Procalcitonin: present and future

Diagnostic value of procalcitonin and red blood cell distribution width at admission on the prognosis of patients with severe burns: A retrospective analysis

The plasma procalcitonin (PCT) concentration and red blood cell distribution (RDW) value after severe burns can be used as prognostic indicators, but at present, it is difficult to give consideration to sensitivity and specificity in diagnosing the prognosis of severe burns with a single indicator. This study analysed the diagnostic value of plasma PCT concentration and RDW value at admission on the prognosis of severe burn patients to improve its sensitivity and specificity. A total of 205 patients with severe burns who were treated in the First Affiliated Hospital of Anhui Medical University from November 2017 to November 2022 were retrospectively analysed. The optimal cut-off values of plasma PCT concentration and RDW were analysed and counted through the subject curve (ROC curve). According to the cut-off value, patients were divided into high PCT group and low PCT group, high RDW group and low RDW group. The independent risk factors of severe burns were analysed by single-factor and multiple-factor COX regression. Kaplan-Meier survival was used to analyse the mortality of high PCT group and low PCT group, high RDW group and low RDW group. The area under the curve of plasma PCT concentration and RDW value at admission was 0.761 (95% CI, 0.662-0.860, P < .001), 0.687 (95% CI, 0.554-0.820, P = .003) respectively, and the optimal cut-off values of serum PCT concentration and RDW were 2.775 ng/mL and 14.55% respectively. Cox regression analysis found that age, TBSA, and RDW were independent risk factors for mortality within 90 days after severe burns. Kaplan-Meier survival analysis showed that there was a significant difference in the 90-day mortality rate of severe burns between the PCT ≥ 2.775 ng/mL group and the PCT < 2.775 ng/mL group (log-rank: 24.162; P < .001), with the mortality rate of 36.84% versus 5.49%, respectively. The 90-day mortality rate of severe burns was significantly different between the RDW ≥ 14.55% group and the RDW < 14.55% group (log-rank: 14.404; P < .001), with the mortality rate of 44% versus 12.2% respectively. The plasma PCT concentration and RDW value at admission are both of diagnostic value for the 90-day mortality of severe burns, but the plasma PCT concentration has higher sensitivity and the RDW value has higher specificity. Age, TBSA, and RDW were independent risk factors for severe burns, and then plasma PCT concentration was not independent risk factors.

Changes in salivary biomarkers of stress, inflammation, redox status, and muscle damage due to Streptococcus suis infection in pigs

BACKGROUND

Streptococcus suis (S. suis) is a Gram-positive bacteria that infects pigs causing meningitis, arthritis, pneumonia, or endocarditis. This increases the mortality in pig farms deriving in severe economic losses. The use of saliva as a diagnostic fluid has various advantages compared to blood, especially in pigs. In this study, it was hypothesized that saliva could reflect changes in different biomarkers related to stress, inflammation, redox status, and muscle damage in pigs with S. suis infection and that changes in these biomarkers could be related to the severity of the disease.

RESULTS

A total of 56 growing pigs from a farm were selected as infected pigs (n = 28) and healthy pigs (n = 28). Results showed increases in biomarkers related to stress (alpha-amylase and oxytocin), inflammation (haptoglobin, inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), total protein, S100A8-A9 and S100A12), redox status (advanced oxidation protein producs (AOPP)) and muscle damage (creatine kinase (CK), CK-MB, troponin I, lactate, aspartate aminotransferase, and lactate dehydrogenase). An increase in adenosine deaminase (ADA), procalcitonin, and aldolase in infected animals were also observed, as previously described. The grade of severity of the disease indicated a significant positive correlation with total protein concentrations, aspartate aminotransferase, aldolase, and AOPP.

CONCLUSIONS

This report revealed that S. suis infection caused variations in analytes related to stress, inflammation, redox status, and muscle damage in the saliva of pigs and these can be considered potential biomarkers for this disease.

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.

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.

Measurement of procalcitonin in saliva of pigs: a pilot study

Background

Procalcitonin (PCT) is a widely used biomarker of sepsis in human medicine and can have potential applications in the veterinary field. This study aimed to explore whether PCT could be measured in the saliva of pigs and whether its concentration changes in sepsis. Therefore, a specific assay was developed and analytically validated, and changes in PCT concentration were evaluated in two conditions: a) in an experimental model of sepsis produced by the administration of lipopolysaccharide (LPS) to pigs (n = 5), that was compared with a model of non-septic inflammation induced by turpentine oil (n = 4), and b) in healthy piglets (n = 11) compared to piglets with meningitis (n = 20), a disease that usually involves sepsis and whose treatment often requires large amounts of antibiotics in farms.

Results

The assay showed coefficients of variation within the recommended limits and adequate linearity after serial sample dilutions. The method's detection limit was set at 68 μg/L, and the lower limit of quantification was 414 μg/L. In the LPS experiment, higher concentrations of PCT were found after 24 h in the animals injected with LPS (mean = 5790 μg/L) compared to those treated with turpentine oil (mean = 2127 μg/L, P = 0.045). Also, animals with meningitis had higher concentrations of PCT (mean = 21515 μg/L) than healthy pigs (mean = 6096 μg/L, P value < 0.0001).

Conclusions

According to these results, this assay could be potentially used as a tool for the non-invasive detection of sepsis in pigs, which is currently a topic of high importance due to antibiotic use restriction.

Inflammatory markers in clinical practice

Inflammation is the general defense response of the body against various harmful irritations. Diagnosis of the inflammatory process and monitoring of its treatment is based on a combination of clinical and laboratory findings. Biochemical inflammatory markers usually serve to support the diagnosis of the infection, to monitor it, and to monitor the effectiveness of anti-infective treatment. The inflammatory marker should be selected according to the clinical condition with regard to the treachery and deficiencies of the markers, with knowledge of their dynamics and with regard to the length of the anamnesis. As an optimal procedure for detecting bacterial infection, it is recommended to screen for several acute phase proteins. The role of the physician is to determine when, under which circumstances, and which markers to have examined, with a view to ensuring that the patient is correctly diagnosed in time and receives appropriate treatment, and on the other hand, that he is not unnecessarily iatrogenized and that the medical facility does not lose money unnecessarily.

Clinical utility of procalcitonin and its association with pathogenic microorganisms

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

Procalcitonin 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.

Relationships between serum procalcitonin level, severity and different stresses of non-septic critically ill patients

Background: To explore the relationships between serum procalcitonin (PCT) level, severity and different stresses of non-septic critically ill patients.

Materials and Methods: Patients were divided into traumatic stress, stroke-induced stress and non-infectious inflammatory stress groups. According to 28-day prognosis, they were divided into survival and death groups. The factors affecting prognosis were studied by multivariate logistic regression analysis.

Results: PCT level was significantly positively correlated with Acute Physiology and Chronic Health Evaluation II (APACHE II) and sequential organ failure assessment (SOFA) scores (P=0.001). The PCT level and abnormality rate of the traumatic stress group significantly exceeded those of other groups (P---lt---0.05). The APACHE II score, SOFA score and 28-day mortality rate of traumatic stress and stroke-induced stress groups significantly exceeded those of the non-infectious inflammatory stress group (P---lt---0.05). The PCT level, APACHE II score and SOFA score of the death group significantly surpassed those of the survival group (P---lt---0.05). With rising PCT level, APACHE II score, SOFA score and 28-day mortality rate all increased, with significant intergroup differences (P---lt---0.01). Multivariate logistic analysis showed that serum PCT level, APACHE II score and SOFA score were independent risk factors for prognosis. The area under ROC curve for prognosis evaluated by PCT level was 0.797 (95%CI = 0.710~0.878, P=0.000). At a 4.3 μg/L cut-off, the sensitivity and specificity for predicting 28-day mortality were 87.4% and 78.1%, respectively.

Conclusion: The serum PCT level of non-septic critically ill patient was positively correlated with severity, which was more likely elevated by traumatic stress than other stresses.

A preliminary study: the role of preoperative procalcitonin in predicting postoperative fever after mini-percutaneous nephrolithotomy in patients with a negative baseline urine culture

To evaluate the role of preoperative procalcitonin (PCT) levels in predicting postoperative fever after mini-percutaneous nephrolithotomy (mini-PCNL) in patients with a negative baseline urine culture. Between January 2014 and October 2017, 329 patients with a negative baseline urine culture and who underwent mini-PCNL were enrolled in this study. Patients were stratified into the control or febrile group based on a body temperature either less than or greater than 38 °C, respectively. Demographic and perioperative data were compared between the groups, and variables found to be statistically significant were included in a binary logistic regression analysis. A total of 68 (20.6%) patients experienced postoperative fever. The univariate analysis revealed a statistically significant difference between groups in preoperative fever (p = 0.032), stone burden (p < 0.001), C-reactive protein (p = 0.011), PCT (p < 0.001) and interleukin-6 (p = 0.035) levels. Binary logistic regression analysis indicated that stone burden > 353 mm³ (p = 0.003) and PCT > 0.05 ng/mL (p < 0.001) are independent risk factors for postoperative fever in mini-PCNL-treated patients with a negative baseline urine culture. We concluded that patients with stone burden > 353 mm³ or PCT > 0.05 ng/mL were more likely to develop postoperative fever after mini-PCNL, though with a negative baseline urine culture.

Extended-spectrum β-lactamase-producing E. coli septicemia among rectal carriers in the ICU

The aim of this study was to identify risk factors for extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E coli) bloodstream infection (BSI) among carriers hospitalized between March 2011 and June 2016 at the ICU of the West China Hospital.The cases were patients with at least 1 episode of ESBL-producing E coli BSI within 1 week after a positive rectal swab. Controls were selected randomly 1:2 among ESBL-producing E coli rectal carriers who did not develop BSI.Among 19,429 ICU patients, 9015 (46.4%) had a positive rectal swab for ESBL-producing E coli. Of them, 42 (0.5%) were diagnosed with ESBL-producing E coli BSI. The in-hospital mortality was higher for the BSI patients compared with controls (19.1% vs. 6.0%, P = .031). In the past 72 hours, patients in case group were more likely to use penicillin (odds ratio [OR] = 12.076; 95% confidence interval [CI]: 1.397-104.251, P = .02), cephalosporin (OR = 6.900; 95% CI: 1.493-31.852, P = .01), and carbapenem (OR = 5.422; 95% CI: 1.228-23.907, P = .03) as compared to patients in control group. Also, when compared to patients in control group, patients in case group were likely to stay for a longer time in ICU before positive rectal swab test (OR = 1.041, 95% CI: 1.009-1.075, P = .01) and have higher maximum body temperature before positive rectal swab (OR = 8.014; 95% CI: 2.408-26.620, P = .001).Bacteremia owing to ESBL-producing E coli was associated with high antimicrobial exposure, hospital stay, and maximum body temperature.

Procalcitonin in heart failure: hic et nunc

Although procalcitonin (PCT) was evaluated for the first time in the setting of heart failure (HF) in 1999, its utility in HF patients is still under examination. Patients with HF have significantly higher plasma PCT concentrations than healthy subjects and PCT levels are associated with severity of HF. It has been confirmed that higher levels of PCT are associated with worse outcomes, such as increased mortality and higher rate of rehospitalization, in HF patients with no evidence of infection. Furthermore, it has been approved that PCT-guided antibiotic treatment in HF patients reduces duration of antibiotic therapy and improves outcomes. This review summarizes current evidence from the published literature of the usefulness and limitations of PCT as a biomarker in HF.

Cell-free deoxyribonucleic acid as a prognostic marker of bowel ischemia in patients with small bowel obstruction

BACKGROUND

Patients with strangulation small bowel obstruction are at a high risk for serious morbidity and mortality due to ischemic bowel. Measuring serum, cell-free deoxyribonucleic acid levels could help recognize early cell death. Our hypothesis was that small bowel ischemia or necrosis is associated with increases in serum cell-free deoxyribonucleic acid and that recovery is associated with a decrease in cell-free deoxyribonucleic acid levels.

METHODS

A prospective cohort study in addition to standard treatment of patients admitted with a diagnosis of small bowel obstruction. The participants were divided into groups depending on the presence of ischemic or necrotic bowel according to operative and clinical outcome. Clinical data and serum-based cell-free deoxyribonucleic acid levels were compared. Cell-free deoxyribonucleic acid levels from these 2 groups also were compared with a third group of healthy controls.

RESULTS

In the study, 58 patients were enrolled, and 18 patients (31%) underwent operation. During the operative procedure, ischemic or necrotic bowel was found in 10 cases (17%). Serum levels of cell-free deoxyribonucleic acid at the time of admission in the ischemic/necrotic bowel group were increased compared with patients with well perfused or spontaneously recovered bowel (P = .03). Cell-free deoxyribonucleic acid levels decreased on the day after admission in 88% of the nonoperated patients. No significant differences were found in demographics, medical background, imaging performed, and cause of obstruction nor in clinical admission data.

CONCLUSION

Surgeons currently rely on imprecise clinical parameters, including degree of pain, abdominal tenderness, leukocytosis etc to decide when operative intervention is needed. The association of cell-free deoxyribonucleic acid with small bowel obstruction, ischemia, and recovery supports our hypothesis and suggests that this biomarker is a potential surrogate of small bowel perfusion.

Serum Procalcitonin and Peripheral Venous Lactate for Predicting Dengue Shock and/or Organ Failure: A Prospective Observational Study

Background

Currently, there are no biomarkers that can predict the incidence of dengue shock and/or organ failure, although the early identification of risk factors is important in determining appropriate management to reduce mortality. Therefore, we sought to determine the factors associated with dengue shock and/or organ failure and to evaluate the prognostic value of serum procalcitonin (PCT) and peripheral venous lactate (PVL) levels as biomarkers of dengue shock and/or organ failure.

Methodology/Principal Findings

A prospective observational study was conducted among adults hospitalized for confirmed viral dengue infection at the Hospital for Tropical Diseases in Bangkok, Thailand between October 2013 and July 2015. Data, including baseline characteristics, clinical parameters, laboratory findings, serum PCT and PVL levels, management, and outcomes, were recorded on pre-defined case report forms. Of 160 patients with dengue, 128 (80.0%) patients had dengue without shock or organ failure, whereas 32 (20.0%) patients developed dengue with shock and/or organ failure. Using a stepwise multivariate logistic regression analysis, PCT ≥0.7 ng/mL (odds ratio [OR]: 4.80; 95% confidence interval [CI]: 1.60–14.45; p = 0.005) and PVL ≥2.5 mmol/L (OR: 27.99, 95% CI: 8.47–92.53; p <0.001) were independently associated with dengue shock and/or organ failure. A combination of PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L provided good prognostic value for predicting dengue shock and/or organ failure, with an area under the receiver operating characteristics curve of 0.83 (95% CI: 0.74–0.92), a sensitivity of 81.2% (95% CI: 63.6–92.8%), and a specificity of 84.4% (95% CI: 76.9–90.2%). Dengue shock patients with non-clearance of PCT and PVL expired during hospitalization.

Conclusions/Significance

PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L were independently associated with dengue shock and/or organ failure. The combination of PCT and PVL levels could be used as prognostic biomarkers for the prediction of dengue shock and/or organ failure.

Dengue is a major global health concern, particularly in tropical countries, and affects all age groups. Mortality rates among patients who have been hospitalized with severe dengue are 1.6–10.9%, and death in adults is mainly due to the development of dengue shock and organ dysfunction. In states of poor tissue circulation or shock, lactate is produced. Additionally, procalcitonin is a highly specific biomarker of systemic inflammation. Therefore, we assessed whether procalcitonin and peripheral venous lactate could be used to predict the incidence of dengue shock and/or organ failure in patients with dengue. Our study showed that a combination of serum procalcitonin levels ≥0.7 ng/mL and peripheral venous lactate levels ≥2.5 mmol/L at admission could discriminate between patients who did and did not develop shock and/or organ failure, with high sensitivity and specificity. These parameters may therefore be useful as prognostic biomarkers. Our results suggest that serum procalcitonin is indicative of an extensive early inflammatory response, which may occur during the systemic phase of dengue. Peripheral venous lactate may be produced as a result of the poor tissue circulation that precedes dengue shock. Our findings may help clinicians to predict dengue shock and/or organ failure earlier to reduce in-hospital mortality.

A Pathophysiological Insight into Sepsis and Its Correlation with Postmortem Diagnosis

BACKGROUND

Sepsis is among the leading causes of death worldwide and is the focus of a great deal of attention from policymakers and caregivers. However, sepsis poses significant challenges from a clinical point of view regarding its early detection and the best organization of sepsis care. Furthermore, we do not yet have reliable tools for measuring the incidence of sepsis. Methods based on analyses of insurance claims are unreliable, and postmortem diagnosis is still challenging since autopsy findings are often nonspecific.

AIM

The objective of this review is to assess the state of our knowledge of the molecular and biohumoral mechanisms of sepsis and to correlate them with our postmortem diagnosis ability.

CONCLUSION

The diagnosis of sepsis-related deaths is an illustrative example of the reciprocal value of autopsy both for clinicians and for pathologists. A complete methodological approach, integrating clinical data by means of autopsy and histological and laboratory findings aiming to identify and demonstrate the host response to infectious insults, is mandatory to illuminate the exact cause of death. This would help clinicians to compare pre- and postmortem findings and to reliably measure the incidence of sepsis.

Utility of blood procalcitonin concentration in the management of cancer patients with infections

Diagnosis of infections in cancer patients is usually problematic since differentiating between infection and fever of unknown origin is often a considerable clinical challenge. In general, increase concentration of blood procalcitonin (PCT) is associated with severe bacterial infection. PCT with an optimal cutoff level of 0.5 ng/mL seems to be the most helpful biochemical parameter in detecting severe infections, mainly bloodstream infection, in patients with hematological cancers. In all clinical situations, the elevated level of PCT should be carefully analyzed, always with a thorough physical examination and an appropriate microbiological assessment.