Procalcitonin assay in systemic inflammation, infection, and sepsis: clinical utility and limitations. Crit Care Med. 2008;36:941-952. [PMID: 18431284 DOI: 10.1097/ccm.0b013e318165babb]

Prognostic impact of elevated C-reactive protein and procalcitonin in patients with extensive-stage small cell lung cancer

Small cell lung cancer (SCLC) constitutes around 15% of lung cancer cases and stands as the primary cause of cancer-related fatalities in men and the second leading cause in women globally. In this study, our objective was to evaluate the levels of C-reactive protein (CRP) and procalcitonin (PCT) in newly diagnosed extensive-stage SCLC patients without evidence of infection. We aimed to demonstrate that elevated CRP and PCT levels may not solely indicate infection but could also be elevated in malignancies. Furthermore, we sought to correlate these marker levels with patient and disease characteristics to elucidate the relationship between these inflammation markers and disease progression. A total of 115 patients who were pathologically and radiologically diagnosed with extensive-stage SCLC between January 2020 and December 2022 and who had received no prior treatment were included in the study. The Kaplan-Meier analysis revealed a median progression-free survival (PFS) of 7.46 months [95% confidence interval (CI), 6.85-8.07] and a median overall survival (OS) of 10.50 months (95% CI, 8.69-12.30) for all patients. In the group with elevated PCT, the median PFS was 6.73 months (95% CI, 3.92-9.54), whereas it was 7.86 months (95% CI, 7.13-8.59) in the group with normal PCT ( P  = 0.002). Similarly, the median OS was 9.10 months (95% CI, 5.61-12.58) in the elevated PCT group and 11.66 months (95% CI, 9.59-13.74) in the normal PCT group ( P  = 0.006). Patients with elevated procalcitonin (PRC) levels at the time of diagnosis exhibited shorter PFS and OS durations compared to patients with normal PRC levels. Furthermore, elevated CRP has also been demonstrated to correlate with poorer prognosis in extensive-stage SCLC.

Utility of C-reactive protein and procalcitonin in community-acquired pneumonia in children: a narrative review

The purpose of this narrative review is to analyze the most recent studies about the role of C-reactive protein (CRP) and procalcitonin (PCT), two of the main biomarkers of infection, in distinguishing viral from bacterial etiology, in predicting the severity of infection and in guiding antibiotic stewardship in children with community-acquired pneumonia (CAP). The studies examined reveal that both CRP and PCT play a valuable role in diagnosing pediatric CAP, though each has limitations. CRP has moderate accuracy in distinguishing bacterial from viral infections, but its elevated levels are not exclusive to bacterial infections; PCT, however, shows higher specificity for bacterial CAP, with studies confirming its ability to differentiate bacterial causes, especially in severe cases. When integrated with clinical findings, CRP and PCT improve the sensitivity of pneumonia diagnoses and help in predicting severe outcomes such as sepsis and empyema; furthermore, both biomarkers prove useful in guiding antibiotic therapy, with PCT showing a more dynamic response to treatment. However, even though CRP and PCT offer valuable insights into the diagnosis and management of pediatric CAP, their application should be always integrated with clinical assessment rather than used in isolation. More studies are needed to define standardized thresholds and decision algorithms that incorporate these biomarkers.

Diagnostic test accuracy of cellular analysis of bronchoalveolar lavage fluid in distinguishing pulmonary infectious and non-infectious diseases in patients with pulmonary shadow

Purpose

This study aims to assess the diagnostic accuracy of cellular analysis of bronchoalveolar lavage fluid (BALF) in distinguishing between pulmonary infectious and non-infectious diseases in patients with pulmonary shadows. Additionally, it will develop and validate a novel scoring system based on a nomogram for the purpose of differential diagnosis.

Methods

A retrospective analysis was conducted involving data from 222 patients with pulmonary shadows, whose etiological factors were determined at our institution. The cohort was randomly allocated into a training set comprising 155 patients and a validation set of 67 patients, (ratio of 7:3), the least absolute shrinkage and selection operator (LASSO) regression model was applied to optimize feature selection for the model. Multivariable logistic regression analysis was applied to construct a predictive model. The receiver operating characteristic curve (ROC) and calibration curve were utilized to assess the prediction accuracy of the model. Decision curve analysis (DCA) and clinical impact curve (CIC) were employed to evaluate the clinical applicability of the model. Moreover, model comparison was set to evaluate the discrimination and clinical usefulness between the nomogram and the risk factors.

Results

Among the relevant predictors, the percentage of neutrophils in BALF (BALF NP) exhibited the most substantial differentiation, as evidenced by the largest area under the ROC curve (AUC = 0.783, 95% CI: 0.713-0.854). A BALF NP threshold of ≥16% yielded a sensitivity of 72%, specificity of 70%, a positive likelihood ratio of 2.07, and a negative likelihood ratio of 0.38. LASSO and multivariate regression analyses indicated that BALF NP (p < 0.001, OR = 1.04, 95% CI: 1.02-1.06) and procalcitonin (p < 0.021, OR = 52.60, 95% CI: 1.83-1510.06) serve as independent predictors of pulmonary infection. The AUCs for the training and validation sets were determined to be 0.853 (95% CI: 0.806-0.918) and 0.801 (95% CI: 0.697-0.904), respectively, with calibration curves demonstrating strong concordance. The DCA and CIC analyses indicated that the nomogram model possesses commendable clinical applicability. In models comparison, ROC analyses revealed that the nomogram exhibited superior discriminatory accuracy compared to alternative models, with DCA further identifying the nomogram as offering the highest net benefits across a broad spectrum of threshold probabilities.

Conclusion

BALF NP ≥16% serves as an effective discriminator between pulmonary infectious and non-infectious diseases in patients with pulmonary shadows. We have developed a nomogram model incorporating BALF NP and procalcitonin (PCT), which has proven to be a valuable tool for predicting the risk of pulmonary infections. This model holds significant potential to assist clinicians in making informed treatment decisions.

Procalcitonin Guided Antibiotic Stewardship

Despite infection and sepsis being a major public health challenge, early detection and timely management are often hindered by several factors. These includes the similarity of clinical presentations between infectious and non-infectious conditisons, as well as limitations of current diagnostic methods such as lengthy turnaround times and low sensitivity. Consequently, there is increasing interest in identifying biomarkers that can quickly and accurately differentiate bacterial sepsis from other inflammatory processes, whether infectious or non-infectious. Procalcitonin has emerged as one of the most extensively studied and utilized biomarkers in managing infection and sepsis, especially within the framework of antibiotic stewardship. This review aims to examine the role of Procalcitonin in guiding antibiotic stewardship. It explores the production and release of procalcitonin and its relevance in the context of infection and sepsis. The discussion focus on the clinical and economic impacts of using procalcitonin to guide the initiation and discontinuation of antibiotics in managing these conditions.

Procalcitonin serum level in patients with pemphigus vulgaris: can it be used as an inflammatory biomarker?

Procalcitonin (PCT) is a peptide precursor of calcitonin, considered as an infection marker in many settings. Recently, a few studies reported its rise in some inflammatory processes such as still's disease, anaphylactic shock and Kawasaki disease. To investigate the serum level of PCT in patients with pemphigus vulgaris (PV) and examine the relationship between serum level of PCT and the severity of disease. A cross-sectional study was conducted on 50 patients with PV, visited at a tertiary care hospital from August 2021 to May 2023. After recording the demographic and clinical characteristics of patients, PCT level as well as CRP and ESR levels were measured and analyzed. The median ESR, CRP and procalcitonin serum level for the patients was 6.40 mm/hr, 11.00 mg/dL and 0.025 ng/ml, respectively. Considering the mean serum PCT level of normal population which is reported as < 0.1 ng/ml, its level among our patients was in a normal range. A significant and positive correlation was observed between procalcitonin and ESR, as well as CRP. In opposite to PCT, CRP and ESR levels showed a significant and positive correlation with disease severity (P values: 0.002 and < 0.001, respectively). Our findings suggest that PCT might not be useful as a biomarker of inflammatory milieu or prognostic factor in patients with PV without any infection.

A Retrospective Study: Evaluating the Impact of the COVID-19 Pandemic on Inflammatory Markers in Hospitalized Patients

BACKGROUND

The COVID-19 pandemic has had a significant impact globally, and understanding the relationship between inflammatory markers and disease progression is crucial for effective management. This retrospective study aimed to examine the association between various inflammatory markers, such as C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), lactate dehydrogenase (LDH), D-dimer, ferritin, and procalcitonin (PCT), and the characteristics of disease progression and outcomes in individuals affected by COVID-19.

METHODS

This study collected raw data from 470 patients who tested positive for SARS-CoV-2 using RT-PCR.

RESULTS

The logistic regression analysis revealed that elevated LDH levels were associated with male gender, ICU admission, low oxygen saturation (O2 < 93%), the need for mechanical ventilation, death, and the presence of lung infiltrates. Higher D-dimer levels were associated with older age, diabetes mellitus, cardiac disease, and low oxygen saturation. Ferritin levels were significantly associated with older age, ICU admission, low oxygen saturation, mechanical ventilation, and lung infiltrates. In contrast, CRP was only significant regarding lung infiltrates and procalcitonin levels were not significantly associated with any of the examined factors.

CONCLUSION

This study highlights the importance of monitoring key inflammatory markers, such as LDH, D-dimer, and ferritin, as they are significantly associated with the severity of COVID-19 illness. These findings can inform clinical decision-making and guide the development of targeted interventions to improve patient outcomes.

Role of procalcitonin, interleukin-6 and interleukin-10 as a predictive marker for the use of perioperative steroid in maxillofacial trauma patients

Maxillofacial trauma often brings significant challenges for surgeons in terms of preoperative oedema. Steroids offer oedema reduction, yet potentially increase the risks of postoperative infection. This study explores procalcitonin (PCT), as a marker for bacterial infection risk, and interleukins IL-6 and IL-10, which respectively signify pro-inflammatory and anti-inflammatory responses, as potential indicators of infection and inflammation in these trauma cases and thereby aid in refining perioperative guidelines for the use of steroids. A prospective study was conducted at a tertiary public hospital in India from 2019 to 2022 on patients >18 years with facial trauma. After specific exclusions, patients were randomised into steroid (Group A) and non-steroid (Group B) groups. Various parameters including oedema, PCT, IL-6, and IL-10 levels were measured and analysed using SPSS software. Out of 80 patients, 44 were in Group A and 36 in Group B. Post-24 hours, Group A showed significant oedema reduction, with 25 patients displaying a decline to mild oedema, versus 10 patients in Group B (p = 0.034). However, Group A witnessed a higher infection risk, with 20 patients showing positive wound cultures versus three in Group B. Subgroup analysis revealed a link between higher PCT levels and infections (p = 0.039). Additionally, Group A showed less intraoperative bleeding and reduced operating time. While perioperative steroids mitigate swelling, they might increase postoperative infection risk. Elevated PCT levels indicate potential wound infections, suggesting those patients should avoid perioperative steroids. IL-6 and IL-10 trends during perioperative phases can predict pronounced oedema outcomes.

Genetically predicted systemic inflammation and the risk of atrial fibrillation: A bidirectional two-sample Mendelian randomization study

Background

Systemic inflammation has been proposed to be associated with the incidence of atrial fibrillation (AF), but whether it is a cause or a consequence of AF remains uncertain. We sought to explore the causal associations between systemic inflammation and AF using bidirectional Mendelian randomization (MR) analysis.

Methods

Independent genetic variants strongly associated with AF were selected as instrumental variables from the largest genome-wide association study (GWAS) with up to 1,030,836 individuals. Regarding inflammation traits, genetic associations with 41 inflammatory cytokines and 5 inflammatory biomarkers were obtained from their corresponding GWASs databases. Effect estimates were primarily evaluated using the inverse-variance weighted (IVW) method, supplemented by sensitivity analyses using MR-Egger, weighted median, and MR-PRESSO methods.

Results

In our initial MR analyses, we observed suggestive associations of genetically predicted interleukin-17 (IL-17), interleukin-2 receptor subunit alpha (IL-2rα), and procalcitonin (PCT) with AF. One standard deviation (SD) increase in IL-17, IL-2rα, and PCT caused an increase in AF risk by 6.3 % (OR 1.063, 95 %CI 1.011---1.118, p = 0.018), 4.9 % (OR 1.049, 95 %CI 1.007---1.094, p = 0.023) and 3.4 % (OR 1.034, 95 %CI 1.005---1.064, p = 0.022), respectively. Furthermore, our reverse MR analyses indicated that genetically predicted AF contributed to a suggestive increase in the levels of macrophage inflammatory protein-1β (MIP1β) (β 0.055, 95 %CI 0.006 to 0.103, p = 0.028), while a decrease in the levels of fibrinogen (Fbg) (β -0.091, 95 %CI -0.140 to -0.041, p < 0.001), which remained significant after multiple test correction.

Conclusions

Our MR study identified several inflammatory biomarkers with suggestive causal associations regarding the upstream and downstream regulation of AF occurrence, offering new insights for therapeutic exploitation of AF. Further research is required to validate the underlying link between systemic inflammation and AF in larger cohorts.

Overlapping Physiologic Signs of Sepsis and Paroxysmal Sympathetic Hyperactivity After Traumatic Brain Injury: Exploring A Clinical Conundrum

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) occurs in a subset of patients with traumatic brain injury (TBI) and is associated with worse outcomes. Sepsis is also associated with worse outcomes after TBI and shares several physiologic features with PSH, potentially creating diagnostic confusion and suboptimal management of each. This is the first study to directly investigate the interaction between PSH and infection using robust diagnostic criteria.

METHODS

We performed a retrospective cohort study of patients with TBI admitted to a level I trauma center intensive care unit with hospital length of stay of at least 2 weeks. From January 2016 to July 2018, 77 patients diagnosed with PSH were 1:1 matched by age and Glasgow Coma Scale to 77 patients without PSH. Trauma infectious diseases subspecialists prospectively documented assessments corroborating diagnoses of infection. Extracted data including incidence, timing, classification, and anatomical source of infections were compared according to PSH diagnosis. We also evaluated daily PSH clinical feature severity scores and systemic inflammatory response syndrome (SIRS) criteria and compared values for patients with and without confirmed infection, stratified by PSH diagnosis.

RESULTS

During the first 2 weeks of hospitalization, there were no differences in rates of suspected (62%) nor confirmed (48%) infection between patients with PSH and controls. Specific treatments for PSH were initiated on median hospital day 7 and for confirmed infections on median hospital day 8. SIRS criteria could identify infection only in patients who were not diagnosed with PSH.

CONCLUSIONS

In the presence of brain injury-induced autonomic nervous system dysregulation, the initiation and continuation of antimicrobial therapy is a challenging clinical decision, as standard physiologic markers of sepsis do not distinguish infected from noninfected patients with PSH, and these entities often present around the same time. Clinicians should be aware that PSH is a potential driver of SIRS, and familiarity with its diagnostic criteria as proposed by the PSH assessment measure is important. Management by a multidisciplinary team attentive to these issues may reduce rates of inappropriate antibiotic usage and misdiagnoses.

Inflammatory biomarkers as predictors of systemic vs isolated pocket infection in patients undergoing transvenous lead extraction

Background

Cardiovascular implantable electronic device (CIED) infections are a common indication for device extraction. Early diagnosis and complete system removal are crucial to reduce morbidity and mortality. The lack of clear infectious symptoms makes the diagnosis of pocket infections challenging and may delay referral for extraction.

Objective

We aimed to determine if inflammatory biomarkers can help diagnose CIED isolated pocket infection.

Methods

We performed a retrospective analysis of all patients undergoing transvenous lead extraction for CIED infection at the University of California San Diego from 2012 to 2022 (N = 156). Patients were classified as systemic infection (n = 88) or isolated pocket infection (n = 68). Prospectively collected preoperative procalcitonin (PCT), C-reactive protein, and white blood cell count were compared between groups.

Results

Pairwise comparisons revealed that the systemic infection group had a higher PCT than the control group (P < .001) and the pocket infection group (P = .009). However, there was no significant difference in PCT value between control subjects and isolated pocket infection subjects. Higher white blood cell count was only associated with systemic infection when compared with our control group (P = .018).

Conclusion

In patients diagnosed with CIED infections requiring extraction, inflammatory biomarkers were not elevated in isolated pocket infection. Inflammatory markers are not predictive of the diagnosis of pocket infections, which ultimately requires a high level of clinical suspicion.

Procalcitonin and qSOFA as a Marker of Mortality in Sepsis

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. The qSOFA and procalcitonin are currently used for both diagnostic as well as prognostic purposes.

OBJECTIVE

To explore the combined use of day one procalcitonin level and qSOFA scores for prognostication of sepsis-related mortality.

DESIGN

This was a prospective observational study.

PARTICIPANTS

All patients who fulfilled the inclusion criteria for sepsis with an age of more than 16 years were enrolled in the study.

RESULTS

In this study of 211 patients, 15 patients died (7.1%) during hospital stay. Among the 15 patients who died, the highest mortality of 29.4% was seen in patients with qSOFA of "3", qSOFA of "2" had a mortality of 12.8%, qSOFA of "1" had a mortality of 1% and qSOFA of "0" had zero mortality. In this study, procalcitonin had a statistically significant positive correlation/association with both qSOFA and mortality.

CONCLUSION

The qSOFA and procalcitonin at presentation to the emergency department in septic patients have a significant correlation with mortality in patients hospitalized with sepsis. Obtaining these two parameters at presentation will help in managing aggressively these patients who at presentation have higher qSOFA and procalcitonin levels.

Exploring the Relationship between Plasma Adiponectin, Gender, and Underlying Diseases in Severe Illness

Adiponectin is low in obesity, plays a crucial role in metabolic health, and, moreover, possesses immunoregulatory properties. However, studies examining its levels in patients with systemic inflammatory response syndrome (SIRS) or sepsis have yielded conflicting results. While females typically have higher systemic adiponectin levels than males, research on sex-specific associations in this context is limited. In this study of 156 SIRS/sepsis patients, including those with liver cirrhosis, we aimed to explore the relationship between plasma adiponectin, body mass index (BMI), gender, disease severity, and underlying etiological conditions. Our findings revealed that patients with liver cirrhosis, who are susceptible to infections, exhibited elevated circulating adiponectin levels, irrespective of sex. When excluding cirrhosis patients, plasma adiponectin levels were similar between male SIRS/sepsis patients and controls but lower in female patients compared to female controls. Plasma adiponectin was inversely related to BMI in female but not male patients. Further analysis within the non-cirrhosis subgroup demonstrated no significant differences in adiponectin levels between sexes among SIRS, sepsis, and septic shock patients. Ventilation, dialysis, and vasopressor therapy had no discernible impact on adiponectin levels in either sex. A negative correlation between adiponectin and C-reactive protein (CRP) existed in males only. Notably, patients with pancreatitis showed the lowest plasma adiponectin concentrations, although sex-specific differences were not significant. Infection with Gram-negative or Gram-positive bacteria had minimal effects on plasma adiponectin levels in both sexes. However, infection with the severe acute respiratory syndrome coronavirus type 2 led to decreased adiponectin levels in females exclusively. Multivariate analysis considering all factors affecting plasma adiponectin levels in males or females identified BMI in females and CRP levels in males to predict plasma adiponectin levels in SIRS/sepsis patients. Additionally, our study observed a trend where the 25 patients who did not survive had higher plasma adiponectin levels, particularly among males. In summary, our investigation highlights the influence of underlying diseases and sex on plasma adiponectin levels in SIRS/sepsis patients, shedding light on potential implications for disease management and prognosis.

The Clinical Performance of Cell Population Data for Diagnosis of Bloodstream Infection in Cancer Patients

Background Bloodstream infection (BSI) induces a change in the number and morphology of blood cells. In this study, we compared cell population data (CPD) parameters between cancer patients with or without BSI to determine whether these parameters could serve as biomarkers of BSI. Methods Between April and June 2021, 43 BSI-negative and 22 BSI-positive cancer patients were enrolled in this study. We compared 18 CPD parameters and biomarkers between cancer patients with BSI-positive and BSI-negative. Results There were significant differences in the levels of several CPD parameters, including MO-WZ (p=0.040), MO-X (p<0.01), MO-Y (p=0.012), NE-SFL (p<0.01), and NE-WX (p=0.037), but not C-reactive protein (p=0.347) and procalcitonin (p=0.237) between BSI-positive and BSI-negative patients. The areas under the receiver-operating characteristic curves (AUCs) were above 0.7 for MO-X (0.762; 95% confidence intervals (CI): 0.624-0.901), NE-SFL (0.766; 95% CI: 0.625-0.880). And LY-WY (p=0.024) showed a significant difference between gram-negative and gram-positive BSI patients with high AUC (0.883; 95% CI: 0.703-1). Conclusion CPD parameters (MO-X and NE-SFL) provide additional information for discriminating between BSI-negative and BSI-positive BSI. And LY-WY provides useful information for discriminating between cancer patients with gram-negative BSI and gram-positive BSI.

Procalcitonin and C-reactive protein to rule out early bacterial coinfection in COVID-19 critically ill patients

PURPOSE

Although the prevalence of community-acquired respiratory bacterial coinfection upon hospital admission in patients with coronavirus disease 2019 (COVID-19) has been reported to be < 5%, almost three-quarters of patients received antibiotics. We aim to investigate whether procalcitonin (PCT) or C-reactive protein (CRP) upon admission could be helpful biomarkers to identify bacterial coinfection among patients with COVID-19 pneumonia.

METHODS

We carried out a multicentre, observational cohort study including consecutive COVID-19 patients admitted to 55 Spanish intensive care units (ICUs). The primary outcome was to explore whether PCT or CRP serum levels upon hospital admission could predict bacterial coinfection among patients with COVID-19 pneumonia. The secondary outcome was the evaluation of their association with mortality. We also conducted subgroups analyses in higher risk profile populations.

RESULTS

Between 5 February 2020 and 21 December 2021, 4076 patients were included, 133 (3%) of whom presented bacterial coinfection. PCT and CRP had low area under curve (AUC) scores at the receiver operating characteristic (ROC) curve analysis [0.57 (95% confidence interval (CI) 0.51-0.61) and 0.6 (95% CI, 0.55-0.64), respectively], but high negative predictive values (NPV) [97.5% (95% CI 96.5-98.5) and 98.2% (95% CI 97.5-98.9) for PCT and CRP, respectively]. CRP alone was associated with bacterial coinfection (OR 2, 95% CI 1.25-3.19; p = 0.004). The overall 15, 30 and 90 days mortality had a higher trend in the bacterial coinfection group, but without significant difference. PCT ≥ 0.12 ng/mL was associated with higher 90 days mortality.

CONCLUSION

Our study suggests that measurements of PCT and CRP, alone and at a single time point, are not useful for ruling in or out bacterial coinfection in viral pneumonia by COVID-19.

Misleading Procalcitonin in Patients With Staphylococcus aureus Bacteremia: A Report of Two Cases

Procalcitonin (PCT) is an important biomarker for bacterial infection with a high negative predictive value. It is almost always positive in patients who are bacteremic with pathogenic bacteria. Here, we report two cases of Staphylococcus aureus bacteremia, where PCT levels were unexpectedly negative. This uncommon occurrence challenges the assumption of PCT's infallibility as a diagnostic marker in patients with true bacteremia. The first case is a 55-year-old woman with no past medical issues who presented with one week of generalized weakness and two days of fever and chills. Though her white blood cell (WBC) count and c-reactive protein (CRP) were elevated, PCT was normal, with no apparent source of infection, and hence antibiotic differed. However, her blood cultures returned positive for methicillin-resistant Staphylococcus aureus (MRSA). The patient was started on vancomycin and discharged on daptomycin, she responded appropriately and improved. The second case is an intravenous (IV) drug user, a 40-year-old woman, who presented with septic arthritis and osteomyelitis involving the right hip. She had blood cultures positive for methicillin-susceptible Staphylococcus aureus (MSSA); however, a PCT check on the day of positive blood cultures and various occasions subsequently was normal. These two cases remind us that we cannot over-rely on one test to rule out bacterial infection and should consider the whole clinical picture. They highlight the need for vigilance among clinicians that PCT can rarely be negative in cases of true bacteremia in spite of its high negative predictive value. Physicians and antibiotic stewardship programs should be cautious and aware of this potential pitfall when utilizing PCT as a diagnostic tool.

Biomarker-Based Assessment Model for Detecting Sepsis: A Retrospective Cohort Study

The concept of the quick sequential organ failure assessment (qSOFA) simplifies sepsis detection, and the next SOFA should be analyzed subsequently to diagnose sepsis. However, it does not include the concept of suspected infection. Thus, we simply developed a biomarker-based assessment model for detecting sepsis (BADS). We retrospectively reviewed the electronic health records of patients admitted to the intensive care unit (ICU) of a 2000-bed university tertiary referral hospital in South Korea. A total of 989 patients were enrolled, with 77.4% (n = 765) of them having sepsis. The patients were divided into a ratio of 8:2 and assigned to a training and a validation set. We used logistic regression analysis and the Hosmer-Lemeshow test to derive the BADS and assess the model. BADS was developed by analyzing the variables and then assigning weights to the selected variables: mean arterial pressure, shock index, lactate, and procalcitonin. The area under the curve was 0.754, 0.615, 0.763, and 0.668 for BADS, qSOFA, SOFA, and acute physiology and chronic health evaluation (APACHE) II, respectively, showing that BADS is not inferior in sepsis prediction compared with SOFA. BADS could be a simple scoring method to detect sepsis in critically ill patients quickly at the bedside.

Detecting Diabetic Ketoacidosis with Infection: Combating a Life-Threatening Emergency with Practical Diagnostic Tools

BACKGROUND

Diabetic ketoacidosis (DKA) is a life-threatening acute complication of diabetes mellitus and can lead to patient demise if not immediately treated. From the recent literature, the diabetic ketoacidosis mortality rate, depending on age, is 2-5%. Insulin discontinuation and infection remain the two most common triggers for diabetic ketoacidosis. About 50% of cases of ketoacidosis result from bacterial infections like urinary tract infections and pneumonia. It is also important to diagnose the presence of infection in diabetic ketoacidosis patients to prevent the excessive use of antibiotics, which may lead to antibiotic resistance. Although performing bacterial culture is confirmatory for the presence or absence of bacterial infection, the time required to obtain the result is long. At the same time, emergency treatment needs to be started as early as possible.

METHODS

This narrative review examines various septic markers to identify the appropriate tools for diagnosis and to distinguish between diabetic ketoacidosis with and without infection. Electronic databases were searched using the Google engine with the keywords "Diabetes Mellitus", "Diabetic Ketoacidosis", "Infection with Diabetic Ketoacidosis", "biomarkers for infection in Diabetic Ketoacidosis", "Procalcitonin", "Inflammatory cytokines in DKA", "Lactic acidosis in DKA", and "White blood cell in infection in DKA".

RESULTS

This narrative review article presents the options for diagnosis and also aims to create awareness regarding the gravity of diabetic ketoacidosis with infection and emphasizes the importance of early diagnosis for appropriate management. Diabetes mellitus is a clinical condition that may lead to several acute and chronic complications. Acute diabetic ketoacidosis is a life-threatening condition in which an excess production of ketone bodies results in acidosis and hypovolemia. Infection is one of the most common triggers of diabetic ketoacidosis. When bacterial infection is present along with diabetic ketoacidosis, the mortality rate is even higher than for patients with diabetic ketoacidosis without infection. The symptoms and biomarkers of diabetic ketoacidosis are similar to that of infection, like fever, C reactive protein, and white blood cell count, since both create an environment of systemic inflammation. It is also essential to distinguish between the presence and absence of bacterial infection to ensure the appropriate use of antibiotics and prevent antimicrobial resistance. A bacterial culture report is confirmatory for the existence of bacterial infection, but this may take up to 24 h. Diagnosis needs to be performed approximately in the emergency room upon admission since there is a need for immediate management. Therefore, researching the possible diagnostic tools for the presence of infection in diabetic ketoacidosis patients is of great importance. Several of such biomarkers have been discussed in this research work.

Plasma Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) as a Possible Biomarker for Severe COVID-19

Proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces low density lipoprotein (LDL) uptake, leading to increased plasma levels of LDL. In addition, PCSK9 has been implicated in inflammation independently of the effects on cholesterol metabolism. The current analysis showed that our 156 patients with systemic inflammatory response syndrome (SIRS) or sepsis had higher plasma PCSK9 levels in contrast with the 68 healthy controls. COVID-19 sepsis patients had increased plasma PCSK9 levels in comparison to sepsis patients not infected by SARS-CoV-2. For further analysis, patients were divided in two groups based on COVID-19. In both sub-cohorts, plasma PCSK9 levels did not correlate with C-reactive protein, leukocyte count, and procalcitonin. Plasma PCSK9 levels of both patient groups did not significantly differ among SIRS/sepsis patients with and without dialysis and patients with and without ventilation. Furthermore, vasopressor therapy was not significantly associated with altered plasma PCSK9 levels. In the non-COVID-19 SIRS/sepsis group, patients with Gram-negative and Gram-positive infections had similar plasma PCSK9 levels as patients without a detectable pathogen in their blood. In conclusion, the current study suggests PCSK9 as a possible biomarker for COVID-19, but this needs to be validated in larger cohorts.

Diagnostic and Prognostic Roles of Procalcitonin and Other Tools in Community-Acquired Pneumonia: A Narrative Review

Community-acquired pneumonia (CAP) is among the most common causes of death and one of the leading healthcare concerns worldwide. It can evolve into sepsis and septic shock, which have a high mortality rate, especially in critical patients and comorbidities. The definitions of sepsis were revised in the last decade as "life-threatening organ dysfunction caused by a dysregulated host response to infection". Procalcitonin (PCT), C-reactive protein (CRP), and complete blood count, including white blood cells, are among the most commonly analyzed sepsis-specific biomarkers also used in pneumonia in a broad range of studies. It appears to be a reliable diagnostic tool to expedite care of these patients with severe infections in the acute setting. PCT was found to be superior to most other acute phase reactants and indicators, including CRP as a predictor of pneumonia, bacteremia, sepsis, and poor outcome, although conflicting results exist. In addition, PCT use is beneficial to judge timing for the cessation of antibiotic treatment in most severe infectious states. The clinicians should be aware of strengths and weaknesses of known and potential biomarkers in expedient recognition and management of severe infections. This manuscript is intended to present an overview of the definitions, complications, and outcomes of CAP and sepsis in adults, with special regard to PCT and other important markers.

Procalcitonin and Pediatric Traumatic Brain Injury: Differentiating Neuro-Storming From Infection

INTRODUCTION

Recurrent febrile episodes represent a diagnostic challenge in the pediatric traumatic brain injury (TBI) population as they may indicate presence of infection versus sterile neuro-storming. Procalcitonin (PCT) is a promising biomarker used in pediatric sepsis; however, data are limited regarding use in TBI. We hypothesized PCT helps discern neuro-storming from sepsis in children with TBI.

MATERIALS AND METHODS

A single-institution retrospective review (2014-2021) identified pediatric patients (aged 0-18 y) with moderate-to-severe TBI and intensive care unit admission > 2 d. Patients with multiple febrile events who underwent infectious evaluation including cultures and PCT drawn within 48 h of fever were included. Demographics, vital signs, infectious biomarkers including PCT, and culture data were captured. Univariate and multivariate analyses were performed to determine variables associated with culture positive status.

RESULTS

One hundred and fifty six patients were admitted to the intensive care unit with moderate-to-severe TBI during the study period. Eighty five patients (54%) experienced recurrent febrile episodes. Twenty four (28%) met inclusion criteria, undergoing 32 total infectious workups. Twenty one workups were culture-positive (66%) in a total of 18 patients. Median PCT levels were not statistically different between culture-positive and culture-negative workups (P = 0.94). In multivariate modeling, neither PCT [odds ratio 0.89 (confidence interval: 0.75-1.05)] nor temperature [odds ratio 7.34 (confidence interval: 0.95-57.16)] correlated with positive bacterial cultures.

CONCLUSIONS

In this small pilot analysis, recurrent febrile episodes were common and PCT did not correlate with sepsis or neuro-storming in pediatric TBI patients. Prospective protocols are needed to better understand the utility of PCT and identify predictors of bacterial infection to improve early diagnosis of sepsis in this population.

Short treatment duration for community-acquired pneumonia

PURPOSE OF REVIEW

Lower respiratory tract infections are one of the most common indications for antibiotic use in community and hospital settings. Usual guidelines for adults with community-acquired pneumonia (CAP) recommend 5-7 days of antibiotic treatment. In daily practice, physicians often prescribe 9-10 days of antibiotic treatment. Among available strategies to decrease antibiotic use, possibly preventing the emergence of bacterial resistance, reducing treatment durations is the safest and the most acceptable to clinicians. We aim to review data evaluating the efficacy of short antibiotic duration in adult CAP and which criteria can help clinicians to reduce antibiotic treatment.

RECENT FINDINGS

Several studies and meta-analyses demonstrated that the treatment duration of 7 days or less was sufficient for CAP. Two trials found that 3-day treatments were effective, even in hospitalized CAP.To customize and shorten duration, clinical and biological criteria have been studied and reflect patient's response. Indeed, stability criteria were recently shown to be effective to discontinue antibiotic treatment. Procalcitonin was also studied but never compared with clinical criteria.

SUMMARY

Treatment duration for CAP is still under debate, but several studies support short durations. Clinical criteria could be possibly used to discontinue antibiotic treatment.

Age, comorbidities, c-reactive protein and procalcitonin as predictors of severity in confirmed COVID-19 patients in the Philippines

Background

The Coronavirus Disease 2019 (COVID-19) pandemic has been affecting people globally, and the Philippines is one of the countries greatly struck by the virus. The continued rise of new positive cases has drawn attention to the urgent need for healthcare management to cope with this challenge. Severity prediction could help improve medical decision-making and optimise the patient's treatment plan with a good clinical outcome. This study aimed to identify the determinants of COVID-19 disease severity.

Methods

Demographic characteristics and laboratory findings were collected from electronic medical records and paper forms of all confirmed COVID-19 cases reported by the University of Perpetual Help DALTA Medical Center between the September 1, 2020 and the October 31, 2021. We performed statistical analyses and interpretation of data to compare severe and non-severe groups.

Results

5,396 confirmed cases were examined. Most of the severe cases were elderly, male, had blood type A, and with comorbidities. Cycle threshold (Ct) values were lower in the severe group. Most patients had higher-than-normal levels of all blood parameters except platelet, white blood cell (WBC), neutrophil, and lymphocyte counts. Age, sex, ABO blood groups, comorbidities, open reading frame 1 ab (ORF1ab) and nucleocapsid (N) gene Ct values, ferritin, C-reactive protein (CRP), procalcitonin (PCT), D-dimer, white blood cell (WBC) count, neutrophil count, and lymphocyte count were significantly associated with disease severity. In multivariate analysis, age groups >60 and 30-59 years, presence of comorbidities, CRP level >5 ng/mL, and PCT >0.05 ng/mL were identified as disease severity predictors.

Conclusions

Based on our results, age, comorbidities, CRP, and PCT level may be utilised as primary assessment factors for possible hospital admission and close monitoring upon testing. Early detection of these risk factors may provide strategic interventions that help reduce mortality, hospital admissions, and more expensive and extensive treatments.

Usefulness of serum procalcitonin and point-of-care multiplex PCR gastro-intestinal panel in acute diarrhea or colitis in the emergency department

Introduction: Acute infectious diarrhea is one of the most common diseases worldwide. Procalcitonin (PCT) is useful for antibiotic stewardship in lower respiratory tract infections but has been poorly studied in infectious diarrhea. Our objective is to describe the PCT concentrations according to diarrhea etiology.Methods: This is a single-center prospective cohort study involving adults consulting the emergency department (ED) for an acute diarrhea or colitis. Serum PCT was measured and a stool sample was tested with FilmArray® Gastro-Intestinal Panel. The primary endpoint is the PCT concentration according to each type of pathogen identified using Gastro-Intestinal-panel and/or stool cultures at ED admission.Results: 125 patients were included: 80 had an acute infectious diarrhea, 21 an acute colitis and 24 another illness causing diarrhea. The median (interquartile ranges) PCT values (ng/ml) were 0.13 (0.08-0.28), 0.07 (0.06-0.54), 0.13 (0.09-0.26) and 0.05 (0.03-0.17), respectively if there was a bacteria (n = 41), parasite (n = 3), virus (n = 10) or no pathogen identified and 0.34 (0.13-1.03) if the diarrhea was due to another illness (n = 24).Conclusion: In patients admitted to the ED with an acute infectious diarrhea or acute colitis, PCT remained low when a bacteria was identified. It may not be informative in current practice to guide antibiotic therapy.

Procalcitonin for the early discrimination of fever etiology in patients with systemic autoimmune diseases attending the emergency department

In febrile patients with known systemic autoimmune disease, early discrimination between infection and disease flare often represents a clinical challenge. This study aimed at evaluating the efficacy of procalcitonin (PCT) and other common inflammatory biomarkers in discriminating disease flare from bacterial infections in the Emergency Department (ED). In a cross-sectional observational retrospective study, we identified consecutive febrile patients with a known diagnosis of systemic autoimmune disease, admitted to the ED, and subsequently hospitalized. Flare vs infective disease was defined on clinical records at hospital discharge. Dosage of common inflammatory markers was performed at ED admission. Out of 177 patients, those with infection were most commonly elderly, frail, and with reduced peripheral oxygen saturation at admission. When compared to C-reactive protein (CRP) and white blood count (WBC), PCT showed the best performance in discriminating infections vs flare. However, only at a very high threshold value of 2 ng/ml, the PCT had a satisfactory negative predictive value of 88.9%, although with a very low specificity of 13.6% and a positive predictive value of 35.8%. Our data suggest that in the ED setting, the early PCT determination has low accuracy in the differentiation of disease flare from infection in patients with known rheumatologic disease. However, the PCT could be useful in elderly and comorbid subjects, in supporting clinical assessment and in recognizing those febrile patients needing prompt antibiotic treatment.

Antimicrobial Stewardship Techniques for Critically Ill Patients with Pneumonia

Pneumonia is common in the intensive care unit (ICU), infecting 27% of all critically ill patients. Given the high prevalence of this disease state in the ICU, optimizing antimicrobial therapy while minimizing toxicities is of utmost importance. Inappropriate antimicrobial use can increase the risk of antimicrobial resistance, Clostridiodes difficile infection, allergic reaction, and other complications from antimicrobial use (e.g., QTc prolongation, thrombocytopenia). This review article aims to discuss methods to optimize antimicrobial treatment in patients with pneumonia, including the following: procalcitonin use, utilization of methicillin-resistant Staphylococcus aureus nares testing to determine need for vancomycin therapy, utilization of the Biofire^® FilmArray^® pneumonia polymerase chain reaction (PCR), and microbiology reporting techniques.

Severity of Illness Scores and Biomarkers for Prognosis of Patients with Coronavirus Disease 2019

The spectrum of disease severity and the insidiousness of clinical presentation make it difficult to recognize patients with coronavirus disease 2019 (COVID-19) at higher risk of worse outcomes or death when they are seen in the early phases of the disease. There are now well-established risk factors for worse outcomes in patients with COVID-19. These should be factored in when assessing the prognosis of these patients. However, a more precise prognostic assessment in an individual patient may warrant the use of predictive tools. In this manuscript, we conduct a literature review on the severity of illness scores and biomarkers for the prognosis of patients with COVID-19. Several COVID-19-specific scores have been developed since the onset of the pandemic. Some of them are promising and can be integrated into the assessment of these patients. We also found that the well-known pneumonia severity index (PSI) and CURB-65 (confusion, uremia, respiratory rate, BP, age ≥ 65 years) are good predictors of mortality in hospitalized patients with COVID-19. While neither the PSI nor the CURB-65 should be used for the triage of outpatient versus inpatient treatment, they can be integrated by a clinician into the assessment of disease severity and can be used in epidemiological studies to determine the severity of illness in patient populations. Biomarkers also provide valuable prognostic information and, importantly, may depict the main physiological derangements in severe disease. We, however, do not advocate the isolated use of severity of illness scores or biomarkers for decision-making in an individual patient. Instead, we suggest the use of these tools on a case-by-case basis with the goal of enhancing clinician judgment.

Use of biomarkers to individualize antimicrobial therapy duration: a narrative review

BACKGROUND

Reducing the overuse of antimicrobials is imperative for the sake of minimizing antimicrobial-associated adverse effects, optimizing resource utilization, and curtailing the rise in multidrug-resistant organisms. Biomarkers reflect the host responses to infection and may assist with minimizing unnecessary antimicrobial usage.

OBJECTIVES

To review the literature pertaining to the performance of biomarkers specifically used to guide the duration of antimicrobial therapy (AMT).

SOURCES

Randomized controlled trials, observational studies, and meta-analyses assessing biomarker-guided approaches to AMT decision-making and their impact on the duration of therapy were reviewed.

CONTENT

Several randomized controlled trials and real-world observational studies have shown that a procalcitonin (PCT)-guided strategy can help clinicians individualize the duration of AMT, particularly among non-critically ill patients hospitalized with suspected respiratory tract infections when using a PCT cut-off value of <0.25 μg/L and critically ill patients with respiratory tract infections or undifferentiated sepsis when using a PCT cut-off value of <0.5 μg/L or ≥80% decline in the peak level. C-reactive protein is a non-specific marker of inflammation that may also assist with an early discontinuation of AMT; however, data are limited. Haematological biomarkers are prone to variance between individuals and are often influenced by medications and non-infectious conditions, making them less reliable for the purposes of AMT decision-making. Novel biomarkers such as multi-protein signatures and host gene expression tests have shown promise as tools to better differentiate between bacterial and non-bacterial infections; clinical studies are needed to determine whether they can be used to help optimize the duration of AMT.

IMPLICATIONS

Studies have demonstrated that a PCT-guided strategy, when utilized appropriately, can help guide clinicians to individualize and often reduce the duration of AMT, especially in patients hospitalized with respiratory tract infections and those admitted to the intensive care unit with suspected respiratory tract infections or sepsis. The impact of utilizing other biomarkers is less clear and requires further study.

Usefulness of procalcitonin at admission as a risk-stratifying biomarker for 50-day in-hospital mortality among patients with community-acquired bloodstream infection: an observational cohort study

PURPOSE

To assess the association between plasma procalcitonin concentration at hospital admission and the risk of 50-day in-hospital mortality among patients with community-acquired bloodstream infections.

METHODS

We carried out a retrospective, observational cohort study with all consecutive patients with bacteriologically confirmed community-acquired bloodstream infections hospitalized between 2006 and 2012. We aimed to assess the association between plasma procalcitonin at admission and 50-day in-hospital mortality. Patients were included in the analysis if they had undergone a blood culture test within 48 hours of hospitalization with a concomitant procalcitonin assay (time < 12 hours between the two tests). Inclusion in the study began on the day of hospital admission, and each patient was followed until death, discharge from the hospital, or last known follow-up in the 50 days following hospital admission. The endpoint was the occurrence of all-cause in-hospital mortality during the 50 days following hospital admission.

RESULTS

During the 7-year study period, 1593 patients were admitted to one of the healthcare facilities of the University Hospital of Nancy from home or through the emergency department and had positive blood cultures and concomitant procalcitonin assays. Among the patients, 452 met the selection criteria and were analyzed. In ROC analysis, procalcitonin at baseline was significantly associated with 50-day in-hospital mortality, with an optimal threshold > 4.24 ng/mL. A baseline procalcitonin > 4.24 ng/mL was independently associated with an increased risk of in-hospital mortality (multivariable logistic regression: odds ratio, 2.58; 95% CI, 1.57-4.25; P = 0.0002; Cox proportional hazard regression: hazard ratio, 2.01; 95% CI, 1.30-3.11; P = 0.002). In sensitivity analyses, baseline procalcitonin quartiles were independently associated with 50-day in-hospital mortality (multivariable logistic regression: odds ratio, 1.47; 95% CI, 1.17-1.85; P = 0.001; Cox proportional hazard regression: hazard ratio, 1.31; 95% CI, 1.07-1.60; P = 0.008). The independent associations between baseline procalcitonin and the risk of 50-day in-hospital mortality were maintained after adjusting for C-reactive protein and sepsis status at admission.

CONCLUSION

Our data provide the first evidence of the usefulness of plasma procalcitonin at admission as a risk-stratifying biomarker for predicting 50-day in-hospital mortality among patients with community-acquired bloodstream infections.

The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This "narrative" review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.

Trends in the Use of Procalcitonin at US Children's Hospital Emergency Departments

OBJECTIVES

Procalcitonin (PCT) was approved by the Food and Drug Administration in 2016. We assessed changes in PCT utilization over time in emergency departments (EDs) at US Children's Hospitals and identified the most common conditions associated with PCT testing.

METHODS

We performed a cross-sectional study of children <18 years of age presenting to 1 of 33 EDs contributing data to the Pediatric Health Information System between 2016 and 2020. We examined trends in PCT utilization during an ED encounter between institutions and over the study period. Using All Patients Refined Diagnosis Related Groups, we identified the most common conditions for which PCT was obtained (overall, and relative to the performance of a complete blood count).

RESULTS

The overall rate of PCT testing increased from 0.2% of all ED visits in 2016 to 1.8% in 2020. Across hospitals, the proportion of ED encounters with PCT obtained ranged from 0.0005% to 4.3% with marked variability in overall use. Among children who had PCT testing performed, the most common diagnoses were fever (10.7%), infections of the upper respiratory tract (9.2%), and pneumonia (5.9%). Relative to the performance of a complete blood count, rates of PCT testing were highest among children with sepsis (28.7%), fever (21.4%), pulmonary edema/respiratory failure (17.3%), and bronchiolitis/respiratory syncytial virus pneumonia (15.6%).

CONCLUSIONS

PCT utilization in the ED has increased over the past 5 years with variation between hospitals. PCT is most frequently obtained for children with respiratory infections and febrile illnesses.

Characterization of a proteomic profile associated with organ dysfunction and mortality of sepsis and septic shock

INTRODUCTION

The search for new biomarkers that allow an early diagnosis in sepsis and predict its evolution has become a necessity in medicine. The objective of this study is to identify, through omics techniques, potential protein biomarkers that are expressed in patients with sepsis and their relationship with organ dysfunction and mortality.

METHODS

Prospective, observational and single-center study that included adult patients (≥ 18 years) who were admitted to a tertiary hospital and who met the criteria for sepsis. A mass spectrometry-based approach was used to analyze the plasma proteins in the enrolled subjects. Subsequently, using recursive feature elimination classification and cross-validation with a vector classifier, an association of these proteins with mortality and organ dysfunction was established. The protein-protein interaction network was analyzed with String software.

RESULTS

141 patients were enrolled in this study. Mass spectrometry identified 177 proteins. Of all of them, and by recursive feature elimination, nine proteins (GPX3, APOB, ORM1, SERPINF1, LYZ, C8A, CD14, APOC3 and C1QC) were associated with organ dysfunction (SOFA > 6) with an accuracy of 0.82 ± 0.06, precision of 0.85 ± 0.093, sensitivity 0.81 ± 0.10, specificity 0.84 ± 0.10 and AUC 0.82 ± 0.06. Twenty-two proteins (CLU, LUM, APOL1, SAA1, CLEBC3B, C8A, ITIH4, KNG1, AGT, C7, SAA2, APOH, HRG, AFM, APOE, APOC1, C1S, SERPINC1, IGFALS, KLKB1, CFB and BTD) were associated with mortality with an accuracy of 0.86 ± 0.05, a precision of 0.91 ± 0.05, a sensitivity of 0.91 ± 0.05, a specificity of 0.72 ± 0.17, and an area under the curve (AUC) of 0.81 ± 0.08 with a confidence interval of 95%.

CONCLUSION

In sepsis there are proteomic patterns associated with organ dysfunction and mortality.

Implementation of Procalcitonin in Antibiotic Stewardship: Derivation of a Consensus Algorithm for Procalcitonin Use in Clinical Practice

Reducing antibiotics overuse is essential to minimize antibiotics related side effects and to prevent the emergence of multidrug-resistant bacteria. Procalcitonin (PCT) guided antibiotics therapy has been reported to be safe in patients with acute respiratory infections and sepsis, improving clinical outcomes as well as reducing the duration of antibiotics use. However, there is still no universal agreement on clinical guidelines in Korea for optimal PCT applications. Through this expert consensus meeting, clinical research findings in the PCT-guided antibiotics treatment interventions and real-world clinical applications were discussed. From the perspective of antibiotic stewardship, PCT application target groups, cut-offs, and testing cycles were discussed to reach a consensus on the PCT-guided antibiotics treatment algorithm for application in Korea. Combining clinical assessment for patients with an appropriate PCT-guided antibiotics treatment algorithm could improve the diagnosis and treatment of acute respiratory infections and sepsis. In addition, continuous education and regular feedback would improve the effectiveness of antibiotic stewardship.

Role of Biomarkers in Periprosthetic Joint Infections

Periprosthetic joint infection (PJI) is one of the most serious complications after joint arthroplasty. The incidence rate of PJI after total joint replacement is 1-3%. Although there are different guidelines and diagnostic criteria used to diagnose PJI, diagnosing PJI is a highly difficult process for orthopedists. The current Musculoskeletal Infection Society (MSIS) criteria are widely used for the diagnosis of PJI. These criteria include results from blood/synovial fluid tests, physical examination, and histological and microbiological analyses of intra-operative samples. However, there is currently no blood or synovial test that can definitively diagnose PJI. To make a more effective diagnosis of PJI, a large number of studies have explored and continue to investigate biomarkers. This review aims to provide general information about serum and synovial markers used for the diagnosis of PJI that may be used to create a database to guide researchers in new studies.

Evolution of thyroid cancer biomarkers: from laboratory test to patients’ clinical management

Over the past three decades, laboratory medicine has significantly evolved thanks to technological advances made possible by new materials and evidence. Clinicians’ ongoing requests for powerful, rapid, and minimally invasive tests has led manufacturers to develop rapid, accurate, and sensitive tests that can increase diagnostic accuracy and improve follow-up, bringing laboratory medicine ever closer to personalized medicine. The aim of this study was to critically review the main problems of the current Tg and CT biomarkers for the diagnosis/monitoring of DTC and MTC, respectively, and to identify the advantages and challenges of using the new laboratory biomarkers in the clinical management of patients with differentiated and medullary thyroid cancer. Insufficient harmonization of Tg and CT assays and lack of interchangeability of laboratory results and cutoff values pose challenges for comparability and standardization of procedures and methods. New diagnostic and monitoring approaches such as PCT or the Tg doubling time have proven to be effective. Close collaboration between clinicians and laboratory specialists remains essential to translate the advantages and limitations of current assays into appropriate clinical interpretation criteria. Over the years, the journal Clinical Chemistry and Laboratory Medicine (CCLM) has taken many steps to develop advanced research and technology in the diagnosis and monitoring of tumor cancer and to help clinicians translate it into clinical practice.

Prognostic Value of Plasma Presepsin and Pneumonia Severity Index in Patients with Community-Acquired Pneumonia in the Emergency Department

Background and Objectives: Presepsin (PSS) is an independent predictor for estimating disease severity and prognosis in septic patients. Few studies have reported the associations between plasma PSS and the severity and prognosis in patients with community-acquired pneumonia (CAP). We investigated whether a high plasma PSS level was associated with 30-day mortality in CAP patients. Materials and Methods: This retrospective single-center study was conducted in an emergency department. The PSS level was measured in 211 adult CAP patients admitted to the hospital and followed for up to 30 days. We recorded the pneumonia severity index (PSI) and the CURB-65 score. The primary outcome was death from any cause within 30 days. Results: The plasma PSS levels were significantly elevated in the high-risk group (PSI > 130) compared with the low- (PSI < 91) or moderate-risk groups (PSI 91−130). Forty-four patients (20.9%) died within 30 days of admission. Non-survivors had significantly higher plasma PSS levels than survivors among CAP patients: 1083 (697−1736) pg/mL vs. 385 (245−554) pg/mL (p < 0.001). The area under the curve (AUC) to predict 30-day mortality was highest for PSS (0.867), followed by procalcitonin (0.728) and lactate (0.616). The cutoff level of plasma PSS for 30-day mortality was >754 pg/mL. The combination of PSI and plasma PSS level improved the predictive ability for 30-day mortality (AUC = 0.892). Cox regression analysis showed that higher PSS levels (>754 pg/mL) and higher PSI (>126) were associated with 30-day mortality in CAP patients (hazard ratios of 19.472 and 6.375, respectively). Conclusion: Elevated plasma PSS is associated with severity and 30-day mortality in hospitalized CAP patients. Combining plasma PSS level and PSI could significantly improve the predictive ability of PSS for 30-day mortality.

Elevated procalcitonin levels in the absence of infection in procalcitonin-secretin hepatocellular carcinoma: A case report

BACKGROUND

Serum procalcitonin (PCT) is widely used to diagnose bacterial infection and sepsis. However, PCT may be elevated in some neoplasms. It is important to distinguish infection from no infection in such neoplasms. The relationship between hepatocellular carcinoma (HCC) and PCT is unknown.

CASE SUMMARY

A 62-year-old male was admitted due to a hepatic lesion of unknown origin. The patient had an elevated PCT level. Infectious diseases were excluded after appropriate examination. He then underwent exploratory laparotomy and a left lateral hepatectomy was performed. The patient recovered with an uneventful postoperative course and PCT level decreased gradually and was normal on day 16. HCC was diagnosed by histopathology and no evidence of infection was observed. Furthermore, immunohistochemical analyses revealed that tumor cells were positive for PCT.

CONCLUSION

HCC cells can secrete PCT in the absence of infection and PCT may be used as a marker to monitor the efficacy of tumor therapy.

Electrochemiluminescence in paired signal electrode (ECLipse) enables modular and scalable biosensing

Electrochemiluminescence (ECL) has an inherently low background and enables precise chemical reactions through electrical control. Here, we report an advanced ECL system, termed ECLipse (ECL in paired signal electrode). We physically separated ECL generation from target detection: These two processes were carried out in isolated chambers and coupled through an electrode. The strategy allowed us to minimize cross-chemical reactions, design electrodes for high ECL signals, and integrate multiple sensors in a chip. As a proof of concept, we implemented an eight-plex ECLipse and applied it to detect host factors in human plasma. ECLipse achieved higher signal-to-noise ratio than conventional ECL assays and was >7000-fold more sensitive than enzyme-linked immunosorbent assay. In a pilot clinical study, we could detect septic conditions by measuring host factors [i.e., interleukin-3 (IL-3), IL-6, and procalcitonin (PCT)]. ECLipse assay further revealed distinct IL-3 and IL-6 patterns in patients with severe acute respiratory syndrome coronavirus 2 infection.

Triple quantitative detection of three inflammatory biomarkers with a biotin-streptavidin-phycoerythrin based lateral flow immunoassay

Quantified inflammatory biomarkers are effective clinical strategy for correct and reasonable drug treatment. In the study, a triple lateral flow immunoassay (triple LFIA) had firstly been developed for specific and simultaneous detection of three pivotal inflammatory biomarkers (PCT, CRP and SAA) via biotin-streptavidin-phycoerythrin signal amplification system in one strip. The developed triple LFIA adopted phycoerythrin (PE) as chromophore to eliminate auto-fluorescence interference from plasma biomolecules and anti-PE mAb as single control line to reduce the nonspecific adsorption, which featured particular advantages in high sensitivity and specificity in a large range of analyte concentrations with the LODs of 0.106 ng/mL for PCT, 0.345 μg/mL for CRP and 3.112 μg/mL SAA, respectively. And the linear quantitative detection ranges were from 0.106 to 100 ng/mL, from 0.345 to 200 μg/mL, and from 3.112 to 200 μg/mL, respectively. Compared to commercial chemiluminescence immunoassay method, the correlations for tested PCT, CRP and SAA in 108 clinical samples were 0.989, 0.987 and 0.988, respectively. In summary, we had proposed a rapid and accurate plasma detection to measure inflammation factors, which facilitated the clinical value to achieve precise treatment.

Serum Procalcitonin Levels in Newly Diagnosed Hodgkin Lymphoma: Correlation with Other Inflammatory Biomarkers

Background and Objectives: Procalcitonin (PCT) is a useful biomarker for the diagnosis of sepsis. Inflammatory markers are elevated in patients with Hodgkin lymphoma (HL), and yet ongoing infection rarely coexists at diagnosis. PCT levels might be helpful in differentiating bacterial from disease-related inflammation. Materials and Methods: We evaluated serum PCT levels and other inflammation markers in newly diagnosed HL patients. Values < 0.50 ng/mL were considered normal (0.10−0.50 ng/mL: detectable, <0.10 ng/mL: undetectable), while values ≥ 0.50 ng/L were considered elevated. Results: Among 137 patients, 55 had B symptoms (40%), 77/130 (59%) had elevated Erythrocyte Sedimentation Rate (ESR) and 116 (85%) had elevated C-Reactive Protein (CRP) (median 38.1 mg/L (range; 2.97−328)). PCT levels were normal in most patients (undetectable 94/137 (68.5%) and detectable 41/137(30%)) with median value < 0.10 ng/mL (range; <0.10−15.90). Elevated PCT was recorded in only two patients (1.5%). Patients with PCT < 0.10 ng/mL had significantly lower median CRP (25.75; range (2.97−203.0)) compared to patients with PCT ≥ 0.1 ng/mL (median CRP 92.50 mg/L; range (3.34−328.0)). Almost all patients (40/41, 97.6%) with detectable PCT had elevated CRP. Conclusions: This is the first study showing that the inflammation characterizing HL is not associated with PCT elevations, although CRP levels are elevated in 85% of the patients. Normal PCT levels may rule out the possibility of occult infection, thus preventing extensive evaluation, which may delay treatment initiation.

The Etiology of Community-Acquired Pneumonia Correlates with Serum Inflammatory Markers in Children

Community-acquired pneumonia (CAP) severely affects pediatric hospitalizations. This study assessed the contribution of CAP to hospitalizations, its etiology in relationship with age, and the inflammatory markers. Between 2013 and 2018, 1064 CAP patients were hospitalized and diagnosed with bacterial/possibly bacterial pneumonia (BP), viral/possibly viral pneumonia (VP) and atypical pneumonia (AP). The etiology was confirmed using blood/pleural fluid culture/polymerase chain reaction (PCR), rapid antigen test/PCR in nasopharyngeal swabs, or serological studies. CAP accounted for 9.9% of hospitalizations and 14.8% of patient days. BP was diagnosed in 825 (77.5%), VP in 190 (17.9%), and AP in 49 (4.6%) cases; the confirmed etiology (n = 209; 20%) included mostly influenza (39%; n = 82), respiratory syncytial virus (RSV, 35%; n = 72), and Mycoplasma pneumoniae (19%; n = 39). VP frequency decreased with age (41% in < 3 mo to 9% in ≥ 60 mo), in contrast to AP (13% in ≥ 60 mo). Among the analyzed parameters, the best differentiating potential was shown by: C-reactive protein (CRP, AUCBP-VP = 0.675; 95% CI: 0.634−0.715), procalcitonin (AUCBP-AP = 0.73; 95% CI: 0.67−0.794), and CRP/procalcitonin (AUCAP-VP = 0.752; 95% CI: 0.67−0.83); a good positive predictive value (88.8%, 98.3%, and 91.6%, respectively) but a low negative predictive value (29.5%, 13.1%, and 40.7%, respectively) was observed. CAP influences hospital patient days more than the crude number of patients would suggest. On a clinical basis, BP is mainly recognized, although viral pneumonia is confirmed most often. RSV and influenza are responsible for a huge percentage of hospitalized cases, as well as M. pneumoniae in children aged ≥ 5 years. Serum inflammatory markers may help differentiate etiological factors.

Markedly elevated procalcitonin due to anaphylactic shock, a case report

Procalcitonin (PCT) is a well-known biomarker that is directly connected to bacterial infection especially when it reaches significantly high levels. It is extremely rare to be witnessed in non-bacterial infections such as viral or parasitic. It may be elevated in other conditions such as trauma and autoimmune diseases. We present a rare case of a young gentleman, who had an extremely high PCT level that appeared to be a result of anaphylaxis due to worm infestation.

Interleukin-6 cytokine: An overview of the immune regulation, immune dysregulation, and therapeutic approach

Several studies have shown that interleukin 6 (IL-6) is a multifunctional cytokine with both pro-inflammatory and anti-inflammatory activity, depending on the immune response context. Macrophages are among several cells that secrete IL-6, which they express upon activation by antigens, subsequently inducing fever and production of acute-phase proteins from the liver. Moreover, IL-6 induces the final maturation of B cells into memory B cells and plasma cells as well as an adaptive role for short-term energy allocation. Activation of IL-6 receptors results in the intracellular activation of the JAK/STAT pathway with resultant production of inflammatory cytokines. Several mechanisms-controlled IL-6 expression, but aberrant production was shown to be crucial in the pathogenesis of many diseases, which include autoimmune and chronic inflammatory diseases. IL-6 in combination with transforming growth factor β (TGF-β) induced differentiation of naïve T cells to Th17 cells, which is the cornerstone in autoimmune diseases. Recently, IL-6 secretion was shown to form the backbone of hypercytokinemia seen in the Coronavirus disease 2019 (COVID-19)-associated hyperinflammation and multiorgan failure. There are two classes of approved IL-6 inhibitors: anti-IL-6 receptor monoclonal antibodies (e.g., tocilizumab) and anti-IL-6 monoclonal antibodies (i.e., siltuximab). These drugs have been evaluated in patients with rheumatoid arthritis, juvenile idiopathic arthritis, cytokine release syndrome, and COVID-19 who have systemic inflammation. JAK/STAT pathway blockers were also successfully used in dampening IL-6 signal transduction. A better understanding of different mechanisms that modulate IL-6 expression will provide the much-needed solution with excellent safety and efficacy profiles for the treatment of autoimmune and inflammatory diseases in which IL-6 derives their pathogenesis.

Role of serum and synovial procalcitonin in differentiating septic from non-septic arthritis- a prospective study

INTRODUCTION

Septic arthritis is a serious orthopaedic emergency that must be diagnosed and managed early to prevent devastating complications. The current gold standard for diagnosing septic arthritis is synovial fluid culture, but results are delayed by 48-72 h, and the sensitivity of the test is very low. Differentiating Septic from non-septic arthritis is vital to prevent unnecessary use of antibiotics and prevent complications. Serum Procalcitonin (PCT) is a useful marker in differentiating septic from non-septic arthritis but there are very few studies that have studied the role of synovial PCT for the same.

AIM

To determine the role of serum and synovial PCT in differentiating acute Septic from non-septic arthritis.

MATERIALS AND METHODS

Prospective clinical study in which 60 patients presenting with acute inflammatory arthritis (<2 weeks duration) were enrolled from May 2018 to May 2020. Serum and synovial fluid samples were drawn at presentation and routine blood investigations, synovial fluid culture sensitivity, and Procalcitonin levels were measured. Patients were divided into 3 groups, with group-1 having confirmed pyogenic, group-2 having presumed pyogenic, and group-3 having non -pyogenic patients, respectively. All data was tabulated and statistically analysed using appropriate tests.

RESULTS

Mean serum PCT values in groups 1, 2 and 3 were 1.06 ± 1.11, 0.85 ± 0.74, and 0.11 ± 0.24, respectively. Patients in the Pyogenic group (group1 and group 2) had significantly higher mean serum PCT as compared to group3 (p < 0.0001). Group 1 had higher serum PCT as compared to group 2, but the difference was not significant (p = 0.58). Mean synovial PCT in group 1, 2 and 3 were 2.42 ± 1.98, 1.89 ± 1.18, and 0.22 ± 0.40, respectively. Patients in the Pyogenic group (Group1 and Group2) had significantly higher mean synovial PCT as compared to Group 3 (p < 0.0001). Group 1 had higher mean synovial PCT as compared to group 2, but the difference was not significant (p = 0.54). The area under the ROC curve of the serum levels of PCT was 0.0.895, and the area under the ROC curve of the synovial fluid levels of PCT was 0.914, which was higher than the serum PCT level.

CONCLUSION

Serum and synovial Procalcitonin may be used as a diagnostic marker in differentiating septic from inflammatory arthritis and can help in reducing unnecessary use of antibiotics and early diagnosis and management of septic arthritis, thereby preventing complications.

Paper-Based Interleukin-6 Test Strip for Early Detection of Wound Infection

The early stage of wound infection is always non-specific. Prompt intervention may help to prevent the wound from worsening. We developed a new protocol, based on previous research, that employs a paper-based IL-6 test strip used in combination with a spectrum-based optical reader to detect IL-6 in normal tissue (n = 19), acute wounds (n = 31), and chronic wounds (n = 32). Our data indicated the presence of significantly higher levels of IL-6 in acute wound tissues, but no significant difference in serum CRP. Receiver operating characteristics were used to determine clinical sensitivity and specificity of tissue IL-6 and systemic CRP. The area under the curve values were 0.87 and 0.63, respectively. The cut-off value of 30 pg/mL for IL-6 provided good sensitivity (75.0%) and superior specificity (88.9%). We found a high correlation between the IL-6 test strip and conventional ELISA results (R2 = 0.85, p < 0.001), and good agreement was also observed according to Bland-Altman analysis. We showed a promising role of tissue IL-6 to help early diagnosis of wound infection when clinical symptoms were non-specific. The advantages of this wound detection protocol included minimal invasiveness, small sample requirements, speed, sample preparation ease, and user-friendliness. This methodology could help care providers quickly clarify wound infection status and implement timely, optimal management.

Construction of a predictive model and prognosis of left ventricular systolic dysfunction in patients with sepsis based on the diagnosis using left ventricular global longitudinal strain

BACKGROUND

Cardiac dysfunction, a common complication of sepsis, is associated with increased mortality. However, its risk factors are poorly understood, and a predictive model might help in the management of cardiac dysfunction.

METHODS

A monocentric prospective study of patients with sepsis was performed. Left ventricular global longitudinal strain (LV GLS) was measured using echocardiography within 72 h of the patients diagnosed with sepsis, and the patients were categorized into two groups: LV GLS > -17%, left ventricular systolic dysfunction group (LVSD group); and LV GLS ≤ -17%, non-left ventricular systolic dysfunction group (Non-LVSD group). The baseline characteristics and prognosis of the two groups were analyzed. Based on the results of the multivariate logistic regression analysis, a predictive model of LVSD was established and a nomogram was drawn.

RESULTS

Fifty-one left ventricular systolic dysfunction in patients with sepsis and 73 non-LVSD sepsis patients were included. Prognostic analysis showed that patients with LVSD had higher ICU mortality, in-hospital mortality, the incidence of atrial fibrillation (P < 0.05), and risk of death (HR = 3.104, 95% CI = 1.617-5.957, P < 0.001) compared to patients with non-LVSD. There were no significant differences in the rate of tracheal intubation, the incidence of acute kidney injury (AKI), the proportion of continuous renal replacement therapy (CRRT), length of ICU stay, and length of hospital stay between the 2 groups (P > 0.05). High sensitive troponin I (Hs-TnI) ≥ 0.131 ng/ml, procalcitonin (PCT) ≥ 40 ng/ml, lactate (Lac) ≥ 4.2 mmol/L, and N-terminal pro-brain natriuretic peptide (NT-proBNP) ≥ 3270 pg/ml were found to be the best cut-off values for the prediction of LVSD.

CONCLUSION

Sepsis patients with left ventricular systolic dysfunction had a higher risk of death and atrial fibrillation. Hs-TnI, PCT, Lac, and NT-proBNP were independent risk factors of LVSD, and the LVSD predictive model constructed using these factors showed good diagnostic performance.

TRIAL REGISTRATION

Chinese Clinical Trial Registry No: ChiCTR2000032128. Registered on 20 April 2020, http://www.chictr.org.cn/showproj.aspx ?proj=52531.

Thymoquinone modulates the expression of sepsis‑related microRNAs in a CLP model

Sepsis is a clinical syndrome common in critical care settings. In the present study, the therapeutic effect of thymoquinone (TQ) on the expression of sepsis-related microRNAs (miRNAs/miRs), levels of inflammatory markers, organ dysfunction and mortality were investigated in a cecal ligation and puncture (CLP) rat model. A single dose of TQ (1 mg/kg) was administered to animals 24 h after CLP and the mortality rate was assessed up to 7 days following the induction of sepsis. In addition, blood samples were collected at different time points and the expression levels of miRNAs (i.e. miR-16, miR-21, miR-27a and miR-34a) were examined, along with the levels of inflammatory cytokines (i.e. TNF-α, IL-1α, IL-2, IL-6 and IL-10) and sepsis markers (i.e. C-reactive protein, endothelial cell-specific molecule-1, VEGF, procalcitonin and D-dimer). Liver, kidney and lung tissues were also collected for further histological examination. Treatment with TQ significantly downregulated the miRNA expression levels, as well as the levels of inflammatory cytokines and early-stage sepsis biomarkers by 30-70% at 12-36 h (P<0.05). Furthermore, CLP model rats treated with TQ exhibited an ~80% increase in survival rate compared with that in the untreated CLP group. In addition, TQ induced the preservation of organ function and structure. In conclusion, the present study demonstrated a promising therapeutic effect of TQ against the sequelae of sepsis.

Usefulness of presepsin for the early detection of infectious complications after elective colorectal surgery, compared with C-reactive protein and procalcitonin

Infectious complications remain a major clinical problem in colorectal surgery. Presepsin has been reported to be a useful marker to diagnose sepsis, similar or superior to procalcitonin (PCT) and C-reactive protein (CRP). The aim of this study was to assess the diagnostic value of presepsin in the early detection of infectious complications after elective colorectal surgery, compared with CRP and PCT. This study was a prospective observational study. Patients of age > 18 who underwent elective colon resections were enrolled. Blood samples were collected just before surgery and on postoperative day (POD) 1, 2, 3, 4, and 6 to measure plasma levels of biomarkers. We evaluated the association between circulating biomarkers and infections. A total of 114 patients were examined, and 27 patients (23.7%) developed infectious complications. CRP and PCT markedly increased from POD 1 to POD 3 and then gradually decreased toward POD 6 in both groups, but the trends of the decrease in the infected group were blunt, compared with those in the non-infected group. On the other hand, presepsin did not show major changes just after surgery, but it increased on POD 4 and POD 6, when the complications occurred. Monitoring the presepsin trends after colorectal surgeries could be helpful to detect postoperative infectious complications.

Trial registration: UMIN000025313. Registered on 17 December 2016.

Prognostic significance of soluble CD25 in patients with sepsis: a prospective observational study

OBJECTIVES

The diagnosis of sepsis is challenging, the need for sensitive and specific diagnostic and prognostic biomarkers has not been met. Soluble CD25 (sCD25) is a readily available biomarker reported to represent the severity of the disease. This study aimed to assess the association between sCD25 and mortality in patients with sepsis.

METHODS

In total, 329 adult patients with sepsis were screened through a prospective, observational study. We investigated the severity scores and sCD25 levels at admission to the intensive care unit (ICU), defined by sepsis (sepsis-3). The prognostic value of sCD25 was assessed using receiver operating characteristic (ROC) curves and binary logistic regression models in predicting unfavourable outcome. The correlations between variables and severity of disease were analysed by Spearman correlation tests.

RESULTS

After entering the ICU, the sCD25 level and sequential organ failure assessment (SOFA) score were significantly higher in nonsurvivors than in survivors. The prognostic values estimated by the ROC curves were 0.678 for sCD25 and 0.945 for SOFA score at ICU admission. sCD25 had a modest ability to predict poor outcome. Logistic regression showed that increased levels of sCD25 were independently associated with unfavourable outcome. Spearman correlation tests showed that sCD25 levels were positively correlated with disease severity.

CONCLUSIONS

In sepsis patients, increased sCD25 levels were independently associated with poor clinical outcomes. Further research is needed to improve the understanding of the pathophysiology of this relationship.