The potential benefit of a second C-reactive protein measurement in patients with gram-negative bacteraemia presenting to the emergency medicine department

Inflammation-Associated Tubulopathy in Patients with Acute Bacterial Infections

Background

Acute kidney injury associated with the underlying inflammatory process of an acute bacterial infection affects patient morbidity and mortality. Clinicians use creatinine and estimated glomerular filtration rate (EGFR) to assess this renal injury, however, these measures may lag behind and change only once significant kidney injury has occurred. Neutrophil gelatinase-associated lipocalin (NGAL) is up-regulated by inflammation and infection and may serve as an early detection biomarker of kidney injury.

Methods

Patients hospitalized with bacterial infections were assessed demographically, clinically and had their creatinine levels, EGFR and inflammatory biomarker levels, including urinary NGAL measured. Findings were compared between controls and patients across different EGFRs.

Results

Fifty-one participants were included in the study. Among this cohort, 31 suffered bacterial infection. Inflammatory biomarkers including urinary NGAL were found to be higher in the infection group compared to the control group. Urinary NGAL level was significantly higher across all EGFRs of patients diagnosed with infection, including those with normal EGFR.

Conclusion

Urinary NGAL identifies early kidney damage associated with bacterial infection even at normal EGFR and alerts the treating physician to undertake the necessary measures to mitigate the renal injury.

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.

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.

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.

Sepsis Related Mortality Associated with an Inflammatory Burst in Patients Admitting to the Department of Internal Medicine with Apparently Normal C-Reactive Protein Concentration

Background: Patients who are admitted to the Department of Internal Medicine with apparently normal C-reactive protein (CRP) concentration impose a special challenge due the assumption that they might not harbor a severe and potentially lethal medical condition. Methods: A retrospective cohort of all patients who were admitted to the Department of Internal Medicine with a CRP concentration of ≤31.9 mg/L and had a second CRP test obtained within the next 24 h. Seven day mortality data were analyzed. Results: Overall, 3504 patients were analyzed with a mean first and second CRP of 8.8 (8.5) and 14.6 (21.6) mg/L, respectively. The seven day mortality increased from 1.8% in the first quartile of the first CRP to 7.5% in the fourth quartile of the first CRP (p < 0.0001) and from 0.6% in the first quartile of the second CRP to 9.5% in the fourth quartile of the second CRP test (p < 0.0001), suggesting a clear relation between the admission CRP and in hospital seven day mortality. Conclusions: An association exists between the quartiles of CRP and 7-day mortality as well as sepsis related cause of death. Furthermore, the CRP values 24 h after hospital admission improved the discrimination.

Septic arthritis of the wrist and the hand: - An Emergency department case study

Joint pain is a common presentation in the Emergency department. There are countless potential causes for pain and swelling in a joint. Septic arthritis is a true joint emergency as it can lead to rapid, irreversible destruction of the joint. If not diagnosed early this infection can lead to considerable functional deficit. Our case is unique in that our patient presented to the Emergency department requesting referral to the fracture clinic for continued management of a suspected scaphoid bone fracture but was found to have Neisseria gonorrhoea causing septic arthritis of the joint. This case highlights the importance of accurate history taking, clinical examination and assessment of the patients presenting with joint pain.

Use of infection biomarkers in the emergency department

The use of infection biomarkers in the emergency department is discussed in terms of their possible contributions to diagnostic-prognostic uncertainties, appropriate antibiotic treatments, and triage and follow-up planning. Procalcitonin (PCT), C-reactive protein (CRP), proadrenomedullin (proADM), and presepsin are among the most discussed infection biomarkers for use in the emergency department. Due to the variable sensitivity results and cutoff values, there are insufficient data to recommend the widespread use of CRP and procalcitonin (PCT) for the diagnosis and prognosis of infection in the emergency department. However, these biomarkers can be used for appropriate antibiotic use in selected infection groups, such as community-acquired pneumonia, especially to reduce unnecessary antibiotic prescribing. With its prognostic superiority over other biomarkers and its contribution to prognostic score systems in community-acquired pneumonia (CAP), proADM can be used to predict hospitalization, preferably within the scope of clinical studies. Although presepsin has been shown to have some advantages over other biomarkers to rule out sepsis, there are insufficient data for its clinical use in the emergency department.

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

Background

To assess the utility of C-reactive protein (CRP) velocity to discriminate between patients with acute viral and bacterial infections who presented with relatively low CRP concentrations and were suspected of having a bacterial infection.

Methods

We analyzed a retrospective cohort of patients with acute infections who presented to the emergency department (ED) with a relatively low first CRP measurement (CRP1) ≤ 31.9 mg/L and received antibiotics shortly after. We then calculated C-reactive protein velocity (CRPv), milligram per liter per hour, for each patient based on CRP1 and the second CRP value (CRP2) measured within the first 24 h since admission. Finally, we compared CRPv between patients with bacterial and viral infections.

Results

We have presently analyzed 74 patients with acute bacterial infections and 62 patients with acute viral infections at the mean age of 80 and 66 years respectively, 68 male and 68 female. CRP1 did not differ between both groups of patients (16.2 ± 8.6 and 14.8 ± 8.5 for patients with viral and bacterial infections respectively, p value = 0.336). However, the CRP2 was significantly different between the groups (30.2 ± 21.9 and 75.6 ± 51.3 for patients with viral and bacterial infections respectively, p-value < 0.001) and especially the CRPv was much higher in patients with acute bacterial infections compared to patients with acute viral infections (0.9 ± 1.2 and 4.4 ± 2.7 respectively, p-value < 0.001).

Conclusion

CRPv and CRP2 are useful biomarkers that can discriminate significantly between patients who present with acute bacterial and viral infections, and relatively low CRP concentration upon admission who were suspected of having a bacterial infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06878-y.

Patients who are admitted to the Department of Internal Medicine with a very low C-reactive protein concentration

Introduction

C-reactive protein (CRP) is a marker commonly used in clinical practice as a reference for the inflammatory activity in vivo. Low levels are often associated with good health and lower risk for adverse outcomes.

Patients and methods

We examined medical records of the last 6 years, of all patients admitted for hospitalization in internal medicine wards who had the first CRP measurement below ≤ 0.03 mg/L (detection limit). Diagnosis criteria and 7 days’ survival were reviewed.

Results

Out of 61,590 total admissions to internal medicine wards, three hundred and thirteen patients had CRP equal to or lower than 0.03 mg/L (0.5%). Second CRP measurement revealed gradual increment up to 10.8 ± 35.4 mg/L. Four patients died within 7 days from admission.

Discussion

Presentation to the internal medicine department with a very low concentration of CRP is highly unusual, but it does not exclude the existence of significant acute morbidities. Clinicians should take additional CRP tests before any conclusion is considered regarding the presence or absence of an inflammatory response.

The superiority of 72 h leukocyte descent over CRP for mortality prediction in patients with sepsis

BACKGROUND

Detection of an eventful course in the early days of sepsis treatment is clinically relevant. The white blood cell count (WBCC) and C-reactive protein (CRP) are used in daily practice to monitor the intensity of the inflammatory response associated with sepsis. It is not entirely clear which of the two might better discriminate the outcomes of patients with sepsis.

METHODS

30-day mortality was assessed in a cohort of patients who were hospitalized with sepsis in the departments of Internal Medicine in a tertiary medical center. Admission and 72-hour time points were analyzed to discriminate between patients with increased versus decreased 30 days mortality risk.

RESULTS

The study included 195 patients. Higher 72 h CRP, WBCC, neutrophil counts and neutrophils to lymphocyte ratio were associated with increased mortality (p < 0.02). Baseline WBCC and CRP failed to discriminate between patients who died and those who survived (AUC = 0.551, 0.479). In multivariate analysis of the 72 h tests, higher WBCC count (OR = 1.12, 95%CI 1.05-1.20, p = 0.001), was associated with increased mortality whereas CRP was not (OR = 1.004, 95%CI 0.998-1.01, p = 0.146).

CONCLUSION

Patients who presented a 72-hour leukocyte descent had a better outcome and in this regard, WBCC was superior to 72-hour CRP in predicting 30 days mortality.