Accuracy of C - Reactive protein as a bacterial infection marker in critically immunosuppressed patients: A systematic review and meta-analysis

A 29-mRNA host-response classifier identifies bacterial infections following liver transplantation - a pilot study

PURPOSE

Infections are common complications in patients following liver transplantation (LTX). The early diagnosis and prognosis of these infections is an unmet medical need even when using routine biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT). Therefore, new approaches are necessary.

METHODS

In a prospective, observational pilot study, we monitored 30 consecutive patients daily between days 0 and 13 following LTX using the 29-mRNA host classifier IMX-BVN-3b that determine the likelihood of bacterial infections and viral infections. True infection status was determined using clinical adjudication. Results were compared to the accuracy of CRP and PCT for patients with and without bacterial infection due to clinical adjudication.

RESULTS

Clinical adjudication confirmed bacterial infections in 10 and fungal infections in 2 patients. 20 patients stayed non-infected until day 13 post-LTX. IMX-BVN-3b bacterial scores were increased directly following LTX and decreased until day four in all patients. Bacterial IMX-BVN-3b scores detected bacterial infections in 9 out of 10 patients. PCT concentrations did not differ between patients with or without bacterial, whereas CRP was elevated in all patients with significantly higher levels in patients with bacterial infections.

CONCLUSION

The 29-mRNA host classifier IMX-BVN-3b identified bacterial infections in post-LTX patients and did so earlier than routine biomarkers. While our pilot study holds promise future studies will determine whether these classifiers may help to identify post-LTX infections earlier and improve patient management.

CLINICAL TRIAL NOTATION

German Clinical Trials Register: DRKS00023236, Registered 07 October 2020, https://drks.de/search/en/trial/DRKS00023236.

Reduced C-reactive protein level at hospital admission in patients treated with Tocilizumab - An attention may be required

Background

C-reactive protein (CRP) is a marker of inflammation and infection. The main proinflammatory cytokine that leads to CRP gene expression is IL-6. The study aimed to compare CRP level between patients who were treated with Tocilizumab (TCZ), an il-6 receptor blocker, and other advanced anti-inflammatory treatments (AAIT), as well as with other admitted and non-admitted populations.

Methods

A cross-sectional study of all patients (≥18 years) hospitalized at tertiary medical center between December 2009 and February 2020 and treated before hospitalization with (AAIT). Only the first hospitalization of each patient was included. Women admitted to obstetrics department were excluded. Demographic data, first blood tests results, and comorbidities were collected.

Results

The study included 563 patients treated with AAIT (2.5% received TCZ). Patients treated with TCZ were older (median 75 vs. 50 years, p < 0.001), had higher Charlson score (median 5 vs. 1, p < 0.001) and more infectious diseases at admission (50% vs. 23.4%, p = 0.05). Patients treated with TCZ had lower CRP levels (median 0.5 vs. 25 mg/l, p < 0.001) and more common normal values (64.3% vs. 20.8%, p < 0.001) compared to patients treated with other AAIT.CRP level in patients treated TCZ (median 0.5 mg/l) was lower than that of 58,548 patients admitted to the hospital between 2010 and 2020 (median 12.55 mg/l, p < 0.001) and not statistically different from 140 non-admitted randomly selected individuals without acute disease (1.33 mg/l, p = 0.294).

Conclusion

Tocilizumab is associated with lower levels of CRP in patients admitted to acute care hospital. This finding must be considered by treating physician to avoid misinterpretation of CRP results.

ImmunoDisk—A Fully Automated Bead-Based Immunoassay Cartridge with All Reagents Pre-Stored

In this paper, we present the ImmunoDisk, a fully automated sample-to-answer centrifugal microfluidic cartridge, integrating a heterogeneous, wash-free, magnetic- and fluorescent bead-based immunoassay (bound-free phase detection immunoassay/BFPD-IA). The BFPD-IA allows the implementation of a simple fluidic structure, where the assay incubation, bead separation and detection are performed in the same chamber. The system was characterized using a C-reactive protein (CRP) competitive immunoassay. A parametric investigation on air drying of protein-coupled beads for pre-storage at room temperature is presented. The key parameters were buffer composition, drying temperature and duration. A protocol for drying two different types of protein-coupled beads with the same temperature and duration using different drying buffers is presented. The sample-to-answer workflow was demonstrated measuring CRP in 5 µL of human serum, without prior dilution, utilizing only one incubation step, in 20 min turnaround time, in the clinically relevant concentration range of 15–115 mg/L. A reproducibility assessment over three disk batches revealed an average signal coefficient of variation (CV) of 5.8 ± 1.3%. A CRP certified reference material was used for method verification with a concentration CV of 8.6%. Our results encourage future testing of the CRP-ImmunoDisk in clinical studies and its point-of-care implementation in many diagnostic applications.

Analysis of Multiple Vitamins Serum Levels and Disease-Related Factors in Children with Acute Leukemia

Objective

To explore the relationship between vitamins levels and disease-related indicators in children with acute leukemia (AL).

Methods

A total of 107 hospitalized children with AL were enrolled in this study and assigned to one group in each of the following categories: infected group (n = 52) and noninfected group (n = 55); treatment remission group (n = 56) and nonremission group (n = 51); high-risk (HR) group (n = 44), intermediate risk (IR) group (n = 53), and slight risk (SR) group (n = 8); cyclophosphamide + cytosine arabinoside+6-mercaptopurine + pegaspargase group (CAML, n = 15); methotrexate group (MTX, n = 9); and vindesine + daunomycin + L-asparaginasum + prednisone (VALP, n = 38). Hematological and serological parameters, hepatic and renal function, and changes in vitamins A, B1, B2, B6, B9, B12, C, D, and E serum content in children with AL were analyzed to investigate their relationship with AL disease-related factors.

Results

The vitamin D level was significantly higher in the noninfected group than in the infected group (P < 0.05). Compared with the nonremission group, the level of vitamin B1 in the treatment remission group was significantly higher, while the levels of vitamin B6 and B12 were notably lower (P < 0.05). The levels of vitamins B6 and B12 were notably different among the treatment groups. Multivariate analysis showed that hemoglobin (Hb) and C-reactive protein (CRP) were predisposing factors of AL in children. The disease type (acute lymphoblastic leukemia/acute myelogenous leukemia) was the factor affecting remission in AL children. Abnormal kidney function and the occurrence of icterus were the influencing factors for the risk degree in AL children. Platelet (PLT) count, activated partial thromboplastin time (APTT), neutrophils (N), and immunophenotype were shown to affect the choice of therapeutic regimens.

Conclusion

There are notable vitamins imbalances in children with AL. The imbalances influence disease-related factors and therefore provide some references for the prognosis and treatment of AL.

Myristic Acid Serum Levels and Their Significance for Diagnosis of Systemic Inflammatory Response, Sepsis, and Bacteraemia

Myristic acid is identified as a metabolite with the highest diagnostic sensitivity and specificity in the metabolome of patients with bacteraemia. Its significant decrease has been observed in patients with septic shock not responding to treatment. Another study has reported a close correlation of myristic acid levels with the outcome of severe trauma patients. Myristic acid concentrations were investigated in a cohort of septic patients and patients with Systemic Inflammatory Response Syndrome (SIRS) in 5 consecutive days following diagnosis and compared to healthy controls. The study population groups-Sepsis 34, SIRS 31, and Healthy Control 120 patients were included. Serum samples were analyzed using gas chromatography and mass spectrometry. The myristic acid levels in the Sepsis Group and SIRS Group were found to be significantly higher when compared to healthy controls. The serum concentration of myristic acid in septic patients with bacteraemia was higher than in septic patients without bacteraemia. Most patients with sepsis and SIRS had the highest levels of myristic acid within 24 h after an established diagnosis. Myristic acid should be considered as a new candidate marker of severe inflammation and sepsis. A simplified analysis and sufficient body of validated data are necessary steps towards the introduction of this metabolite into routine clinical practice.

The Effect of Tocilizumab on Inflammatory Markers in Patients Hospitalized with Serious Infections. Case Series and Review of Literature

Background: The human anti-IL-6 receptor antibody tocilizumab (TCZ) has been approved for the treatment of rheumatoid arthritis (RA) and giant cell arteritis (GCA). It is observed that CRP levels drop quickly after starting TCZ treatment. This may lead to misinterpretation of laboratory results when accessing the patient with infectious disease while on TCZ. We conducted this study to report cases treated with tocilizumab who developed serious infections with special reference to levels of CRP and to review the literature on the effect of tocilizumab on acute phase response (APR) during infections. Methods: The files of RA and GCA patients hospitalized in the Tel Aviv medical center between 2009–2019 were reviewed. Cases of patients with RA and GCA treated with tocilizumab who were hospitalized due to severe infections were reviewed with special emphasis on the duration of treatment, type of infection, and APR. Results: We identified nine admissions. Seven patients were treated with tocilizumab for RA, two for GCA. The diagnosis was pneumonia in three cases, osteomyelitis in one, cellulitis in one, endocarditis due to Whipple disease in one, abscess of cervix uteri in one, meningitis in one, and perforated diverticulitis in one. The mean CRP levels on admission were 4.75 mg/L (normal range, up to 5 mg/L). All cases were diagnosed correctly on admission. Conclusions: CRP levels may not correctly reflect the severity of infectious diseases during tocilizumab treatment. Increased awareness of the masking effect of tocilizumab on the APR during infection is needed in order to avoid a delay in the diagnosis.

Host Diagnostic Biomarkers of Infection in the ICU: Where Are We and Where Are We Going?

Purpose of Review

Early identification of infection in the critically ill patient and initiation of appropriate treatment is key to reducing morbidity and mortality. On the other hand, the indiscriminate use of antimicrobials leads to harms, many of which may be exaggerated in the critically ill population. The current method of diagnosing infection in the intensive care unit relies heavily on clinical gestalt; however, this approach is plagued by biases. Therefore, a reliable, independent biomarker holds promise in the accurate determination of infection. We discuss currently used host biomarkers used in the intensive care unit and review new and emerging approaches to biomarker discovery.

Recent Findings

White cell count (including total white cell count, left shift, and the neutrophil-leucocyte ratio), C-reactive protein, and procalcitonin are the most common host diagnostic biomarkers for sepsis used in current clinical practice. However, their utility in the initial diagnosis of infection, and their role in the subsequent decision to commence treatment, remains limited. Novel approaches to biomarker discovery that are currently being investigated include combination biomarkers, host 'sepsis signatures' based on differential gene expression, site-specific biomarkers, biomechanical assays, and incorporation of new and pre-existing host biomarkers into machine learning algorithms.

Summary

To date, no single reliable independent biomarker of infection exists. Whilst new approaches to biomarker discovery hold promise, their clinical utility may be limited if previous mistakes that have afflicted sepsis biomarker research continue to be repeated.

Disruption of CCR5 signaling to treat COVID-19-associated cytokine storm: Case series of four critically ill patients treated with leronlimab

Coronavirus disease 2019 (COVID-19) is associated with considerable morbidity and mortality. The number of confirmed cases of infection with SARS-CoV-2, the virus causing COVID-19 continues to escalate with over 70 million confirmed cases and over 1.6 million confirmed deaths. Severe-to-critical COVID-19 is associated with a dysregulated host immune response to the virus, which is thought to lead to pathogenic immune dysregulation and end-organ damage. Presently few effective treatment options are available to treat COVID-19. Leronlimab is a humanized IgG4, kappa monoclonal antibody that blocks C–C chemokine receptor type 5 (CCR5). It has been shown that in patients with severe COVID-19 treatment with leronlimab reduces elevated plasma IL-6 and chemokine ligand 5 (CCL5), and normalized CD4/CD8 ratios. We administered leronlimab to 4 critically ill COVID-19 patients in intensive care. All 4 of these patients improved clinically as measured by vasopressor support, and discontinuation of hemodialysis and mechanical ventilation. Following administration of leronlimab there was a statistically significant decrease in IL-6 observed in patient A (p=0.034) from day 0–7 and patient D (p=0.027) from day 0–14. This corresponds to restoration of the immune function as measured by CD4+/CD8+ T cell ratio. Although two of the patients went on to survive the other two subsequently died of surgical complications after an initial recovery from SARS-CoV-2 infection.

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Leronlimab is a monoclonal antibody in clinical trials to treat the cytokine storm.

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Critically ill patients received leronlimab through compassionate use and had remarkable recoveries measured objectively.

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The CCR5 receptor is important in recruiting inflammatory cells mainly T cells and macrophages.

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Leronlimab disrupted this signal and may have been responsible for restoration of the immune system, improved survival and decrease in IL-6.

Clinical significance of peripheral blood CD11b+/CD33+/HLA-DR- myeloid cells in infants and children with infectious diseases and increased CRP

Background: At early ages, recurrent or persistent infections are associated with increased serum C-reactive protein (CRP). Inflammatory mediators release inhibitory cells named myeloid-derived suppressor cell (MDSC) into circulating and tumor tissues. In the present study, we assayed the percentage and count of whole blood CD11b+/CD33+/HLA-DR- MDSCs or myeloid cells at early ages with infectious diseases and increased CRP. Methods: In this study, the clinical significance of CD11b+/CD33+/HLA-DR- MDSCs or myeloid cells was evaluated in whole blood samples from 40 patients with infectious disease and 20 healthy controls by flow cytometry analysis. Subsequently, the Pearson correlation between the percentage and absolute count of MDSCs with clinical parameters were obtained by SPSS analysis. A p value of < 0.05 was considered statistically significant. Results: We found a significantly higher level of MDSCs in infants and children with infectious diseases and increased CRP as compared to healthy controls (P=0.003). However, the results of analysis showed no correlation between MDSC percentage and count with grouped age and sex in patient groups. Conclusion: Our findings showed a significant correlation between the high level of serum CRP and peripheral blood CD11b+/CD33+/HLA-DR- MDSCs at early ages. This study could be a roadmap for future studies to use increased CRP as a potential prognostic biomarker to target MDSCs in children with recurrent or persistent infections.

Early detection of infectious complications during induction therapy for acute leukemia with serial C-reactive protein biomarker assessment

Febrile neutropenia (FN) and blood stream infections (BSI) are major complications of induction treatment for acute leukemia. We assessed the predictive utility of C-reactive protein (CRP), an acute phase reactant, for FN and BSI during induction. CRP levels and dynamics were analyzed in 138 consecutive patients. FN and BSI occurred in 110 (80.3%) and 10 (7.5%) patients, respectively. Median peak CRP level in the 24-hours preceding FN was 7.5 mg/dl (0.2-38.1) vs. median peak CRP level of 5.11 mg/dl (0.2-23.1, p = .009) in patients without FN. CRP levels preceding BSI were 13.1 mg/dl (6.9-27.9) vs. 6.3 mg/dl (0.16-38.14, p = .011). CRP increase prior to event (ΔCRP) was higher among patients with BSI vs. patients without BSI (p = .013). CRP was predictive for FN (p = .009) and BSI (p = .01) on ROC curve analysis and was also independently associated with FN on multivariate analysis. In conclusion, CRP is a sensitive biomarker that precedes FN and BSI.

Recombinant Human Proteoglycan-4 Mediates Interleukin-6 Response in Both Human and Mouse Endothelial Cells Induced Into a Sepsis Phenotype

OBJECTIVES

Sepsis is a leading cause of death in the United States. Putative targets to prevent systemic inflammatory response syndrome include antagonism of toll-like receptors 2 and 4 and CD44 receptors in vascular endothelial cells. Proteoglycan-4 is a mucinous glycoprotein that interacts with CD44 and toll-like receptor 4 resulting in a blockade of the NOD-like receptor pyrin domain-containing-3 pathway. We hypothesized that endothelial cells induced into a sepsis phenotype would have less interleukin-6 expression after recombinant human proteoglycan 4 treatment in vitro.

DESIGN

Enzyme-linked immunosorbent assay and reverse transcriptase-quantitative polymerase chain reaction to measure interleukin-6 protein and gene expression.

SETTING

Research laboratory.

SUBJECTS

Human umbilical vascular endothelial cells, human lung microvascular endothelial cells, and transgenic mouse (wild type) (Cd44 +/+/Prg4 +/+), Cd44 -/- (Cd44 tm1Hbg Prg4 +/+), Prg4 GT/GT (Cd44 +/+ Prg4 tm2Mawa/J), and double knockout (Cd44 tm1Hbg Prg4 tm2Mawa/J) lung microvascular endothelial cells.

INTERVENTIONS

Cells were treated with 100 or 250 ng/mL lipopolysaccharide-Escherichia coli K12 and subsequently treated with recombinant human proteoglycan 4 after 30 minutes. Interleukin-6 levels in conditioned media were measured via enzyme-linked immunosorbent assay and gene expression was measured via reverse transcriptase-quantitative polymerase chain reaction with ΔΔ-Ct analysis. Additionally, human umbilical vascular endothelial cells and human lung microvascular endothelial cells were treated with 1:10 diluted plasma from 15 patients with sepsis in culture media. After 30 minutes, either 50 or 100 µg/mL recombinant human proteoglycan 4 was administered. Interleukin-6 protein and gene expression were assayed. Proteoglycan 4 levels were also compared between control and sepsis patient plasma.

MEASUREMENTS AND MAIN RESULTS

Human umbilical vascular endothelial cell, human lung microvascular endothelial cell, and mouse lung microvascular endothelial cell treated with lipopolysaccharide had significantly increased interleukin-6 protein compared with controls. Recombinant human proteoglycan-4 significantly reduced interleukin-6 in human and mouse endothelial cells. Interleukin-6 gene expression was significantly increased after lipopolysaccharide treatment compared with controls. This response was reversed by 50 or 100 µg/mL recombinant human proteoglycan-4 in 80% of sepsis samples in human umbilical vascular endothelial cells and in 60-73% in human lung microvascular endothelial cells. In Cd44 -/- genotypes of the mouse lung microvascular endothelial cells, recombinant human proteoglycan-4 significantly reduced interleukin-6 protein levels after lipopolysaccharide treatment, indicating that Cd44 is not needed for recombinant human proteoglycan-4 to have an effect in a toll-like receptor 4 agonist inflammation model. Patient sepsis samples had higher plasma levels of native proteoglycan-4 than controls.

INTERPRETATION AND CONCLUSIONS

Recombinant human proteoglycan-4 is a potential adjunct therapy for sepsis patients and warrants future in vivo model studies.

Dialyzable Leukocyte Extract (Transferon™) Administration in Sepsis: Experience from a Single Referral Pediatric Intensive Care Unit

Immunomodulatory agents have been proposed as therapeutic candidates to improve outcomes in sepsis. Transferon™, a dialyzable leukocyte extract (DLE), has been supported in Mexico as an immunomodulatory adjuvant in anti-infectious therapy. Here we present a retrospective study describing the experience of a referral pediatric intensive care unit (PICU) with Transferon™ in sepsis. We studied clinical and laboratory data from 123 patients with sepsis (15 in the DLE group and 108 in the control group) that were admitted to PICU during the period between January 2010 and December 2016. Transferon™ DLE use was associated with lower C reactive protein (CRP), increase in total lymphocyte counts (TLC), and decrease in total neutrophil count (TNC) 72 hours after Transferon™ DLE administration. The control group did not present any significant difference in CRP values and had lower TLC after 72 hours of admission. There was no difference in PICU length of stay between control and Transferon™ DLE group. Transferon™ DLE administration was associated with a higher survival rate at the end of PICU stay. This study shows a possible immunomodulatory effect of Transferon™ on pediatric sepsis patients.