Combination of sepsis biomarkers may indicate an invasive fungal infection in haematological patients

Can we predict the influence of inflammation on voriconazole exposure? An overview

Voriconazole is a triazole antifungal indicated for invasive fungal infections that exhibits a high degree of inter-individual and intra-individual pharmacokinetic variability. Voriconazole pharmacokinetics is non-linear, making dosage adjustments more difficult. Therapeutic drug monitoring is recommended by measurement of minimum plasma concentrations. Several factors are responsible for the high pharmacokinetic variability of voriconazole: age, feeding (which decreases absorption), liver function, genetic polymorphism of the CYP2C19 gene, drug interactions and inflammation. Invasive fungal infections are indeed very frequently associated with inflammation, which engenders a risk of voriconazole overexposure. Many studies have reviewed this topic in both the adult and paediatric populations, but few studies have focused on the specific point of the prediction, to evaluate the influence of inflammation on voriconazole pharmacokinetics. Predicting the impact of inflammation on voriconazole pharmacokinetics could help optimize antifungal therapy and improve patient management. This review summarizes the existing data on the influence of inflammation on voriconazole pharmacokinetics in adult populations. We also evaluate the role of C-reactive protein, the impact of inflammation on patient metabolic phenotypes, and the tools that can be used to predict the effect of inflammation on voriconazole pharmacokinetics.

Combination of Interleukin-6, C-Reactive Protein and Procalcitonin Values as Predictive Index of Sepsis in Course of Fever Episode in Adult Haematological Patients: Observational and Statistical Study

Haematological patients represent a vulnerable population to opportunistic infections, mainly due to the disease itself and chemotherapy-induced neutropenia. The level of immune suppression strongly increases the importance of timely antibiotic treatment in order to prevent sepsis-related mortality. During the initial fever episode, serum biomarkers are usually used to estimate the probability of blood stream infection prior to the results of microbial diagnosis. A new serum biomarker combination study on a febrile haematological population, including C-reactive protein (CRP), interleukin-6 (IL-6) and procalcitonin (PCT), is proposed in order to improve their predictive accuracy. In our prospective study, CRP, IL-6 and PCT were evaluated in 34 immunosuppressed haematological patients immediately after the onset of 51 fever episodes, either during the course of standard chemotherapy or high-dose chemotherapy and autologous stem cell transplant. The fever episodes were divided into documented infections and fever alone. Receiver operating characteristic analysis (ROC) was performed for each biomarker and a combination of all three biomarkers (multiROC) to define a new predictive index. Significant differences were evidenced between the two groups (documented infection and no infection) for both PCT and IL-6 (p = 0.03 and p = 0.035, respectively), but none for CRP (p = 0.1). The composite parameter is more reliable than any single biomarker alone, with an area under the curve (AUC) of 79% and with high sensitivity and specificity. IL-6 gave the closest response compared to the composite index. Composite parameters of serum biomarkers could be used for an early diagnosis of infection at fever onset in haematological patients.

Guidelines for the Use of Procalcitonin for Rational Use of Antibiotics

How to cite this article: Khilnani GC, Tiwari P, Zirpe KG, Chaudhary D, Govil D, Dixit S, et al. Guidelines for the Use of Procalcitonin for Rational Use of Antibiotics. Indian J Crit Care Med 2022;26(S2):S77-S94.

Clinical Value of sTREM-1, PCT, and 1,3-β-D Glucan in Diagnosis of Immune-Associated Pulmonary Interstitial Disease with Fungal Infection

Background

Fungal infection in the lungs can cause fungal infectious diseases. This disease develops rapidly and involves a wide range. Pathogenic fungi are also more serious types of pathogenic bacteria. If it invades deep organs and tissues, it will endanger life, so it needs timely diagnosis.

Aim

To investigate the diagnostic value of serum soluble myeloid cell triggering receptor-1 (sTREM-1), procalcitonin (PCT), and 1,3-β-D glucan detection in immune related lung disease complicated with fungal infection.

Methods

In this study, a case-control study was conducted. 50 patients with immune-related pulmonary disease complicated with fungal infection (infection group) diagnosed by sputum culture in our hospital from January 2017 to December 2021 were selected as the control group, and 50 patients with immune-related pulmonary disease without fungal infection were selected as the control group. The levels of sTREM-1, PCT, and 1,3-β-D glucan were compared in the two groups. The receiver operating characteristic (ROC) was used to analyze the value of the three indicators in the diagnosis of immune-related pulmonary disease complicated with fungal infection, and the changes of the three indicators before and after treatment were compared.

Results

The levels of sTREM-1, PCT, and 1,3-β-D glucan in the infection group were higher than those in the control group (P < 0.05). The levels of sTREM-1, PCT, and 1,3-β-D glucan in the infection group after treatment were significantly lower than those before treatment (P < 0.05). The AUC value of sTREM-1 in the diagnosis of immune-related pulmonary diseases complicated with fungal infection was 0.980, the sensitivity was 97.11%, and the specificity was 83.06%. The AUC value of PCT in the diagnosis of immune-related pulmonary diseases complicated with fungal infection was 0.860, the sensitivity was 80.00%, and the specificity was 72.41%. The AUC value of 1,3-β-D glucan in the diagnosis of immune-related pulmonary diseases complicated with fungal infection was 0.993, the sensitivity was 98.74%, and the specificity was 99.16%. The levels of sTREM-1, PCT, and 1,3-β-D glucan in the infection group after treatment were considerably lower than those before treatment, and the difference was statistically significant (P < 0.05).

Conclusion

The detection of sTREM-1, PCT, and 1,3-β-D glucan levels has high clinical value for the diagnosis of immune-related pulmonary diseases complicated with fungal infection.

Combination of C-Reactive Protein and Procalcitonin in Distinguishing Fungal from Bacterial Infections Early in Immunocompromised Children

Invasive fungal infection (IFI) is life-threatening in children with cancer and hematology disorders, especially when diagnosis and treatment are delayed. Conventional β-D-glucan and galactomannan tests have poor positive predictive values in the diagnosis of IFI in children with cancer. This study aims to access the diagnostic performance of C-reactive protein (CRP) and procalcitonin (PCT) in differentiating IFI from bacterial bloodstream infections in children with malignant and hematology disorders. CRP and PCT levels were measured in samples taken from patients between 12 and 24 h after fever onset, of which 24 and 102 were in the IFI and bacterial groups, respectively. We found that the CRP levels were much higher in the IFI group than the bacterial group (100.57 versus 40.04 mg/L, median, p < 0.001), while the PCT levels remained significantly lower (0.45 versus 1.29 μg/L, median, p = 0.007). Both CRP and PCT showed significant diagnostic utilities with an area under the curve (AUC) of 0.780 (95% CI, 0.664−0.896, p < 0.001) and 0.731 (95% CI, 0.634−0.828, p < 0.001) when using the cut-off values of 94.93 mg/L and 2.00 μg/L, respectively. However, the combined biomarker of CRP and PCT yielded a better diagnostic performance with an AUC of 0.934 (95% confidential interval (CI), 0.881−0.987, p < 0.001), which was significantly higher than that of CRP or PCT (both p < 0.001), with a sensitivity of 87.5% and a specificity of 87.3%. Our study demonstrates high levels of CRP combined with low PCT could differentiate IFI from bacterial bloodstream infections in immunocompromised children.

Clinical Characteristics of Bloodstream Infection in Immunosuppressed Patients: A 5-Year Retrospective Cohort Study

Introduction

Immunosuppressed patients with bloodstream infection are at risk of mortality. Our objective was to assess the independent risk factors of bloodstream infection with mortality in immunosuppressive states.

Methods

The medical data of a total of 896 patients who were hospitalized in our hospital were collected from January 2015 to December 2019. Evaluation of the independent risk factors of mortality was done by univariate and multivariate logistic regression analyses.

Results

Of the 896 immunosuppressed patients with bloodstream infection, 698 had over 60-day survivals and 198 had 60-day mortality. In our study, PCT (mean ±; standard: 11.40 ±; 31.89 µg/l vs. 62.45 ±; 17.10 µg/l, p = 0.007) and presence of age >60 years (40% vs. 14.19%, p = 0.001) were significantly different between situations with and without 60-day survivals in both univariate and multivariate logistic regression analyses. Age >60 years and PCT could be used as indicators for bloodstream infection with 60-day death in immunosuppressive states; the OR (95% CI) were 1.532 (1.099–2.135) and 2.063 (1.413–3.013), respectively. In different subgroups, PCT and age were also independent risk factors of blood system diseases, Klebsiella pneumoniae infection, diabetes, and ICU-stay subgroups.

Conclusions

Age and PCT were independently associated with mortality in immunosuppressive states, which may help to identify the highly risky situation of bloodstream infection in immunosuppressive states.

Serum Cytokine Profile in Patients with Candidemia versus Bacteremia

Bloodstream Candida infections constitute a major threat for hospitalized patients in intensive care units and immunocompromised hosts. Certain serum cytokines play a decisive role in anti-microbial host defense. Cytokines may act as discriminatory biomarkers that can significantly increase in candidemia compared to bacteremia patients. The concentration of secreted cytokine/chemokines was determined using a multiplexed cytometric bead array run on a cell analyzer. The cytokines tested during the study were interleukin (IL)-1β, IL-6, IL-17A, IL-10, IFN-γ, IL-4, IL-2, IL-8, IL-12p70 and the tumor necrosis factor (TNF)-α. The cytokines of 51 candidemia patients were characterized and compared to the cytokine levels of 20 bacteremia patients. Levels were significantly elevated in patients with bloodstream infections compared to healthy controls. Cytokines comprising IL-2, IL-17A, IL-6 and IL-10 were significantly elevated in the patients with bloodstream Candida infection as compared to the patients having bloodstream bacterial infections. The levels were found to be promising as a potential diagnostic marker for bloodstream Candida infections.

Presepsin as Early Marker of Sepsis in Emergency Department: A Narrative Review

The diagnosis and treatment of sepsis have always been a challenge for the physician, especially in critical care setting such as emergency department (ED), and currently sepsis remains one of the major causes of mortality. Although the traditional definition of sepsis based on systemic inflammatory response syndrome (SIRS) criteria changed in 2016, replaced by the new criteria of SEPSIS-3 based on organ failure evaluation, early identification and consequent early appropriated therapy remain the primary goal of sepsis treatment. Unfortunately, currently there is a lack of a foolproof system for making early sepsis diagnosis because conventional diagnostic tools like cultures take a long time and are often burdened with false negatives, while molecular techniques require specific equipment and have high costs. In this context, biomarkers, such as C-Reactive Protein (CRP) and Procalcitonin (PCT), are very useful tools to distinguish between normal and pathological conditions, graduate the disease severity, guide treatment, monitor therapeutic responses and predict prognosis. Among the new emerging biomarkers of sepsis, Presepsin (P-SEP) appears to be the most promising. Several studies have shown that P-SEP plasma levels increase during bacterial sepsis and decline in response to appropriate therapy, with sensitivity and specificity values comparable to those of PCT. In neonatal sepsis, P-SEP compared to PCT has been shown to be more effective in diagnosing and guiding therapy. Since in sepsis the P-SEP plasma levels increase before those of PCT and since the current methods available allow measurement of P-SEP plasma levels within 17 min, P-SEP appears a sepsis biomarker particularly suited to the emergency department and critical care.

Presepsin as a Diagnostic and Prognostic Biomarker in Sepsis

Sepsis is a condition characterized by high morbidity and mortality which is commonly encountered in an emergency and critical care setting. Despite a substantial body of research, the ideal biomarker for the diagnosis and prognostic stratification of septic patients remains unknown. This review aimed to summarize the publications referring to the validity of the biomarker presepsin when used for the detection, monitoring and prognosis in patients suffering with sepsis.

This work is a narrative review based on a PubMed/Medline search conducted in order to identify all relevant publications referring to the use of presepsin in sepsis. Search was not limited by year of publication so all articles archived in the database would be retrieved. No article from before 2010 was identified.

A total of 57 publications of the last decade were included, all of which support the use of presepsin as a biomarker for the assessment of septic patients. It has been used alone or in combination with commonly used biomarkers in the evaluation of patients with sepsis in settings such as the emergency department and the intensive care unit. It is useful in the initial workup of patients with suspected sepsis in the emergency setting and may be a predictive factor of mortality and the most severe complication of sepsis.

Presepsin seems to be a valuable tool for the laboratory workup of sepsis, especially when used in conjunction with other biomarkers and clinical rating scores with an established role in this population. Further research is needed to evaluate the clinical implications of utilizing presepsin measurements in the workup of sepsis.

Bronchoalveolar Lavage and Blood Markers of Infection in Critically Ill Patients-A Single Center Registry Study

Microbiological sampling is an indispensable targeted antibiotic therapy for critically ill patients. Invasive respiratory sampling by bronchoalveolar lavage (BAL) can be performed to obtain samples from the lower respiratory tract. It is debated as to whether blood markers of infection can predict the outcome of BAL in a medical intensive care unit (ICU). Retrospectively, all ICU patients undergoing BAL from 2009-2018 were included. A total of 468 BAL samples from 276 patients (average age 60 years, SAPS2 47, ICU-mortality 41.7%) were analyzed. At the time of BAL, 94.4% patients were mechanically ventilated, 92.9% had suspected pneumonia, 96.2% were on antibiotic therapy and 36.3% were immunocompromised. Relevant bacteria were cultured in 114/468 (24.4%) cases of BAL. Patients with relevant bacteria in the culture had a higher ICU mortality rate (45.6 vs. 40.4%, p = 0.33) and were significantly less likely to be on a steroid (36 vs. 52%, p < 0.01) or antimycotic (14.9 vs. 34.2%, p < 0.01), while procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) counts were similar. The area under the receiver operating curve (AUC) values for positive culture and PCT, CRP and WBC counts were low (0.53, 0.54 and 0.51, respectively). In immunocompromised patients, AUC values were higher (0.65, 0.57 and 0.61, respectively). Therefore, microbiological cultures by BAL revealed relevant bacteria in 24.4% of samples. Our data, therefore, might suggest that indication for BAL should not be based on blood markers of infection.

Analysis of Risk Factors and Clinical Indicators in Bloodstream Infections Among Patients with Hematological Malignancy

Purpose

The incidence of bloodstream infection (BSI) is more common in patients with hematological malignancy. It is important to distinguish infectious episodes from noninfectious episodes. The present study was aimed to describe the epidemiology, clinical indexes, and antibiotic use for in-hospital bloodstream infections of hematological malignancy patients.

Patients and Methods

Single-center retrospective research was performed on hematological malignancy patients admitted to our hospital from July 2015 to March 2018. Laboratory and clinical information from 322 febrile patients were acquired. These episodes were divided by blood culture results into two groups: 1) blood culture positive-group, 2) blood culture negative-group.

Results

In the 322 febrile cases, 81 (25.2%) patients were blood culture positive, and among them, Gram-negative (G-) bacteria (51.9%) were more isolated than Gram-positive (G+) bacteria (32.1%) and fungi (7.4%). Gram-negative bacteria were more likely to have drug resistance than G+ bacteria. Independent risk factors revealed that patients with complications, high levels of procalcitonin (PCT), glucose, interleukin-6 (IL-6), and d-dimer (D-D), and low concentration of albumin were correlated with the occurrence of BSI. PCT, IL-6 and D-D performed well in differentiating the positive group from the negative group. Moreover, IL-6 and D-D showed excellent performance in differentiating G- and G+ groups, with the areas under the curve all above 0.8.

Conclusion

We analyzed the risk factors for BSI in patients with hematological malignancy, the distribution of bacteria, antibiotic resistance, and the changes in clinical parameters. This single-center retrospective study may provide clinicians insight into the diagnosis and treatment of BSI.

Biomarkers of inflammation and the etiology of sepsis

Sepsis is characterized as a life-threatening organ dysfunction syndrome that is caused by a dysregulated host response to infection. The main etiological causes of sepsis are bacterial, fungal, and viral infections. Last decades clinical and preclinical research contributed to a better understanding of pathophysiology of sepsis. The dysregulated host response in sepsis is complex, with both pathogen-related factors contributing to disease, as well as immune-cell mediated inflammatory responses that can lead to adverse outcomes in early or advanced stages of disease. Due to its heterogenous nature, clinical diagnosis remains challenging and sepsis-specific treatment options are still lacking. Classification and early identification of patient subgroups may aid clinical decisions and improve outcome in sepsis patients. The initial clinical presentation is rather similar in sepsis of different etiologies, however, inflammatory profiles may be able to distinguish between different etiologies of infections. In this review, we summarize the role and the discriminating potency of host-derived inflammatory biomarkers in the context of the main etiological types of sepsis.

Diagnostic efficacy of serum cytokines and chemokines in patients with candidemia and bacteremia

BACKGROUND

The role of serum cytokines/chemokines in differential diagnosis between fungal infections and bacterial infections have not been fully understood. This study aims to measure the serum levels of cytokines/chemokines in cases of candidemia and to compare them with those observed in cases of bacteremia.

MATERIAL AND METHODS

Patients with febrile episodes and were identified as bloodstream infections through blood culture were enrolled, while healthy people were included as control group. Fourteen serum cytokine and chemokine levels were detected with multiplex platform. ROC analysis was performed and an area under the curve (AUC), sensitivity and specificity values were calculated to determine the efficacy of various cytokines and chemokines for candidemia and bacteremia. Binary logistic regression was performed to further explore the combination mode of cytokines and chemokines, which could increase the diagnostic efficiency.

RESULTS

We included 40 patients with an episode of microbiologically proven fungal infection, 175 patients with bacteremia (85 with Gram-positive bacteremia and 90 with Gram-negative bacteremia) and another 30 healthy controls. Routine laboratory parameters including CRP and PCT were not statistically significant between candidemia group and bacteremia group (both gram-positive and gram-negative). There were significantly higher levels of IFN-γ, TNF-α, IL-10 and lower levels of IL-3, IL-4 in candidemia group, compared with gram-positive and gram-negative bacteremia groups. G-CSF was significantly lower and MIP-1β was higher in candidemia group, when compared with gram-negative bacteremia group. While IL-6, IL-8 and IL-17 were all significantly higher in candidemia group, when compared with gram-positive bacteremia group. Combination of IFN-γ and IL-17 could improve the diagnostic efficiency between candidemia and gram-positive bacteremia, with the AUROC of 0.873 (95% CI: 0.767-0.929). While combination of G-CSF and MIP-1β improved the diagnostic efficiency between candidemia and gram-negative bacteremia, with the AUROC of 0.896 (95% CI: 0.792-0.939).

CONCLUSION

Our study demonstrates that serum cytokines and chemokines including IFN-γ, MIP-1β, IL-17 and G-CSF could be considered as diagnostic markers to distinguish between candidemia and bacteremia. Combination of these biomarkers might improve the diagnostic efficiency of candidemia when compared with bacteremia.

Diagnostic efficacy of serum cytokines and chemokines in fungal bloodstream infection in febrile patients

BACKGROUND

The role of serum cytokines/chemokines in early diagnosis of fungal infections has not been clearly clarified yet. This study aims to measure the serum levels of cytokines/chemokines in cases of fungemia and to compare them with culture-negative controls.

METHODS

In total, fourteen types of serum cytokines and chemokines from 41 patients with fungemia were compared with 57 patients with negative blood culture results. The cytokine and chemokine levels were detected with multiplex platform. We then performed statistical analysis as a two-tailed P < .05. ROC analysis was performed, and an area under the curve (AUC), and sensitivity and specificity values were calculated to determine the efficacy of various cytokines and chemokines for fungemia. Binary logistic regression was performed to further explore the combination mode of cytokines and chemokines, which could increase the diagnostic efficiency.

RESULTS

C-reactive protein and procalcitonin were significantly higher compared with those in negative control group, while white blood cell, percentage of neutrophil, percentage of lymphocyte, and ratio of neutrophil and lymphocyte did not differentiate between two groups. Serum levels of IFN-γ, TNF-α, MIP-1β, IL-6, IL-8, IL-10, IL-12p70, and IL-17 were significantly higher in patients with fungemia compared with the control group. Combination of MIP-1β and IL-17 could improve the AUC, sensitivity, and specificity for the diagnosis of fungemia.

CONCLUSION

Our study demonstrates that serum cytokines and chemokines including IFN-γ, TNF-α, MIP-1β, IL-6, IL-8, IL-10, IL-12p70, and IL-17 could be considered as diagnostic markers for fungemia. Combination of these biomarkers might improve the diagnostic efficiency of fungemia.