Procalcitonin: Between evidence and critical issues

Comparative analysis of inflammatory biomarkers for the diagnosis of neonatal sepsis: IL-6, IL-8, SAA, CRP, and PCT

Neonatal sepsis (NS) is highly likely to cause death; however, early diagnosis of NS is still a great challenge. This study aimed to determine the diagnostic values of IL-6, IL-8, and serum amyloid A (SAA) in NS patients. C-Reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-6, IL-8, and SAA were detected in 120 infants with NS (60 premature infants [NS-PIs] and 60 term infants [NS-TIs]). Sixty noninfected premature infants and 60 noninfected term infants composed the control group. Receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of IL-6, IL-8, and SAA alone and in combination with CRP and PCT. The area under the curve (AUC) was calculated to evaluate the diagnostic value. The clinical characteristics of the subjects were recorded. The expression of CRP, PCT, IL-6, IL-8, and SAA was upregulated in patients with NS compared with control subjects. When the SAA cut-off value was 10.18 mg/L, the greatest AUC for the diagnosis of NS-PIs was for SAA (AUC = 0.833, 95% CI 0.762-0.905, P < 0.001). When the CRP cut-off value was 9.562 mg/L, the smallest AUC for the diagnosis of NS-PIs was for CRP (AUC = 0.776, 95% CI 0.684-0.867, P < 0.001). When the IL-8 cut-off value was 52.03 pg/mL, the greatest AUC for the diagnosis of NS-TIs was for IL-8 (0.821). When the IL-8 cut-off value was 52.03 pg/mL, the greatest AUC for the diagnosis of NS-TIs was for IL-8 (AUC = 0.821, 95% CI 0.745-0.898, P < 0.001). When the CRP cut-off value was 13.18 mg/L, the smallest AUC for the diagnosis of NS-TIs was for CRP (AUC = 0.762, 95% CI 0.667-0.857; P < 0.001). Additionally, according to the AUC value, the best combination was SAA and PCT for NS-PI diagnosis, and the best combination was PCT and IL-6 for NS-TI. In conclusion, compared with PCT and CRP, IL-6, IL-8, and SAA are better diagnostic biomarkers. Moreover, PCT combined with SAA is more suitable for diagnosing NS-PIs, and PCT combined with IL-6 is more suitable for diagnosing NS-TIs.

Thromboelastometry-Based Profiling of Haemostatic Alterations in Neonatal Sepsis by Causative Pathogens

Background: Neonatal sepsis is a serious condition with high mortality, especially in premature and low-birth-weight neonates. This study aims to examine whether the haemostatic profile of neonates with sepsis defers depending on the type of bacteria (Gram-positive or Gram-negative), by using the method of Rotational Thromboelastometry (ROTEM). Methods: This single-centre prospective cohort study was conducted on 128 neonates with sepsis, including 95 cases caused by Gram-negative pathogens and 33 cases caused by Gram-positive bacteria. All participants were hospitalised in the Neonatal Intensive Care Unit (NICU). ROTEM parameters were compared between neonates with Gram-positive and Gram-negative infections. Results: The ROTEM parameters were found to be significantly different between neonates suffering from Gram-positive versus Gram-negative infections, with Gram-positive pathogens associated with an increased clotting potential compared to Gram-negative pathogens. This is reflected in the higher ROTEM values such as A10, α-angle, and MCF in the EXTEM and INTEM assays. Multivariant analysis showed that Gram-positive infections were linked to increased clot thickness at 10 min (coefficient: 8.9, CI: 2.8-15.0, p = 0.004), higher maximum clot stability (coefficient: 10.4, CI: 4.3-16.6, p = 0.001), and a bigger α-angle (coefficient: 8.0, CI: 2.7-13.2, p = 0.003). Similar findings were observed in the INTEM assay parameters. Conclusions: Neonatal sepsis caused by Gram-positive bacteria leads to a hypercoagulable haemostatic state, whereas neonates with sepsis caused by Gram-negative bacteria exhibit a more hypocoagulable profile and a higher incidence of haemorrhagic episodes. These findings provide valuable insights into the haemostatic disorders associated with sepsis, and may aid in developing an individualised approach for the treatment of those disorders, dependent on and adapted for the specific type of causative organism.

Construction and evaluation of a combined diagnostic model for chronic periprosthetic joint infection based on serological tests

BACKGROUND

Early diagnosis of chronic periprosthetic joint infection (CPJI) is crucial for ensuring effective treatment and improving patient outcomes. However, many auxiliary diagnostic tests are challenging to implement on a large scale due to economic and technical constraints, making CPJI diagnosis difficult. This study aims to design and validate a combined diagnostic model based on commonly used serological tests to evaluate its diagnostic value for CPJI and develop a diagnostic nomogram.

METHODS

A retrospective study from January 2019 to February 2024 involving 170 patients undergoing knee and hip arthroplasty revision for CPJI and aseptic loosening (AL) was conducted across two medical centers. These patients were divided into the training set and validation set. Patients were categorized into CPJI and AL groups based on infection status. Serological tests conducted upon admission were collected, and single-factor and multi-factor logistic regression analyses were used to identify independent diagnostic factors for early infection. These factors were integrated to construct a nomogram model. The model's performance was evaluated using the receiver operating characteristic area under the curve (AUC), Hosmer-Lemeshow test, decision curve analysis (DCA), and calibration curve, with external validation conducted on the validation set.

RESULTS

Multivariate logistic regression analysis showed that C-reactive protein (CRP), procalcitonin (PCT), and Platelet count/mean platelet volume ratio (PVR) were independent diagnostic factors for CPJI (p < 0.05). The AUCs for diagnosing CPJI using these individual factors were 0.806, 0.616, and 0.700 (p < 0.05), respectively, while their combined detection achieved an AUC of 0.861 (p < 0.05). The DCA clinical impact curve shows the combined model has good clinical utility when the threshold probability of infection presence is between 0.16 and 0.95. Similar results were obtained in the external validation cohort, with the combined detection having an AUC of 0.893.

CONCLUSION

The combined diagnostic model of CRP, PCT, and PVR significantly improves the The combined diagnostic model of CRP, PCT, and PVR significantly improves the diagnostic performance for CPJI compared to individual serum biomarkers. It exhibits good sensitivity, specificity, and clinical applicability, providing valuable references for CPJI diagnosis.

Serum Procalcitonin, Hematology Parameters, and Cell Morphology in Multiple Clinical Conditions and Sepsis

BACKGROUND

The clinical value of procalcitonin (PCT) in infection diagnosis and antibiotic stewardship is still unclear. This study aimed to investigate the association between serum PCT and different clinical conditions as well as other infectious/inflammatory parameters in different septic patients in order to elucidate the value of PCT detection in infection management.

METHODS

Chemiluminescence immunoassay was used for serum PCT analysis. Hematology analysis was used for complete blood cell count. Digital automated cell morphology analysis was used for blood cell morphology examination. Blood, urine, and stool cultures were performed according to routine clinical laboratory standard operating procedures. C-reactive protein (CRP) was analyzed by immunoturbidimetry. Erythrocyte sedimentation rate test was performed using natural sedimentation methods.

RESULTS

Outpatients, ICU patients, and patients under 2 years of age with respiratory infections had higher serum PCT levels. Septic patients had the highest-serum PCT levels and other infection indexes. PCT levels in the blood, urine, and stool culture-positive patients were significantly higher than in culture-negative patients. The neutrophil granulation and reactive lymphocytes were observed together with the PCT-level increments in different septic patients, and these alterations were lessened after treatment. There was no significant change in monocyte morphology between pre- and posttreatment septic patients.

CONCLUSIONS

Serum PCT is associated with neutrophil cytotoxicity and lymphocyte morphology changes in sepsis; thus, the combination of neutrophil and lymphocyte digital cell morphology evaluations with PCT detection may be a useful examination for guiding the clinical management of sepsis.

Association of procalcitonin with voriconazole concentrations: a retrospective cohort study

Inflammation is a potential risk factor of voriconazole (VCZ) overdose, procalcitonin (PCT) is reported to act as a diagnostic marker for bacterial infections. However, the association of PCT with VCZ trough serum concentrations (VCZ-Cmin) is not fully clear. Our study aims to investigate the associations between PCT and VCZ-Cmin. In this retrospective cohort study, we collected the clinical data of 147 patients who received VCZ and monitored the VCZ concentration of them in our hospital from August 2017 to August 2021. All patients underwent routine clinical examinations on the day or the day before VCZ administration. General information and clinical symptoms of these patients were recorded. Multivariate liner analysis showed that PCT was significantly associated with VCZ-Cmin (p < 0.001). Overall, it was shown that VCZ-Cmin was significantly increased by 0.32 µg/mL for each fold increment in PCT in crude model. In the minor adjusted model (Model 1, adjustment for sex, age, albumin, direct bi1irubin, WBC) and fully adjusted model (Model 2, adjustment for sex, age, albumin, direct bilirubin, WBC, AST and ALT), VCZ-Cmin was significantly increased by 0.23 µg/mL and 0.21 µg/mL, respectively, for each fold increment in PCT. In conclusion, this research reveals the correlation between PCT and VCZ-Cmin, indicating that PCT has the potential to serve as a valuable biomarker for drug monitoring in the treatment of VCZ.

Diagnosis and Management of Neonatal Bacterial Sepsis: Current Challenges and Future Perspectives

Sepsis remains the second cause of death among neonates after the pathological consequences of extreme prematurity. In this review we summarized knowledge about pathogens causing early-onset sepsis (EOS) and late-onset sepsis (LOS), the role of perinatal risk factors in determining the EOS risk, and the tools used to reduce unnecessary antibiotics. New molecular assays could improve the accuracy of standard blood cultures, providing the opportunity for a quick and sensitive tool. Different sepsis criteria and biomarkers are available to date, but further research is needed to guide the use of antibiotics according to these tools. Beyond the historical antibiotic regimens in EOS and LOS episodes, antibiotics should be based on the local flora and promptly modulated if specific pathogens are identified. The possibility of an antibiotic lock therapy for central venous catheters should be further investigated. In the near future, artificial intelligence could help us to personalize treatments and reduce the increasing trend of multidrug-resistant bacteria.

Progress in Procalcitonin Detection Based on Immunoassay

Procalcitonin (PCT) serves as a crucial biomarker utilized in diverse clinical contexts, including sepsis diagnosis and emergency departments. Its applications extend to identifying pathogens, assessing infection severity, guiding drug administration, and implementing theranostic strategies. However, current clinical deployed methods cannot meet the needs for accurate or real-time quantitative monitoring of PCT. This review aims to introduce these emerging PCT immunoassay technologies, focusing on analyzing their advantages in improving detection performances, such as easy operation and high precision. The fundamental principles and characteristics of state-of-the-art methods are first introduced, including chemiluminescence, immunofluorescence, latex-enhanced turbidity, enzyme-linked immunosorbent, colloidal gold immunochromatography, and radioimmunoassay. Then, improved methods using new materials and new technologies are briefly described, for instance, the combination with responsive nanomaterials, Raman spectroscopy, and digital microfluidics. Finally, the detection performance parameters of these methods and the clinical importance of PCT detection are also discussed.

A machine learning strategy to mitigate the inappropriateness of procalcitonin request in clinical practice

Aim

The aim of this study was to develop machine learning (ML) models to mitigate the inappropriate request of Procalcitonin (PCT) in clinical wards.

Material and methods

We built six different ML models based on both demographical data, i.e., sex and age, and laboratory parameters, i.e., cell blood count (CBC) parameters, inclusive of monocyte distribution width (MDW), and C-reactive protein (CRP). The dataset included 1667 PCT measurements of different patients. Based on a PCT cut-off of 0.50 ng/mL, we found 1090 negative (65.4%) and 577 positive (34.6%) results. We performed a 70:15:15 train:validation:test splitting based on the outcome.

Results

Random Forest, Support Vector Machine and eXtreme Gradient Boosting showed optimal performances for predicting PCT positivity, with an area under the curve ranging from 0.88 to 0.89.

Conclusions

The ML models developed could represent a useful tool to predict PCT positivity, avoiding unusefulness PCT requests. ML models are based on laboratory tests commonly ordered together with PCT but have the great advantage to be easy to measure and low-cost.

Usefulness of Procalcitonin Levels for Predicting the Microbiological Orientation in Patients with Sepsis

The main objective of the study was to verify whether levels of procalcitonin (PCT) could guide us toward determining the type of bacteria causing the sepsis and to identify the discriminatory cut-off point in the first urgent laboratory test. This study is a single center retrospective analysis that includes 371 patients with a mean age of 71.7 ± 15.6 years who were diagnosed with sepsis or septic shock. The yield of blood cultures in demonstrating the causative microbiological agent was 24.3% (90), and it was 57, 1% (212) when evaluating all types of cultures. Statistically significant positive differences were observed in the mean value of the PCT between the group that obtained positive cultures and the group that did not (p < 0.0001). The AUC-ROC of PCT values as a guide to the causal bacteria type was 0.68 (95%CI: 0.57-0.78, p < 0.0021). The PCT value that showed the best diagnostic characteristics for identifying Gram-negative rods (GNR) as the causative agent in blood cultures was 2.1 ng/mL. The positive predictive value (PPV) was 78, 9% (66.3-88.1%). The AUC-ROC of the PCT values for sepsis diagnosis, with any positive culture that could be assessed, was 0.67 (95%CI: 0.63-0.73, p < 0.0001). The PCT value that showed the best diagnostic characteristic for predicting sepsis was 3.6 ng/mL.

An inflammation-based model for identifying severe acute pancreatitis: a single-center retrospective study

BACKGROUND AND AIMS

Severe acute pancreatitis (SAP) is potentially lethal. Considering the role of inflammation in the progression of acute pancreatitis (AP), this study aims to develop a model based on inflammatory indexes for identifying the presence of SAP.

METHODS

Overall, 253 patients with AP who were consecutively admitted between July 2018 and November 2020 were screened, of whom 60 had SAP. Systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), neutrophil-to-platelet ratio (NPR), systemic inflammation response index (SIRI), platelet-to-albumin ratio (PAR), C-reactive protein-to-albumin ratio (CAR), C-reactive protein-to-lymphocyte ratio (CLR), and triglyceride glucose (TyG) index were calculated. Multivariate logistic regression analyses were performed to identify independent risk factors of SAP. Then, inflammation-based models were established. Receiver operating characteristics (ROC) curve analyses were performed. Area under ROC curve (AUROC) was calculated.

RESULTS

Diabetes mellitus, fatty liver, high white blood cell count (WBC), C-reactive protein (CRP), red blood cell distribution width (RDW), procalcitonin (PCT), SII, NLR, NPR, CAR, CLR, and TyG index, and a low LMR were significantly associated with SAP. Considering the collinearity among these variables, 10 multivariate logistic regression analyses were separately performed. Finally, four independent inflammation-based models were established. Of them, the best one, which was calculated as follows: 1.204*fatty liver (yes = 1; no = 0) + 0.419*PCT + 0.005*CLR - 2.629, had an AUROC of 0.795 with a specificity of 73.4% and a sensitivity of 71.7%.

CONCLUSION

The inflammation-based model consisting of fatty liver, PCT, and CLR has a good diagnostic performance for SAP.

A decade of clinical microbiology: top 10 advances in 10 years: what every infection preventionist and antimicrobial steward should know

The past 10 years have brought paradigm-shifting changes to clinical microbiology. This paper explores the top 10 transformative innovations across the diagnostic spectrum, including not only state of the art technologies but also preanalytic and post-analytic advances. Clinical decision support tools have reshaped testing practices, curbing unnecessary tests. Innovations like broad-range polymerase chain reaction and metagenomic sequencing, whole genome sequencing, multiplex molecular panels, rapid phenotypic susceptibility testing, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry have all expanded our diagnostic armamentarium. Rapid home-based testing has made diagnostic testing more accessible than ever. Enhancements to clinician-laboratory interfaces allow for automated stewardship interventions and education. Laboratory restructuring and consolidation efforts are reshaping the field of microbiology, presenting both opportunities and challenges for the future of clinical microbiology laboratories. Here, we review key innovations of the last decade.

Advancement in biomarker based effective diagnosis of neonatal sepsis

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.

Values of combined C-reactive protein, procalcitonin and serum amyloid A in differential diagnosis of bacterial and non-bacterial community acquired pneumonia in children

This research aimed to explore the clinical value of C-reactive protein (CRP), procalcitonin (PCT), and serum amyloid A (SAA) in early diagnosis of bacterial pneumonia. CRP, PCT, and SAA levels of children with bacterial pneumonia, children with non-bacterial pneumonia, and healthy children were compared. The sensitivity and specificity of CRP, PCT, and SAA in the diagnosis of bacterial pneumonia in children were compared. CRP, PCT, and SAA levels were significantly lower in healthy children when compared with children with Community acquired pneumonia (CAP). ROC analyses showed that CRP, PCT, and SAA all had good accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. The combination of CRP, PCT, and SAA further enhanced the accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. In conclusion, the expression levels of CRP, PCT, and SAA could indicate the status of bacterial pneumonia. The combined test of CRP, PCT, and SAA had the highest diagnostic accuracy.

Diagnostic value of soluble biomarkers for parapneumonic pleural effusion

Parapneumonic pleural effusion (PPE) is a common complication in patients with pneumonia. Timely and accurate diagnosis of PPE is of great value for its management. Measurement of biomarkers in circulating and pleural fluid have the advantages of easy accessibility, short turn-around time, objectiveness and low cost and thus have utility for PPE diagnosis and stratification. To date, many biomarkers have been reported to be of value for the management of PPE. Here, we review the values of pleural fluid and circulating biomarkers for the diagnosis and stratification PPE. The biomarkers discussed are C-reactive protein, procalcitonin, presepsin, soluble triggering receptor expressed on myeloid cells 1, lipopolysaccharide-binding protein, inflammatory markers, serum amyloid A, soluble urokinase plasminogen activator receptor, matrix metalloproteinases, pentraxin-3 and cell-free DNA. We found that none of the available biomarkers has adequate performance for diagnosing and stratifying PPE. Therefore, further work is needed to identify and validate novel biomarkers, and their combinations, for the management of PPE.

Development of a Nomogram for Predicting Mortality Risk in Sepsis Patients During Hospitalization: A Retrospective Study

Purpose

We attempted to establish a model for predicting the mortality risk of sepsis patients during hospitalization.

Patients and Methods

Data on patients with sepsis were collected from a clinical record mining database, who were hospitalized at the Affiliated Dongyang Hospital of Wenzhou Medical University between January 2013 and August 2022. These included patients were divided into modeling and validation groups. In the modeling group, the independent risk factors of death during hospitalization were determined using univariate and multi-variate regression analyses. After stepwise regression analysis (both directions), a nomogram was drawn. The discrimination ability of the model was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, and the GiViTI calibration chart assessed the model calibration. The Decline Curve Analysis (DCA) was performed to evaluate the clinical effectiveness of the prediction model. Among the validation group, the logistic regression model was compared to the models established by the SOFA scoring system, random forest method, and stacking method.

Results

A total of 1740 subjects were included in this study, 1218 in the modeling population and 522 in the validation population. The results revealed that serum cholinesterase, total bilirubin, respiratory failure, lactic acid, creatinine, and pro-brain natriuretic peptide were the independent risk factors of death. The AUC values in the modeling group and validation group were 0.847 and 0.826. The P values of calibration charts in the two population sets were 0.838 and 0.771. The DCA curves were above the two extreme curves. Moreover, the AUC values of the models established by the SOFA scoring system, random forest method, and stacking method in the validation group were 0.777, 0.827, and 0.832, respectively.

Conclusion

The nomogram model established by combining multiple risk factors could effectively predict the mortality risk of sepsis patients during hospitalization.

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

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

Use of serum procalcitonin (PCT) level and PCT mRNA expression as a potential clinical biomarker in cats with bacterial and viral infections

OBJECTIVES

The aim of this study was to investigate the use of procalcitonin (PCT) as a biomarker in differentiating bacterial infections from viral infections in cats. In addition, the relationship between PCT and mortality rate was also examined.

METHODS

Forty-five cats were included in the study. The cats were categorised into two groups: bacterial (n = 20) and viral (n = 25) infection. Serum PCT level and PCT mRNA expression were analysed from blood samples collected before treatment.

RESULTS

Serum PCT level and PCT mRNA expression of the cats with presumed bacterial infection were higher than those with viral infection (P = 0.001 and P = 0.001, respectively). The receiver operating characteristic (ROC) curve analysis revealed an area under the ROC curve value of 0.888 for serum PCT and 0.850 for PCT mRNA expression. There was no statistically significant difference among respiratory, urinary and gastrointestinal tract infections regarding serum PCT level and PCT mRNA expression in the presumed bacterial infection group (P = 0.741 and P = 0.141, respectively). In the presumed bacterial infection group, serum PCT level and PCT mRNA expression in the non-surviving cats were higher than those of the surviving cats (P = 0.021 and P = 0.026, respectively).

CONCLUSIONS AND RELEVANCE

Serum PCT level and PCT mRNA expression were considered efficient biomarkers in cats to distinguish a bacterial infection from a viral infection. Moreover, ROC curve analysis was highly accurate in the discriminative capacity of these two parameters. PCT level and PCT mRNA expression offer substantial assistance in an efficient therapeutic approach and in avoiding unnecessary antibiotic use in feline clinical practice, particularly in emergency patients and those with non-specific clinical signs, decreasing the mortality rate. However, it should be noted that these data are only research data. More detailed future studies are needed.

Clinical Utility of Procalcitonin on Antibiotic Stewardship: A Narrative Review

Procalcitonin (PCT) was discovered as a useful marker for bacterial infection. Following its discovery, there have been a substantial number of clinical studies conducted to evaluate the presence of bacterial infections, and to guide antibiotic treatment by the stratified levels of PCT. Clinical evidence suggests that antibiotic treatment by PCT-guided antibiotic stewardship has been associated with a reduction in antibiotic usage without an increase in adverse outcomes. The use of PCT was approved by the Food and Drug Administration in the United States of America in 2017 to guide antibiotic treatment in sepsis and lower respiratory tract infections (LRTIs). In Korea, the use of PCT for sepsis and for pneumonia was approved in 2015 and 2022, respectively. This review will discuss the clinical utility of PCT on antibiotic stewardship in the management of sepsis and LRTIs including pneumonia.

Developing a new sepsis screening tool based on lymphocyte count, international normalized ratio and procalcitonin (LIP score)

Exploring an effective sepsis screening tool that can be widely implemented is important for improving the prognosis of sepsis worldwide. This study aimed to develop a new simple screening tool for sepsis (LIP scoring system) that includes the peripheral blood lymphocyte count, international normalized ratio, and procalcitonin level. In a single-center, prospective, observational study, 444 acute sepsis inpatients and 444 nonsepsis inpatients were ultimately included based on the Sepsis-3 and exclusion criteria. The differences in the Lym, INR, PCT level and other clinical biomarkers were compared between the two groups. Univariable and multivariable logistic regression analyses and receiver operating characteristic analysis were used to establish a LIP screening tool for sepsis with a combination of biomarkers. The Kappa and McNemar tests were used to evaluate the differences between the LIP screening results (LIP score ≥ 3) and Sepsis-3 criteria (SOFA score ≥ 2). Logistic regression analysis showed that the lymphocyte count, INR, PCT level, platelets, neutrophil/lymphocyte ratio (NLR) and prothrombin time (PT) were independent risk factors for the development of sepsis. The ROC analysis showed that the lymphocyte count, INR, and PCT level had high area under the ROC curve values (AUROC (95% CI): Lym 0.84 (0.810-0.860), INR 0.921 (0.902-0.938), PCT level 0.928 (0.909-0.944)). The LIP tool had satisfactory screening efficacy for sepsis (sensitivity, 92.8%; specificity, 94.1%), and a LIP score equal to or greater than 3 points had good agreement with Sepsis-3 criteria in the diagnosis of sepsis (Kappa = 0862 in the Kappa test and P = 0.512 in the McNemar test). The LIP tool has satisfactory sensitivity and specificity for sepsis screening, and it can be used for rapid screening of patients with sepsis in outpatient and emergency departments or in economically underdeveloped areas with limited resources.

Pleural fluid biochemical analysis: the past, present and future

Identifying the cause of pleural effusion is challenging for pulmonologists. Imaging, biopsy, microbiology and biochemical analyses are routinely used for diagnosing pleural effusion. Among these diagnostic tools, biochemical analyses are promising because they have the advantages of low cost, minimal invasiveness, observer independence and short turn-around time. Here, we reviewed the past, present and future of pleural fluid biochemical analysis. We reviewed the history of Light’s criteria and its modifications and the current status of biomarkers for heart failure, malignant pleural effusion, tuberculosis pleural effusion and parapneumonic pleural effusion. In addition, we anticipate the future of pleural fluid biochemical analysis, including the utility of machine learning, molecular diagnosis and high-throughput technologies. Clinical Chemistry and Laboratory Medicine (CCLM) should address the topic of pleural fluid biochemical analysis in the future to promote specific knowledge in the laboratory professional community.

Pursuing appropriateness of laboratory tests: a 15-year experience in an academic medical institution

Appropriateness in Laboratory Medicine has been the object of various types of interventions. From published experiences, it is now clear that to effectively manage the laboratory test demand it is recommended to activate evidence-based preventative strategies stopping inappropriate requests before they can reach the laboratory. To guarantee appropriate laboratory test utilization, healthcare institutions should implement and optimize a computerized provider order entry (CPOE), exploiting the potential of electronic requesting as "enabling factor" for reinforcing appropriateness and sustaining its effects over time. In our academic institution, over the last 15 years, our medical laboratory has enforced various interventions to improve test appropriateness, all directly or indirectly based on CPOE use. The following types of intervention were implemented: (1) applying specific recommendations supported by monitoring by CPOE as well as a continuous consultation with clinicians (tumour markers); (2) removing outdated tests and avoiding redundant duplications (cardiac markers, pancreatic enzymes); (3) order restraints to selected wards and gating policy (procalcitonin, B-type natriuretic peptide, homocysteine); (4) reflex testing (bilirubin fractions, free prostate-specific antigen, aminotransferases, magnesium in hypocalcemia); and (5) minimum retesting interval (D-Dimer, vitamin B₁₂, C-reactive protein, γ-glutamyltranspeptidase). In this paper, we reviewed these interventions and summarized their outcomes primarily related to the changes in total test volumes and cost savings, without neglecting patient safety. Our experience confirmed that laboratory professionals have an irreplaceable role as "stewards" in designing, implementing, evaluating, and maintaining interventions focused to improving test appropriateness.

'Penelope test': a practical instrument for checking appropriateness of laboratory tests

In medical laboratories, the appropriateness challenge directly revolves around the laboratory test and its proper selection, data analysis, and result reporting. However, laboratories have also a role in the appropriate management of those phases of total testing process (TTP) that traditionally are not under their direct control. So that, the laboratory obligation to act along the entire TTP is now widely accepted in order to achieve better care management. Because of the large number of variables involved in the overall TTP structure, it is difficult to monitor appropriateness in real time. However, it is possible to retrospectively reconstruct the body of the clinical process involved in the management of a specific laboratory test to track key passages that may be defective or incomplete in terms of appropriateness. Here we proposed an appropriateness check-list scheme along the TTP chain to be potentially applied to any laboratory test. This scheme consists of a series of questions that healthcare professionals should answer to achieve laboratory test appropriateness. In the system, even a single lacking answer may compromise the integrity of all appropriateness evaluation process as the inability to answer may involve a significant deviation from the optimal trajectory, which compromise the test appropriateness and the quality of subsequent steps. Using two examples of the check-list application, we showed that the proposed instrument may offer an objective help to avoid inappropriate use of laboratory tests in an integrated way involving both laboratory professionals and user clinicians.

Procalcitonin to Predict Severity of Acute Cholangitis and Need for Urgent Biliary Decompression: Systematic Scoping Review

Serum procalcitonin (PCT) has been reported as a potential biomarker to predict the severity of acute cholangitis (AC) or the need for urgent biliary decompression. This study aimed to identify and summarize the existing research about serum PCT and the severity of AC, and to find gaps towards which future studies can be targeted. Following the PRISMA extension for scoping reviews, MEDLINE, EMBASE, and Google Scholar were searched for all peer-reviewed articles with relevant keywords including "cholangitis" and "procalcitonin" from their inception to 13 July 2021. We identified six studies. All the studies employed a case-control design and aimed to evaluate the usefulness of serum PCT to predict the severity of AC with key identified outcomes. While the potential cut-off values of serum PCT for severe AC ranged from 1.8-3.1 ng/mL, studies used different severity criteria and the definition of urgent biliary decompression. No studies proposed cut-off PCT values for the need for urgent biliary decompression. This scoping review identified the current level of evidence regarding the usefulness of serum PCT in assessing the severity of AC. Further clinical research is warranted with a focus on standardized outcome measures employing prospective or experimental designs.

Role of Polypeptide Inflammatory Biomarkers in the Diagnosis and Monitoring of COVID-19

The COVID-19 (coronavirus disease 2019) pandemic that took over the world in December 2019 has had everlasting devastating impacts on the lives of people globally. It manifests a huge symptom spectrum ranging from asymptomatic to critically ill patients with an unpredictable outcome. Timely diagnosis and assessment of disease severity is imperative for effective treatment. Possibilities exist that by the time symptoms appear the viral load might increase beyond control. However, it is advisable to get adequately diagnosed as soon as the first symptom appears. There is an immediate requirement of reliable biomarkers of COVID-19 manifesting an early onset for effective clinical management, stratification of high risk patients and ensuring ideal resource allocation. In this review, we attempt to explore and describe important polypeptide inflammatory biomarkers, namely C-reactive protein, Procalcitonin, Ferritin, Lactate Dehydrogenase, Serum amyloid A, Interleukin-6, Tumor necrosis factor-alpha and LIGHT used in the detection and management of COVID-19. Viral pathogenesis and the role of these inflammatory biomarkers is highlighted, based on the evidences available till date. An integrative data monitoring along with their correlation with the natural disease progression is of utmost importance in the management of COVID-19. So further research and in-depth analysis of these biomarkers is warranted in the present scenario.

Early changes in white blood cell, C-reactive protein and procalcitonin levels in children with severe multiple trauma

BACKGROUND

To analyze early changes in white blood cells (WBCs), C-reactive protein (CRP) and procalcitonin (PCT) in children with multiple trauma, before secondary inflammation develops.

METHODS

This single-center retrospective study collected data from patients with blunt traumatic injury admitted to the pediatric intensive care unit (PICU). According to the prognostic outcome of 28 d after admission to the PICU, patients were divided into survival group (n=141) and non-survival group (n=36). Characteristics between the two groups were compared. Receiver operation characteristic (ROC) curve analysis was conducted to evaluate the capacity of different biomarkers as predictors of mortality.

RESULTS

The percentages of children with elevated WBC, CRP, and PCT levels were 81.36%, 31.07%, and 95.48%, respectively. Patients in the non-survival group presented a statistically significantly higher injury severity score (ISS) than those in the survival group: 37.17±16.11 vs. 22.23±11.24 (t=6.47, P<0.01). WBCs were also higher in non-survival group than in the survival group ([18.70±8.42]×10⁹/L vs. [15.89±6.98] ×10⁹/L, t=2.065, P=0.040). There was no significant difference between the survival and non-survival groups in PCT or CRP. The areas under the ROC curves of PCT, WBC and ISS for predicting 28-day mortality were 0.548 (P=0.376), 0.607 (P=0.047) and 0.799 (P<0.01), respectively.

CONCLUSIONS

Secondary to multiple trauma, PCT levels increased in more patients, even if their WBC and CRP levels remained unchanged. However, early rising WBC and ISS were superior to PCT at predicting the mortality of multiple trauma patients in the PICU.

Diagnosis of neonatal sepsis: the past, present and future

Sepsis remains a significant cause of neonatal mortality and morbidity, especially in low- and middle-income countries. Neonatal sepsis presents with nonspecific signs and symptoms that necessitate tests to confirm the diagnosis. Early and accurate diagnosis of infection will improve clinical outcomes and decrease the overuse of antibiotics. Current diagnostic methods rely on conventional culture methods, which is time-consuming, and may delay critical therapeutic decisions. Nonculture-based techniques including molecular methods and mass spectrometry may overcome some of the limitations seen with culture-based techniques. Biomarkers including hematological indices, cell adhesion molecules, interleukins, and acute-phase reactants have been used for the diagnosis of neonatal sepsis. In this review, we examine past and current microbiological techniques, hematological indices, and inflammatory biomarkers that may aid sepsis diagnosis. The search for an ideal biomarker that has adequate diagnostic accuracy early in sepsis is still ongoing. We discuss promising strategies for the future that are being developed and tested that may help us diagnose sepsis early and improve clinical outcomes. IMPACT: Reviews the clinical relevance of currently available diagnostic tests for sepsis. Summarizes the diagnostic accuracy of novel biomarkers for neonatal sepsis. Outlines future strategies including the use of omics technology, personalized medicine, and point of care tests.

The correlation between the expression of ATF4 and procalcitonin combined with the detection of RET mutation and the pathological stage and clinical prognosis of medullary thyroid carcinoma

To explore the correlation between the activating transcription factor 4 (ATF4) and procalcitonin (PCT) expressions combined with RET mutation and the pathological staging and clinical prognosis of sporadic medullary thyroid carcinoma (SMTC). Fifty cases (tumor tissue) of SMTC diagnosed by clinicopathology were collected and the patients with nodular goiter were selected as normal control. The RET mutation site was analyzed by detection kit and expressions of PCT and ATF4 in SMTC were analyzed by Western blot and immunohistochemistry. Multiple linear regression was used to analyze the correlation of risk factors (PCT or ATF4 expression, RET mutation, tumor differentiation, SMTC stage, lymphatic metastasis) for 5-year recurrence and survival of SMTC. The ATF4 and PCT expressions were significantly decreased and increased, respectively, with the increase of the SMTC stage. The most frequent mutation of RET gene in cancer tissue was M 22458A in exon 16. The ATF4 and PCT expressions, as well as RET mutation, were significantly associated with a 5-year recurrence, while the ATF4 expression was significantly related to better 5-year survival. ATF4 and PCT expressions combined with RET mutation are related to the clinical prognosis of SMTC and can predict SMTC staging.

MiR-539-5p inhibits the inflammatory injury in septic H9c2 cells by regulating IRAK3

Background

MicroRNAs (miRNAs) have been confirmed to play a potential role in sepsis, but little is known about their role in sepsis-induced cardiomyopathy (SIC).

Methods

The model of septic cardiomyopathy was constructed with H9c2 cells induced by lipopolysaccharide (LPS), and the expression of miR-539-5p was detected by qRT-PCR assay. ELISA, CCK-8, EdU TUNEL analysis were performed to evaluate the role of miR-539-5p in inflammation response, viability, proliferation and apoptosis of LPS-treated H9c2 cells. Moreover, miRWalk and TargetScan prediction, and dual-luciferase reporter gene assays were carried out to predict and confirm the target of miR-539-5p. Furthermore, the effects of target on inflammation response, proliferation and apoptosis of LPS-induced H9c2 cells mediated by miR-539-5p was further explored.

Results

The expression of miR-539-5p was obviously down-regulated in LPS-induced H9c2 cells. In addition, over-expression of miR-539-5p significantly inhibited the inflammation response, promoted viability and proliferation, and suppressed apoptosis of LPS-treated H9c2 cells. Moreover, interleukin-1 receptor-associated kinase 3 (IRAK3) was verified as a target of miR-539-5p by dual-luciferase reporter gene assay. Besides, IRAK3 was highly expressed in H9c2 cells transfected with miR-539-5p inhibitor detected with qRT-PCR and western blot assays. Furthermore, over-expression of IRAK3 partially weakened the effects of miR-539-5p mimic on the inflammation response, proliferation and apoptosis of LPS-induced H9c2 cells.

Conclusions

MiR-539-5p potentially plays an important role in the pathogenesis of LPS-induced sepsis by targeting IRAK3, suggesting that miR-539-5p may be a potential new target for the treatment of LPS-induced sepsis.

Clinical utility of procalcitonin and its association with pathogenic microorganisms

In this review, we summarize the relationship of PCT with pathogens, evaluate the clinical utility of PCT in the diagnosis of clinical diseases, condition monitoring and evaluation, and guiding medical decision-making, and explore current knowledge on the mechanisms by which pathogens cause changes in PCT levels. The lipopolysaccharides of the microorganisms stimulate cytokine production in host cells, which in turn stimulates production of serum PCT. Pathogens have different virulence mechanisms that lead to variable host inflammatory responses, and differences in the specific signal transduction pathways result in variable serum PCT concentrations. The mechanisms of signal transduction have not been fully elucidated. Further studies are necessary to ascertain the PCT fluctuation range of each pathogen. PCT levels are helpful in distinguishing between certain pathogens, in deciding if antibiotics are indicated, and in monitoring response to antibiotics.

Procalcitonin Assay Has No Role in the Routine Assessment of Severe Trauma Patients at Admission to the Emergency Department

Introduction A key challenge in emergency departments (ED) is the early recognition of sepsis or the potential for sepsis in patients. Appropriate and accurate ED triage will ensure improved case management. This study analysed the association between ED findings at admission and outcomes in patients presenting with severe trauma. Methods This was a prospective study conducted at a tertiary level ED and included severely injured adult patients who presented to the ED within 24 hours of injury. Data collected included clinical findings and imaging reports at initial assessment, serum procalcitonin (PCT), length of ICU and hospital stay, the incidence of bloodstream and other infections, and patient outcome as discharge from care or death. Multiple logistic regression was used to assess the association between outcome variables and independent variables. Results A total of 155 patients were included in the study. Head and neck (61.9%), extremity (58%), and chest (45%) were more commonly injured. Injury Severity Score (ISS) >25, Glasgow Coma Scale (GCS) score <8, head and neck injuries, and extremity injuries were found to be significantly associated with mortality. Bloodstream infections were more common in the presence of lung contusions, abdominal injury, operative management, and blood transfusions. PCT levels at admission did not have a significant predictive value for mortality, bloodstream infections, other infectious complications, or length of ICU stay. Conclusions Head injuries were the most common cause of mortality in our study. In addition to the anatomical region involved, ISS and GCS have a significant association with mortality. PCT levels at ED admission do not have any prognostic value and need not be routinely analysed.

The predictive value of serum procalcitonin for non-invasive positive pressure ventilation in the patients with acute exacerbation of chronic obstructive pulmonary disease

This study aimed to estimate the value of serum procalcitonin (PCT) for non-invasive positive pressure ventilation (NIPPV) prediction in the patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).A total of 220 AECOPD patients were divided into NIPPV group (n = 121) and control group (routine treatment, n = 99) based on the routine standards and physicians' experience. Logistic regression analysis was performed to identify the independent factors for NIPPV treatment. Additionally, the predictive values of the factors were measured through receiver operation characteristic (ROC) curve.NIPPV group and control group showed significant differences in respiratory rate (RR), PaO2, PaCO2, pH, oxygenation index, erythrocyte sedimentation rate (ESR), neutrophil, CRP (C-reaction protein), and PCT (P < .05 for all). PCT, CRP, PaCO2, RR, and neutrophil were independently correlated with NIPPV treatment in AECOPD. ROC curve showed that PCT had superior predictive value, with AUC of 0.899, the sensitivity of 86%, and the specificity of 91.9%. The cut-off value of serum PCT for NIPPV prediction was 88.50 ng/l.AECOPD patients who require NIPPV treatment frequently have high levels of PCT, CRP, PaCO2, RR and neutrophil. Serum PCT may be employed as an indicator for NIPPV treatment in AECOPD patients.

Dynamic Immune/Inflammation Precision Medicine: The Good and the Bad Inflammation in Infection and Cancer

Normal or “good” inflammation process starts from a local cellular response against injury or any infectious agent, with the activation of neutrophils, macrophages, Langerhans cells, dendritic cells, and innate immune cells. Cytokines and chemokines are produced to amplify the local inflammatory process followed by the migration of immune cells to the regional lymph nodes where adaptive immune response is initiated. Systemic inflammation enhances the biological response to mobilize additional cells from central and peripheral immune/hematopoietic system. Local mechanisms to limit inflammation are initiated and lead to healing. During the normal inflammatory process, there is a balance between the production of inflammatory chemokines/cytokines such as Tumor Necrosis Factor (TNF)-α, interleukin (IL)-6 and IL-1 and the production of compounds that limit inflammation and have an immune suppressive effect, such as IL-10 and Transforming Factor (TGF) β. IL-6 and IL-6/soluble IL-6 Receptor (R) complex stimulate liver cells to produce inflammatory proteins, which represents the systemic inflammation response. The magnitude and the duration of the systemic inflammatory response are linked to the cause, under genetic and epigenetic control. Significant inflammation as seen in septic shock, in severe forms of infections or in certain active cancers, represents the “bad inflammation”, correlated with a poor prognosis. In addition, the persistence of a chronic smoldering inflammation may lead to pathological situations which are observed in the majority of inflammatory, degenerative, dysmetabolic, or dysimmune diseases and cancer. Chronic smoldering inflammation is a cross between different pathological situations possibly linked. In addition, within the tumor microenvironment, inflammatory process results from different cellular mechanisms modulated by metabolic and vascular changes. On the contrary, a limited and balanced inflammation initiates the normal immune response, including the adaptive response which amplifies any immunotherapy, including vaccines. Immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cells are associated with cytokine release syndrome, a clinical risk leading to the use of anti-cytokine drugs. Nowadays, it is time to monitor the dynamic inflammatory process for a better immune precision medicine in both infections and cancer.

Increased circulating level of interleukin-6 and CD8+ T cell exhaustion are associated with progression of COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is pandemic. It is critical to identify COVID-19 patients who are most likely to develop a severe disease. This study was designed to determine the clinical and epidemiological features of COVID-19 patients associated with the development of pneumonia and factors associated with disease progression.

METHODS

Seventy consecutive patients with etiologically confirmed COVID-19 admitted to PLA General Hospital in Beijing, China from December 27, 2019 to March 12, 2020 were enrolled in this study and followed-up to March 16, 2020. Differences in clinical and laboratory findings between COVID-19 patients with pneumonia and those without were determined by the χ2 test or the Fisher exact test (categorical variables) and independent group t test or Mann-Whitney U test (continuous variables). The Cox proportional hazard model and Generalized Estimating Equations were applied to evaluate factors that predicted the progression of COVID-19.

RESULTS

The mean incubation was 8.67 (95% confidence interval, 6.78-10.56) days. Mean duration from the first test severe acute respiratory syndrome coronavirus 2-positive to conversion was 11.38 (9.86-12.90) days. Compared to pneumonia-free patients, pneumonia patients were 16.5 years older and had higher frequencies of having hypertension, fever, and cough and higher circulating levels of neutrophil proportion, interleukin-6, low count (< 190/µl) of CD8+ T cells, and neutrophil/lymphocyte ratio. Thirteen patients deteriorated during hospitalization. Cox regression analysis indicated that older age and higher serum levels of interleukin-6, C-reactive protein, procalcitonin, and lactate at admission significantly predicted the progression of COVID-19. During hospitalization, circulating counts of T lymphocytes, CD4+ T cells, and CD8+ T cells were lower, whereas neutrophil proportion, neutrophil/lymphocyte ratio, and the circulating levels of interleukin-6, C-reactive protein, and procalcitonin were higher, in pneumonia patients than in pneumonia-free patients. CD8+ lymphocyte count in pneumonia patients did not recover when discharged.

CONCLUSIONS

Older age and higher levels of C-reactive protein, procalcitionin, interleukin-6, and lactate might predict COVID-19 progression. T lymphocyte, especially CD8+ cell-mediated immunity is critical in recovery of COVID-19. This study may help in predicting disease progression and designing immunotherapy for COVID-19.

Searching for a role of procalcitonin determination in COVID-19: a study on a selected cohort of hospitalized patients

Objectives

Procalcitonin (PCT) has been proposed for differentiating viral vs. bacterial infections. In COVID-19, some preliminary results have shown that PCT testing could act as a predictor of bacterial co-infection and be a useful marker for assessment of disease severity.

Methods

We studied 83 COVID-19 hospitalized patients in whom PCT was specifically ordered by attending physicians. PCT results were evaluated according to the ability to accurately predict bacterial co-infections and death in comparison with other known biomarkers of infection and with major laboratory predictors of COVID-19 severity.

Results

Thirty-three (39.8%) patients suffered an in-hospital bacterial co-infection and 44 (53.0%) patients died. In predicting bacterial co-infection, PCT showed a relatively low accuracy (area under receiver-operating characteristic [ROC] curve [AUC]: 0.757; 95% confidence interval [CI]: 0.651-0.845), with a strength for detecting the outcome not significantly different from that of white blood cell count and C-reactive protein (CRP). In predicting patient death, PCT showed an AUC of 0.815 (CI: 0.714-0.892), not better than those of other more common laboratory tests, such as blood lymphocyte percentage (AUC: 0.874, p=0.19), serum lactate dehydrogenase (AUC: 0.860, p=0.47), blood neutrophil count (AUC: 0.845, p=0.59), and serum albumin (AUC: 0.839, p=0.73).

Conclusions

Procalcitonin (PCT) testing, even when appropriately ordered, did not provide a significant added value in COVID-19 patients when compared with more consolidated biomarkers of infection and poor clinical outcome. The major application of PCT in COVID-19 is its ability, associated with a negative predictive value >90%, to exclude a bacterial co-infection when a rule-out cut-off (<0.25 μg/L) is applied.

Performance verification of a new domestic chemiluminescence detection system

Background

Procalcitonin (PCT) is an acute phase response protein, which can be used as an indicator for early diagnosis of infection. At present, the main detection methods for PCT are electrochemiluminescence and enzyme-linked immunofluorescence. We aimed to explore the accuracy of PCT determination in a domestic chemiluminescence detection system and its correlation with other systems.

Methods

Clinical specimens were collected, and the precision, linearity, biological reference interval, contamination rate, Clinical reportable scope, and methodological comparison of the determination of PCT in a Chinese chemiluminescence detection system were evaluated and preliminarily verified by referring to Clinical and Laboratory Standards Institute (CLSI) documents or industry standards.

Results

The results of precision verification showed that the coefficient of variation (CV) values of the variation coefficient of precision in the samples of low and high values were 2.07% and 0.83% respectively, while the CV values of the total variation coefficient of precision were 3.05% and 1.81% respectively; these findings all met the experimental requirements. The results of linear verification test showed that the linear range was 0.006–96.96 ng/mL, and the linear relationship was well within the detection range (R2 =0.9891). The biological reference interval and the carrying contamination rate were also verified. The clinical reportable range was 0.02–369.585 ng/mL. The results showed that the correlation coefficient between the Mindray CL900I and the Roche E602 was 0.9986, and that between the Mindray CL900I and the Snibe 2000 was 0.983. Meanwhile, when the PCT was higher than 0.1 ng/mL, the correlation coefficient was 100%.

Conclusions

The domestic chemiluminescence detection system has a good performance in the determination of calcitonin, as indicated by the measures of precision, linearity, biological reference interval, carrying contamination rate, and Clinical reportable scope, and can thus be used for clinical specimen detection. The results of methodological comparison showed that the correlation coefficient between the Mindray CL900I and Roche E602 was 0.9986, while the correlation coefficient between the Mindray CL900I and the Snibe 2000 was 0.983. The test results were consistent with the experimental requirements.

Clinical Value of Serum Amyloid-A Protein, High-density Lipoprotein Cholesterol and Apolipoprotein-A1 in the Diagnosis and Follow-up of Neonatal Sepsis

BACKGROUND

To evaluate the performance of serum amyloid-A (SAA), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein-A1 (Apo-A1) levels in the identification and monitoring of neonatal sepsis.

METHODS

This prospective study included 113 full-term septic neonates (postnatal age 4-28 days) admitted to the Special Care Neonatal Unit of a University Hospital from January 1, 2016, to April 30, 2019, and 68 healthy neonates (controls). Blood samples were drawn serially in septic neonates at enrollment and on days 1, 3 and 7, and once in controls, for SAA, HDL-C and Apo-A1 determination.

RESULTS

At enrollment, SAA levels were significantly higher in septic neonates in comparison with controls (median 50.7 vs. 3.5 mg/L; P < 0.0001); HDL-C and Apo-A1 levels were significantly lower in patients than in controls (P < 0.001 and P < 0.006, respectively). SAA levels were higher in culture-positive compared with culture-negative sepsis (median 202.0 vs. 14.2 mg/L; P < 0.0001). HDL-C and Apo-A1 levels did not differ significantly between culture-positive and culture-negative sepsis. Receiver operating characteristic curve analysis of SAA levels at enrollment resulted in significant areas under the curve (AUC) for detecting sepsis {AUC = 0.929 [95% confidence interval: 0.885-0.973]; P < 0.0001} and also for discriminating between culture-positive and culture-negative sepsis [AUC = 0.933 (95% confidence interval: 0.882-0.984); P < 0.0001]. The combination of HDL-C and Apo-A1 with SAA increased its diagnostic performance. Furthermore, serial SAA levels following enrollment could indicate clinical response in septic neonates.

CONCLUSIONS

SAA seems to be a useful biomarker for identification and monitoring of neonatal sepsis, and also for discriminating between culture-positive and culture-negative sepsis. HDL-C and Apo-A1 could be used as complementary markers.

The predictive value of procalcitonin in ventilator-associated pneumonia after cardiac valve replacement

This study aimed to evaluate the predictive value of procalcitonin (PCT) in ventilator-associated pneumonia (VAP) after cardiac valve replacement. A total of 80 patients who underwent cardiac valve replacement in our department were enrolled in this study. Of these patients,40 were diagnosed with VAP and assigned to the observation group, while the other 40 patients not diagnosed with VAP were assigned to the control group. The changes in serum PCT, white blood cell count and C-reactive protein (CRP) were observed before each operation (T0), on the first day after the operation (T1), the second day after the operation (T2) and the third day after the operation (T3). After the operation, the serum PCT in the observation group was significantly higher than those at different time points after the operation, and also significantly higher than those in the control group (p < .05). In the control group, PCT was significantly higher after the operation than before the operation (p < .05), but the differences among the different postoperative time points were not statistically significant (p > .05). In the two groups, the white blood cell count and CRP were significantly higher after the operation than before the operation (p < .05), but the differences between the two groups were not statistically significant (p > .05). Serum PCT is an early, sensitive and highly specific high-risk monitoring index and has an early prediction value for VAP after cardiac valve replacement.

Marked Elevation in Serum Procalcitonin Levels Do Not Correlate With Severity of Disease or Mortality in Hospitalized Patients: A Retrospective Study

Background:

Bacteremia and sepsis are significant contributors to the morbidity, mortality, and economic burden of health care systems worldwide. Procalcitonin has been identified as a potentially useful marker of disease and severity in sepsis. However, the assumption that greater procalcitonin levels correlate with greater burden of disease has not been adequately studied.

Methods:

A retrospective chart review of adult patients admitted to an urban teaching hospital with suspected sepsis was undertaken to test the association of elevated procalcitonin (>30 ng/mL) with other markers of sepsis (lactic acid, white blood cell count, percent bands), severity of disease (Sequential Organ Failure Assessment [SOFA] and Acute Physiology and Chronic Health Evaluation–II [APACHE II] scores), and mortality.

Results:

In total, 168 patients were identified over 18 months (42% ward, 11% Stepdown, 44% medical intensive care unit [MICU], 2% surgical intensive care unit (STICU), 1% gynecology [GYN]). The Spearman correlation analysis showed that serum procalcitonin level did not correlate with SOFA (P = .238) or APACHE II (P = .918) scores on admission, and did not correlate with survival (Kruskal-Wallis test, P = .937). However, higher serum procalcitonin levels were associated with patients who had positive blood cultures (Kruskal-Wallis test, P = .0016 for Gram-positive and P = .0007 for Gram-negative bacteria). Lactic acid levels on admission strongly correlated with SOFA APACHE II (the Spearman correlation, P < .0001 for both) and mortality (P = .0001 for both).

Conclusions:

Higher serum procalcitonin levels above 30 ng/mL failed to correlate with indicators of sepsis, severity of disease (SOFA and APACHE II scores), and mortality but were associated with positive blood cultures. Lactic acid levels did show correlation to both severity of disease and mortality. Serum procalcitonin levels >30 ng/mL do not appear to correlate with the severity of disease in a sample of patients with markedly elevated initial procalcitonin levels.

Procalcitonin as a prognostic marker of patients with acute ischemic stroke

BACKGROUND

The information on mortality after an acute stroke patient is still limited.

OBJECTIVES

The aim of this study was to investigate the prognostic potential of procalcitonin (PCT) serum levels in acute ischemic stroke.

METHODS

A total of 748 patients were enrolled in this study. Prognostic potential of PCT was evaluated by Kaplan-Meier analysis and multivariable Cox hazard regression analyses.

RESULTS

Procalcitonin levels were found to be significantly higher in acute ischemic stroke patients who died in 30 days than those who survived. Univariate logistic regression analysis showed that PCT was significantly associated with 30-day mortality, and Cox regression analysis revealed that PCT was a strong predictor of 30-day overall mortality. Kaplan-Meier analysis revealed that overall cumulative 30-day mortality was significantly higher in those with PCT levels >1.5 ng/mL when compared to those with PCT levels <1.5 ng/mL.

CONCLUSIONS

Procalcitonin is a significant independent prognostic marker of 30-day mortality after the one set of acute ischemic stroke.

Clinical Progress Note: Procalcitonin in the Management of Pediatric Lower Respiratory Tract Infection

Procalcitonin (PCT) is a biomarker that has shown promise to identify bacterial etiology in acute infections, including bacterial lower respiratory tract infection (LRTI). In 2017, the United States Food and Drug Administration (FDA) approved the use of PCT as a diagnostic aid to guide the decisions around antibiotic therapy in acute LRTI.1 Although most of the data supporting the use of PCT for LRTI stems from adult studies, the high disease burden, predominance of viral etiologies, and frequent diagnostic uncertainty resulting in antibiotic overuse make pediatric LRTI an ideal target for the use of PCT as a diagnostic aid. This review evaluates and summarizes the current evidence regarding the role of PCT in the clinical care of pediatric LRTI, including its use in guiding antibiotic use and prognosticating disease severity.