must be prepared to face this menace.

Serum Sphingosine-1-phosphate level and peritonitis in peritoneal dialysis patients

BACKGROUND

Given the important role of Sphingosine-1-phosphate (S1P) in maintaining the hemostasis in intestinal barrier function and regulation of inflammation and immune, we hypothesize that S1P might be a biomarker to predict peritonitis in peritoneal dialysis (PD) patients.

METHODS

In this case-control study, 78 stable, continuous ambulatory peritoneal dialysis patients were enrolled and followed for the episode of PD associated peritonitis. Patients were divided into two groups by whether or not they had peritonitis during follow-up: non-peritonitis (n = 65) and peritonitis (n = 13) group. S1P was analyzed by enzyme-linked immunosorbent assay. Logistic regression analysis was used to assess factors associated with peritonitis. The variables identified by univariable regression models (p < 0.1) were further selected into the multivariable logistic regression model to determine whether they could independently affect peritonitis.

RESULTS

Patients with peritonitis had a lower level of S1P than that of patients without peritonitis (1.3 ng/mL IQ 0.8, 3.6 ng/mL vs. 2.8 ng/mL IQ 1.5, 5.4 ng/mL, p = 0.018). The peritonitis group had lower serum albumin, lower blood leukocyte, lower hemoglobin and lower platelet count as compared to the non-peritonitis group. Logistic regression analysis showed that S1P (OR = 0.381, 95% CI = 0.171-0.848, p = 0.018), blood leukocyte count (OR = 0.438, 95% CI = 0.207-0.925, p = 0.030), and serum albumin (OR = 0.732, 95% CI = 0.556-0.962, p = 0.025) were independent factors associated with peritonitis in the present PD population.

CONCLUSION

Our study showed that S1P was an independent determinant of subsequent peritonitis in PD patients. S1P might serve as a biomarker to predict peritonitis in PD patients.

Severe Clostridium difficile infection with extremely high leucocytosis complicated by a concomitant bloodstream infection caused by Klebsiella pneumoniae after osteomyelitis surgery: A case report

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Exposure to antibiotics after surgery increase risk of Cl. difficile infection.

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Sudden high leucocytosis may be sign of poor outcome in Cl. difficile case.

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Oral Vancomycin could be responsible for the growth of bloodstream Kl. pneumonia.

Introduction

Clostridium difficile is one of the most common healthcare-associated infections. Pseudomembranous colitis is a serious complication of Clostridium difficile infection (CDI) after septic surgery and antibacterial therapy. A sudden white blood cell (WBC) count increase and extremely high leucocytosis may be a predictor of a poor outcome.

Presentation of case

A 77 years old male was hospitalised because of lower leg osteomyelitis and was operated. He received antibacterial treatment with Cefazolin for three days and then developed a high WBC count. The course of the disease was fulminant, with a rapid increase in the WBC count up to 132,000/mm³ and a septic shock, and required cardiovascular and ventilatory support. The patient was started on intravenous Metronidazole (500 mg every eight hours) and oral Vancomycin (500 mg every six hours). The patient’s condition gradually improved over a period of six days. Then a hyperthermia above 39 degrees Celsius, hypotension and painful abdominal bloating developed, and the WBC count peaked to 186,000/mm³. The blood cultures were positive for Klebsiella pneumoniae. The patient died.

Discussion

In our case, we describe a community-onset, healthcare-facility-associated, severe CDI complicated by a blood stream infection. The administration of oral Vancomycin, which is highly active against the intestinal flora, could have been responsible for the persistence and overgrowth of Klebsiella pneumoniae.

Conclusions

Severe CDIs after orthopaedic surgery and antibacterial treatment complicated by the development of nosocomial infection significantly worsen the prognosis of the disease. Careful consideration of antibacterial therapy and early symptom recognition may help prevent catastrophic events.

The Traditional Chinese Medicine Fufang Shatai Heji (STHJ) Enhances Immune Function in Cyclophosphamide-Treated Mice

Fufang Shatai Heji (STHJ) is a mixture of traditional Chinese medicines, such as Radix Adenophorae, Radix Pseudostellariae, and Radix Astragali. STHJ is commonly used to treat diseases caused by low immune function, for example, Sjögren's syndrome (SS). The primary objective of this study was to assess the immunopotentiating effect of STHJ using an immunosuppressive mouse model receiving cyclophosphamide (CTX). Following CTX treatment, STHJ was administered by oral gavage for 30 consecutive days. The percentage of specific lymphocyte subpopulations in the spleen was measured by flow cytometry. Levels of inflammatory factors in serum were detected by enzyme-linked immunosorbent assays (ELISAs). The administration of STHJ significantly elevated thymus and spleen indices, increased B cell and natural killer (NK) cell activities, and decreased CD8⁺ T, CD8⁺CD122⁺ T, NKT, and γδT cell activities in the CTX-treated mice. In addition, STHJ upregulated the expression of interleukin- (IL-) 2, IL-6, and tumor necrosis factor-α (TNF-α) and downregulated IL-10 expression in CTX-treated mice. In conclusion, STHJ effectively remitted CTX-induced immunosuppression by modulating the balance of lymphocyte subsets and cytokines. Our results suggest STHJ treatment could be used as an effective therapeutic approach to improve immune function in patients with low immunity.

Targeting Clostridium difficile Surface Components to Develop Immunotherapeutic Strategies Against Clostridium difficile Infection

New therapies are needed to prevent and treat Clostridium difficile infection and to limit the rise in antibiotic resistance. Besides toxins, several surface components have been characterized as colonization factors and have been shown as immunogenic. This review will focus on passive and active immunization strategies targeting C. difficile surface components to combat C. difficile. Concerning passive immunization, the first strategies used antisera raised against the entire bacterium to prevent infection in the hamster model. Then, surface components such as the flagellin and the S-layer proteins were used for immunization and the passive transfer of antibodies was protective in animal models. Passive immunotherapy with polyvalent immunoglobulins was used in humans and bovine immunoglobulin concentrates were evaluated in clinical trials. Concerning active immunization, vaccine assays targeting surface components were tested mainly in animal models, mouse models of colonization and hamster models of infection. Bacterial extracts, spore proteins and surface components of vegetative cells such as cell wall proteins, flagellar proteins, and polysaccharides were used as vaccine targets. Vaccine assays were performed by parenteral and mucosal routes of immunization. Both gave promising results and pave the way to development of new vaccines.

The association between hematological parameters and metabolic syndrome in Iranian men: A single center large-scale study

AIMS

Some studies have demonstrated that metabolic syndrome is associated with hematological parameters. The present study explores the relationship between hematological parameters and numbers of metabolic syndrome conditions in Iranian men.

METHODS

This cross-sectional study included 11,114 participants who were professional drivers of commercial motor vehicles, and were enrolled in the Iranian Health Surveys between 2014 and 2016. Diagnosis of metabolic syndrome was made according to International Diabetes Federation criteria. Clinical data, including anthropometric measurements and serum parameters, were collected. Odds ratios for hematological parameters and metabolic syndrome were calculated using binary logistic regression models.

RESULTS

We found that hemoglobin; platelet, and white blood cell counts increased with increasing numbers of metabolic syndrome components (p<0.05 for all). The odds ratio of metabolic syndrome significantly increased across successive quartiles of platelet (1.00, 1.25, 1.29, and 1.51) and white blood cell counts (1.00, 1.51, 1.79, and 2.11) with the lowest quartile as the referent group. Similar associations for hemoglobin and hematocrit in the top quartile were also observed. We did not observe any significant difference in the mean of neutrophil count, mean platelet volume (MPV), red cell distribution width, or platelet distribution width among participants with or without metabolic syndrome.

CONCLUSIONS

Our findings indicate that high levels of major hematological parameters such as hemoglobin, hematocrit, as well as platelet and white blood cell counts could be novel indicators for the development of metabolic syndrome.

Lifestyle alters GUT-bacteria function: Linking immune response and host

Microbiota in human is a "mixture society" of different species (i.e. bacteria, viruses, funguses) populations with a different way of relationship classification to Human. Human GUT serves as the host of the majority of different bacterial populations (GUT flora, more than 500 species), which are with us ("from the beginning") in an innate manner known as the commensal (no harm to each other) and symbiotic (mutual benefit) relationship. A homeostatic balance of host-bacteria relationship is very important and vital for a normal health process. However, this beneficial relationship and delicate homeostatic state can be disrupted by the imbalance of microbiome-composition of gut microbiota, expressing a pathogenic state. A strict homeostatic balance of microbiome-composition strongly depends on several factors; 1- lifestyle, 2- geography, 3- ethnicities, 4- "mom" as prime of the type of bacterial colonization in infant and 5- the disease. With such diversity in individuals combined with huge number of different bacterial species and their interactions, it is wise to perform an in-depth systems biology (e.g. genomics, proteomics, glycomics, and etcetera) analysis of personalized microbiome. Only in this way, we are able to generate a map of complete GUT microbiota and, in turn, to determine its interaction with host and intra-interaction with pathogenic bacteria. A specific microbiome analysis provides us the knowledge to decipher the nature of interactions between the GUT microbiota and the host and its response to the invading bacteria in a pathogenic state. The GUT-bacteria composition is independent of geography and ethnicity but lifestyle well affects GUT-bacteria composition and function. Microbiome knowledge obtained by systems biology also helps us to change the behavior of GUT microbiota in response to the pathogenic microbes as protection. Functional microbiome changes in response to environmental factors will be discussed in this review.