Differentiating between bacterial and viral infections by estimated CRP velocity

Optoelectronic microfluidic device for point-of-care blood plasma viscosity measurement

Physical properties of blood plasma, such as viscosity, serve as crucial indicators of disease. The inherent capillary effect of paper microchannels, coupled with minimal sample requirement, stimulated the advancement of paper-based viscometers. This study presents a precise, non-contact optoelectronic system using a microfluidic platform for the measurement of blood plasma viscosity. Microchannels were defined onto the filter paper using an available and inexpensive wax crayon, without the need for conventional wax printing equipment. The time required for the 5 μL sample to pass a specific distance was measured using two pairs of infrared sensors. Subsequently, this data was sent to the microcontroller, which automatically calculated the viscosity. Throughout the measurements, sample temperature was maintained at a constant 37 °C through an integrated heater with automated control. The microfluidic platform successfully processed real samples, yielding viscosity measurements in under three minutes. Evaluation with fetal bovine serum, spiked with varying protein concentrations in both native and denatured states, demonstrated a precision exceeding 96% compared to conventional Ostwald viscometer readings. For human subjects exhibiting pathologies affecting serum and plasma viscosity compared to physiological norms, strong correlations were observed between resultant values and clinical diagnoses. The proposed device aims to replace expensive and complex optical equipment, offering a safer alternative for measuring plasma viscosity. Unlike similar devices, it eliminates the risk of component deformation due to chemical contact or unsafe irradiation.

Full-Length Single Protein Molecules Tracking and Counting in Thin Silicon Channels

Emerging single-molecule protein sensing techniques are ushering in a transformative era in biomedical research. Nevertheless, challenges persist in realizing ultra-fast full-length protein sensing, including loss of molecular integrity due to protein fragmentation, biases introduced by antibodies affinity, identification of proteoforms, and low throughputs. Here, a single-molecule method for parallel protein separation and tracking is introduced, yielding multi-dimensional molecular properties used for their identification. Proteins are tagged by chemo-selective dual amino-acid specific labels and are electrophoretically separated by their mass/charge in custom-designed thin silicon channel with subwavelength height. This approach allows analysis of thousands of individual proteins within a few minutes by tracking their motion during the migration. The power of the method is demonstrated by quantifying a cytokine panel for host-response discrimination between viral and bacterial infections. Moreover, it is shown that two clinically-relevant splice isoforms of Vascular endothelial growth factor (VEGF) can be accurately quantified from human serum samples. Being non-destructive and compatible with full-length intact proteins, this method opens up ways for antibody-free single-protein molecule quantification.

Development of a double antibody sandwich ELISA method for the quantitative detection of serum C-reactive protein based on nanobody

In this study, we successfully developed a nanobody-based double antibody sandwich ELISA kit for the detection of clinical serum C-reactive protein (CRP) by using two novel CRP specific nanobodies. The developed method exhibited a linear detection range of approximately 6-200 ng/mL, with a detection limit of 1 ng/mL. Furthermore, the method demonstrated excellent specificity, as there was no cross-reactivity with interfering substances such as total bilirubin and hemoglobin and so on. To assess reproducibility, independent measurements of the samples were conducted under experimental conditions, resulting in intra- and inter-batch coefficients of variation below 10% and a recovery rate of 93%-102%. These results indicate robust reproducibility of the method. To evaluate the performance of the developed kit, we collected 90 clinical samples for correlation analysis with commercial kits. The results showed a high correlation coefficient value (R2) of 0.98, indicating accurate concordance between the developed and commercial kits. In conclusion, our study successfully developed a nanobody-based double antibody sandwich ELISA kit to detect clinical serum CRP. The utilization of nanobodies represents a significant advancement in the field of CRP immunoassay development. The developed kit demonstrates excellent performance characteristics and holds promise for clinical applications.

Estimated C-reactive protein (CRP) velocity for rapidly distinguishing bacterial from other etiologies in children presenting to emergency department with remarkably elevated CRP levels

The use of a single C-reactive protein (CRP) value to differentiate between bacterial and non-bacterial causes is limited. Estimated CRP velocity (eCRPv) has shown promise in enhancing such discrimination in adults. This study aims to investigate the association between eCRPv and bacterial etiologies among pediatric patients with very elevated CRP levels. We conducted a retrospective analysis of patients under 18 years of age who had been admitted to our Pediatric Emergency Department from 2018 to 2020 with a fever and CRP levels ≥ 150 mg/L. Bacterial and non-bacterial etiologies were determined from hospital discharge diagnoses, which were monitored independently by three physicians from the research team. The records of 495 suitable patients (51.2% males, median age 3.2 years) were retrieved of whom 444 (89.7%) were eventually diagnosed with bacterial infections. The mean CRP levels were significantly higher for bacterial etiologies compared with other causes (209.2 ± 59.8 mg/L vs. 185.6 ± 35.8 mg/L, respectively, p < .001), while the mean eCRPv values did not differ significantly (p = .15). In a time course analysis, we found that specifically in patients presenting ≥ 72 h after symptom onset, only a eCRPv1 level > 1.08 mg/L/h was an independent predictor of bacterial infection (aOR = 5.5 [95% CI 1.7-17.8], p = .004).   Conclusion: Pediatric patients with very high CRP levels and fever mostly have bacterial infections. eCRPv levels, unlike CRP values alone, can serve as the sole independent predictor of bacterial infection > 72 h from symptom onset, warranting further prospective investigations into CRP kinetics in pediatric patients. What is Known: • The use of a single C-reactive protein (CRP) value to differentiate between bacterial and non-bacterial causes is limited. • Estimated CRP velocity (eCRPv) has shown promise in enhancing such discrimination in adults, but data on CRP kinetics in pediatric patients is sparse. What is New: • eCRPv levels, unlike CRP values alone, can serve as the sole independent predictor of bacterial infection > 72 h from symptom onset in pediatric patients with remarkably elevated CRP levels.

Protocol for the diagnostic performance of C reactive protein, procalcitonin and interleukin-6 for serious bacterial infections among children ≤36 months old presenting with fever without source: a systematic review and meta-analysis

INTRODUCTION

The management of fever without source in children ≤36 months old remains a diagnostic challenge as the underlying aetiologies can vary from self-limiting viral infections to serious bacterial infections (SBIs). Biomarkers such as C reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) have varying thresholds in the prediction of SBIs due to differences in SBI definitions, SBI prevalence, patient characteristics and timing of presentation. This protocol describes a systematic review and meta-analysis that aims to determine the thresholds at which CRP, PCT and IL-6 can perform optimally in distinguishing the presence of SBIs in children ≤36 months old, as well as to determine their performances in early detection of bacterial infections within 48 hours of fever onset.

METHODS AND ANALYSIS

We will systematically search electronic databases including MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane CENTRAL, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and Science Citation Index from 1 July 2023 to 31 July 2023. We will include studies that report the diagnostic accuracy of CRP, PCT and IL-6 in detecting SBIs in children aged ≤36 months presenting with fever without apparent source. Randomised controlled trials (RCTs) and non-randomised studies including non-RCTs and controlled before-and-after studies will be included. A meta-analysis will be performed and diagnostic performances of these biomarkers will be reported.

ETHICS AND DISSEMINATION

The results of this study will provide guidance on clinical decision-making in young children presenting with fever without source. Ethics approval will not be required for this study. The authors aim to publish the findings in a peer-reviewed journal as well as present at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42023439093.

Leveraging machine learning to distinguish between bacterial and viral induced pharyngitis using hematological markers: a retrospective cohort study

Accurate differentiation between bacterial and viral-induced pharyngitis is recognized as essential for personalized treatment and judicious antibiotic use. From a cohort of 693 patients with pharyngitis, data from 197 individuals clearly diagnosed with bacterial or viral infections were meticulously analyzed in this study. By integrating detailed hematological insights with several machine learning algorithms, including Random Forest, Neural Networks, Decision Trees, Support Vector Machine, Naive Bayes, and Lasso Regression, for potential biomarkers were identified, with an emphasis being placed on the diagnostic significance of the Monocyte-to-Lymphocyte Ratio. Distinct inflammatory signatures associated with bacterial infections were spotlighted in this study. An innovation introduced in this research was the adaptation of the high-accuracy Lasso Regression model for the TI-84 calculator, with an AUC (95% CI) of 0.94 (0.925-0.955) being achieved. Using this adaptation, pivotal laboratory parameters can be input on-the-spot and infection probabilities can be computed subsequently. This methodology embodies an improvement in diagnostics, facilitating more effective distinction between bacterial and viral infections while fostering judicious antibiotic use.

Association of mTOR Pathway and Conformational Alterations in C-Reactive Protein in Neurodegenerative Diseases and Infections

Inflammatory biomarkers have been very useful in detecting and monitoring inflammatory processes along with providing helpful information to select appropriate therapeutic strategies. C-reactive protein (CRP) is a nonspecific, but quite useful medical acute inflammatory biomarker and is associated with persistent chronic inflammatory processes. Several studies suggest that different levels of CRP are correlated with neurological disorders such as Alzheimer's disease (AD). However, dynamics of CRP levels have also been observed in virus/bacterial-related infections leading to inflammatory responses and this triggers mTOR-mediated pathways for neurodegeneration diseases. The biophysical structural transition from CRP to monomeric CRP (mCRP) and the significance of the ratio of CRP levels on the onset of symptoms associated with inflammatory response have been discussed. In addition, mTOR inhibitors act as immunomodulators by downregulating the expression of viral infection and can be explored as a potential therapy for neurological diseases.

Lower levels of FOXP3 are associated with prolonged inflammatory responses in kidney transplant recipients

Background

Immunosuppressive treatment of kidney transplant recipients is mainly aimed at pro-inflammatory T effector cells, yet they also target the immunosuppressive T regulatory cells. Here, we test the hypothesis that low levels of the master gene regulator of T regulatory cells, forkhead box P3 (FOXP3) splice variants, are associated with prolonged inflammatory responses to stimuli.

Methods

From blood samples obtained the first - and 29th day post-transplant, we extracted peripheral blood mononuclear cells and measured mRNA levels of Total FOXP3, pre-mature RNA FOXP3 (pre-mRNA FOXP3), full length FOXP3 (FOXP3fl) and, FOXP3 splice variant excluding exon two (FOXP3d2). We defined the primary outcome as the number of days in which C reactive protein (CRP) was above 50 mg/L. CRP levels were gathered in two periods, the first from the second to 29 days post-transplant, and the second from 30 to 57 days post-transplant. The association was tested using adjusted negative binomial regression.

Results

From 507 included kidney transplant recipients, 382 recipients had at least one CRP measurement >50 mg/L in the first period, median duration of elevated CRP was 4 days [interquartile range (IQR) 2 to 6]. In the second period, 69 recipients had at least one CRP measurement >50 mg/L, median duration of elevated CRP was 3 days [IQR 2 to 5]. In the first period, we found a significant association between lower levels of Total FOXP3 and prolonged duration of CRP elevation, incidence rate ratio 0.61 (95% confidence interval 0.46-0.80), p<0.01.

Conclusion

Lower levels of total FOXP3 mRNA levels in peripheral blood of kidney transplant recipients are associated with prolonged duration of inflammatory responses regardless of the underlying stimuli.