Procalcitonin for the clinical laboratory: a review

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Ultrasensitive and Rapid Detection of Procalcitonin via Waveguide-Enhanced Nanogold-Linked Immunosorbent Assay for Early Sepsis Diagnosis

Sepsis, a life-threatening inflammatory response, demands economical, accurate, and rapid detection of biomarkers during the critical "golden hour" to reduce the patient mortality rate. Here, we demonstrate a cost-effective waveguide-enhanced nanogold-linked immunosorbent assay (WENLISA) based on nanoplasmonic waveguide biosensors for the rapid and sensitive detection of procalcitonin (PCT), a sepsis-related inflammatory biomarker. To enhance the limit of detection (LOD), we employed sandwich assays using immobilized capture antibodies and detection antibodies conjugated to gold nanoparticles to bind the target analyte, leading to a significant evanescent wave redistribution and strong nanoplasmonic absorption near the waveguide surface. Experimentally, we detected PCT for a wide linear response range of 0.1 pg/mL to 1 ng/mL with a record-low LOD of 48.7 fg/mL (3.74 fM) in 8 min. Furthermore, WENLISA has successfully identified PCT levels in the blood plasma of patients with sepsis and healthy individuals, offering a promising technology for early sepsis diagnosis.

RDW-SD and PCT Are Potential Prognostic Factors for In-hospital Death in Patients With Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

PURPOSE

Our study aimed to explore potential prognostic factors in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) patients from easily accessible laboratory data and to investigate whether the combination of these indicators with a score for toxic epidermal necrolysis (SCORTEN) can improve the predictive value.

METHODS

Data from 85 SJS/TEN patients hospitalized from 2010 to 2021 were retrospectively analyzed. The primary outcome was in-hospital mortality. Univariate analysis was used to screen for laboratory indexes associated with death. Logistic regression was used to analyze significant risk factors for death. The differentiation and calibration of SCORTEN and modified score were assessed using receiver operating characteristic (ROC) curves and Hosmer-Lemeshow goodness-of-fit test. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used to evaluate the incremental prognostic value.

RESULTS

Among the 85 patients (37 males, 48 females) aged 14-88 years, the mortality rate was 11.8% (n = 10). SCORTEN had good discrimination and calibration to predict mortality in this cohort of patients (area under the ROC curve [AUC] of 0.874, 95% confidence interval [CI], 0.758-0.990; Hosmer-Lemeshow goodness-of-fit test P = 0.994). Red cell distribution width-standard deviation index (RDW-SD) > 47.9 fL and procalcitonin (PCT) > 0.67 ng/mL were significant risk factors for death. When adding the 2 factors to SCORTEN, AUC was 0.915 (95% CI, 0.833-0.997), but not statistically different compared to SCORTEN alone (P = 0.091). The NRI was 1.2 (95% CI, 0.672-1.728; P < 0.001) and the IDI was 0.09 (95% CI, 0.011-0.173; P = 0.026), still suggesting that the modified score had better discriminatory and predictive power than SCORTEN alone. The modified score also showed good calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.915).

CONCLUSIONS

SCORTEN is a good predictor of mortality in SJS/TEN patients in southwest China. Combining RDW-SD > 47.9 fL and PCT > 0.67 ng/mL with SCORTEN may enhance the ability to predict prognosis.

Preparation and characterization of a homogeneous immunoassay for point-of-care testing (POCT) of procalcitonin (PCT)

Procalcitonin (PCT) has been recognized as a specific and early marker for microbial infection and sepsis. Sensitive measuring interaction-triggered luminescence experiment (SMILE), a homogeneous immunoassay method, was established for point-of-care testing (POCT) of PCT. SMILE is achieved through the principle of double antibody sandwich, where two antibodies immobilized on the surface of polystyrene microspheres (donor and acceptor beads) bind to the PCT antigen. The donor bead contains phthalocyanine dye (luminol chemiluminescent substance) and the acceptor bead contains dimethylthiophene derivatives and Eu chelates. Therefore, singlet oxygen can be transferred when the distance between donor and acceptor beads is within 200 nm, generating detectable luminescent signals. Scanning electron microscopy (SEM) was used to detect the diameter and polymer dispersity index (PDI) of microspheres before and after binding with antibodies to characterize the immobilization of antibodies. The reaction conditions for antibody immobilization including pH, mass ratio and reaction time have also been optimized. The limit of quantitation (LOQ) of the SMILE method (0.01 ng mL-1) was lower than that of the LFI method (0.1 ng mL-1), the working range (0.01-500 ng mL-1) was wider than that of the LFI method (0.1-50 ng mL-1), and the assay time (10 min) was shorter than that of the LFI method (15 min). So, SMILE is more suitable for POCT of PCT compared with lateral flow immunochromatography (LFI), which is the most used measuring method, due to its advantages of simple operation, saving time, convenience, wide detection range, and high sensitivity and accuracy.

Procalcitonin as an Endogenous Biomarker for Mastitis in Cows

Mastitis is one of the most common diseases of dairy cows. Procalcitonin (PCT) has been described as an endogenous inflammatory biomarker for bacterial infections. The aim of this study was to find possible correlations between PCT concentrations in the serum and milk of cows with mastitis and their clinical signs and disease progression. In total, 88 dairy cows were examined, of which 30 animals were diagnosed with clinical mastitis, 30 had subclinical mastitis, and 28 were designated as a healthy control group. The diseased animals were re-examined after 12 days. All PCT levels in this study were determined by a species-specific ELISA. All three groups could be differentiated from each other based on serum and milk PCT levels. The animals with clinical mastitis showed the highest mean concentrations of PCT (serum: 2641 pg/mL; milk: 1326 pg/mL), and the lowest PCT concentrations were found in the healthy control group (serum: 1166 pg/mL; milk: 176 pg/m). Over the course of the disease, results from the kinetics study showed that PCT levels remained high for the entire observation period. The results from this study showed that the PCT concentration could be used to differentiate between clinical mastitis, subclinical mastitis, and healthy cows.

Other markers of medullary thyroid cancer, not only calcitonin

BACKGROUND

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor originating from parafollicular C-cells. It represents 2% of all thyroid malignancies and 0.4-1.4% of all thyroid nodules. MTC has a variable clinical course, with complete remission often difficult to achieve. An early diagnosis is still crucial in MTC management, enabling a radical surgical treatment, the only chance for curing the patient. Calcitonin (Ct) is a very sensitive MTC tumor marker in patients with thyroid nodules, although Ct-negative MTCs have been described, but not all clinical guidelines recommend the Ct routine measurement in thyroid nodules because of the absolute low prevalence of MTC in the general population and the consequent scarce positive predictive value of Ct. Moreover, the specificity of moderately high Ct levels is not high. Thus, the scientific community has been investigating the possible role of other tumor markers for MTC diagnosis and prognosis.

AIM OF THE REVIEW

The present review is an attempt to summarize the knowledge available today on the role of other serum markers for MTC alternative to Ct.

CONCLUSIONS

At present, literature data does not seem solid enough yet to establish effective flowcharts in evaluating a thyroid nodule for MTC, involving alternative serum markers, particularly in cases of moderately high CT levels. MTC is a rare diagnosis in thyroid nodules, and this makes the evaluation of any tumor serum marker accuracy problematic. More extensive and prospective studies are needed to shed more light on this intriguing challenge.

Biomarkers of sepsis in pigs, horses and cattle: from acute phase proteins to procalcitonin

Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.

Antimicrobial Photodynamic Therapy Involving a Novel Photosensitizer Combined With an Antibiotic in the Treatment of Rabbit Tibial Osteomyelitis Caused by Drug-Resistant Bacteria

Osteomyelitis is deep tissue inflammation caused by bacterial infection. If such an infection persists, it can lead to dissolution and necrosis of the bone tissue. As a result of the extensive use of antibiotics, drug-resistant bacteria are an increasingly common cause of osteomyelitis, limiting the treatment options available to surgeons. Photodynamic antibacterial chemotherapy has attracted increasing attention as a potential alternative treatment. Its advantages are a broad antibacterial spectrum, lack of drug resistance, and lack of toxic side effects. In this study, we explored the impact of the new photosensitizer LD4 in photodynamic antimicrobial chemotherapy (PACT), both alone and in combination with an antibiotic, on osteomyelitis. A rabbit tibial osteomyelitis model was employed and microbiological, histological, and radiological studies were performed. New Zealand white rabbits (n = 36) were randomly divided into a control group, antibiotic group, PACT group and PACT + antibiotic group for treatment. In microbiological analysis, a reduction in bacterial numbers of more than 99.9% was recorded in the PACT group and the PACT + antibiotic group 5 weeks after treatment (p < 0.01). In histological analysis, repair of the damaged bone tissue was observed in the PACT group, and bone repair in the PACT + antibiotic group was even more significant. In radiological analysis, the X-ray Norden score showed that the severity of bone tissue defects or destruction followed the pattern: PACT + antibiotic group < PACT group < antibiotic group < control group.

Ratiometric electrochemical immunoassay for procalcitonin based on dual signal probes: Ag NPs and Nile blue A

In order to determine procalcitonin, a sandwich-type ratiometic electrochemical immunosensor was developed by differential pulse voltammetry (DPV). Due to high chemical stability and good biocompatibility, graphitic carbon nitride (g-C₃N₄) could be used as feasible supporter to carry silver nanoparticles (Ag NPs) with an obvious oxidative peak (measured typically at + 0.3 V vs. SCE). Ag NPs loaded onto g-C₃N₄ were not only beneficial to prevent the agglomeration of Ag NPs, but also favorable to improve the electron transfer velocity of g-C₃N₄. Moreover, the g-C₃N₄-Ag NPs as the matrix could immobilize primary antibody by Ag-N bond. Nile blue A (NBA), an excellent redox probe based on the redox reaction with two-electrons, provides a current signal at - 0.38 V (vs. SCE). Zr-based metal organic framework (UiO-67), an ideal framework material with large specific surface area and high porosity, could absorb the substantial water-soluble NBA by electrostatic adsorption. The UiO-67 modified by NBA (NBA-UiO-67) owned admirable biocompatibility and was a qualifying marker to load the secondary antibody. For the immunosensor, the current ratio of NBA to Ag NPs (I_NBA/I_{Ag NPs}) was increased as the concentrations of PCT increased. Under the optimum conditions, the linear range of the immunosensor was 0.005 to 50 ng/mL; the detection limit was 1.67 pg/mL (S/N = 3), which reflected the excellent analytical performance of the sensor. The proposed immunosensor strategy is a simple and dependable platform, with great application potential in biometric analysis.

A diagnostic platform for rapid, simultaneous quantification of procalcitonin and C-reactive protein in human serum

Background

Early and accurate determination of bacterial infections as a potential cause for a patient's systemic inflammatory response is required for timely administration of appropriate treatment and antibiotic stewardship. Procalcitonin (PCT) and C-reactive protein (CRP) have both been used as biomarkers to infer bacterial infections, particularly in the context of sepsis. There is an urgent need to develop a platform for simultaneous quantification of PCT and CRP, to enable the potential use of these biomarkers at the point-of-care.

Methods

A multiplexed lateral flow assay (LFA) and a fluorescence optical reader were developed. Assay performance was validated by testing spiked antigens in the buffer, followed by a validation study comparing results with conventional assays (Roche Cobas e411 Elecsys PCT and Siemens ADVIA XPT CRP) in 25 archived remnant human serum samples.

Findings

A linear regression correlation of 0·97 (P < 0·01) was observed for PCT, and a correlation of 0·95 (P < 0·01) was observed for CRP using direct patient samples. We also validated our platform's ability to accurately quantify high-dose CRP in the hook effect range where excess unlabeled analytes occupy binding sites at test lines.

Interpretation

A fluorescence reader-based duplex LFA for simultaneous quantification of PCT and CRP was developed and successfully validated with clinical samples. The rapid, portable, and low-cost nature of the platform offers potential for differentiation of bacterial and viral infections in emergency and low-resource settings at the point-of-care.

Funding

NIH/NIBIB Award 1R01EB021331, and Academic Venture Fund from the Atkinson Center for a Sustainable Future at Cornell University.

Bio-Functionalized Magnetic Nanoparticles for the Immunoassay of C-Reactive Protein and Procalcitonin in Cervicovaginal Secretions of Pregnant Women with Preterm Prelabor Rupture of Membranes to Predict Early-Onset Neonatal Sepsis

Purpose

Early-onset sepsis is a major cause of neonatal morbidity and mortality. C-reactive protein (CRP) and procalcitonin (PCT) are acute phase reactants related to infection. The aim of this study was to explore the feasibility of measuring CRP and PCT concentrations in cervicovaginal secretions of pregnant women with preterm prelabor rupture of membranes (PPROM) using an immunomagnetic reduction (IMR) assay to predict early-onset neonatal sepsis.

Patients and Methods

This prospective study was performed at Mackay Memorial Hospital, Taipei, Taiwan from February 2015 to January 2018. Pregnant women with PPROM between 22 and 34 weeks of gestation were recruited. CRP and PCT concentrations in cervicovaginal secretions were measured using an IMR assay.

Results

Thirty-five cervicovaginal secretion samples were obtained. After excluding two neonatal deaths, early-onset neonatal sepsis was diagnosed in 15 of the 33 surviving neonates. There was no significant relationship between cervicovaginal secretion CRP level and neonatal sepsis; however, cervicovaginal secretion PCT levels were significantly higher in the neonatal sepsis group than in the non-sepsis group (45.99 vs 9.54 ng/mL, P = 0.039). Receiver operating characteristic (ROC) curve analysis revealed a PCT cut-off level of 20.60 ng/mL to predict early-onset sepsis, and the area under the ROC curve was 0.71 (95% confidence interval 0.52 to 0.90, P = 0.039), with sensitivity and specificity of 73.3% and 77.8%, respectively.

Conclusion

Measuring the concentration of PCT in cervicovaginal secretions with an IMR assay can predict early-onset sepsis in neonates born to mothers with PPROM.

Procalcitonin as an Alternative Tumor Marker of Medullary Thyroid Carcinoma

CONTEXT

Calcitonin (CT) measurement is pivotal in the management of medullary thyroid carcinoma (MTC), but several pitfalls can affect its reliability. Procalcitonin (ProCT) has been reported as a promising alternative MTC tumor marker.

OBJECTIVE

This study aimed to determine the ProCT diagnostic accuracy in prediction and treatment monitoring of MTC.

METHODS

Electronic databases were searched for observational studies published until May 2021 without language or time restrictions. Studies comparing ProCT and calcitonin accuracy were included. After removing duplicates and exclusion of not-eligible articles, relevant articles were screened independently by 2 reviewers. Eleven studies (4.5% of the identified studies) met the selection criteria. Two reviewers independently extracted data and assessed data quality and validity through QUADAS-2.

RESULTS

A meta-analysis was performed on 11 sufficiently clinically and statistically homogeneous studies (n = 5817 patients, 335 MTC patients). Hierarchical summary receiver operating characteristics and bivariate methods were applied. Serum ProCT was found to be a highly accurate test for MTC diagnosis and monitoring. The pooled sensitivity, specificity, positive and negative likelihood ratios, area under the curve, and positive and negative predictive values for ProCT were 0.90 (95% CI: 0.71-0.97), 1.00 (95% CI: 0.85-1.00), 288 (95% CI: 5.6-14 929.3), 0.10 (95% CI: 0.03-0.33), 0.97 (95% CI: 0.95-0.98), 99%, and 2%, respectively.

CONCLUSIONS

The high accuracy, compounded with favorable analytical characteristics, give ProCT great potential to replace calcitonin as a new standard of care in the management of MTC.

Mining of a Clinical Database: The Interpretation of Intense Serial Procalcitonin in the Prediction for Bloodstream Infection

Background: Procalcitonin (PCT) is a promising biomarker for predicting infection. Bloodstream infection (BSI) is usually a deteriorating stage of sepsis. The purpose of this study was to explore the predictive value of intense serial PCT assays for BSI in the intensive care unit (ICU). Methods: This study was a retrospective study based on a clinical database. We analyzed the data of critically ill patients from February 2016 to May 2020. The patients who received PCT assays and blood cultures (BCs) were classified into four groups according to the BCs: (i) BC negative, (ii) bacteria positive, (iii) fungi-positive, and (iv) combined-positive, and the patients with bacteremia were further subdivided into Gram+ and Gram- bacteremia. Results: The database included 11,219 patients. There were 3,593 patients who met the criteria for the analysis. The PCT concentration differed significantly across BC groups (p < 0.0001). The fluctuation of PCT significantly increased in the BC positive groups (p < 0.0001). According to the receiver operating characteristic (ROC), the optimum cutoff of the fluctuation of PCT was around 8 ng/ml for predicting BSI. Conclusion: Our study indicated that the fluctuation of PCT could be an indicator for screening BSI, but less accurate for Gram-positive infections. With a fluctuation of PCT less than 8 ng/ml, BSI should not be a rational cause for sepsis exacerbating.

Evaluation of Serum Levels of Procalcitonin and C-Reactive Protein as Prognostic Indicators in Burns

Background Burn is a leading cause of fatality in a developing country. C-reactive protein levels (CRP) and procalcitonin (PCT) can be prognostic indicators for the burn patients' mortality.

Aim To assess serial levels of serum PCT and serum CRP as prognostic indicators in burns.

Patient and Methods In patients admitted with burns, alternate-day serum PCT and CRP were measured from the time of admission until the time of discharge or until survival. The change in trends of CRP and PCT serum levels were studied, and it was then correlated with mortality among these burn patients.

Results The first-day value of serum PCT > 1772 pg/mL and serum CRP > 71 mg/mL or any value of serum PCT > 2163 pg/mL and of serum CRP > 90 mg/L indicate a poor prognosis in burns.

Conclusions The day-1 values of PCT and CRP were significantly higher in nonsurvivors than survivors in burns. The increasing trends of serum PCT and CRP levels are independent predictors of mortality in burns requiring prompt intervention. Rising PCT and CRP level denote poor prognosis in burns with an increased likelihood of death by 4.5 and 23.6 times, respectively.

Procalcitonin measured by three different assays is an excellent tumor marker for the follow-up of patients with medullary thyroid carcinoma

OBJECTIVES

Procalcitonin (PCT) has been suggested as a tumor marker in patients with medullary thyroid carcinoma (MTC). Clinical application data in long term follow-up are missing.

METHODS

210 serum samples of 169 consecutive patients with MTC (92 sporadic, 77 hereditary, 158 postoperative follow-up, 11 preoperative) were collected between 2018 and 2020. Postoperative patients were stratified into three groups according to their disease status at the end of follow-up: cured (n=51, calcitonin (CT) levels < limit of quantitation), minimal residual disease (n=55, detectable CT and no metastases provable by imaging methods), metastatic disease (n=52). In five patients CT and PCT were measured while on therapy with tyrosine kinase inhibitors (TKI). CT was analyzed by the Roche ECLIA, PCT by three assays from Roche, PES, Abbott.

RESULTS

The mean ± SD values seen with the three PCT assays in the MTC response groups, cured: <0.06, 0.016 ± 0.007, 0.014 ± 0.007 ng/mL, minimal residual disease: 0.511 ± 0.800, 0.389 ± 0.687, 0.341 ± 0.614 ng/mL, metastatic disease 109 ± 202, 60.4 ± 110, 63.3 ± 115 ng/mL correlate well with the CT results in these groups: cured <1.0 pg/mL, minimal residual disease 91.3 ± 121.5 pg/mL, metastatic disease 14,489 ± 30,772 pg/mL. There was a significant correlation (p<0.001) between the three PCT assays (Roche/PES r=0.970, Roche/Abbott r=0.976, Abbott/PES r=0.995). In the course of treatment with TKI both CT and PCT reflected clinical state. Preoperative PCT in hereditary MTC has the same diagnostic validity than CT.

CONCLUSIONS

PCT measured with three different immunoassays is as good as the standard tumor marker CT in the follow-up of MTC but has a superior analytical stability.

Postpartum fibroid degeneration associated with elevated procalcitonin levels

Objectives

To describe a novel presentation of severely elevated procalcitonin (PCT) levels associated with postpartum fibroid degeneration.

Case presentation

We report a case of a 34-year-old woman with multiple large fibroids who was found to have fevers and a severely elevated PCT level of 34.03 ng/mL 2 days postpartum. MRI revealed carneous degeneration of her fibroids, and other etiologies such as infection were ruled out. She was successfully treated with the use of intravenous non-steroidal anti-inflammatory drugs and antibiotics, as a precaution. This report indicates procalcitonin may be elevated secondary to the inflammatory state caused by degenerating fibroids. Informed consent was obtained from all individuals included in this study.

Conclusions

Uterine leiomyomas, or fibroids, are tumors of the female reproductive tract affecting anywhere from 20–40% of women. One known complication of fibroids is degeneration, when the fibroid can infarct due to a decrease in blood supply. This can cause an inflammatory state with the release of multiple inflammatory markers. During pregnancy, routine markers such as white blood cell counts may be unreliable. Other markers such as procalcitonin are not well-studied in pregnancy. This case provides practitioners an example where the marker procalcitonin can be used to more accurately assess an inflammatory state during pregnancy. It also provides alterative diagnoses in the workup of postpartum fever.

Combining Calcitonin and Procalcitonin and Rheumatoid Arthritis-Related Biomarkers Improve Diagnostic Outcomes in Early Rheumatoid Arthritis

Objective

To demonstrate whether procalcitonin (PCT) combined with calcitonin (CT) could provide additional diagnostic value to other clinically available rheumatoid arthritis- (RA-) related biomarkers in the early diagnosis of RA.

Method

The blood samples aseptically collected by venipuncture were centrifuged within 1 hour and frozen at -80°C. PCT and CT levels were measured using electrochemiluminescence immunoassay (ECLIA) in 260 subjects (48 patients with early RA, 34 patients with established RA, 37 patients with systemic lupus erythematosus, 30 with osteoarthritis, 31 with gouty arthritis, and 80 healthy participants). Anti-cyclic citrullinated peptide (Anti-CCP) and anti-RA33 antibodies (Anti-RA33) were analyzed by ELISA. RF was detected by transmission immunoturbidimetry. Mann-Whitney U tests and Kruskal-Wallis tests compared differences among groups. Spearman's rank correlation analysis determined the relationship between biomarkers. Receiver-operator characteristic (ROC) curves were generated, and diagnostic performance was assessed by area under the curve (AUC), as well as specificity, sensitivity, likelihood ratios (LR).

Results

Median serum PCT concentrations were significantly higher (p < 0.0001) in patients with early RA (0.065 ng/ml) when compared with healthy controls (0.024 ng/ml), and patients with osteoarthritis (0.025 ng/ml). When compared with gouty arthritis (GA) controls (0.072 ng/ml) and systemic lupus erythematosus (SLE) controls (0.093 ng/ml), median serum PCT concentrations were not significant in patients with early RA (0.065 ng/ml). Median serum CT concentrations were significantly lower (p < 0.0001) in patients with early RA (0.880 pg/ml) compared with healthy controls (3.159 pg/ml), patients with SLE (2.480 pg/ml), and patients with GA (2.550 pg/ml). When compared with osteoarthritis controls (0.586 pg/ml), median serum CT concentrations were not significant in patients with early RA (0.880 pg/ml). ROC curve analysis comparing early RA with healthy controls demonstrated that the AUC of RF, anti-CCP, and anti-RA33 were 0.66, 0.73, and 0.64, respectively; the additions of PCT and CT further improved the diagnostic ability of early RA with the AUC of 0.97, 0.98, and 0.97, respectively (p < 0.01). The sensitivities of RF, anti-CCP, and anti-RA33 for early RA were 33.33%, 44.74%, and 58.33%, respectively, and the additions of PCT and CT showed very high sensitivities of 83.33%, 92.11%, and 87.50%. The high-value groups of PCT moderately correlated with the anti-RA33 levels (r = 0.417, p < 0.05). CT had no significant correlation with disease duration, radiographic progression, or clinical/serological variables, such as ESR levels, CRP levels, RF, anti-CCP, and anti-RA33 levels in early RA.

Conclusions

Serum PCT and CT combined with clinically available RA-related biomarkers could further improve the diagnostic efficiency of early RA.

Blood Procalcitonin Level as a Diagnostic Marker of Pediatric Bacterial Meningitis: A Systematic Review and Meta-Analysis

Early diagnosis and treatment of bacterial meningitis in children are essential, due to the high mortality and morbidity rates. However, lumbar puncture is often difficult, and cerebrospinal fluid (CSF) culture takes time. This meta-analysis aims to determine the diagnostic accuracy of blood procalcitonin for detecting bacterial meningitis in children. We conducted a systematic search on electronic databases to identify relevant studies. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated, and a hierarchical summary receiver operating characteristic curve and area under the curve (AUC) were determined. Eighteen studies with 1462 children were included in the analysis. The pooled sensitivity, specificity, and the DOR of blood procalcitonin for detecting bacterial meningitis were 0.87 (95% confidence interval (CI): 0.78–0.93); 0.85 (95% CI: 0.75–0.91), and 35.85 (95% CI: 10.68–120.28), respectively. The AUC for blood procalcitonin was 0.921. Blood procalcitonin also showed higher diagnostic accuracy for detecting bacterial meningitis than other conventional biomarkers, including serum C-reactive protein and leukocyte count, CSF leukocyte and neutrophil count, and CSF protein and glucose levels. Blood procalcitonin can be a good supplemental biomarker with high diagnostic accuracy in detecting bacterial meningitis in children.

Increased Risk of Migraine in Patients with Chronic Periodontitis: A Population-Based Cohort Study

Migraine is considered to be a neurovascular disease that manifests as a throbbing headache, possibly caused by the activation of the trigeminovascular system. Several studies have supported the role of inflammation in the pathogenesis of migraine. Chronic periodontitis (CP) is an infectious inflammatory disease triggered by bacterial products evoking an immune response which could result in the destruction of the periodontium. However, little is known about the longitudinal association between CP and migraine. In this study, we designed a nationwide population-based cohort study to investigate the risk of migraine and CP exposure in Taiwan. In total, 68,282 patients with CP were identified from the National Health Insurance Research Database (NHIRD), and 68,282 comparisons were randomly captured and matched by age, sex, monthly income, urbanization and comorbidities. The association between CP exposure and migraine risk was evaluated by Cox proportional hazards regression models. In this study, 785 migraine patients were identified in the CP cohort, and 641 migraine cases were found in the non-CP cohort. The incidence rate of migraine was significantly higher in the CP cohort than the non-CP cohort (adjusted HR: 1.21, 95% CI: 1.09–1.34, p < 0.001) during the 13-year follow-up period. Females had a 2.69-fold higher risk for migraine than males (95% CI: 2.38–3.04, p < 0.001). In summary, CP is associated with an increased risk of subsequent migraine in Taiwan.

The pathogenesis and diagnosis of sepsis post burn injury

Burn is an under-appreciated trauma that is associated with unacceptably high morbidity and mortality. Although the survival rate after devastating burn injuries has continued to increase in previous decades due to medical advances in burn wound care, nutritional and fluid resuscitation and improved infection control practices, there are still large numbers of patients at a high risk of death. One of the most common complications of burn is sepsis, which is defined as “severe organ dysfunction attributed to host's disordered response to infection” and is the primary cause of death in burn patients. Indeed, burn injuries are accompanied by a series of events that lead to sepsis and multiple organ dysfunction syndrome, such as a hypovolaemic state, immune and inflammatory responses and metabolic changes. Therefore, clear diagnostic criteria and predictive biomarkers are especially important in the prevention and treatment of sepsis and septic shock. In this review, we focus on the pathogenesis of burn wound infection and the post-burn events leading to sepsis. Moreover, the clinical and promising biomarkers of burn sepsis will also be summarized.

Serum procalcitonin as a biomarker for differentiating between infectious and non-infectious fever after pancreas transplantation

Laboratory biomarkers that can differentiate non-infectious fever from infectious fever after pancreas transplantation have yet to be discovered. Non-infectious fever was defined as the presence of fever (>38.3°C) in the absence of a documented clinical diagnosis of infection or a positive culture. Among 184 consecutive recipients, a total of 91 recipients developed fever within 1-month post-transplant, of whom 46 had infectious fever and 45 had non-infectious fever at our center between August 2014 and July 2019. The onset of fever was earlier in the non-infectious fever group (14.4 ± 3.7 post-transplant days) compared with the infectious fever group (16.5 ± 5.8 post-transplant days; p = .033). Multivariate analysis showed that serum procalcitonin at the peak of fever could significantly differentiate infectious fever from non-infectious fever (OR 53.378, 95% CI: 6.819-417.802, p < .001). The area under the curve for differentiating between the two groups was 0.853 (95% CI, 0.780-0.926) for procalcitonin and 0.667 (95% CI, 0.549-0.785) for CRP. The best cutoff values of serum procalcitonin and CRP were 0.405 ng/ml (sensitivity, 77.1%; specificity, 80.8%) and 7.355 mg/dl (sensitivity, 66.7%; specificity, 67.3%), respectively. Serum procalcitonin may be useful for differentiating non-infectious fever from infectious fever after pancreas transplantation.

Procalcitonin for Antibiotic Prescription in Chronic Obstructive Pulmonary Disease Exacerbations: Systematic Review, Meta-Analysis, and Clinical Perspective

The 2020 Global Initiative for Obstructive Lung Disease report indicates that the blood biomarker procalcitonin (PCT) may assist in decision-making regarding the initiation of antibiotics for chronic obstructive pulmonary disease (COPD) exacerbations. PCT is an acute-phase reactant that increases in response to inflammation and infection, and has been studied in various bacterial infections for initiation and de-escalation of antibacterials. The purpose of this systematic review and meta-analysis was to evaluate the strength of the data on the use of PCT to guide antibiotic prescription in COPD exacerbations. Among the randomized clinical trials included in our meta-analysis, almost all of which were conducted exclusively in the hospital setting. PCT was found to decrease overall antibiotic exposure in COPD exacerbations by 2.01 days (p = 0.04), while no apparent effects were found on clinical outcomes (length of hospital stay, p = 0.88; treatment failure p = 0.51; all-cause mortality p = 0.28). However, the majority of blood PCT levels in COPD exacerbations were below the manufacturer-recommended cutoff for antibiotics, and the use of this marker was associated with worse outcomes in the intensive care setting. Further, based on additional sensitivity analysis excluding studies with high risk of bias or with converted outcome value, the effect of PCT on antibiotic duration in RCTs was no longer significant (MD = -1.88 days, 95% CI [-3.95, 0.19] days, p = 0.08, and MD = -1.72 days, 95% CI [-4.28, 0.83] days, p = 0.19, respectively). Our review and analysis does not support the use of PCT to guide antibiotic prescription in COPD exacerbations.

Development of magnetic particle-based chemiluminescence immunoassay for measurement of human procalcitonin in serum

BACKGROUND

Serum procalcitonin (PCT) has been recognized as a primary biomarker in bacterial infections, and monitoring its concentration could help to evaluate the prognosis of sepsis and guide the antibiotic administration. We aimed to establish a fast and accurate immunoassay for PCT quantitation.

METHODS

Our newly developed monoclonal antibodies (mAbs) against human PCT were preliminarily evaluated by enzyme-linked immunosorbent assay and then used to develop a chemiluminescence enzyme immunoassay (CLEIA). The proposed CLEIA was assessed in analytical performance and applied to measurement of serum PCT.

RESULTS

mAb 2D3 and mAb 8F6 were selected as capture and detection antibody respectively, due to the highest sensitivity for PCT detection with no cross reaction to calcitonin gene-related peptides. The proposed CLEIA based on mAb pair of 2D3/8F6-AP was characterized for a working range from 0.03 to 100 μg/L. An excellent correlation was observed between our proposed assay and the VIDAS BRAHMS PCT assay (r: 0.9825).

CONCLUSION

Our newly developed mAbs and CLEIA can serve as important diagnostic tools for measurement of human PCT in serum.

Procalcitonin -Vital Tool to Differentiate Septic Progression of Spondylodiscitis from Drug Hypersensitivity: A Case Report and Brief Review of Literature

Introduction

Drug hypersensitivity is an important differential diagnosis in patients of infective spondylodiscitis, who develop systemic symptoms such as fever, rash, and arthralgia while on treatment with antibiotics. As these symptoms may also be present in sepsis progression, differentiation between two is very difficult. Procalcitonin (PCT) is one of the important and specific biomarkers of early sepsis.

Case Report

We present a case of a 33-year-old male with deep post-operative spinal infection complicated by drug hypersensitivity and worsening of systemic parameters. Serum PCT levels helped us to make correct diagnosis and prevent unnecessary surgical debridement.

Conclusion

PCT, as a biomarker, can help distinguish the septic progression of spondylodiscitis from drug hypersensitivity and prove vital in clinical decision-making in these difficult scenarios.

Procalcitonin Detection in Veterinary Species: Investigation of Commercial ELISA Kits

Simple Summary

Among sepsis biomarkers, procalcitonin resulted to be a specific indicator of bacterial infection or severity of infection, and to be a good control of the success of a therapeutic procedure. The clinical studies on the relevance of procalcitonin as a sepsis predictor in veterinary patients are few, likely due to the total absence of validated assays. For this reason, this study aimed to investigate commercial ELISA kits for the detection of canine and equine procalcitonin. Validation was performed evaluating linearity, limits of detection (LOD), recovery, and intra-assay and inter-assay variability; furthermore, clinical samples were analyzed. The results of the present study demonstrate that the human PCT ELISA kit is suitable to detect equine procalcitonin with a LOD of 56 ng/mL, and the canine recombinant PCT ELISA kit can be used to measure canine procalcitonin in plasma samples, showing an intra-assay and inter-assay coefficient of variation less than 20% and a LOD of 11 pg/mL.

Abstract

In human medicine, procalcitonin (PCT), the precursor of calcitonin, is used for the rapid identification of the origin and severity of sepsis. In veterinary medicine, PCT has been studied in horses, cattle, and dogs, but the use of PCT in diagnostic and/or prognostic settings is not possible because of the lack of validated assays to obtain reference ranges. The aim of the present study was the investigation of commercially available ELISA kits for the detection of canine and equine PCT in plasma samples. Validation of the ELISA kits was performed by using species-specific recombinant proteins spiked both in plasma and buffer samples; linearity, limit of detection (LOD), recovery, and intra-assay and inter-assay variability were calculated. Moreover, clinical samples obtained from sick and healthy animals were also analyzed with the tested kits. Canine PCT was measured with a recombinant canine and a canine PCT ELISA kit. Equine PCT was measured with an equine and a human ELISA PCT kit. Our data demonstrate that the canine recombinant PCT ELISA kit can be used to measure canine PCT in plasma samples, showing an intra-assay and inter-assay coefficient of variation less than 20% and a LOD of 11 pg/mL, whereas the present results do not support the use of the canine PCT ELISA kit. The human PCT ELISA kit is suitable to detect equine PCT with a LOD of 56 ng/mL, whereas the equine PCT ELISA kit did not detect recombinant equine PCT.

Kinetics of procalcitonin, C-reactive protein and interleukin-6 in cardiogenic shock - Insights from the CardShock study

BACKGROUND

Inflammatory responses play an important role in the pathophysiology of cardiogenic shock (CS). The aim of this study was to investigate the kinetics of procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6) in CS and to assess their relation to clinical presentation, other biochemical variables, and prognosis.

METHODS

Levels of PCT, CRP and IL-6 were analyzed in serial plasma samples (0-120h) from 183 patients in the CardShock study. The study population was dichotomized by PCT_max ≥ and < 0.5 μg/L, and IL-6 and CRP_max above/below median.

RESULTS

PCT peaked already at 24 h [median PCT_max 0.71 μg/L (IQR 0.24-3.4)], whereas CRP peaked later between 48 and 72 h [median CRP_max 137 mg/L (59-247)]. PCT levels were significantly higher among non-survivors compared with survivors from 12 h on, as were CRP levels from 24 h on (p < 0.001). PCT_max ≥ 0.5 μg/L (60% of patients) was associated with clinical signs of systemic hypoperfusion, cardiac and renal dysfunction, acidosis, and higher levels of blood lactate, IL-6, growth-differentiation factor 15 (GDF-15), and CRP_max. Similarly, IL-6 > median was associated with clinical signs and biochemical findings of systemic hypoperfusion. PCT_max ≥ 0.5 μg/L and IL-6 > median were associated with increased 90-day mortality (50% vs. 30% and 57% vs. 22%, respectively; p < 0.01 for both), while CRP_max showed no prognostic significance. The association of inflammatory markers with clinical infections was modest.

CONCLUSIONS

Inflammatory markers are highly related to signs of systemic hypoperfusion in CS. Moreover, high PCT and IL-6 levels are associated with poor prognosis.

Effects of advanced age and pituitary pars intermedia dysfunction on components of the acute phase reaction in horses

Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concentrations of pro- and anti-inflammatory cytokines and acute phase proteins were measured. The data were analyzed using the Mann-Whitney U-test, and correlations between groups of data were assessed using Spearman's correlation coefficient. The tests were statistically significant if P < 0.05. No differences in the whole blood cytokine gene expression, serum cytokine concentrations, or acute phase proteins were noted between the groups. In the PPID ID group, there was a strong correlation between the ACTH concentration after the administration of thyrotropin-releasing hormone and the expression of IL-8 (r = 0.941; P = 0.0321). In the PPID ID+ group, there was a strong correlation between basal insulin concentrations and serum amyloid A (SAA; r = 0.936; P = 0.0083) as well as between postprandial insulin concentrations and SAA (r = 0.965; P = 0.001). These data suggest that neurodegeneration in horses moderately affects circulating markers of inflammation and that ID in horses with PPID influences acute phase inflammatory markers.

Effects of equine metabolic syndrome on inflammation and acute-phase markers in horses

Obesity and metabolic disorders are associated with systemic low-grade chronic inflammation, both in humans and animals. The aim of the study is to assess the effects of obesity and hyperinsulinemia on individual components of the acute-phase reaction in equine metabolic syndrome (EMS) horses. Eight mixed-breed EMS and six control, age-matched horses of both sexes were included in the study. Animals were classified as EMS or control based on the assessment of BCS, cresty neck score, and basal insulin >50 μU/mL and/or insulin responses to the oral sugar test (OST) >60 μU/mL. Peripheral venous blood was collected. The expression of proinflammatory cytokines, the concentration of circulating cytokines, and acute-phase proteins (serum amyloid A, C-reactive protein, haptoglobin, activin A, and procalcitonin) were measured. The data were analyzed using the Mann-Whitney test, whereas correlations were examined using Spearman's correlation coefficient. The tests were statistically significant if P ≤ 0.05. There were no differences in cytokine gene expression, circulating cytokine concentrations, or concentrations of acute-phase proteins between the EMS and the control groups. There was a strong correlation between the basal concentration of insulin and the serum concentrations of IL-6 (r = 0.71, P < 0.05). Activin A was positively correlated with post-OST insulin concentrations (r = 0.707, P = 0.05), indicating that this marker of inflammation could warrant further investigation in horses with EMS.

Quantum Dots-Based Point-of-Care Measurement of Procalcitonin in Finger-Prick Blood and Venous Whole Blood Specimens

OBJECTIVE

To determine whether the performance of a new quantum dots-based point-of-care test (POCT) devices is qualified for procalcitonin testing.

METHODS

Finger-prick and venous blood specimens from 153 patients were measured with a quantum dots-based POCT device; the results were compared with those from the reference method.

RESULTS

The quantum dots-based POCT device correlated well with the reference method in measuring plasma, venous whole blood, and finger-prick blood. No significant bias was observed (-0.08 ng/mL). At 0.5 ng per mL cutoff value, the concordances were 96.6%, 94.6%, and 90.5% for plasma, venous whole blood, and finger-prick blood, respectively. And at 2 ng per mL cutoff value, the concordances were 98.0%, 96.6%, and 95.3%, respectively.

CONCLUSIONS

The quantum dots-based POCT device measured procalcitonin with multiple specimen types, high sensitivity, wide detection range, and short turnaround time. It would allow a more widespread use of procalcitonin and help lessen the burden of overcrowding in healthcare facilities in China.

A Comparison of Acute Physiology and Chronic Health Evaluation II Score and Serum Procalcitonin Change for Predicting Mortality in Acute Pancreatitis

Introduction

The prediction of mortality in acute pancreatitis (AP) is a useful estimate for effective treatment. Scoring systems such as acute physiology and chronic health evaluation (APACHE) II, computed tomography (CT) severity index (CTSI), bedside index of severity in acute pancreatitis (BISAP), etc., are used for prediction. Biomarkers like C-reactive protein (CRP) and procalcitonin (PCT) are also considered useful for prognostication. The aim of this retrospective study was to correlate the changes in serum PCT level with APACHE II score between admission and 48 hours as mortality predictor in AP.

Materials and methods

The observational study was conducted in a cohort of 42 patients admitted consecutively in the seven-bedded general intensive care unit (ICU) of our institute between June 2016 and May 2018, with the diagnosis of AP. The APACHE II score and serum PCT level at admission and 48 hours were retrieved from the hospital database. The change in APACHE II and PCT level was compared between ICU “survivors” and “nonsurvivors.” The predictive accuracy of APACHE II and PCT was measured using area under receiver–operator characteristics (ROC) curve. A p value <0.05 was considered as significant.

Results

Of the 42 patients enrolled, 30 patients (71.42%) were survivors and 12 (28.58%) were nonsurvivors. The median APACHE II score in nonsurvivors increased from 16 (7–19) to 23 (11–29) and remained unchanged at 16 (9–19 at admission; 10–22 at 48 hours) in survivors. The median PCT levels increased from 3.8 (1.2–5.6) to 6.2 (1.9–12.5) in nonsurvivors and decreased from 3.8 (1.2–5.6) to 2.2 (0.6–2.9) in survivors. Serum PCT change compared better than the APACHE II score change among survivors (r = 0.455, p = 0.011) with a mean (±standard deviation SD) change of 1.41 (±1.59).

Conclusion

The change in serum PCT and APACHE II between admission and 48 hours correlates well and is useful for mortality prediction in AP. Serum PCT change compares better than APACHE II score change in survivors.

How to cite this article

Choudhuri AH, Duggal S, Biswas PS, Uppal R. A Comparison of Acute Physiology and Chronic Health Evaluation II Score and Serum Procalcitonin Change for Predicting Mortality in Acute Pancreatitis. Indian J Crit Care Med 2020;24(3):190–194.

A novel approach to photoelectrochemical immunoassay for procalcitonin on the basis of SnS2/CdS

A label-free photoelectrochemical (PEC) immunoassay system based on the one-step synthesis of SnS₂/CdS nanocomposites is successfully constructed for sensitively analyzing procalcitonin (PCT).

The prognostic value of serum procalcitonin measurements in critically injured patients: a systematic review

Background

Major trauma is associated with high incidence of septic complications and multiple organ dysfunction (MOD), which markedly influence the outcome of injured patients. Early identification of patients at risk of developing posttraumatic complications is crucial to provide early treatment and improve outcomes. We sought to evaluate the prognostic value of serum procalcitonin (PCT) levels after trauma as related to severity of injury, sepsis, organ dysfunction, and mortality.

Methods

We searched PubMed, MEDLINE, EMBASE, the Cochrane Database, and references of included articles. Two investigators independently identified eligible studies and extracted data. We included original studies that assessed the prognostic value of serum PCT levels in predicting severity of injury, sepsis, organ dysfunction, and mortality among critically injured adult patients.

Results

Among 2015 citations, 19 studies (17 prospective; 2 retrospective) met inclusion criteria. Methodological quality of included studies was moderate. All studies showed a strong correlation between initial PCT levels and Injury Severity Score (ISS). Twelve out of 16 studies demonstrated significant elevation of initial PCT levels in patients who later developed sepsis after trauma. PCT level appeared a strong predictor of MOD in seven out of nine studies. While two studies did not show association between PCT levels and mortality, four studies demonstrated significant elevation of PCT levels in non-survivors versus survivors. One study reported that the PCT level of ≥ 5 ng/mL was associated with significantly increased mortality (OR 3.65; 95% CI 1.03–12.9; p = 0.04).

Conclusion

PCT appears promising as a surrogate biomarker for trauma. Initial peak PCT level may be used as an early predictor of sepsis, MOD, and mortality in trauma population.

The Role of Serum Procalcitonin in Predicting Bacterial Sepsis in Patients With Hypothyroidism

CONTEXT

Serum levels of procalcitonin (PCT), a protein produced by the thyroid C cells under physiologic conditions, are high during sepsis.

OBJECTIVE

To assess the test performance of serum PCT in predicting bacterial sepsis and septic shock in patients with hypothyroidism compared with those who have euthyroidism.

DESIGN AND METHODS

This retrospective study evaluated patients with no history of thyroid dysfunction (euthyroid), primary hypothyroidism [medical hypothyroidism (MH)], and postsurgical hypothyroidism from total thyroidectomy (TT) identified from a prospectively maintained database who had PCT testing from 2005 to 2018. Quick Sequential Organ Failure Assessment score ≥ 2 or positive bacterial cultures identified bacterial sepsis, and a mean arterial pressure less than 65 mm Hg or a vasopressor requirement defined septic shock. Sensitivity and specificity of PCT for evaluation of bacterial sepsis and septic shock were measured.

RESULTS

We identified 217 euthyroid patients, 197 patients with MH, and 84 patients with TT. Bacterial sepsis was found in 98 (45.2%), 92 (46.7%), and 36 (42.9%) of these patients, respectively (P > 0.05). Septic shock was identified in 13 (6.0%), 13 (6.6%), and 5 (6.0%) patients (P > 0.05), respectively. With use of a PCT cutoff of 0.5 µg/L for bacterial sepsis, the sensitivity was 59%, 61%, and 53% (P > 0.05) and specificity was 81%, 77%, and 81% (P > 0.05) for the diagnosis of bacterial sepsis in euthyroid, MH, and TT patients, respectively. With use of a PCT cutoff of 2.0 µg/L for septic shock, the sensitivity was 46%, 62%, and 63% (P > 0.05) and specificity was 86%, 82%, and 91% (P > 0.05) for the diagnosis of septic shock in these patients, respectively.

CONCLUSIONS

Despite the thyroidal origin of PCT, hypothyroidism did not affect the diagnostic performance of serum PCT levels in predicting bacterial sepsis or septic shock.

The predictive value of procalcitonin for early detection of infection in elderly type 2 diabetes mellitus

OBJECTIVE

Aimed to investigate the predictive value of procalcitonin (PCT) in early detection of infections in elderly patients with type 2 diabetes, and to discover the optimum cut-off points of PCT.

METHODS

A retrospective study was conducted with type 2 diabetic patients (≥65 years) with lung infection (LI), urinary tract infection (UTI) or skin and soft tissue infection (SSTI). The receiver operating characteristic (ROC) curves of the 3 markers (PCT, WBC count, and CRP) were constructed and compared to assess their accuracies in diagnosing.

RESULTS

Among the three different groups with LI, UTI or SSTI, the area under the ROC curve (AUC) of PCT was 0.98 (95% confidence interval (CI): 0.96-0.99, p < 0.05) for the LI group, 0.98 (95% CI: 0.96-0.99, p < 0.05) for the UTI group, and 0.97 (95% CI: 0.94-1.00, p < 0.05) for the SSTI group. The optimum cut-off point of PCT level was 0.73 ng/mL (Sn 89.7%, Sp 97.7%) for the LI group, 1.48 ng/mL (Sn 88.9%, Sp 100%) for the UTI group, and 0.73 ng/mL (Sn 85.7%, Sp 97.7%) for the SSTI group.

CONCLUSION

PCT demonstrated the strongest correlation with each of the infection types, indicating significant diagnostic value. Optimum cut-off points of PCT levels in elderly diabetes were higher.

Maternal Serum and Fetal Cord Blood C-Reactive Protein Levels but not Procalcitonin Levels Are Increased in Idiopathic Intrauterine Growth Restriction

BACKGROUND The aim of the present study was to compare procalcitonin and CRP levels in maternal serum and fetal cord blood samples of patients with idiopathic intrauterine growth restriction (IUGR) vs. a control group of appropriate for gestational age (AGA) infants. MATERIAL AND METHODS The present prospective study included 43 patients: 27 patients with idiopathic IUGR (IUGR group) and 26 AGA infants at similar gestational ages (control group). Maternal serum and fetal cord blood samples were collected from the control group and IUGR group at time of delivery. Procalcitonin and CRP levels were analyzed in maternal blood. Procalcitonin and CRP levels were analyzed in fetal cord blood. RESULTS The median value of CRP levels in maternal blood was 47.5 mg/dl in the IUGR group and 15.255 mg/dl in the AGA group (p=0.001). The mdian CRP level in cord blood was 36.4 mg/dl (range, 17.3-47.2) in the IUGR group and 10.1 mg/dl (range, 4.07-16.5) in the control group, and the difference was statistically significant (p=0.001). The median maternal serum procalcitonin level was 0.05 µg/l in the IUGR group and 0.04 µg/l in the AGA group, and the difference was not statistically significant (p=0.435). The median procalcitonin value in fetal cord blood was 0.06 µg/l in the IUGR group and 0.04 µg/l in the AGA group, and the difference was not statistically significant (p=0.741). CONCLUSIONS Maternal serum and fetal cord CRP levels were higher in the IUGR group; however, there was no difference in procalcitonin, which is another inflammatory indicator, between the groups.

Can biomarkers improve the rational use of antibiotics?

PURPOSE OF REVIEW

We aim to review recent literature about the use of biomarkers to guide the initiation and duration of antibiotic treatments for suspected bacterial infections.

RECENT FINDINGS

Several good quality meta-analyses show that procalcitonin can be safely used to guide antibiotic-related decisions, especially for respiratory infections, thereby decreasing unnecessary antibiotic exposure. Furthermore, the use of CRP-based algorithms to guide antibiotic initiation in primary care patients with acute respiratory infections is associated with a reduction in antibiotic use without an increase in adverse events. Regarding neutrophil CD64 and serum amyloid A, more good-quality evidence is needed to assess their utility as biomarkers to tailor antibiotic use. Finally, transcriptomics, metabolomics and proteomics are promising tools for the development of tests to differentiate specific host responses to viral, bacterial and noninfectious stimuli, but such tests still need further validation.

SUMMARY

Evidence shows that the use of biomarkers, procalcitonin and CRP, can safely reduce unnecessary antibiotic prescriptions in certain infectious syndromes. The clinical utility of host-based strategies such as transcriptomics, metabolomics and proteomics for the diagnosis of infectious diseases has yet to be evaluated, as well as considerations such as costs, technical complexity and result turnaround time.

Prognostic Value of Serum Procalcitonin level for the Diagnosis of Bacterial Infections in Critically-ill Patients

Background

Procalcitonin (PCT) is a diagnostic biomarker for bacterial infections in critically-ill patients. However, the cut-off value of PCT for the diagnosis of bacterial infections is unclear and unreliable. This study aimed to determine the optimal cut-off value of PCT for the diagnosis of bacterial infections in critically-ill patients.

Materials and Methods

We conducted a retrospective study involving 311 adult patients who had been admitted to the medical or surgical intensive care unit for more than 24 hours from 2013 to 2015. At least one blood test for PCT level was performed for all patients within the first 24 hours of suspecting an infection.

Results

One hundred and fifty-seven patients had bacterial infections, while 154 did not. Patients with bacterial infections had a significantly higher median PCT level than those without bacterial infections (1.90 ng/mL vs. 0.16 ng/mL, P <0.001). The area under the receiver operating characteristic curve of PCT for discriminating between bacterial and non-bacterial infections was 0.874 (95% confidence interval: 0.834, 0.914; P <0.001). The optimal cut-off value of PCT for differentiating between fevers due to bacterial infections from those due to non-bacterial infections was 0.5 ng/mL, with a sensitivity of 84.7%, specificity of 79.9%, positive predictive value of 81.1%, and negative predictive value of 83.7%.

Conclusion

PCT was found to be an accurate biomarker for the diagnosis of bacterial infections among patients admitted to medical and surgical intensive care units. The optimal cut-off value of PCT for the diagnosis of bacterial infections was 0.5 ng/mL.

Quantitative detection of procalcitonin using an electrochemical immunosensor based on MoO3/Au@rGO nanocomposites

In this work, a sandwich-type electrochemical immunosensor for the detection of procalcitonin (PCT) is constructed layer-by-layer with a novel label based on MoO₃/Au@rGO nanocomposites.

Inflammatory and coagulatory parameters linked to survival in critically ill children with sepsis

BACKGROUND

Sepsis is associated with a deflection of inflammatory and coagulative parameters, since some clotting factors are known to be involved in the host's defense against infection and inflammation. These parameters could play a crucial role in the course of sepsis and be used as prognostic markers in critically ill children.

METHODS

A total of 250 critically ill pediatric patients diagnosed with sepsis were retrospectively analyzed to identify routinely measured predictors for in-hospital mortality at the peak level of C-reactive protein. Those parameters entered multivariate logistic regression analysis as well as a decision tree for survival.

RESULTS

Multivariate logistic regression analysis revealed fibrinogen, platelets and activated partial thromboplastin time (aPTT) at the peak level of C-reactive protein to be predictors for survival (p = 0.03, p = 0.01 and p = 0.02, respectively). An increase in fibrinogen and platelets is linked to survival, whereas an aPTT prolongation is associated with higher mortality; adjusted odds ratios (95% CI) for an increase of 100 mg/dl in fibrinogen are 1.35 (1.04-1.82) per 50 G/l platelets 1.94 (1.3-3.29) and 0.83 (0.69-0.96) for an aPTT prolongation of 10 s. Decision tree analysis shows that a fibrinogen level below 192 mg/dl (90.9% vs. 13% mortality) is most distinctive in non-survivors.

CONCLUSIONS

High levels of fibrinogen and platelets as well as a non-overshooting aPTT are associated with a higher survival rate in pediatric patients with diagnosed sepsis. In particular, hypofibrinogenemia is distinctive for a high mortality rate in septic critically ill children.

Procalcitonin may not be a differential diagnostic marker for bacterial infection in febrile patients with chronic gouty arthritis

Objective This study aimed to examine the diagnostic value of serum procalcitonin (PCT) levels for identifying bacterial infection in febrile patients with chronic gouty arthritis. Methods Sixty-six febrile patients with chronic gouty arthritis were divided into non-bacterial infection (n = 45) and bacterial infection groups (n = 21). PCT levels were measured by an immunoassay. Other laboratory parameters, including the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cells (WBCs), and the neutrophil ratio were extracted from medical records. Receiver-operating characteristic curves were used to evaluate diagnostic values and accuracy. Results Serum PCT levels, the ESR, CRP levels, WBC count, and neutrophil ratio were not different between the groups. To assess the ability of PCT to discriminate bacterial infection in febrile patients with chronic gouty arthritis (cut-off value: 0.5 ng/mL), the sensitivity and specificity of PCT were 22.2% and 61.5%, respectively. The area under the curve (AUC) of serum PCT levels was 0.526. The AUCs of related inflammatory indicators were 0.530 for the ESR, 0.635 for CRP, 0.577 for the WBC count, and 0.712 for the neutrophil ratio. Conclusion Serum PCT levels may not be a good biomarker for bacterial infection in febrile patients with chronic gouty arthritis.

The Role of Procalcitonin in the Diagnosis of Meningitis: A Literature Review

OBJECTIVE

To review the current published literature on the use of procalcitonin as a diagnostic and prognostic marker in adult patients with meningitis.

METHODS

We conducted a PubMed search to identify all relevant publications regarding the diagnostic and prognostic value of serum procalcitonin in patients with a known or suspected central nervous system infection. We also reviewed the bibliographies of all identified manuscripts in an attempt to identify additional relevant references.

RESULTS

A significant body of evidence suggests that serum procalcitonin has a promising role and can be a useful biomarker in the assessment of patients with meningitis.

CONCLUSIONS

Our literature review suggests that data on the role of Cerebrospinal Fluid (CSF) procalcitonin are limited, whereas serum procalcitonin (S⁻PCT) is probably a useful tool in the evaluation of patients with a known or suspected central nervous system infection and can help distinguish between bacterial and viral meningitis.

The Use of Serum Procalcitonin as a Diagnostic and Prognostic Biomarker in Chronic Obstructive Pulmonary Disease Exacerbations: A Literature Review Update

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a major complication in COPD patients which can be triggered by bacterial or viral infections, environmental pollutants and other causes. Procalcitonin (PCT), a peptide that markedly increases in cases of bacterial infection, has been extensively investigated as a biomarker in the diagnosis, prognosis and treatment in patients with AECOPD. A number of studies published in the last decade, tried to investigate whether PCT levels can differentiate between bacterial and other causes of exacerbations, if they can be used as a guide for optimal antibiotic therapy and if they can be a tool in the assessment of the severity and the need for further interventions in the management of those patients. This review aims to gather, summarize and critically present all the available data to date.