Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

Physiologic disruption and metabolic reprogramming in infection and sepsis

Effective responses against severe systemic infection require coordination between two complementary defense strategies that minimize the negative impact of infection on the host: resistance, aimed at pathogen elimination, and disease tolerance, which limits tissue damage and preserves organ function. Resistance and disease tolerance mostly rely on divergent metabolic programs that may not operate simultaneously in time and space. Due to evolutionary reasons, the host initially prioritizes the elimination of the pathogen, leading to dominant resistance mechanisms at the potential expense of disease tolerance, which can contribute to organ failure. Here, we summarize our current understanding of the role of physiological perturbations resulting from infection in immune response dynamics and the metabolic program requirements associated with resistance and disease tolerance mechanisms. We then discuss how insight into the interplay of these mechanisms could inform future research aimed at improving sepsis outcomes and the potential for therapeutic interventions.

Pseudo-NRBC in the Mindray BC-6800Plus analyzer: A clue for diagnostic anticipation of fungemia. Experimental and preliminary clinical reports

INTRODUCTION

Candidemia can be a significant cause of death in immunosuppressed or debilitated patients particularly. Abnormalities of the instrumental cytograms of some hematological analyzers, such as Mindray BC-6800Plus, can be related to circulating Candida. We studied the possible diagnostic usefulness of this information.

METHODS

A fungal bloodstream infection has been simulated by adding aliquots of Candida albicans, Candida parapsilosis, and Candida glabrata to 75 leftovers and anonymized peripheral blood samples. Cytographic abnormalities like those of experimental samples were used to select patients with possible fungemia. The microscopic review of peripheral blood smears constituted the confirmatory method.

RESULTS

In all experimental samples, the various Candida types caused pseudo-NRBC and morphological abnormalities of WNB and DIFF cytograms. Circulating blastospores, free or engulfed by neutrophils, were the microscopic findings in the peripheral blood smears. In the clinical verification, 72 patients were recruited based on the presence of an evocative cluster in the WNB and DIFF cytograms. The microscopic review of 39 out of 72 samples was positive for NRBC. According to blood cultures, light microscopy revealed fungal forms of several Candida or non-Candida types in the remaining 33 samples. Nine of these cases were not yet known to suffer from bloodstream infection.

CONCLUSIONS

Although further confirmatory clinical studies are required for these diagnostic abilities, the BC 6800Plus cytographic abnormalities related to fungemia have proven helpful in rapidly monitoring persistent fungemia in already diagnosed patients. In unknown or undiagnosed cases, they could be the trigger point for the subsequent diagnostic-therapeutic pathway.

Clinical characteristics, diagnosis, treatment, and outcome of patients with liver abscess due to Aspergillus spp: a systematic review of published cases

BACKGROUND

Aspergillus spp liver abscess is a relatively rare entity and thus far no systematic review has been performed examining patients' demographics, clinical manifestations, diagnosis, management, and outcome.

METHODS

We performed a systematic review of the literature using MEDLINE and LILACS databases. We searched for articles published in the period from January 1990 to December 24, 2022, to identify patients who developed liver abscesses due to Aspergillus spp.

RESULTS

Our search yielded 21 patients all of whom had invasive aspergillosis confirmed on liver biopsy. Of these patients 81% were adults, and 60% were males. The majority (86%) of patients were immunocompromised and 95% had symptomatic disease at the time of diagnosis. The most common symptoms were fever (79%), abdominal pain (47%), and constitutional symptoms (weight loss, chills, night sweats, fatigue) (38%). Liver enzymes were elevated in 50%, serum galactomannan was positive in 57%, and fungal blood cultures were positive in only 11%. Co-infection with other pathogens preceded development of apsergillosis in one-third of patients, and the majority of the abscesses (43%) were cryptogenic. In the remaining patients with known source, 28% of patients developed liver abscess through dissemination from the lungs, 19% through the portal vein system, and in 10% liver abscess developed through contiguous spread. The most common imaging modality was abdominal computerized tomography done in 86% of patients. Solitary abscess was present in 52% of patients while 48% had multiple abscesses. Inadequate initial empiric therapy was prescribed in 60% of patients and in 44% of patients definite treatment included combination therapy with two or more antifungal agents. Percutaneous drainage of the abscesses was done in 40% of patients, while 20% required liver resection for the treatment of the abscess. Overall mortality was very high at 38%.

CONCLUSION

Further studies are urgently needed for a better understanding of pathophysiology of liver aspergillosis and for developement of newer blood markers in order to expedite diagnosis and decrease mortality.

Antimicrobial and Synergistic Effects of Syzygium cumini, Moringa oleifera, and Tinospora cordifolia Against Different Candida Infections

Introduction The burden of multiple drug resistance in human pathogens has necessitated the search for and development of antimicrobial agents with a wide range of structural classes and potentials to selectively act on the several mechanisms of actions exhibited by the pathogens. However, most synthetic antimicrobial agents have been linked with adverse side effects and high costs, furthering the need to explore more options. Syzygium cumini, Moringa oleifera, and Tinospora cordifolia are three medicinal plants used in traditional medicine systems for various infectious diseases. They contain various phytochemicals that exhibit antimicrobial activities against various bacteria, fungi, and parasites. The mechanisms of their antimicrobial action may involve the disruption of microbial cell walls and membranes, the inhibition of microbial enzyme and biofilm formation, the modulation of microbial gene expression and quorum sensing, and the induction of microbial cell death. Therefore, the present study evaluated the potentials of aqueous and ethanol extracts of S. cumini, M. oleifera, and T. cordifolia in managing infections as measured by their inhibitory effects on species. Materials and method Syzygium cumini, M. oleifera, and T. cordifolia were obtained and authenticated, and their aqueous and ethanol extracts were prepared. The antibacterial properties of the aqueous and ethanol extracts were examined. In addition to broth microdilution and biofilm development experiments, we also employed disk diffusion and agar-well diffusion techniques. The inocula of various species, including krusei, parapsilosis, utilis, albicans, and glabrata, were prepared for these assays. The synergistic effect of plant extracts with fluconazole was also evaluated. Results Syzygium cumini, M. oleifera, and T. cordifolia emerge as promising sources for the development of effective and sustainable antimicrobial interventions. Interestingly, the aqueous and ethanol extracts were effective against the selected species. Also, the synergistic combination of plant extracts with fluconazole was observed to triple the potency of the extracts. Furthermore, the potency of the plant extract as an antifungal and synergistic agent was ranked as S. cumini > M. oleifera > T. cordifolia. Conclusively, the plant extracts are effective in the management of opportunistic fungal infections.

Acute kidney injury should not be neglected - optimization of quick Pitt bacteremia score for predicting mortality in critically ill patients with bloodstream infection: a retrospective cohort study

Background

Considering the therapeutic difficulties and mortality associated with bloodstream infection (BSI), it is essential to investigate other potential factors affecting mortality in critically ill patients with BSI and examine the utility of the quick Pitt bacteremia (qPitt) score to improve the survival rate.

Objectives

To improve the predictive accuracy of the qPitt scoring system by evaluating the five current components of qPitt and including other potential factors influencing mortality in critically ill patients with BSI.

Design

This was a retrospective cohort study.

Methods

Medical information from the Medical Information Mart for Intensive Care IV database was used in this retrospective cohort study. The risk factors associated with mortality were examined using a multivariate logistic regression model. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminatory capability of the prediction models.

Results

In total, 1240 eligible critically ill patients with BSI were included. After adjustment for age, community-onset BSI, indwelling invasive lines, and Glasgow Coma Scale (GCS) ⩽ 8, acute kidney injury (AKI) was identified as a notable risk factor for 14-day mortality. Except for altered mental status, the four other main components of the original qPitt were significantly associated with 14-day mortality. Hence, we established a modified qPitt (m-qPitt) by adding AKI and replacing altered mental status with GCS ⩽ 8. The AUCs for m-qPitt and qPitt were 0.723 [95% confidence interval (CI): 0.683-0.759] and 0.708 (95% CI: 0.669-0.745) in predicting 14-day mortality, respectively. Moreover, m-qPitt also had acceptable performance and discrimination power [0.700 (95% CI: 0.666-0.732)] in predicting 28-day mortality.

Conclusion

AKI significantly influenced the survival of critically ill patients with BSIs. Compared with the original qPitt, our new m-qPitt was proven to have a better predictive performance for mortality in critically ill patients with BSI. Further studies should be conducted to validate the practicality of m-qPitt.

Phytochemicals and Vitamin D for a Healthy Life and Prevention of Diseases

A variety of phytocompounds contained in medical plants have been used as medication, including Kampo (traditional Japanese) medicine. Phytochemicals are one category of the chemical compounds mainly known as antioxidants, and recently, their anti-inflammatory effects in preventing chronic inflammation have received much attention. Here, we present a narrative review of the health-promotion and disease-prevention effects of phytochemicals, including polyphenols, the latter of which are abundant in onions, oranges, tea, soybeans, turmeric, cacao, and grapes, along with the synergetic effects of vitamin D. A phenomenon currently gaining popularity in Japan is finding non-disease conditions, so-called ME-BYO (mibyou) and treating them before they develop into illnesses. In addition to lifestyle-related diseases such as metabolic syndrome and obesity, dementia and frailty, commonly found in the elderly, are included as underlying conditions. These conditions are typically induced by chronic inflammation and might result in multiple organ failure or cancer if left untreated. Maintaining gut microbiota is important for suppressing (recently increasing) intestinal disorders and for upregulating immunity. During the COVID-19 pandemic, the interest in phytochemicals and vitamin D for disease prevention increased, as viral and bacterial infection to the lung causes fatal inflammation, and chronic inflammation induces pulmonary fibrosis. Furthermore, sepsis is a disorder inducing severe organ failure by the infection of microbes, with a high mortality ratio in non-coronary ICUs. However, antimicrobial peptides (AMPs) working using natural immunity suppress sepsis at the early stage. The intake of phytochemicals and vitamin D enhances anti-inflammatory effects, upregulates immunity, and reduces the risk of chronic disorders by means of keeping healthy gut microbiota. Evidence acquired during the COVID-19 pandemic revealed that daily improvement and prevention of underlying conditions, in terms of lifestyle-related diseases, is very important because they increase the risk of infectious diseases. This narrative review discusses the importance of the intake of phytochemicals and vitamin D for a healthy lifestyle and the prevention of ME-BYO, non-disease conditions.

Differentiating infection, colonisation, and sterile inflammation in critical illness: the emerging role of host-response profiling

Infection results when a pathogen produces host tissue damage and elicits an immune response. Critically ill patients experience immune activation secondary to both sterile and infectious insults, with overlapping clinical phenotypes and underlying immunological mechanisms. Patients also undergo a shift in microbiota with the emergence of pathogen-dominant microbiomes. Whilst the combination of inflammation and microbial shift has long challenged intensivists in the identification of true infection, the advent of highly sensitive molecular diagnostics has further confounded the diagnostic dilemma as the number of microbial detections increases. Given the key role of the host immune response in the development and definition of infection, profiling the host response offers the potential to help unravel the conundrum of distinguishing colonisation and sterile inflammation from true infection. This narrative review provides an overview of current approaches to distinguishing colonisation from infection using routinely available techniques and proposes matrices to support decision-making in this setting. In searching for new tools to better discriminate these states, the review turns to the understanding of the underlying pathobiology of the host response to infection. It then reviews the techniques available to assess this response in a clinically applicable context. It will cover techniques including profiling of transcriptome, protein expression, and immune functional assays, detailing the current state of knowledge in diagnostics along with the challenges and opportunities. The ultimate infection diagnostic tool will likely combine an assessment of both host immune response and sensitive pathogen detection to improve patient management and facilitate antimicrobial stewardship.

The clinical application of metagenomic next-generation sequencing in sepsis of immunocompromised patients

Background

Metagenomic next-generation sequencing (mNGS) was commonly applied given its ability to identify and type all infections without depending upon culture and to retrieve all DNA with unbiasedness. In this study, we strive to compare outcomes of mNGS with conventional culture methods in adults with sepsis, investigate the differences between the immunocompromised and control group, and assess the clinical effects of mNGS.

Methods

In our study, 308 adult sepsis patients were included. We used both mNGS and conventional culture methods to analyze diagnostic results, pathogens, and sample types. The correlation between some laboratory tests and the frequency of pathogens by groups was also analyzed. Furthermore, the clinical impacts of mNGS were estimated.

Results

308 samples were assigned to an immunocompromised group (92/308,29.9%) and a control group (216/308,70.1%). There was the sensitivity of mNGS considered greater than that of the culture method in all samples (88.0% vs 26.3%; P <​ 0.001), in the immunocompromised group (91.3% vs 26.1%; P <​ 0.001), and the control group (86.6% vs 26.4%; P <​ 0.001), particularly in all sample types of blood (P <​ 0.001), BALF (P <​ 0.001), CSF (P <​ 0.001), sputum (P <​ 0.001) and ascitic fluid (P = 0.008). When examining the mNGS results between groups, Pneumocystis jirovecii (P < 0.001), Mucoraceae (P = 0.014), and Klebsiella (P = 0.045) all showed significant differences. On the whole, mNGS detected more pathogens than culture methods (111 vs 25), found 89 organisms that were continuously overlooked in entire samples by culture methods, and showed a favorable positive clinical effect in 76.3% (235 of 308) of patients. In 185 (60.1%) patients, mNGS prompted a modification in the course of management, which included antibiotic de-escalation in 61(19.8%) patients.

Conclusions

The research discovered that mNGS was more sensitive than the culture method, particularly in samples of blood, BALF, CSF, sputum, and ascitic fluid. When examining the mNGS results, Pneumocystis jirovecii and Mucoraceae were the pathogens seen more commonly in immunocompromised patients with sepsis, which required more attention from clinicians. There was a substantial benefit of mNGS in enhancing the diagnosis of sepsis and advancing patient treatment.

Prospective validation of a transcriptomic severity classifier among patients with suspected acute infection and sepsis in the emergency department

BACKGROUND AND IMPORTANCE

mRNA-based host response signatures have been reported to improve sepsis diagnostics. Meanwhile, prognostic markers for the rapid and accurate prediction of severity in patients with suspected acute infections and sepsis remain an unmet need. IMX-SEV-2 is a 29-host-mRNA classifier designed to predict disease severity in patients with acute infection or sepsis.

OBJECTIVE

Validation of the host-mRNA infection severity classifier IMX-SEV-2.

DESIGN, SETTINGS AND PARTICIPANTS

Prospective, observational, convenience cohort of emergency department (ED) patients with suspected acute infections.

OUTCOME MEASURES AND ANALYSIS

Whole blood RNA tubes were analyzed using independently trained and validated composite target genes (IMX-SEV-2). IMX-SEV-2-generated risk scores for severity were compared to the patient outcomes in-hospital mortality and 72-h multiorgan failure.

MAIN RESULTS

Of the 312 eligible patients, 22 (7.1%) died in hospital and 58 (18.6%) experienced multiorgan failure within 72 h of presentation. For predicting in-hospital mortality, IMX-SEV-2 had a significantly higher area under the receiver operating characteristic (AUROC) of 0.84 [95% confidence intervals (CI), 0.76-0.93] compared to 0.76 (0.64-0.87) for lactate, 0.68 (0.57-0.79) for quick Sequential Organ Failure Assessment (qSOFA) and 0.75 (0.65-0.85) for National Early Warning Score 2 (NEWS2), ( P  = 0.015, 0.001 and 0.013, respectively). For identifying and predicting 72-h multiorgan failure, the AUROC of IMX-SEV-2 was 0.76 (0.68-0.83), not significantly different from lactate (0.73, 0.65-0.81), qSOFA (0.77, 0.70-0.83) or NEWS2 (0.81, 0.75-0.86).

CONCLUSION

The IMX-SEV-2 classifier showed a superior prediction of in-hospital mortality compared to biomarkers and clinical scores among ED patients with suspected infections. No improvement for predicting multiorgan failure was found compared to established scores or biomarkers. Identifying patients with a high risk of mortality or multiorgan failure may improve patient outcomes, resource utilization and guide therapy decision-making.

Immune response to third SARS-CoV-2 vaccination in seronegative kidney transplant recipients: Possible improvement by mycophenolate mofetil reduction

Modification of vaccination strategies is necessary to improve the immune response to SARS-CoV-2 vaccination in kidney transplant recipients (KTRs). This multicenter observational study analyzed the effects of the third SARS-CoV-2 vaccination in previously seronegative KTRs with the focus on temporary mycophenolate mofetil (MMF) dose reduction within propensity matched KTRs. 56 out of 174 (32%) previously seronegative KTRs became seropositive after the third vaccination with only three KTRs developing neutralizing antibodies against the omicron variant. Multivariate logistic regression revealed that initial antibody levels, graft function, time after transplantation and MMF trough levels had an influence on seroconversion (P < .05). After controlling for confounders, the effect of MMF dose reduction before the third vaccination was calculated using propensity score matching. KTRs with a dose reduction of ≥33% showed a significant decrease in MMF trough levels to 1.8 (1.2-2.5) μg/ml and were more likely to seroconvert than matched controls (P = .02). Therefore, a MMF dose reduction of 33% or more before vaccination is a promising approach to improve success of SARS-CoV-2 vaccination in KTRs.

Clinical Value of Metagenomic Next-Generation Sequencing in Immunocompromised Patients with Sepsis

BACKGROUND Sepsis is a serious threat to human life, particularly in immunocompromised patients; hence, early diagnosis and targeted treatment are important. Metagenomic next-generation sequencing (NGS) has significant advantages over traditional diagnostic methods. This study investigated the clinical value of NGS for pathogen identification in immunocompromised patients with sepsis. MATERIAL AND METHODS From July 2020 to September 2021, 90 consecutive patients with sepsis were enrolled in this prospective study. The patients were divided into 2 groups: an immunocompromised group (n=30) and an immunocompetent group (n=60). The pathogens causing sepsis were concurrently identified using NGS and traditional diagnostic methods. The pathogen detection rates and the spectrum of pathogens identified were compared according to the method of detection and between the immunocompromised and immunocompetent groups. RESULTS Of the 90 patients, 77 (86%) were positive for 1 or more pathogens using NGS, and 50 (56%) were positive using traditional detection methods. The positivity rate of sputum and bronchoalveolar lavage fluid was higher than that of blood samples. Pneumocystis jirovecii and cytomegalovirus infections were more common in the immunocompromised group than in the immunocompetent group. CONCLUSIONS The performance of NGS in identifying pathogens for patients with sepsis is better than that of traditional detection methods, especially in immunocompromised patients. Pneumocystis jirovecii and cytomegalovirus infections are more common in immunocompromised patients.

Bacterial and Viral Infection and Sepsis in Kidney Transplanted Patients

Kidney transplanted patients are a unique population with intrinsic susceptibility to viral and bacterial infections, mainly (but not exclusively) due to continuous immunosuppression. In this setting, infectious episodes remain among the most important causes of death, with different risks according to the degree of immunosuppression, time after transplantation, type of infection, and patient conditions. Prevention, early diagnosis, and appropriate therapy are the goals of infective management, taking into account that some specific characteristics of transplanted patients may cause a delay (the absence of fever or inflammatory symptoms, the negativity of serological tests commonly adopted for the general population, or the atypical anatomical presentation depending on the surgical site and graft implantation). This review considers the recent available findings of the most common viral and bacterial infection in kidney transplanted patients and explores risk factors and outcomes in septic evolution.

Impact of Sepsis on High-Density Lipoprotein Metabolism

Background: High-density lipoproteins (HDL) are thought to play a protective role in sepsis through several mechanisms, such as promotion of steroid synthesis, clearing bacterial toxins, protection of the endothelial barrier, and antioxidant/inflammatory activities. However, HDL levels decline rapidly during sepsis, but the contributing mechanisms are poorly understood.

Methods/Aim: In the present study, we investigated enzymes involved in lipoprotein metabolism in sepsis and non-sepsis patients admitted to the intensive care unit (ICU).

Results: In 53 ICU sepsis and 25 ICU non-sepsis patients, we observed significant differences in several enzymes involved in lipoprotein metabolism. Lecithin-cholesterol acyl transferase (LCAT) activity, LCAT concentration, and cholesteryl transfer protein (CETP) activity were significantly lower, whereas phospholipid transfer activity protein (PLTP) and endothelial lipase (EL) were significantly higher in sepsis patients compared to non-sepsis patients. In addition, serum amyloid A (SAA) levels were increased 10-fold in sepsis patients compared with non-sepsis patients. Furthermore, we found that LCAT activity was significantly associated with ICU and 28-day mortality whereas SAA levels, representing a strong inflammatory marker, did not associate with mortality outcomes.

Conclusion: We provide novel data on the rapid and robust changes in HDL metabolism during sepsis. Our results clearly highlight the critical role of specific metabolic pathways and enzymes in sepsis pathophysiology that may lead to novel therapeutics.

A Nomogram Based on Comorbidities and Infection Location to Predict 30 Days Mortality of Immunocompromised Patients in ICU: A Retrospective Cohort Study

Background

The existing comorbidity indexes, like Charlson Comorbidity Index (CCI) and the Elixhauser Comorbidity Index (ECI), do not take infection factors into account for critically ill patients with immunocompromise, bringing about a decrease of prediction accuracy. Therefore, we attempted to incorporate infection location into the analysis to construct a rapid comorbidity scoring system independent of laboratory tests.

Methods

Data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care III database. A total of 3904 critically ill patients with immunocompromise admitted to ICU were enrolled and assigned into training or validation sets according to the date of ICU admission. The predictive nomogram was constructed in the training set based on logistic regression analysis and then undergone validation in the validation set in comparison with SOFA, CCI and ECI.

Results

Factors eligible for the nomogram included patient’s age, gender, ethnicity, underlying disease of immunocompromise like metastatic cancer and leukemia, possible infection on admission including pulmonary infection, urinary tract infection and blood infection, and one comorbidity, coagulopathy. The nomogram we developed exhibited better discrimination than SOFA, CCI and ECI with an area under the receiver operating characteristic curve (AUC) of 0.739 (95% CI 0.707–0.771) and 0.746 (95% CI 0.713–0.779) in the training and validation sets, respectively. Combining the nomogram and SOFA could bring a new prediction model with a superior predictive effect in both sets (training set AUC = 0.803 95% CI 0.777–0.828, validation set AUC = 0.818 95% CI 0.783–0.854). The calibration curve exhibited coherence between the nomogram and ideal observation for two cohorts (p>0.05). Decision curve analysis revealed the clinical usefulness of the nomogram in both sets.

Conclusion

We established a nomogram that could provide an accurate assessment of 30 days ICU mortality in critically ill patients with immunocompromise, which can be employed to evaluate the short-term prognosis of those patients and bring more clinical benefits without dependence on laboratory tests.

Survival Outcome of Sepsis in Recipients of Solid Organ Transplant

Sepsis is a complex disease stemming from a dysregulated immune response toward an infectious agent. In transplantation, sepsis remains one of the leading causes of morbidity and mortality. Solid organ transplant recipients have impaired adaptive immunity due to immunosuppression required to prevent rejection. Immunosuppression has unintended consequences, such as increasing the risk of infections and sepsis. Due to its high morbidity and mortality, early detection of sepsis is paramount to start aggressive treatment. Several biomarkers or combination of biomarkers of sepsis have emerged in the last decade, but they are not dependable for early diagnosis or for outcome prognosis.