C-reactive protein velocity discriminates between acute viral and bacterial infections in patients who present with relatively low CRP concentrations

Comparative Efficacy of Ultrasound and Laser Therapy in Modulating Inflammatory Markers in a Rat Model of Testicular Inflammation

Introduction: All three degrees of inflammation (cellular, tissue, and systemic) are normal reactions that our bodies have to foreign substances. Cellular damage from bacteria, viruses, and even cancer can be warded off with the aid of these reactions. An efficient non-pharmaceutical method of treating inflammation is frequently seen as physiotherapy. In this study, the effects of ultrasonic treatment (US) and low-level laser therapy (LLLT) on the levels of C-reactive protein (CRP) in rats with inflamed testicles are investigated. Methods: Three groups, each including eighteen male rats, were established: the control group (C), the US group (which received ultrasonic treatment), and the LLLT group (which received low-level laser therapy). Results: The blood CRP levels in the US group were significantly lower than those in the control and LLLT groups. Conclusion: Findings suggest that ultrasound might be more effective than LLLT in treating testicular inflammation, as shown by the decrease in blood CRP levels.

Characterizing CRP dynamics during acute infections

PURPOSE

C-reactive protein (CRP) is a common proxy of inflammation, but accurate characterizations of its dynamics during acute infections are scant. The goal of this study was to examine C-reactive protein (CRP) trajectories in hospitalized patients with viral infections, confirmed bacteremia (stratified by Gram-negative or Gram-positive bacteria), and non-bacteremic infections/inflammations, considering antibiotic treatment.

METHODS

Electronic medical records from Tel Aviv Sourasky Medical Center (July 2007-May 2023) were analyzed. Patients with blood cultures or positive viral tests were included. CRP levels were modeled using generalized additive mixed-effects models (GAMMs) and observed up to 150 h after initial infection diagnosis. Patients with initial CRP levels > 31.9 were excluded, to remove individuals already in a highly active inflammatory process. The shapes of the CRP curves were characterized and peak CRP as well as area under the CRP curve were the primary variables of interest.

RESULTS

Viral infections had the lowest and flattest CRP curves. Non-bacteremic infections showed intermediate levels, while bacteremia (especially Gram-negative under antibiotic treatment) had the highest CRP peaks. For instance, peak CRP ranged from 15.4 mg/L in viral infections without antibiotics to 140.9 mg/L in Gram-negative bacteremia with antibiotics.

CONCLUSIONS

CRP trajectories significantly differ based on infection type and antibiotic treatment. Frequent CRP measurement could be a valuable diagnostic and risk stratification tool in hospitalized patients.

The value of C-reactive protein velocity (CRPv) on mortality in sepsis patients who are emergently hospitalized in the ICU: A retrospective single-center study

Purpose

The C-reactive protein (CRP) velocity (CRPv) is an indicator of the change in CRP over time. In individuals with sepsis, the second values of CRP and CRPv have been shown to have more importance than the first CRP value measured at admission. This study examined the importance of CRPv for mortality among individuals who were hospitalized in the intensive care unit (ICU).

Methods

The study was conducted between January 2021 and December 2022. CRPv was calculated according to the change in the second CRP value compared to the first.

Results

The median age of the patients was 79 years (interquartile range (IQR), 69-85 years), and 53.2 % were male. The in-hospital mortality rate was 45.5 %. The presence of diabetes increased the odds of mortality by 2.17 times (confidence interval (CI): 1.06-4.4, p=0.032). Each increase in CRPv by 1 mg/dl/hour increased the odds of mortality by 1.07 times (CI: 1.01-1.14, p=0.015), while each one-point increase in the Sequential Organ Failure Assessment (SOFA) score increased the odds of mortality by 1.21 times (CI: 1.07-1.35, p=0.002). The SOFA score had the highest area under the curve (AUC) value for in-hospital mortality (AUC = 0.699 p=<0.001). When the SOFA was >7, its sensitivity in predicting mortality was 46.7 %, and its specificity was 85.1 %. The AUC value of CRPv in predicting mortality was 0.629 (p=0.006). When CRPv was >0.75, its sensitivity in predicting mortality was 68.2 %, and its specificity was 57 %.

Conclusion

CRPv performed well in predicting mortality and had satisfactory discriminative ability. Additionally, diabetes, SOFA score, and CRPv elevation were significant risk factors for mortality.

Altered anthropometrics and HA1c levels, but not dyslipidemia, are associated with elevated hs-CRP levels in middle-aged adults: A population-based analysis

Population-based studies of cardiovascular disease markers, such as hs-CRP, are crucial. However, studies exploring the effect of metabolic indices on hs-CRP while controlling for confounding variables adequately in middle-aged adults are limited. Using Wave 5 data from the National Longitudinal Study of Adolescent Health (Add Health), we examined the impact of various metabolic indices on hs-CRP in adults aged 32-42, controlling for eight allergic and infectious factors that may elevate hs-CRP levels. We used multiple linear regression analysis to determine which factors predict hs-CRP levels after log transformation of the dependent variable. The total number of participants was N = 1839 (weighted N = 1390763), with a mean age of 38.1 (SD = 2.0) and 46.4% having obesity. Among the controlled variables, recent surgery was the only confounder to significantly predict increased hs-CRP levels (P = 0.029, exponentiated estimate (EE) = 1.61; 95% Cl: [1.31-1.91]). Notably, current smoking and altered LDL or TG levels did not show a significant association with hs-CRP levels (P > 0.05). However, a significant increase in hs-CRP levels was observed in females compared to males (P < 0.001, EE = 1.43; 95%Cl: [1.35-1.51]). Similar findings were noted for diabetic HbA1c levels (P = 0.001, EE = 1.6; 95%CL: [1.42-1.78]), high waist circumference (P = 0.015, EE = 1.25; 95%CL: [1.15-1.35]), and grade 3 obesity (P = 0.006, EE = 7.62; 95%CL: [2.86-12.38]). Although not statistically significant, hs-CRP levels exhibited a gradual increase with rising BMI after controlling for other variables. These findings will improve the clinical application of hs-CRP in predicting coronary artery disease, especially in younger adults.

C-reactive protein (CRP) evaluation in human urine using optical sensor supported by machine learning

The rapid and sensitive indicator of inflammation in the human body is C-Reactive Protein (CRP). Determination of CRP level is important in medical diagnostics because, depending on that factor, it may indicate, e.g., the occurrence of inflammation of various origins, oncological, cardiovascular, bacterial or viral events. In this study, we describe an interferometric sensor able to detect the CRP level for distinguishing between no-inflammation and inflammation states. The measurement head was made of a single mode optical fiber with a microsphere structure created at the tip. Its surface has been biofunctionalized for specific CRP bonding. Standardized CRP solutions were measured in the range of 1.9 µg/L to 333 mg/L and classified in the initial phase of the study. The real samples obtained from hospitalized patients with diagnosed Urinary Tract Infection or Urosepsis were then investigated. 27 machine learning classifiers were tested for labeling the phantom samples as normal or high CRP levels. With the use of the ExtraTreesClassifier we obtained an accuracy of 95% for the validation dataset. The results of real samples classification showed up to 100% accuracy for the validation dataset using XGB classifier.

An in-depth investigation of serum Krebs von den Lungen-6 and other biomarkers in COVID-19 severity and mortality

Krebs von den Lungen-6 (KL-6) is a glycoprotein mainly expressed by type II pneumocytes and recently known as a lung injury biomarker. However, the number of studies is still limited, especially in Indonesian COVID-19 populations. Therefore, we aim to provide correlation, sensitivity, and specificity analyses of KL-6 and other biomarkers in Indonesian COVID-19 severity and mortality. We conducted a cross-sectional study involving adult COVID-19 patients at Universitas Airlangga Hospital, Surabaya, East Java, Indonesia, between March 26, 2021, and August 25, 2021. KL-6 and other biomarker levels were compared according to severity (severe versus non-severe) and mortality (non-survivor versus survivor). We also included the receiver operating characteristic analysis to define the optimal cut-off, sensitivity, and specificity of KL-6 to determine COVID-19 severity and mortality. We enrolled 78 COVID- 19 patients (23 non-survivors), including 39 non-severe and 39 severe patients. There was no significant difference in serum KL-6 levels, neither in severity nor mortality groups. KL-6 had the strongest positive correlations with ferritin in severe patients (r=0.313) and non-survivors (r=0.467). We observed that the best sensitivity was KL-6 combined with platelet-to- lymphocyte ratio (PLR) (0.818) in severe patients and with neutrophil-to-lymphocyte ratio (NLR)/PLR/ferritin/C-reactive protein (0.867) in non-survivors. In contrast, the best specificity was found when KL-6 was combined with NLR/D-dimer (0.750) in severe patients and with D-dimer (0.889) in non-survivors. Serum KL-6 is a useful auxiliary laboratory evaluation index for COVID-19 lung injury to depict its severity and mortality.

The Feasibility of C-Reactive Protein Point-of-Care Testing to Reduce Overuse of Antibiotics in Children with Acute Respiratory Tract Infections in Rural Kyrgyzstan: A Pilot Study

Background

In Kyrgyzstan, the morbidity prevalence of and morbidity from acute respiratory tract infections (ARTI) in children is high. Local healthcare workers (HCW) often prescribe antibiotics that are not indicative due to a mix of professional and societal factors. It is suggested to precede with a decision on antibiotics by a point-of-care test (POCT) on the appropriateness of the treatment, eg, a measurement of C-reactive protein (CRP). CRP-guided antibiotic stewardship in children with ARTI has not previously been studied in Central Asia.

Purpose

This pilot study was conducted to examine the feasibility of the methods and procedures to be used in the upcoming randomised controlled COORDINATE clinical trial (NCT05195866) and in daily clinical practice in primary care.

Patients and methods

HCWs from three selected rural healthcare facilities were trained in the CRP POCT and in interpretation of results. Children aged 6 months to 12 years attending the primary healthcare facilities with respiratory symptoms were randomly assigned to CRP-guided management or standard care, guided by clinical findings only. Children were followed up for 14 days by scheduled telephone calls to caregivers.

Results

Eighty-one children participated in this pilot study. The CRP POCT and the trial procedures were acceptable to the target group as well as to the HCWs. Children from both groups recovered equally well, with an observed significant lower use of antibiotics in the CRP group. HCWs generally adhered to the CRP guidelines, and only once was an antibiotic prescribed despite low CRP results. No safety concerns were observed. Four parents provided wrong phone numbers impeding follow-up. We will collect all mobile phone numbers in the household for the main trial.

Conclusion

The pilot provided satisfactory results, suggesting that the COORDINATE trial of CRP POCT is effective, feasible with minor adjustments and without apparent safety concerns for the participants.

An exploration of the value of NLR, PLR, LMR, and WBC × CRP for the diagnosis and treatment of influenza B in adults

The aim of the study was to study the diagnostic and therapeutic utility of NLR (neutrophil-to-lymphocyte ratio), LWR (lymphocyte-to-monocyte ratio), PLR (platelet-to-lymphocyte ratio), and WBC × CRP (WBC: white cell count, CRP: C-reactive protein) in patients with influenza B. This retrospective study included 122 adult patients with influenza B, 176 adult patients with bacterial infection, and 119 adult healthy physical examinees for routine blood examination and CRP testing, calculation of NLR, LMR, PLR, and WBC × CRP for relevant statistical analysis, monitoring of NLR, LMR, PLR and WBC × CRP in patients with influenza B during relevant treatment. All indicators, except for WBC and NLR, had no statistical differences between the influenza B group, the normal control group, and the influenza B group and bacterial infection group, respectively, and showed no statistical significance for the differences between the groups. The diagnostic effect of LMR and WBC × CRP was deemed good or excellent in patients with influenza B, healthy people, and patients with a bacterial infection. Conversely, NLR and PLR could only distinguish patients with influenza B from healthy people but remained unable to identify different pathogens. Moreover, many false negatives were noted for WBC and CRP during the diagnosis of influenza B. Also, NLR, LMR, PLR, and WBC × CRP exerted a good effect in evaluating curative effect and conditions for influenza B. LMR and WBC × CRP have a relatively high value in the early diagnosis of adults suffering from influenza B. Also, NLR and PLR excelled at differentiating adult patients with influenza B from healthy people. Therefore, NLR, PLR, LMR, and WBC × CRP can all be used for disease course monitoring and efficacy evaluation.

Early signaling of inflammation in patients following traumatic injury with accurately estimated time of injury by profiling C-reactive protein levels

BACKGROUND

Despite its widespread use, the precise dynamics of CRP response in clinical practice remain poorly defined. We employed a novel quadratic model to explore the time-course analysis of CRP values in trauma patients with known precise time of injury.

METHODS

Relevant data on all adult patients admitted to our hospital following traumatic incidents between January 1st 2010 to December 31, 2020 were retrospectively collected. Those with a documented time of injury and who underwent CRP evaluation within the first 24 h since injury were studied.

RESULTS

Based on the findings from our annual health check-up center, we established a reference upper normal CRP value of 12.99 mg/L. Within the first 7 h after injury, the CRP levels of 8-9% of the 1545 study patients exceeded the reference threshold. The proportion of patients with CRP levels > 12.99 mg/L increased to 18.5% at 8-9 h later and rose sharply to 91.6% at 22-24 h later. Our quadratic model yielded the equation: CRP = 5.122-0.528xTime + 0.139xTime 2. It accounted for > 40% of the variance in CRP levels (R2 = 42.4%).

CONCLUSIONS

Clear and prominent CRP elevations following atraumatic event are detected only 9-12 h following the insult. This novel finding has crucial implications for accurate CRP assessment of inflammatory responses to physical injuries.

Why C-reactive protein is one of the most requested tests in clinical laboratories?

C-reactive protein (CRP) is an acute-phase protein which is synthesized by the liver in response to the secretion of several inflammatory cytokines including interleukin 6 (IL-6), IL-1 and tumor necrosis factor (TNF). CRP was the first acute-phase protein to be described and adopted in clinical laboratories as an exquisitely sensitive systemic marker of inflammation and tissue damage. The measurement of CRP is widely used for the diagnosis and monitoring of inflammatory conditions, including sepsis, trauma, and malignancies. In the last decades, impressive advances in analytical methods (from qualitative to high-sensitivity assays), automation and availability of results in a short time, not only translated in an increasing demand for the right management of systemic inflammatory diseases, but also in evaluating subclinical inflammatory processes underlying atherothrombotic events. CRP measurement is one of the most requested laboratory tests for both the wide range of clinical conditions in which it may assure a valuable information and some analytical advantages due to the evidence that it is a "robust biomarker". Even recently, the measurement of CRP received new interest, particularly as a biomarker of severity of Coronavirus disease 2019 (COVID-19), and it deserves further concern for improving demand appropriateness and result interpretation.

Early signaling of bacteremia in patients who present to the Department of Emergency Medicine with relatively low C-Reactive Protein (CRP) concentrations

OBJECTIVES

Examiningthe usefulness of C-reactive protein velocity (CRPv) as an early biomarker for the presence of bacteraemia in patients presenting to the Department of Emergency Medicine with acute infection/inflammation and suspected bacteraemia.

METHODS

A retrospective study examining a cohort of patients who presented to the E.R and in whom blood cultures were taken. CRPv was calculated as the difference in mg/hour/litter between two consecutive CRP tests performed within 12 hours.

RESULTS

256 patients were included in the cohort. Using CRPv in patients who at first presented with a relatively low (17.9≤mg/L 1^stquartile) CRP concentration, we found an AUC of 0.808±0.038 (p<0.001) for the presence of positive versus negative blood cultures (what is AUC?). This was better than the AUC that was obtained when the WBC for the same purpose.

CONCLUSIONS

CRPv may be a useful biomarker in the identification of patients with suspected bacteremiaand a low CRP-a challenging situation for clinicians who may underestimate the severity of illness in this patient group.

Discrepancy of C-Reactive Protein, Procalcitonin and Interleukin-6 at Hospitalization: Infection in Patients with Normal C-Reactive Protein, Procalcitonin and High Interleukin-6 Values

C-reactive protein (CRP) or procalcitonin (PCT) alone has limitations in the early detection of infection or inflammation due to shortcomings in specificity and varied cut-off values. Recently, interleukin (IL)-6 has been assessed, but it is not known to what extent the three values are homogeneous in reality. This retrospective study was conducted with two large datasets (discrepancy set with results within 24 h of admission [7149 patients] and follow-up set until 2 weeks of hospital stay [5261 tests]) consisting of simultaneous examinations of CRP, PCT, and IL-6 between January 2015 and August 2021. The specific discrepant group (n = 102, 1.4%) with normal CRP (<10 mg/L) and PCT (<0.1 ng/mL) and high IL-6 (≥100 pg/mL) values was extracted from the discrepancy set. Dimensionality reduction and visualization were performed using Python. The three markers were not clearly clustered after t-distributed stochastic neighbor embedding. Pearson’s correlation coefficients between two markers were substantially low (0.23−0.55). Among the high normalized IL-6 levels (≥0.5) (n = 349), 17.8% and 38.7% of CRP and PCT levels were very low (≤0.01). 9.2% and 13.4% of normal CRP (n = 1522) had high PCT (≥0.5 ng/mL) and IL-6 (≥100 pg/mL) values, respectively. Infection and bacteremia among 102 patients occurred in 36 (35.3%) and 9 (8.8%) patients, respectively. In patients with bacteremia, IL-6 was the first to increase, followed by PCT and CRP. Our study revealed that CRP, PCT, and IL-6 levels were considerably discrepant, which could be misinterpreted if only CRP tests are performed.

Diagnostic des pneumonies aiguës communautaires aux urgences et distinction entre étiologie virale ou bactérienne

La pandémie actuelle liée à l’émergence du SARSCoV-2 en 2019 a considérablement modifié la perception des médecins de l’impact des virus respiratoires et de leur rôle dans les pneumonies aiguës communautaires (PAC). Alors que plus de 25 % des tableaux de PAC chez l’adulte étaient d’origine virale, les virus respiratoires étaient souvent perçus comme des agents pathogènes peu graves. Devant le défi que représente encore à nos jours la documentation microbiologique d’une PAC, l’instauration d’un traitement empirique par antibiotiques est souvent réalisée aux urgences. La pandémie de COVID-19 a surtout mis en exergue le rôle déterminant de la biologie moléculaire et du scanner thoracique dans l’algorithme diagnostique de la PAC. En effet, un diagnostic rapide et fiable est la clé pour améliorer les mesures de précaution et réduire la prescription inutile d’antibiotiques. Du fait de prises en charges très différentes, il est nécessaire de distinguer l’étiologie virale de la bactérienne d’une PAC.

C-Reactive Protein Velocity (CRPv) as a New Biomarker for the Early Detection of Acute Infection/Inflammation

C-reactive protein (CRP) is considered a biomarker of infection/inflammation. It is a commonly used tool for early detection of infection in the emergency room or as a point-of-care test and especially for differentiating between bacterial and viral infections, affecting decisions of admission and initiation of antibiotic treatments. As C-reactive protein is part of a dynamic and continuous inflammatory process, a single CRP measurement, especially at low concentrations, may erroneously lead to a wrong classification of an infection as viral over bacterial and delay appropriate antibiotic treatment. In the present review, we introduce the concept of C-reactive protein dynamics, measuring the velocity of C-reactive protein elevation, as a tool to increase this biomarker’s diagnostic ability. We review the studies that helped define new metrics such as estimated C-reactive protein velocity (velocity of C-reactive protein elevation from symptoms’ onset to first C-reactive protein measurement) and the measured C-reactive protein velocity (velocity between sequential C-reactive protein measurements) and the use of these metrics in different clinical scenarios. We also discuss future research directions for this novel metric.