Monocyte human leukocyte antigen-DR but not β-D-glucan may help early diagnosing invasive Candida infection in critically ill patients

[The Immune System of the Critically Ill Patient]

Critically ill patients often experience a dysregulated immune response, leading to immune dysfunction. Sepsis, trauma, severe infections, and certain medical conditions can trigger a state of systemic inflammation, known as the cytokine storm. This hyperactive immune response can cause collateral damage to healthy tissues and organs, exacerbating the patient's condition. On the other hand, some critically ill patients may suffer from immune paralysis which can increase the risk of nosocomial infections.Fever is an evolutionary adaptation that evolved as an effective defense mechanism to fight invading pathogens. By raising body temperature, fever enhances the immune response, inhibits pathogen growth, promotes recovery, and aids in the formation of immune memory. Understanding the role of fever in the context of immune defense is crucial for optimizing medical interventions and supporting the body's natural ability to combat infections.Future Directions: Advancements in immunology research and technology hold promise for better understanding the immune system's complexities in critically ill patients. Personalized medicine approaches may be developed to tailor therapies to individual patients based on their immune profile, optimizing treatment outcomes. Based on recent studies prognostic parameters such as lymphocyte count, IL-10 concentration and mHLA-DR expression can be used to stratify the immunological response pattern in septic patients.Conclusion: The immune system's response in critically ill patients is a multifaceted process, involving intricate interactions between various immune cells, cytokines, and organs. Striking the delicate balance between immune activation and suppression remains a significant challenge in clinical practice. Continued research and therapeutic innovations are vital to improve patient outcomes and reduce the burden of critical illness on healthcare systems.

Host Transcriptional Regulatory Genes and Microbiome Networks Crosstalk through Immune Receptors Establishing Normal and Tumor Multiomics Metafirm of the Oral-Gut-Lung Axis

The microbiome has shown a correlation with the diet and lifestyle of each population in health and disease, the ability to communicate at the cellular level with the host through innate and adaptative immune receptors, and therefore an important role in modulating inflammatory process related to the establishment and progression of cancer. The oral cavity is one of the most important interaction windows between the human body and the environment, allowing the entry of an important number of microorganisms and their passage across the gastrointestinal tract and lungs. In this review, the contribution of the microbiome network to the establishment of systemic diseases like cancer is analyzed through their synergistic interactions and bidirectional crosstalk in the oral-gut-lung axis as well as its communication with the host cells. Moreover, the impact of the characteristic microbiota of each population in the formation of the multiomics molecular metafirm of the oral-gut-lung axis is also analyzed through state-of-the-art sequencing techniques, which allow a global study of the molecular processes involved of the flow of the microbiota environmental signals through cancer-related cells and its relationship with the establishment of the transcription factor network responsible for the control of regulatory processes involved with tumorigenesis.

A scoring system based on novel biomarkers and clinical risk factors to predict invasive candidiasis in immunocompetent critically ill patients

Background

Delayed diagnosis further increases the mortality of invasive candidiasis (IC) in intensive care unit (ICU) patients. This study aimed to develop and validate a score based on novel serological biomarkers and clinical risk factors for predicting IC in immunocompetent ICU patients.

Methods

We retrospectively collected clinical data and novel serological markers on admission to ICU. Multivariate logistic regression was used to identify the risk factors associated with IC, which were adopted to establish a scoring system.

Results

Patients with IC had a higher C-reactive protein-to-albumin ratio (CAR) and neutrophil-to-lymphocyte ratio (NLR) and lower prognostic nutritional index than those without IC. The NLR, CAR, sepsis, total parenteral nutrition, 1,3-β-D-glucan (BDG)-positivity, and Sequential Organ Failure Assessment score were identified as independent risk factors for IC by multivariate logistic regression analysis and entered into the final scoring system. The area under receiver operating characteristic curve of the score were 0.883 and 0.892, respectively, in the development and validation cohort, higher than Candida score (0.883 vs.0.730, p < 0.001).

Conclusion

We established a parsimonious score based on NLR, CAR, BDG-positivity, and clinical risk factors, which can accurately identify IC in ICU patients to give treatment on time and reduce mortality.

Performance of existing clinical scores and laboratory tests for the diagnosis of invasive candidiasis in critically ill, nonneutropenic, adult patients: a systematic review with qualitative evidence synthesis

BACKGROUND

The Fungal Infections Definitions in Intensive Care Unit (ICU) patients (FUNDICU) project aims to provide standard sets of definitions for invasive fungal diseases in critically ill, adult patients.

OBJECTIVES

To summarize the available evidence on the diagnostic performance of clinical scores and laboratory tests for invasive candidiasis (IC) in nonneutropenic, adult critically ill patients.

METHODS

A systematic review was performed to evaluate studies assessing the diagnostic performance for IC of clinical scores and/or laboratory tests vs. a reference standard or a reference definition in critically ill, nonneutropenic, adult patients in ICU.

RESULTS

Clinical scores, despite the heterogeneity of study populations and IC prevalences, constantly showed a high negative predictive value (NPV) and a low positive predictive value (PPV) for the diagnosis of IC in the target population. Fungal antigen-based biomarkers (with most studies assessing serum beta-D-glucan) retained a high NPV similar to that of clinical scores, with a higher PPV, although the latter showed important heterogeneity across studies, possibly reflecting the targeted or untargeted use of these tests in patients with a consistent clinical picture and risk factors for IC.

CONCLUSIONS

Both clinical scores and laboratory tests showed high NPV for the diagnosis of IC in nonneutropenic critically ill patients. The PPV of laboratory tests varies significantly according to the baseline patients' risk of IC. This qualitative synthesis will provide the FUNDICU panel with baseline evidence to be considered during the development of definitions of IC in critically ill, nonneutropenic adult patients in ICU.

Monitoring of circulating monocyte HLA-DR expression in a large cohort of intensive care patients: relation with secondary infections

Introduction

The reports of an early and profound acquired immunodepression syndrome (AIDs) in ICU patients had gained sufficient credence to modify the paradigm of acute inflammation. However, despite several articles published on AIDs and its assessment by monocytic HLA-DR monitoring, several missing informations remained: 1—Which patients’ are more prone to benefit from mHLA-DR measurement, 2—Is the nadir or the duration of the low mHLA-DR expression the main parameter to consider? 3—What are the compared performances of leukocytes’ count analyses (lymphocyte, monocyte).

Material and method

We conducted an observational study in a surgical ICU of a French tertiary hospital. A first mHLA-DR measurement (fixed flow cytometry protocol) was performed within the first 3 days following admission and a 2nd, between day 5 and 10. The other collected parameters were: SAPS II and SOFA scores, sex, age, comorbidities, mortality and ICU-acquired infections (IAI). The associations between mHLA-DR and outcomes were tested by adjusted Fine and Gray subdistribution competing risk models.

Results

1053 patients were included in the study, of whom 592 had a 2nd mHLA-DR measurement. In this cohort, 223 patients (37.7%) complicated by IAI. The initial decrement in mHLA-DR was not associated with the later occurrence of IAI, (p = 0.721), however, the persistence of a low mHLA-DR (< 8000 AB/C), measured between day 5 and day 7, was associated with the later occurrence of IAI (p = 0.01). Similarly, a negative slope between the first and the second value was significantly associated with subsequent IAI (p = 0.009). The best performance of selected markers was obtained with the combination of the second mHLA-DR measurement with SAPSII on admission. Persisting lymphopenia and monocytopenia were not associated with later occurrence of IAI.

Conclusion

Downregulation of mHLA-DR following admission is observed in a vast number of patients whatever the initial motif for admission. IAI mostly occurs among patients with a high severity score on admission suggesting that immune monitoring should be reserved to the most severe patients. The initial downregulation did not preclude the later development of IAI. A decreasing or a persisting low mHLA-DR expression below 8000AB/C within the first 7 days of ICU admission was independently and reliably associated with subsequent IAI among ICU patients with performances superior to leukocyte subsets count alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01010-y.