Procalcitonin behaves as a fast responding acute phase protein in vivo and in vitro

Reduced Reliability of Procalcitonin (PCT) as a Biomarker of Bacterial Superinfection: Concerns about PCT-Driven Antibiotic Stewardship in Critically Ill COVID-19 Patients-Results from a Retrospective Observational Study in Intensive Care Units

BACKGROUND

The aim of this study was to assess whether procalcitonin levels is a diagnostic tool capable of accurately identifying sepsis and ventilator-associated pneumonia (VAP) even in critically ill COVID-19 patients.

METHODS

In this retrospective, observational study, all critically ill COVID-19 patients who survived for ≥2 days in a single university hospital and had at least one serum procalcitonin (PCT) value and associated blood culture and/or culture from a lower respiratory tract specimen available were eligible for the study.

RESULTS

Over the research period, 184 patients were recruited; 67 VAP/BSI occurred, with an incidence rate of 21.82 episodes of VAP/BSI (95% CI: 17.18-27.73) per 1000 patient-days among patients who were included. At the time of a positive microbiological culture, an average PCT level of 1.25-3.2 ng/mL was found. Moreover, also in subjects without positive cultures, PCT was altered in 21.7% of determinations, with an average value of 1.04-5.5 ng/mL. Both PCT and PCT-72 h were not linked to a diagnosis of VAP/BSI in COVID-19 patients, according to the multivariable GEE models (aOR 1.13, 95% CI 0.51-2.52 for PCT; aOR 1.32, 95% CI 0.66-2.64 for PCT-72 h).

CONCLUSION

Elevated PCT levels might not always indicate bacterial superinfections or coinfections in a severe COVID-19 setting.

Management of Intra-Abdominal Infections: The Role of Procalcitonin

Patients with intra-abdominal sepsis suffer from significant mortality and morbidity. The main pillars of treatment for intra-abdominal infections are (1) source control and (2) early delivery of antibiotics. Antibiotic therapy should be started as soon as possible. However, the duration of antibiotics remains a matter of debate. Prolonged antibiotic delivery can lead to increased microbial resistance and the development of nosocomial infections. There has been much research on biomarkers and their ability to aid the decision on when to stop antibiotics. Some of these biomarkers include interleukins, C-reactive protein (CRP) and procalcitonin (PCT). PCT's value as a biomarker has been a focus area of research in recent years. Most studies use either a cut-off value of 0.50 ng/mL or an >80% reduction in PCT levels to determine when to stop antibiotics. This paper performs a literature review and provides a synthesized up-to-date global overview on the value of PCT in managing intra-abdominal infections.

Interest of Procalcitonin in ANCA Vasculitides for Differentiation between Flare and Infections

Procalcitonin (PCT) was established as a biomarker to discriminate bacterial infections from other proinflammatory conditions. Our objective was to determine whether PCT is effective in differentiating infection from antineutrophil-cytoplasmic-antibody (ANCA)-associated vasculitides (AAV) flare. In this retrospective, case-control study, PCT and other inflammatory biomarkers of patients with AAV relapse (relapsing group) were compared to infected AAV patients (infected group). In our population of 74 patients with AAV, PCT was significantly higher in the infected group than in the relapsing group (0.2 µg/L [0.08; 0.935] vs. 0.09 µg/L [0.05; 0.2], p < 0.001). Sensitivity and specificity were 53.4% and 73.6%, respectively, for an ideal threshold of 0.2 µg/L. C-reactive protein (CRP) was significantly higher in cases of infection than in relapse (64.7 mg/L [25; 131] vs. 31.5 mg/L, [10.6; 120], p = 0.001). Sensitivity and specificity for infections were 94.2% and 11.3%, respectively. Fibrinogen, white blood cell count, eosinophil count, and neutrophil count were not significantly different. In the multivariate analysis, the relative risk of infection was 2 [1.02; 4.5] (p = 0.04) for a PCT above 0.2 µg/L. In AAV, PCT may be useful for discriminating between infections and flare in patients suffering from AAVs.

Plasma procalcitonin kinetics in healthy dogs and dogs undergoing tibial plateau leveling osteotomy

BACKGROUND

Procalcitonin (PCT) is a well-established biomarker for bacterial infection in human patients.

OBJECTIVES

We aimed to analyze the kinetics of plasma PCT (pPCT) in healthy dogs and dogs with canine cranial cruciate ligament (CCL) rupture undergoing tibial plateau leveling osteotomy (TPLO).

METHODS

This prospective, longitudinal study included 15 healthy dogs and 25 dogs undergoing TPLO. Hematology, pPCT, and C-reactive protein (CRP) were assessed on 3 consecutive days in healthy dogs and 1 day preoperatively and days 1, 2, 10, and 56 postoperatively. Inter- and intraindividual variability of pPCT were assessed in healthy dogs. Median pPCT concentrations of dogs with CCL rupture preoperatively were compared with healthy controls, and median pPCT concentrations, as well as percentage change post anesthesia, arthroscopy, and TPLO, were compared with baseline. For the correlation analysis, the Spearman rank correlation test was used.

RESULTS

Inter- and intraindividual variabilities of pPCT in healthy dogs were 36% and 15%, respectively. Median baseline pPCT concentrations were not significantly different between healthy dogs (118.9 pg/mL; IQR: 75.3-157.3 pg/mL) and dogs undergoing TPLO (95.9 pg/mL; IQR: 63.8-117.0 pg/mL). Plasma PCT concentrations were significantly lower immediately post- than preoperatively (P < 0.001). CRP, WBC, and neutrophil concentrations increased significantly on post-OP day 2 and had normalized by day 10.

CONCLUSIONS

These results indicate that CCL rupture, as well as anesthesia, arthroscopy, and TPLO combined, are not associated with increased pPCT concentrations in dogs with uncomplicated recovery. Considering the high intraindividual variability, individual serial measurements rather than a population-based reference interval should be considered.

Procalcitonin in early allograft dysfunction after orthotopic liver transplantation: a retrospective single centre study

Background

Ischemia–reperfusion injury (IRI) is the pathophysiological hallmark of hepatic dysfunction after orthotopic liver transplantation (OLT). Related to IRI, early allograft dysfunction (EAD) after OLT affects short- and long-term outcome. During inflammatory states, the liver seems to be the main source of procalcitonin (PCT), which has been shown to increase independently of bacterial infection. This study investigates the association of PCT, IRI and EAD as well as the predictive value of PCT during the first postoperative week in terms of short- and long-term outcome after OLT.

Methods

Patients ≥ 18 years undergoing OLT between January 2016 and April 2020 at the University Hospital of Zurich were eligible for this retrospective study. Patients with incomplete PCT data on postoperative days (POD) 1 + 2 or combined liver-kidney transplantation were excluded. The PCT course during the first postoperative week, its association with EAD, defined by the criteria of Olthoff, and IRI, defined as aminotransferase level > 2000 IU/L within 2 PODs, were analysed. Finally, 90-day as well as 12-month graft and patient survival were assessed.

Results

Of 234 patients undergoing OLT, 110 patients were included. Overall, EAD and IRI patients had significantly higher median PCT values on POD 2 [31.3 (9.7–53.8) mcg/l vs. 11.1 (5.3–25.0) mcg/l; p < 0.001 and 27.7 (9.7–51.9) mcg/l vs. 11.5 (5.5–25.2) mcg/l; p < 0.001] and impaired 90-day graft survival (79.2% vs. 95.2%; p = 0.01 and 80.4% vs. 93.8%; p = 0.033). IRI patients with PCT < 15 mcg/l on POD 2 had reduced 90-day graft and patient survival (57.9% vs. 93.8%; p = 0.001 and 68.4% vs. 93.8%; p = 0.008) as well as impaired 12-month graft and patient survival (57.9% vs. 96.3%; p = 0.001 and 68.4% vs. 96.3%; p = 0.008), while the outcome of IRI patients with PCT > 15 mcg/l on POD 2 was comparable to that of patients without IRI/EAD.

Conclusion

Generally, PCT is increased in the early postoperative phase after OLT. Patients with EAD and IRI have a significantly increased PCT maximum on POD 2, and impaired 90-day graft survival. PCT measurement may have potential as an additional outcome predictor in the early phase after OLT, as in our subanalysis of IRI patients, PCT values < 15 mcg/l were associated with impaired outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02486-5.

Prognostic Value of Serum Procalcitonin Based Model in Moderate to Severe Traumatic Brain Injury Patients

Objective

Procalcitonin (PCT) is an acknowledged marker of systemic inflammatory response. Previous studies have not reached agreement on the association between serum PCT and outcome of traumatic brain injury (TBI) patients. We designed this study to confirm the prognostic value of PCT in isolated TBI and those with extracranial injury, respectively.

Methods

Patients hospitalized in our hospital for moderate-to-severe TBI between March 2015 and December 2019 were included. Logistic regression analysis was performed to validate the association between PCT and in-hospital mortality in these patients. AUC (area under the receiver operating characteristics curve) of PCT and constructed model were calculated and compared.

Results

Among the included 211 patients, 81 patients suffered a poor outcome, with a mortality rate of 38.4%. Non-survivors had a higher level of serum PCT (2.73 vs 0.72, p<0.001) and lower GCS (5 vs 7, p<0.001) on admission than survivors. AUC of single PCT for predicting mortality in isolated TBI and those with extracranial injury were 0.767 and 0.553, respectively. Multivariate logistic regression showed that GCS (OR=0.744, p=0.008), glucose (OR=1.236, p<0.001), cholesterol (OR=0.526, p=0.002), and PCT (OR=1.107, p=0.022) were independently associated with mortality of isolated TBI. The AUC of the prognostic model composed of GCS, glucose, cholesterol, and PCT was 0.868 in isolated TBI.

Conclusion

PCT is an efficient marker of outcome in isolated moderate-to-severe TBI but not those with extracranial injury. A prognostic model incorporating PCT is useful for clinicians to make early risk stratification for isolated TBI.

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.

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11-1.70] ng/mL vs 0.24 [0.10-0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51-.60]).

Pattern of change of C-reactive protein levels and its clinical implication in patients with acute poisoning

Objectives:

C-reactive protein is well known as an inflammatory indicator in injury, infection, and cancer. However, little is known about its role in poisoning. C-reactive protein levels first increase and then decrease within several days during poisoning management. This study aimed to verify the C-reactive protein change pattern and its clinical co-infection possibility in patients with poisoning.

Methods:

Daily C-reactive protein levels of the patients with poisoning, who were admitted for more than 5 days, were measured. Microbial cultures were conducted, and fever (⩾38°C) and infection-related symptoms were investigated.

Results:

In the enrolled 56 patients, the initial median C-reactive protein levels at hospital day 1, 2, 3, 4, and 5 were 0.28, 4.85, 10.91, 10.57, and 6.68 mg/dL, respectively. C-reactive protein level was the highest at hospital day 3 and decreased thereafter. No statistical difference was observed in the daily and maximal C-reactive protein levels between the culture-positive and culture-negative groups. The levels at hospital days 3–5 and the maximal level were 8.4, 9.2, 5.49, and 11.02 mg/dL, respectively, in non-fever group. The levels at hospital days 3–5 and the maximal level were 7.4, 9.2, 4.74, and 10.81 mg/dL, respectively, in non-symptoms group. Levels at hospital days 3–5 and the maximal level were 5.21, 4.93, 3.7, and 5.28 mg/dL, respectively, in all-negative (culture-negative without fever or infection symptoms) group.

Conclusions:

Acute rise and fall of C-reactive protein levels can be observed in the infection-unlikely patients with poisoning. The levels were similar to bacterial infection levels, possibly due to the drug reaction itself, rather than for superimposed infections.

Investigation of procalcitonin and beta-defensin2 in the serum and feces of dogs with acute diarrhea

BACKGROUND

Acute diarrhea is a common clinical condition where clinical parameters are used to assess disease severity, course, and prognosis.

OBJECTIVES

The aim of this study was to investigate procalcitonin (PCT) and beta-defensin2 (Bdef2) as biomarkers for disease severity, course, and prognosis of dogs with acute diarrhea.

METHODS

Dogs with acute diarrhea (enteritis group [EG], n = 35) were compared with 30 healthy controls. The dogs in the EG were scored using the Canine Acute Diarrhea Severity (CADS) index and grouped by bacterial fecal culture results. Procalcitonin and Bdef2 were analyzed in serum and feces.

RESULTS

Dogs with acute diarrhea showed higher serum PCT concentrations (P < 0.0001) and lower fecal Bdef2 concentrations (P = 0.0001) than unaffected dogs. Serum PCT was moderately and positively related to the extent of disease classified by the CADS score. Dogs with Clostridium perfringens or hemolyzing Escherichia coli as predominant pathogen had increased serum Bdef2 concentrations (P < 0.01). Differentiation between uncomplicated (≤3 days) and complicated (>3 days) disease courses, determined by receiver operating characteristic (ROC) curves, resulted in a sensitivity of 0.74 and a specificity of 0.69 for serum PCT at a cutoff of 3.9 ng/mL. The serum PCT and fecal Bdef2 quotient resulted in a sensitivity of 0.80 and a specificity of 0.92, with a cutoff of 80.5.

CONCLUSIONS

The results of the present study indicate that PCT and Bdef2 are potential biomarkers that can provide information on the severity, course, and prognosis of acute diarrhea in dogs.

Biomarkers for Diagnosing Febrile Illness in Immunocompromised Children: A Systematic Review of the Literature

OBJECTIVE

This study aims to assess the performance of biomarkers used for the prediction of bacterial, viral, and fungal infection in immunocompromised children upon presentation with fever.

METHODS

We performed a literature search using PubMed and MEDLINE and In-Process & Other Non-indexed Citations databases. Cohort and case-control studies assessing biomarkers for the prediction of bacterial, viral, or fungal infection in immunocompromised children vs. conventional microbiological investigations were eligible. Studies including adult patients were eligible if pediatric data were separately assessable. Data on definitions used for infections, fever, and neutropenia and predictive values were collected. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Fifty-two studies involving 13,939 febrile episodes in 7,059 children were included. In total, 92.2% were in cancer patients (n = 48), and 15.7% also included hematopoietic stem cell transplantation patients (n = 8). Forty-three biomarkers were investigated, of which 6 (CRP, PCT, IL-8, IL-6, IL-10, and TNFα) were significantly associated with bacterial infection at admission, studied in multiple studies, and provided predictive data. Literature on the prediction of viral and fungal infection was too limited. Eight studies compared C-reactive protein (CRP) and procalcitonin (PCT), with PCT demonstrating superiority in 5. IL-6, IL-8, and IL-10 were compared with CRP in six, four, and one study, respectively, with mixed results on diagnostic superiority. No clear superior biomarker comparing PCT vs. IL-6, IL-8, or IL-10 was identified.

DISCUSSION

There is great heterogeneity in the biomarkers studied and cutoff values and definitions used, thus complicating the analysis. Literature for immunocompromised children with non-malignant disease and for non-bacterial infection is sparse. Literature on novel diagnostics was not available. We illustrated the challenges of diagnosing fever adequately in this study population and the need for improved biomarkers and clinical decision-making tools.

Administration of Low-Dose Dexmedetomidine Did Not Affect Acute Inflammatory Response after Cytoreductive Surgery Combined with Hyperthermic Intraperitoneal Chemotherapy: A Double-Blind Randomized Controlled Trial

During cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), attenuation of inflammatory responses that increase susceptibility to postoperative complications, morbidity, and mortality is important. We aimed to evaluate whether intraoperative dexmedetomidine infusion impacted inflammatory response in patients undergoing CRS with HIPEC. Fifty-six patients scheduled for CRS with HIPEC were randomly assigned to the control (n = 28) and dexmedetomidine (n = 28) groups. The primary endpoint was the effect of dexmedetomidine on the interleukin-6 (IL-6) level measured at pre-operation (Pre-OP), before HIPEC initiation (Pre-HIPEC), immediately after HIPEC; after the end of the operation; and on postoperative day (POD) 1. In both groups, the IL-6 levels from Pre-HIPEC until POD 1 and the C-reactive protein (CRP) levels on PODs 1, 2, and 3 were significantly higher than the Pre-OP values (all Bonferroni corrected, p < 0.001). However, total differences in IL-6 and CRP levels, based on the mean area under the curve, were not detected between the two groups. The continuous intraoperative infusion of dexmedetomidine (0.4 μg/kg/h) in patients undergoing CRS with HIPEC did not significantly lower the inflammatory indices. Further dose investigative studies are needed to find the dexmedetomidine dose that provides anti-inflammatory and sympatholytic effects during HIPEC.

Serological Biomarkers of Tissue Turnover Identify Responders to Anti-TNF Therapy in Crohn's Disease: A Pilot Study

INTRODUCTION

Anti-tumor necrosis factor (TNF) therapy is effective in inducing remission in Crohn's disease in 60% of patients. No serological biomarkers are available, which can predict response to anti-TNF. We aimed to investigate serological markers of collagen turnover reflecting tissue inflammation as predictors of response to anti-TNF.

METHODS

In 2 retrospective observational cohorts, markers for matrix metalloproteinase-degraded type III and IV collagens (C3M and C4M, respectively) and for formation of type III and IV collagens (PRO-C3 and PRO-C4, respectively) were measured in serum and compared with standard C-reactive protein in patients with active Crohn's disease who started infliximab (IFX, n = 21) or adalimumab (ADA, n = 21). Disease activity was classified by the Harvey-Bradshaw index (active disease ≥5); response was defined as clinical remission.

RESULTS

Seventeen patients (81%) treated with IFX were in remission at week 14; 15 patients (71%) treated with ADA were in remission at week 8. Serum C4M at baseline was increased in nonresponders compared with responders (IFX: 35.0 ± 2.4 vs 23.2 ± 2.6, P = 0.04, ADA: 53.0 ± 3.2 vs 34.1 ± 2.8, P = 0.006). C4M levels at baseline predicted response in both cohorts (IFX: odds ratio 39 [95% confidence interval, 2.4-523.9] P = 0.02, cutoff 35.2 nmol/L; ADA: odds ratio 26 [95% confidence interval, 1.8-332.5], P = 0.01, cutoff 46.9 nmol/L). C-reactive protein was not able to predict response to anti-TNF.

DISCUSSION

Response to anti-TNF therapy within the first 14 weeks of treatment can be predicted based on baseline levels of basement membrane marker C4M. This marker could be used as biomarker for response to anti-TNF and could aid in early therapy decision making. Validation in larger well-defined cohorts is needed.

Extreme elevation of acute phase reactants and shock secondary to dabrafenib-trametinib

The emerging role of BRAF and MEK tyrosine-kinase inhibitors has shown new opportunities of treatment for patients with advanced melanoma and BRAF mutations. Its use is associated with some toxicities, as pyrexia, that clinicians may not be familiarized with. We present the case of a patient diagnosed with stage IV melanoma BRAF Val600E mutated who was started on dabrafenib and trametinib and developed three severe episodes of fever, hypotension and acute phase reactants elevation during the first 3 months of therapy, in the absence of microbiological demonstration of infection. The episodes were initially managed as a septic shock with broad-spectrum antibiotics and vasoactive drugs, while treatment with dabrafenib and trametinib was withheld. After two subsequent dose reduction of dabrafenib, the patient did not experience new episodes of fever.

Determinants of defence strategies of a hibernating European bat species towards the fungal pathogen Pseudogymnoascus destructans

Pseudogymnoascus destructans (Pd), the causative agent of white-nose syndrome in North America, has decimated bat populations within a decade. The fungus impacts bats during hibernation when physiological functions, including immune responses, are down-regulated. Studies have shown that Pd is native to Europe, where it is not associated with mass mortalities. Moreover, genomic and proteomic studies indicated that European bats may have evolved an effective immune defence, which is lacking in North American bats. However, it is still unclear which defence strategy enables European bats to cope with the pathogen. Here, we analyzed selected physiological and immunological parameters in torpid, Pd infected European greater mouse-eared bats (Myotis myotis) showing three different levels of infection (asymptomatic, mild and severe symptoms). From a subset of the studied bats we tracked skin temperatures during one month of hibernation. Contrasting North American bats, arousal patterns remained unaffected by Pd infections in M. myotis. In general, heavier M. myotis aroused more often from hibernation and showed less severe disease symptoms than lean individuals; most likely because heavy bats were capable of reducing the Pd load more effectively than lean individuals. In the blood of severely infected bats, we found higher gene expression levels of an inflammatory cytokine (IL-1β), but lower levels of an acute phase protein (haptoglobin), reactive oxygen metabolites (ROMs) and plasma non-enzymatic antioxidant capacity (OXY) compared to conspecifics with lower levels of infection. We conclude that M. myotis, and possibly also other European bat species, tolerate Pd infections during torpor by using selected acute phase response parameters at baseline levels, yet without arousing from torpor and without synthesizing additional immune molecules.

Procalcitonin and C-reactive protein predict infection in hematopoietic stem cell transplantation patients

INTRODUCTION

Procalcitonin (PCT) and C-reactive protein (CRP) are known inflammatory markers of severe infection; however, their ability to differentiate between infections of different origins is not clear yet. In this study, we evaluated PCT and CRP as markers of infection in hematopoietic stem cell transplantation (HSCT) patients.

METHODS

Blood samples were collected to determine serum concentrations of PCT, CRP, d-Dimer, and to perform blood culture analysis. Based on blood culture results, the patients were divided into two groups-positive blood culture (n = 271) patients and negative blood culture patients (n = 668); the negative blood culture group served as the control. The positive blood culture group was further divided into three groups based on the etiological agent of infection. PCT and CRP concentrations were compared, and ROC curve, sensitivity, specificity, and cutoff values were calculated.

RESULTS

PCT levels in infected patients were significantly higher than those in control patients (p < 0.001); similarly, CRP and d-Dimer levels were also higher among infected patients when compared with those in the controls. A PCT level of 0.51 ng/mL was the best threshold for detecting the infection, with an AUC-ROC of 0.877, whereas the best threshold for CRP was 49.20 mg/L. PCT levels were the highest in patients with gram-negative bacteremia as compared to in those with gram-positive bacteremia and fungal infection. The optimal cutoff value of PCT for the detection of gram-negative and gram-positive infection was 1.63 ng/mL.

CONCLUSION

PCT seems to be a useful marker for the diagnosis of systemic infection in HSCT patients, probably better than CRP and d-Dimer.

The diagnostic accuracy of procalcitonin in infectious patients after cardiac surgery: a systematic review and meta-analysis

Cardiac surgery with cardiopulmonary bypass (CPB) induces an acute inflammatory response that may lead to a systemic inflammatory response syndrome. The interest in procalcitonin (PCT) in the diagnosis of bacterial infection in patients after cardiac surgery remains less defined. The aim of this meta-analysis is to prospectively examine the discriminatory power of PCT as markers of infection in hospitalized patients with after cardiac surgery. The bivariate generalized nonlinear mixed-effect model and the hierarchical summary receiver operating characteristic model were used to estimate the pooled sensitivity, specificity and summary receiver operating characteristic curve. The pooled sensitivity and specificity were 0.81 (95% CI 0.75-0.87) and 0.78 (95% CI 0.73-0.83), respectively. The pooled positive likelihood ratio, and negative likelihood ratio of PCT were 3.74 (95% CI 2.98-4.69) and 0.24 (95% CI 0.17-0.32), respectively. The pooled area under the summary receiver operating characteristic curve of PCT using the HSROC method was 0.87 (95% CI 0.84- 0.90). This study indicated that PCT is a promising marker for the diagnosis of sepsis for those patients who undergo cardiac surgery.

Serum Procalcitonin Correlates With Renal Function and Immune Components in Early-Stage Renal Transplant Recipients

BACKGROUND

In renal transplantation, monitoring procalcitonin (PCT) in the early post-transplant period can be a promising method for early tracking of infectious complications. However, the correlation between PCT and infection-related factors and immune components and renal function remains unclear.

PATIENTS AND METHODS

Between November 2017 and December 2018, 62 early-stage renal transplant recipients were selected, and 4 mL peripheral blood samples were collected to detect the changes of specific immune cells and cytokines. Our study was in compliance with the Helsinki Congress and the Declaration of Istanbul; no prisoners were used, and participants were neither paid nor coerced in our study.

RESULTS

According to serum PCT levels, recipients were divided into a high group (PCT ≥ 0.5 ng/mL) and a low group (PCT < 0.5 ng/mL). Compared with the low group, creatinine, cystatin C, urea, T helper type (Th) 22 cells, IL-22 + Th17 cells, interleukin (IL)-22, tumor necrosis factor alpha, and IL-17A increased while estimated glomerular filtration rate (eGFR) was decreased in the high group. In addition, PCT was significantly correlated with eGFR in the high group.

CONCLUSIONS

Serum PCT is related with renal function and seems to be associated with immune components in early-stage renal transplant recipients.

Procalcitonin as an Early Predictor of Intra-abdominal Infections Following Gastric Cancer Resection

BACKGROUND

The purpose of this study was to investigate the prognostic value of postoperative procalcitonin (PCT) and C-reactive protein (CRP) for their ability to detect Intra-abdominal infections (IAIs) in patients after GC surgery.

METHODS

Patients who underwent elective gastrectomy for primary GC were retrospectively enrolled between October 2018 and October 2019. The PCT and CRP levels and white blood cell (WBC) count were measured before surgery and on postoperative days (POD) 1, 3, 5, and 7. The differences in serum PCT, CRP, and WBC levels between IAIs and non-IAIs groups were compared. Diagnostic accuracy was determined by the area under the receiver operating characteristic curve. Univariate and multivariate logistic regression analyses identified independent clinical factors that predicted postoperative IAIs.

RESULTS

A total of 155 patients who underwent GC surgery were enrolled. IAIs were observed in 12 patients (7.74%). The postoperative CRP and PCT values in the IAI group were higher than those in the non-IAI group. PCT had superior diagnostic accuracy on POD 3 (area under the curve 0.769) with an optimal cutoff value of 2.03 ng/mL, yielding 75% sensitivity, 87.4% specificity, and 97.6% negative predictive value. Multivariate analysis identified a PCT level of 2.03 mg/mL or greater on POD 3 as a significant predictive factor for IAIs after gastrectomy (odds ratio: 21.447, 95% confidence interval: 5.081-91.672).

CONCLUSIONS

PCT values less than 2.03 ng/mL on POD 3 is an excellent negative predictor of IAIs, which may ensure a safe early discharge after gastric cancer surgery.

Dexmedetomidine Improves Lung Function by Promoting Inflammation Resolution in Patients Undergoing Totally Thoracoscopic Cardiac Surgery

Objective

Totally thoracoscopic cardiac surgery under cardiopulmonary bypass combined with one-lung ventilation has been identified as the trend in cardiac surgery. The aim of this study was to examine the effects of the selective α ₂ adrenergic receptor agonist dexmedetomidine on the pulmonary function of patients who underwent mitral valve surgery using the totally thoracoscopic technique.

Methods

Fifty-seven patients who underwent thoracoscopic mitral valve surgery between July 2019 and December 2019 were selected. The patients were randomly divided into the control (Con) group (n = 28) and the dexmedetomidine (DEX) group (n = 29) using the random number table method. Arterial blood gas analyses were performed, and the oxygenation (PaO₂/FiO₂) and respiratory indexes (P(A-a)O/PaO₂) were calculated 5 min after tracheal intubation (T1), 2 h after operation (T2), 6 h after operation (T3), and 24 h after operation (T4). Moreover, the serum cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1) were detected using the enzyme-linked immunosorbent method at all time points. Chest radiography was performed 24 h after surgery. Peripheral blood samples were collected before and after the operation for a complete hemogram. Additionally, the procalcitonin concentration was measured and recorded when the patients were transported to the intensive care unit (ICU). The postoperative extubation time, length of ICU stay, and pulmonary infection rate were also recorded.

Results

Inflammatory reaction after surgery was evident. However, the inflammatory cytokines IL-6, TNF-α, and ICAM-1 in the DEX group were lower than those in the Con group after surgery (T2 to T4; P < 0.05). Neutrophil counts and procalcitonin concentration were higher in the Con group than in the DEX group (P < 0.05). In addition, in the DEX group, pulmonary exudation on chest radiography was lower, and pulmonary function, as shown by an increase in oxidation index and decrease in the respiratory index, improved after surgery (P < 0.05). Moreover, the duration of mechanical ventilation in the Con group was 3.4 h longer than that in the DEX group.

Conclusion

Dexmedetomidine has a protective effect on pulmonary function in patients undergoing mitral valve surgery using a totally video-assisted thoracoscopic technique, which may be related to a reduction in the concentration of inflammatory cytokines in the early perioperative period.

Procalcitonin as a Biomarker of Unresponsiveness to Intravenous Immunoglobulin for Kawasaki Disease

OBJECTIVE

To investigate the usefulness of procalcitonin (PCT) as predictive factors of intravenous immunoglobulin (IVIG)-resistant Kawasaki disease patients.

METHODS

We retrospectively analyzed the laboratory data from 215 children with Kawasaki disease treated with IVIG from 2014 to 2019. We analyzed the clinical and laboratory parameters just before the IVIG including serum levels of PCT with respect to the IVIG response.

RESULTS

Eventually, 127 patients were analyzed. The median age was 2.4 years. IVIG was effective in 108 children (responders) and was ineffective in 19 (non-responders). Serum PCT concentration was higher in non-responders than those of responders (P < 0.001). Multivariate logistic regression analyses indicated that higher PCT concentration (odds ratio 1.34, 95% confidence interval 1.10-1.64) were associated with IVIG resistance. Analyses of the receiver operating characteristic curve showed that the cutoff value of PCT 2.18 ng/mL had 46.4% of sensitivity and 93.9% of specificity. Receiver operating characteristic analysis yielded an area under the curve of 0.82 (0.72-0.92) to predict IVIG resistance.

CONCLUSIONS

Serum PCT value can be an excellent biomarker for predicting unresponsiveness to IVIG with a good discriminatory ability as well as the existing prediction scores.

Severe respiratory viral infection induces procalcitonin in the absence of bacterial pneumonia

INTRODUCTION

Procalcitonin expression is thought to be stimulated by bacteria and suppressed by viruses via interferon signalling. Consequently, during respiratory viral illness, clinicians often interpret elevated procalcitonin as evidence of bacterial coinfection, prompting antibiotic administration. We sought to evaluate the validity of this practice and the underlying assumption that viral infection inhibits procalcitonin synthesis.

METHODS

We conducted a retrospective cohort study of patients hospitalised with pure viral infection (n=2075) versus bacterial coinfection (n=179). The ability of procalcitonin to distinguish these groups was assessed. In addition, procalcitonin and interferon gene expression were evaluated in murine and cellular models of influenza infection.

RESULTS

Patients with bacterial coinfection had higher procalcitonin than those with pure viral infection, but also more severe disease and higher mortality (p<0.001). After matching for severity, the specificity of procalcitonin for bacterial coinfection dropped substantially, from 72% to 61%. In fact, receiver operating characteristic curve analysis showed that procalcitonin was a better indicator of multiple indices of severity (eg, organ failures and mortality) than of coinfection. Accordingly, patients with severe viral infection had elevated procalcitonin. In murine and cellular models of influenza infection, procalcitonin was also elevated despite bacteriologic sterility and correlated with markers of severity. Interferon signalling did not abrogate procalcitonin synthesis.

DISCUSSION

These studies reveal that procalcitonin rises during pure viral infection in proportion to disease severity and is not suppressed by interferon signalling, in contrast to prior models of procalcitonin regulation. Applied clinically, our data suggest that procalcitonin represents a better indicator of disease severity than bacterial coinfection during viral respiratory infection.

Effect of dexmedetomidine on inflammation in patients with sepsis requiring mechanical ventilation: a sub-analysis of a multicenter randomized clinical trial

BACKGROUND

Administration of dexmedetomidine has been reported to improve inflammatory response in animals. We explored the effects of administering dexmedetomidine on the levels of C-reactive protein (CRP) and procalcitonin, and thus on inflammation, in patients with sepsis enrolled in a randomized clinical trial.

METHODS

The DESIRE trial was a multicenter randomized clinical trial in which adult patients with sepsis were sedated with (DEX group) or without (non-DEX group) dexmedetomidine while on mechanical ventilators. As a prespecified sub-analysis, we compared CRP and procalcitonin levels during the first 14 days of treatment between the two groups. The 14-day mortality rate, albumin level, and the number of patients with disseminated intravascular coagulation (DIC) were also assessed. We used generalized linear models to estimate the differences in these outcomes between groups. We also used the Kaplan-Meier method to estimate the 14-day mortality rate and the log-rank test to assess between-group differences.

RESULTS

Our study comprised 201 patients: 100 in the DEX group and 101 in the non-DEX group. CRP and procalcitonin levels were lower in the DEX vs. non-DEX group during the 14-day treatment period [CRP-range, 5.6-20.3 vs. 8.3-21.1 mg/dL (P = 0.03); procalcitonin-range, 1.2-37.4 vs. 1.7-52.9 ng/mL (P = 0.04)]. Albumin levels were higher in the DEX group (range, 2.3-2.6 g/dL) than in the non-DEX group (range, 2.1-2.7 g/dL; P = 0.01). The percentage of patients with DIC did not significantly differ between the groups (range, 21-59% and 17-56% for the DEX and non-DEX groups, respectively; P = 0.49). The 14-day mortality rates in the DEX and non-DEX groups were 13 and 21%, respectively (P = 0.16).

CONCLUSION

Sedation using dexmedetomidine reduced inflammation in patients with sepsis requiring mechanical ventilation.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01760967 . Registered on 4 January 2013.

The value of biomarker-guided antibiotic therapy

INTRODUCTION

There is an increasing interest to individualize patient management and decisions regarding antibiotic treatment. Biomarkers may provide relevant information for this purpose.

AREAS COVERED

Despite a growing number of clinical trials investigating several biomarkers, there remain open questions regarding the best type of biomarker, timing or frequency of testing, and optimal cutoffs among others. The most promising results in regard to diagnosis of bacterial infection and therapy monitoring are found for procalcitonin (PCT), although some recent trials were not able to validate the promising earlier findings. Furthermore, less specific markers like C-reactive protein (CRP) and new prognostic biomarkers such as proadrenomedullin (MR-proADM) may improve the prognostic assessment of patients and proteomics may help shorten time to microbiological results. The aim of this review is to summarize the current concept of biomarker-guided management and provide an outlook of promising ongoing investigations.

EXPERT OPINION

'Antibiotic stewardship' is complex and needs more than just the measurement of one single biomarker. However, when integrated into the context of a thorough clinical examination, standard blood parameters and a well done risk stratification by clinical scores such as the SOFA-score, biomarkers have great potential to improve the diagnostic and prognostic assessment of patients.

Prognostic Value of Serially Estimated Serum Procalcitonin Levels in Traumatic Brain Injury Patients With or Without Extra Cranial Injury on Early In-hospital Mortality: A Longitudinal Observational Study

Background

Traumatic brain injury (TBI) is associated with majority of trauma deaths, and objective tools are required to understand the severity of injury. The application of a biomarker like procalcitonin (PCT) in TBI may allow for assessment of severity and thus aid in prognostication and correlation with mortality and outcome.

Aims

The primary objective is to determine the correlation between PCT concentrations with TBI outcomes (mainly in terms of mortality) at intensive care unit (ICU)/hospital discharge. Secondary objectives are to evaluate correlation with associated extra cranial injuries and complications during hospital stay.

Methods

In total, 186 TBI patients aged > 18 years with minimum survival for at least 12 h admitted to the ICU at the level 1 trauma center were prospectively included in the study and divided into two groups: TBI with and without extra cranial injuries. All admitted patients were treated according to the standard institutional protocol. The PCT levels were obtained on admission, on day 2, and 5. Clinical, laboratory, diagnostic, and therapeutic data were also collected. Primary mortality is defined as death related to central nervous system (CNS) injury, while secondary mortality defined as death related to sepsis or extracranial cause.

Results

Median PCT levels at admission, day 2, and day 5 in TBI patients with extracranial injuries were 3.0, 0.83, and 0.69 ng/ml. In total, primary mortality was observed in 18 (9.7%) patients, while secondary causes were attributable in 20 (12.3%) patients. Regression analysis for primarily CNS cause of mortality showed PCT cutoff level at admission more than 5.5 ng/ml carried sensitivity and specificity of 75%, but for secondary cause (sepsis) of mortality, PCT cutoff values on day 2 > 1.15 ng/ml were derived significant with sensitivity of 70% and specificity of 66%. No significant association of parameters like length of ICU stay, Glasgow outcome scale (GOS), and primary/secondary mortality with the presence of extracranial injuries in TBI patients as compared with TBI alone was noted.

Conclusion

This observational study demonstrates the poor correlation between PCT concentrations with outcome at days 1, 2, and 5 post-injury. The predicted relationship between PCT levels and outcome was not confirmed, and that these results do not support the prognostic utility of PCT biomarker in this population for outcome (mortality) assessment in TBI patients with or without extracranial injuries.

Early sepsis markers in patients admitted to intensive care unit with moderate-to-severe diabetic ketoacidosis

Background

Bacterial infections are frequent triggers for diabetic ketoacidosis. In this context, delayed antibiotic treatment is associated with increased morbidity and mortality. Unnecessary administration of antimicrobial therapy might however, also negatively impact the prognosis. The usefulness of sepsis markers in diabetic ketoacidosis has not been assessed. Thus, we sought to investigate diagnostic performances of clinical and biological sepsis markers during diabetic ketoacidosis.

Methods

In this monocentric retrospective cohort study, all consecutive episodes of diabetic ketoacidosis (defined as pH ≤ 7.25, glycaemia > 300 mg/dL and presence of ketones) admitted in intensive care unit were included. A proven bacterial infection was defined as bacteriological documentation on any bacterial sample. Clinical (presence of fever: temperature > 38 °C and presence of hypothermia: temperature < 36 °C) and biological markers (whole blood count, neutrophils count, neutrophils-to-lymphocytes count ratio and procalcitonin), recorded at admission, were compared according to the presence or absence of a proven bacterial infection.

Results

Between 2011 and 2018, among 134 episodes of diabetic ketoacidosis, 102 were included (91 patients). Twenty out of 102 were infected. At admission, procalcitonin (median: 3.58 ng/mL vs 0.52 ng/mL, p < 0.001) and presence of fever (25% vs 4%, p = 0.007) were different between episodes with and without proven bacterial infection in both univariate and multivariate analysis. Whole blood count, neutrophils count, neutrophils-to-lymphocytes count ratio and presence of hypothermia were not different between both groups. The diagnostic performance analysis for procalcitonin revealed an area under the curve of 0.87 with an optimal cutoff of 1.44 ng/mL leading to a sensitivity of 0.90 and a specificity of 0.76. Combining procalcitonin and presence of fever allowed to distinguish proven bacterial infection episodes from those without proven bacterial infection. Indeed, all patients with procalcitonin level of more than 1.44 ng/mL and fever had proven bacterial infection episodes. The presence of one of these 2 markers was associated with 46% of proven bacterial infection episodes. No afebrile patient with procalcitonin level less than 1.44 ng/mL had a proven bacterial infection.

Conclusion

At admission, combining procalcitonin and presence of fever may be of value to distinguish ketoacidosis patients with and without proven bacterial infection, admitted in intensive care unit.

Urinary [TIMP-2] × [IGFBP7] and serum procalcitonin to predict and assess the risk for short-term outcomes in septic and non-septic critically ill patients

BACKGROUND

Biomarkers can play a critical role by facilitating diagnosis and stratification of disease, as well as assessment or prediction of disease severity. Urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 product ([TIMP-2] × [IGFBP7]) predict the development and progression of AKI and recently procalcitonin (PCT), a widely used biomarker for sepsis diagnosis and management, has been associated with AKI occurrence in ICU patients. To assess combinations of [TIMP-2] × [IGFBP7] and PCT results for prediction and risk stratification of short-term outcomes in septic and non-septic patients, a retrospective cohort analysis of critically ill patients was performed in a multidisciplinary ICU. ROC curve analysis was used in order to evaluate predictive performance of combined results of [TIMP-2] × [IGFBP7] and PCT at the time of admission for AKI development. To verify the utility of adding [TIMP-2] × [IGFBP7] and PCT results for risk assessment, we evaluated the predictive value of having a single-marker positivity compared to a double-marker positivity using the widely used cut-off of 0.3 (ng/mL)²/1000 for [TIMP-2] × [IGFBP7] and 0.5 μg/L for PCT. Risk assessment for AKI occurrence within 48 h, acute kidney disease (AKD) and mortality at 7 days was performed by logistic/Cox regression analysis.

RESULTS

433 patients were analysed, of whom 168 had AKI within 48 h (93 septic and 65 non-septic patients). Combination of [TIMP-2] × [IGFBP7] and PCT showed a good predictive ability for AKI occurrence (AUC 0.81, 95% CI 0.77-0.86, p < 0.001, Sens 78%, Spec 73%). Combinations of biomarkers increased the odd ratios (OR) considerably. A single-marker positivity showed a fourfold risk increase, while the double-marker positivity a 26-fold risk increase for AKI occurrence. Moreover, the double-marker positivity showed an elevated risk for AKD at 7 days in non-septic patients (OR 15.9, 95% CI 3,21-73,57, p < 0.001) and for mortality within 7 days in septic patients (HR 4.1, 95% CI 1.4-11.8, p = 0.001).

CONCLUSIONS

Although combining the results of [TIMP-2] × [IGFBP7] and PCT may be a useful tool to identify and stratify ICU patients at high risk for septic AKI and short-term adverse outcomes, data should be confirmed in a large prospective study.

Presepsin values as markers of severity of sepsis

OBJECTIVES

Biomarkers are widely used for rapid diagnosis of sepsis. This study evaluated the diagnostic accuracy of presepsin, procalcitonin (PCT), and C-reactive protein (CRP) in differentiating sepsis severity as well as their association with Sepsis-related Organ Failure Assessment (SOFA) score.

METHODS

One hundred septic patients from two university clinical centers were enrolled in the study during two time periods. New Sepsis-3 definitions were used for sepsis stratification. Biomarkers and SOFA score were evaluated four times during the illness. A sandwich ELISA kit was used for presepsin measurement. Generalized linear mixed effects model was used to test the changes in biomarkers concentrations and SOFA score values during the illness and to estimate the differences between severity groups. Multivariate analysis was used to test the association of biomarkers with SOFA score.

RESULTS

Presepsin concentrations were significantly higher on admission in patients with septic shock (n = 34) compared to patients with sepsis (n = 66), mean ± SD: 128.5 ± 47.6 ng/mL vs. 88.6 ± 65.6 ng/mL, respectively (p < 0.001). The same was not observed for PCT and CRP; their concentrations did not differ significantly between severity groups. A strong correlation of presepsin with SOFA score was also found (p < 0.0001).

CONCLUSIONS

Presepsin had a good diagnostic ability to differentiate septic shock from sepsis in the study groups. PCT and CRP failed in differentiating sepsis severity.

Procalcitonin and Conventional Markers of Inflammation in Peritoneal Dialysis Patients and Peritonitis

Objectives

To determine the significance of a newly described marker of inflammation procalcitonin (PCT), and to investigate its relationship to conventional markers of inflammation, such as C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR), in patients on peritoneal dialysis (PD) and with peritonitis.

Design

A prospective, observational clinical study.

Setting

The Nephrology Division of a University-affiliated teaching hospital.

Patients and Methods

51 consecutive patients on PD were included in the study. Of this number, 16 developed peritonitis during the observational period. Baseline PCT, CRP, and fibrinogen concentrations and ESR of 51 PD patients were determined at a time point (TB) prior to any evidence of infection. These results were compared with laboratory values from 74 hemodialysis patients and 34 nonuremic control subjects. All PD patients then were followed prospectively for evidence of peritonitis. In addition to routine blood tests, including hemoglobin and leukocyte count, and routine biochemical tests, blood samples were taken to measure PCT, CRP, and fibrinogen concentrations and ESR at the time (T0) when patients first were diagnosed with PD peritonitis and also on the 4th (T4) and the 14th (T14) days after treatment for peritonitis was initiated. PCT was assayed by immunoluminometry.

Results

No significant difference was observed between baseline median serum PCT concentrations in PD and hemodialysis patients; however, in both groups, baseline median PCT concentrations were significantly higher than those of nonuremic controls ( p < 0.05). The 16 patients on PD who developed peritonitis had 21 PD peritonitis episodes during the study period. The increased PCT concentration observed at T0 in PD peritonitis episodes decreased with therapy, and this change was statistically significant ( p < 0.05). In a receiver operating characteristic curve analysis for peritonitis, the area under the curve (AUC) for PCT was 0.80, which was significantly lower than the AUC for CRP and greater than the AUCs for fibrinogen and ESR. The sensitivity of PCT for peritonitis was lower than the sensitivity of conventional markers of inflammation; however, the specificity of PCT was higher.

Conclusions

Median serum PCT concentration in PD patients was significantly higher than in nonuremic controls but not hemodialysis patients. Serum PCT concentrations may serve as a useful adjunct to traditional markers of inflammation in detecting and monitoring inflammation and peritonitis in PD patients.

Elevated procalcitonin levels in patients with acetaminophen intoxication: two case reports: A CARE-compliant article

RATIONALE

Procalcitonin (PCT) is used as a biomarker for identifying the occurrence of sepsis. Previous studies have reported high levels of PCT with acetaminophen intoxication without evidence of infection. Here, we report two patients with acetaminophen intoxication with high levels of PCT without showing any symptoms of bacterial infection.

PATIENT CONCERNS

This case study examined two unrelated patients with acetaminophen intoxication admitted to emergency at different times. The first patient was admitted to the emergency department after ingesting approximately 8000 mg (153.8 mg/kg) of acetaminophen. On admission, C-reactive protein (CRP), glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) were normal. PCT and acetaminophen levels were 31.89 ng/mL and below 0.5 μg/mL, respectively. The second patient was admitted to the emergency department 8 h after ingesting ∼23,600 mg (280.6 mg/kg) of acetaminophen. By the second day of admission, GOT and GPT increased to 2508 and 1473 IU/L, respectively. PCT was 45.66 ng/mL with acetaminophen level at 116.9 μg/mL. Both patients were clear of symptoms associated with bacterial infection.

DIAGNOSIS

Acetaminophen intoxication.

INTERVENTIONS

N-acetylcysteine was given intravenously to both patients for 20 h per protocol.

OUTCOMES

Both patients were discharged without complications.

LESSONS

Observations suggests that elevated levels of PCT in patients intoxicated with acetaminophen may be associated with involvement of other organs impacted by cytokine stimuli from sterile inflammation resulting from hepatic damage rather than PCT secretion directly caused by hepatic cell damage.

Procalcitonin in respiratory disease: use as a biomarker for diagnosis and guiding antibiotic therapy

Procalcitonin (PCT) is a peptide measurable in serum which becomes elevated in response to bacterial infection. Multiple trials have explored the safety and efficacy of using PCT as a biomarker to guide decisions about starting or stopping antibiotic therapy in a wide variety of situations, and PCT assays have recently been approved by the Federal Drug Administration (FDA) in the US for use in both sepsis and respiratory tract infections. While there have been a number of promising results particularly in acute respiratory tract infections and intensive care unit settings, problems including adherence to protocol, cost of the assay and improved antimicrobial stewardship more generally, have limited more widespread adoption.

This educational article summarises the evidence for the use of procalcitonin as a biomarker of bacterial infection across the spectrum of respiratory disease and reviews how the use of procalcitonin-guided antibiotic therapy is reflected in current major international guidelines.

Procalcitonin has been widely investigated as a biomarker of bacterial infection to aid diagnosis and decisions to start or stop antibiotics in a range of conditions, including in diseases of the lower respiratory tracthttp://bit.ly/2ZgDwNO

The detection of bacterial infections in leukemia patients using procalcitionin levels

Bacteremic infections are the most common complications in patients with leukemia. This study aimed to assess the value of procalctionin levels in the detection of bacterial infections in leukemia patients. Blood samples of in-patients with leukemia were collected. Statistical analysis was performed to assess the correlation between the procalcitionin level on the day of the first positive blood culture and bacteremic infection. Infected patients had significantly higher procalctionin levels than uninfected patients (p < 0.001). Receiver operating characteristic curve analysis showed a high level of accuracy regarding the discrimination of bacterarmic infection (area under the curve, 0.883) and Gram-negative bateremia (area under the curve, 0.779). Procalctionin levels may help in the identification of bacterial infections in leukemia patients. Further multicentre studies are needed to verify our data regarding the use of procalctionin to distinguish between Gram-positive and Gram-negative infections.

Overview of procalcitonin in pregnancy and in pre-eclampsia

Procalcitonin (PCT), a precursor for calcitonin, is a prohormone involved in the inflammatory processes, which has been poorly studied in the context of pregnancy. During severe inflammation, PCT derives from almost all cell types, including monocytes and parenchymal tissues, making it a good predictive and diagnostic marker of an inflammatory state with rapidly increased serum levels in inflammation or sepsis. In normal pregnancy, PCT is basally expressed at very low level by decidual cells, even if decidual macrophages, which in normal pregnancy are skewed to M2 macrophages, are resistant to lipopolysaccharide (LPS)-induced production of PCT. As PCT increase is associated with an inflammatory state, several research groups investigated whether PCT can be considered a marker of pre-eclampsia, a pregnancy disease characterized by systemic inflammation. The first aim of this review is to summarize what is already known about the tissues synthesizing PCT, about the stimuli that cause the increase of circulating PCT levels and how PCT acts as a proinflammatory stimulus by itself. Secondly, we will describe the role of this prohormone in normal pregnancy and in pregnancies complicated by pre-eclampsia, highlighting the involvement of the decidual macrophages and the proinflammatory cytokine tumor necrosis factor-α in the modulation of PCT expression in the decidual microenvironment.

The clinical significance of interleukin-6 in heart failure: results from the BIOSTAT-CHF study

AIMS

Inflammation is a central process in the pathophysiology of heart failure (HF), but trials targeting tumour necrosis factor (TNF)-α were largely unsuccessful. Interleukin (IL)-6 is an important inflammatory mediator and might constitute a potential pharmacologic target in HF. However, little is known regarding the association between IL-6 and clinical characteristics, outcomes and other inflammatory biomarkers in HF. We thus aimed to identify and characterize these associations.

METHODS AND RESULTS

Interleukin-6 was measured in 2329 patients [89.4% with a left ventricular ejection fraction (LVEF) ≤ 40%] of the BIOSTAT-CHF cohort. The primary outcome was all-cause mortality and HF hospitalization during 2 years, with all-cause, cardiovascular (CV), and non-CV death as secondary outcomes. Approximately half (56%) of all included patients had plasma IL-6 values greater than the previously determined 95th percentile of normal values at baseline. Elevated N-terminal pro-brain natriuretic peptide, procalcitonin and hepcidin, younger age, TNF-α/IL-1-related biomarkers, or having iron deficiency, atrial fibrillation and LVEF > 40% independently predicted elevated IL-6 levels. IL-6 independently predicted the primary outcome [HR (95% confidence interval) per doubling: 1.16 (1.11-1.21), P < 0.001], all-cause mortality [1.22 (1.16-1.29), P < 0.001] and CV as well as non-CV mortality [1.16 (1.09-1.24), P < 0.001; 1.31 (1.18-1.45), P < 0.001], but did not improve discrimination in previously published risk models.

CONCLUSIONS

In a large, heterogeneous cohort of HF patients, elevated IL-6 levels were found in more than 50% of patients and were associated with iron deficiency, reduced LVEF, atrial fibrillation and poorer clinical outcomes. These findings warrant further investigation of IL-6 as a potential therapeutic target in specific HF subpopulations.

Serum procalcitonin levels predict acute kidney injury in critically ill patients

AIM

To determine whether admission procalcitonin (PCT) was associated with the subsequent development of acute kidney injury (AKI) in a general population of critically ill patients.

METHODS

The study was a retrospective observational study conducted in a multidisciplinary intensive care unit (ICU) over a period of 1 year. Adult patients who had a PCT performed on admission and who did not have chronic kidney disease (CKD) or AKI on admission, were evaluated for the development of AKI within the first week of ICU admission, according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The association between PCT on admission and the development of AKI was explored for the entire cohort and for septic and non-septic subgroups.

RESULTS

Two hundred and one patients were included in the study. The incidence of AKI in the first 7 days of ICU admission was 36.8%. PCT, age, the presence of shock on admission, and sepsis were significantly associated with AKI on univariate analysis. Multivariable analysis of the entire cohort revealed that age, shock and sepsis remained independent predictors of AKI, while PCT was no longer significant. When the septic and non-septic patients were analyzed separately a PCT ≥10 ng/mL remained the only significant predictor of AKI in the non-septic patients (OR 4.430; 95% CI 1.464-13.399), but was not an independent predictor of AKI in septic patients.

CONCLUSION

The main finding of this study was the significant association of an elevated PCT on admission with the development of AKI in the non-septic patient. An elevated PCT in a non-septic patient identifies a patient at increased risk of AKI. PCT requires further study as a novel biomarker of AKI in non-septic patients.

Validity of biomarkers in screening for neonatal sepsis - A single center -hospital based study

BACKGROUND

The diagnosis of neonatal sepsis still considered to be a challenge for both clinicians and the laboratory due to the non-specific clinical presentations. The present study aimed to compare and assess the diagnostic & prognostic values of C-reactive protein (CRP), high sensitivity CRP (hsCRP), presepsin, interleukin-6 (IL-6) and procalcitonin (PCT) in neonatal sepsis separately and in combination.

METHODS

This hospital-based cross-sectional study has been conducted on 168 neonates recruited from the neonatal intensive care unit (NICU) of Qena University Hospitals, Upper Egypt. Measurements of CRP using latex agglutination test, hsCRP, presepsin, IL6 and PCT assays using commercially available ELISA assay kits were done to all included neonates.

RESULTS

There were significantly higher serum levels of CRP among late onset versus early onset sepsis group with significantly higher serum levels of hsCRP and presepsin among early onset compared with the late onset sepsis group (p < 0.05 for all). There were significantly higher hsCRP, presepsin and PCT serum levels in proven versus probable sepsis group (p < 0.05 for all). Significantly higher serum levels of presepsin and PCT were noted among survivors versus non survivors sepsis group (p < 0.05 for all). The cutoff value of the serum level of CRP >6 mg/dl showed lower sensitivity and specificity than that of hsCRP at cutoff >140 ng/ml in diagnosing neonatal sepsis. The cutoff value of presepsin >200 ng/ml showed equal sensitivity and specificity to IL-6 at cutoff >22 pg/ml. The cutoff value of PCT at > 389 pg/ml showed sensitivity and specificity approximate to that of hsCRP.

CONCLUSIONS

CRP could be a helpful prognostic marker in late onset neonatal sepsis. hsCRP and PCT have higher diagnostic accuracy in neonatal sepsis in comparison to other studied markers. Both IL-6 and presepsin have equal diagnostic utility in neonatal sepsis, but presepsin could be helpful diagnostic marker in early onset neonatal sepsis.

Tissue inhibitor metalloproteinase-2 (TIMP-2) • IGF-binding protein-7 (IGFBP7) levels are associated with adverse outcomes in patients in the intensive care unit with acute kidney injury

The G1 cell cycle inhibitors tissue inhibitor metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) have been identified as novel biomarkers for the prediction of moderate to severe acute kidney injury (AKI) risk. However, the prognostic value of [TIMP-2]•[IGFBP7] in predicting adverse outcomes in intensive care unit (ICU) patients with AKI was not previously described. To evaluate this, we conducted a cohort study, measuring [TIMP2]•[IGFBP7] levels in critically ill patients admitted to the ICU and classified the patients as NephroCheck (NC) (+) or NC (-) according to [TIMP-2]•[IGFBP7] values and AKI (+) or AKI (-) according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. We then evaluated the incidence of continuous renal replacement therapy initiation, all-cause mortality and a composite endpoint of both in the four groups. Baseline [TIMP-2]•[IGFBP7] values were available for 719 patients, of whom 239 developed AKI and 151 met the composite endpoint. Compared to NC (-)/AKI (+) patients, NC (+)/AKI (+) patients had a significant risk of ICU mortality and the composite endpoint. Kaplan-Meier curves showed that the survival estimate for the composite endpoint of NC (+)/AKI (+) patients was 34.4%; significantly worse than NC (-)/AKI (+) patients (67.4%). Multivariate analyses showed strong association between NC positivity and the composite endpoint. The inflammatory marker, procalcitonin, was an additional prognostic biomarker to compare and confirm the incremental value of NephroCheck. No association between procalcitonin and the composite endpoint was found, especially in patients with AKI, suggesting that NephroCheck may be more kidney specific. Thus, the [TIMP-2]•[IGFBP7] values can serve to identify patients with AKI at increased risk for adverse outcomes in the ICU.

Procalcitonin as a Biomarker in Rhinosinusitis: A Systematic Review

OBJECTIVES

(1) To describe the existing literature on procalcitonin (PCT) as a biomarker in patients with acute rhinosinusitis (ARS), (2) to analyze outcomes in ARS patients who were treated with PCT-guided therapy versus traditional management, and (3) to compare PCT to other biomarkers used in diagnosis of bacterial ARS. Data Sources: PubMed and Embase. Review Methods: A systematic search in the PubMed and Embase databases was performed to identify studies related to PCT as a biomarker in ARS. After critical appraisal of validity by 2 authors, 6 studies with a total of 313 patients were selected for data extraction and analysis. We identified 2 randomized control trials (RCTs) of PCT-based guidelines for antibiotic management of ARS in outpatient settings and 4 observational studies that compared PCT to other biomarkers in patients with ARS.

RESULTS

The 2 RCTs demonstrated a reduction (41.6% in 1 study and 71% in the other) in antibiotic prescription rate in the PCT-guided group versus the control group with no change in the number of days with impaired activity due to illness (9.0 vs 9.0 days [ P = .96]; 8.1 vs 8.2 days [95% confidence interval -0.7 to 0.7]), number of days of work missed, and percentage of patients with persistent symptoms at 28 days. In the observational cohort studies, PCT did not consistently correlate with C-reactive protein, body temperature, and/or white blood cell counts.

CONCLUSIONS

The limited existing literature on the role of PCT in diagnosis, management, and prediction of clinical outcomes in ARS suggests that PCT-based guidelines for antibiotic prescription are a safe and effective method of minimizing unnecessary antibiotic use.

Value of procalcitonin as a marker of surgical site infection following spinal surgery

AIM

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

METHODS

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

RESULTS

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

CONCLUSION

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.

Combination of procalcitonin, C-reaction protein and carcinoembryonic antigens for discriminating between benign and malignant pleural effusions

Pleural effusion (PE) is a common manifestation associated with certain chest diseases. However, there is no effective diagnostic marker with high sensitivity and specificity. The aim of the present study was to evaluate the diagnostic performance of several biomarkers in the use of detecting malignant pleural disorder. One hundred and fifty patients with a specific diagnosis of exudative PE were enrolled in this study and were divided into the benign PE group (n=93) and the malignant PE group (n=57). Thoracoscopy was conducted to identify the reasons for the PE. Biomarkers in pleural fluid and in sera were determined either by microparticle enzyme immunoassay [carcinoembryonic antigen (CEA)], fluorescence immunoassay [procalcitonin (PCT)] or light-scattering turbidimetric immunoassay [C-reaction protein (CRP)]. Then, correlation analysis and receiver-operating characteristic (ROC) curve analysis individually or in combination were performed. The CRP and PCT levels were higher in benign PE than they were in malignant PE (PCT: P=0.017, P=0.032; CRP: P=0.001, P<0.001, respectively), while CEA levels were lower in benign PE than in malignant PE (CEA: P=0.001, P=0.001, respectively). During the ROC curve analysis, an optimal discrimination was identified by combining pleural CRP, pleural CEA and serum (s)PCT with an area under the curve of 0.973 (sensitivity, 98.9%; specificity, 89.5%). In the diagnosis of PE, there was no single biomarker that appeared to be adequately accurate. The combination of pleural CRP, pleural CEA and sPCT may represent an efficient diagnostic procedure for guiding the patient towards follow-up clinical treatment.

Expression of the Long Intergenic Non-Coding RNA (lincRNA) of the NED25 Gene Modulates the microRNA-125b, STAT3, Nitric Oxide, and Procalcitonin Signaling Pathways in Patients with Sepsis

Background

The aim of this study was to investigate the long intergenic non-coding RNA (lincRNA) of the NED25 gene, and the microRNA (miR)-125b, STAT3, nitric oxide (NO), and procalcitonin (PCT) pathway in sepsis.

Material/Methods

Seventy-five age-matched and sex-matched patients were divided into three groups: 25 patients with sepsis only; 25 patients with septic shock; and 25 healthy control subjects. Computational analysis and a luciferase assay confirmed that the STAT3 and PCT genes were target genes of miR-125b, whereas the lincRNA of the NED25 gene was validated as an endogenous lincRNA competing with miR-125b for binding to STAT3 and PCT. Real-time polymerase chain reaction (PCR) and Western blot measured the expression of miR-125b, STAT3, and PCT in peripheral blood monocytes (PBM) transfected with miR-125b mimics, miR-125b inhibitors, or small interfering (siRNA).

Results

The expression of miR-125b, the PCT position ratio, the expression of PCT mRNA and protein were increased when compared with healthy individuals. When compared with the siRNA negative control, miR-125b and the lincRNA of the NED25 gene mimics, as well as STAT3 siRNA significantly downregulated the mRNA and protein expression of STAT3 and PCT; mRNA and protein expression of STAT3 and PCT in cells transfected with miR-125b inhibitors were significantly increased. Intracellular nitric oxide (NO) production was upregulated by miR-125b inhibitors and downregulated by miR-125b mimics or siRNA.

Conclusions

Downregulation of the lincRNA of the NED25 gene was associated with sepsis in patients by modulating the signaling pathways downstream of miR-125b/STAT3/PCT/NO signaling pathway.