Procalcitonin for individualizing antibiotic treatment: an update with a focus on COVID-19

Investigation of the diagnostic and prognostic importance of Tumor Necrosis Factor-alfa (TNF-α), Procalcitonin (PCT), Interleukin-6 (IL-6) and Haptoglobin (HP) in calves with neonatal diarrhea

This study aims to investigate the effects of Procalcitonin, Tumor Necrosis Factor-alpha, Interleukin-6, and Haptoglobin levels on the prognosis of calves classified according to the severity of diarrhea. The animal material comprised 48 diarrheic calves of different breeds and sexes, aged 1-30 days, and 16 healthy calves aged 1-30 days. The 48 diarrheic calves used were divided into 3 groups, each consisting of 16 calves. Group 1 was designed as Viral (Rota + Corona n = 16), Group 2 as Bacterial (E. coli n = 16), and Group 3 as Parasitic (Cryptosporidiosis n = 16). Each of these groups was further divided into 2 subgroups (moderate and severe subgroups). Blood samples were taken from the diarrheic calves before treatment (0 h) and at 24 and 72 h after treatment. Complete blood count, biochemical, blood gas analyses, and ELISA tests were performed. It was determined that 18.75 % (9/48) of the 48 diarrheic calves included in the study died, while 81.25 % (39/48) survived. The highest mortality rate among the patient groups was observed in the severe rota + corona group (37.5 %). The average PCT concentration in the diarrheic calves in the Rota-corona and E. coli groups at 0 and 24 hours was found to be higher than both the healthy calves and the diarrheic calves in the Cryptosporidium spp. group (P<0.001). This increase was also observed in the Cryptosporidium spp. group at 72 h (P<0.001). A positive and moderate correlation was observed between Procalcitonin and TNF-α (r = 0.603, P<0.001). As a result, it was concluded that the Procalcitonin value, along with other tests, could be used as a biomarker to determine the prognosis of the disease in diarrheic calves, regardless of the etiological agent. This study was evaluated as an original study in which cytokines and acute phase proteins were investigated before and after treatment, with diarrhea divided into subgroups.

Are C-reactive protein and procalcitonin safe and useful for antimicrobial stewardship purposes in patients with COVID-19? A scoping review

Objective

The primary objectives of this study were to assess the usefulness of C-reactive protein (CRP) and procalcitonin (PCT) in the diagnosis of bacterial co-infections in coronavirus disease 2019 (COVID-19) and if their incorporation in antimicrobial stewardship (AMS) programs is safe and useful, stratified by severity of disease as level of care, intensive care unit (ICU) or non-ICU. Our secondary objectives were to identify cut-off values for antibiotic decision-making and identify reported results from low- and middle-income countries (LMICs).

Design

A scoping review of published literature, adhering to the PRISMA statement for Systematic Reviews and Meta-analyses Extension for Scoping Reviews guidelines. The last search was performed in January 2024.

Results

Fifty-nine studies were included in this scoping review: 20 studies reporting predictive values and/or sensitivity/specificity results for PCT, 8 reporting clear objectives on AMS, and 3 studies from LMICs.

Conclusion

In the context of non-ICU hospitalized COVID-19 patients in high-income countries, a PCT value below 0.25 mg/L can be a useful tool to rule out bacterial co-infection. The wide range of reported negative predictive values suggests that PCT should be interpreted in the context of other clinical findings. Our results do not support the use of CRP in the same manner as PCT. There is a clear need for more studies in LMICs.

Advanced medullary thyroid carcinoma uncovered by persistently elevated procalcitonin in a patient with COVID-19

Summary

We report the case of an 88-year-old man hospitalized for COVID-19 with persistently very high procalcitonin (proCt) levels despite infection resolution. Since proCt is an adjunct tumor marker in the diagnosis of medullary thyroid carcinoma (MTC), serum calcitonin (Ct) was also measured showing very high levels. Computed tomography (CT) scan showed the presence of a thyroid mass and neck ultrasound revealed a solid isoechoic, inhomogeneous, 50 mm nodule in the right thyroid lobe, extended into the mediastinum. Fine needle aspiration (FNA) of the thyroid nodule confirmed the diagnosis of MTC. An 18F-fluorodopa positron emission tomography/computed tomography (PET/CT) scan revealed the presence of distant metastases in ribs, vertebrae, in the right iliac wing and the liver. Since surgery was not feasible, the patient was started on cabozantinib 40 mg/dL. After 16 months the patient is still on cabozantinib at the same dose, he reports complete autonomy in daily life activities, and serum Ct is still elevated; however, the imaging evaluation does not show signs of disease progression.

Learning points

High procalcitonin serum values despite the absence of infection are suggestive of MTC. Advanced MTC with multiple metastases can have an indolent course and can go unrecognized for years. Cabozantinib is a valuable option for the treatment of advanced MTC.

Removal of inflammatory factors and prognosis of patients with septic shock complicated with acute kidney injury by hemodiafiltration combined with HA330-II hemoperfusion

INTRODUCTION

To explore the effect of CRRT using CVVHDF + HP on the removal of inflammatory mediators in patients with septic shock complicated with AKI.

METHODS

A total of 20 patients between January 1, 2018, and December 31, 2021, were included. The patients were randomly divided into the treatment group (CVVHDF + HP) and the control group (CVVHDF). Changes in inflammatory factors, including IL-1β, IL-6, IL-8, TNF-α, PCT, and CRP were compared. Other observed measures were also analyzed, for example, Lac, Scr, BUN, SOFA, and norepinephrine (NE) dosage. The clinical outcomes of both groups were followed up for 28 days.

RESULTS

The IL-6 and PCT levels in the treatment group were significantly lower (p = 0.005, 0.007). Although the IL-1β, TNFα, and CRP levels in the treatment group decreased, there were no statistical differences (p > 0.05). There were significant differences in Lac, SOFA, and NE dosage levels between both groups (p = 0.023, 0.01, 0.023). Survival analysis showed that the 28-day survival rate was significantly higher in the treatment group.

CONCLUSION

CRRT using CVVHDF+HP can effectively remove inflammatory factors and improve the prognosis of patients.

Coagulation and Inflammation in COVID-19: Reciprocal Relationship between Inflammatory and Coagulation Markers

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), formerly known as 2019-nCoV. Numerous cellular and biochemical issues arise after COVID-19 infection. The severe inflammation that is caused by a number of cytokines appears to be one of the key hallmarks of COVID-19. Additionally, people with severe COVID-19 have coagulopathy and fulminant thrombotic events. We briefly reviewed the COVID-19 disease at the beginning of this paper. The inflammation and coagulation markers and their alterations in COVID-19 illness are briefly discussed in the parts that follow. Next, we talked about NETosis, which is a crucial relationship between coagulation and inflammation. In the end, we mentioned the two-way relationship between inflammation and coagulation, as well as the factors involved in it. We suggest that inflammation and coagulation are integrated systems in COVID-19 that act on each other in such a way that not only inflammation can activate coagulation but also coagulation can activate inflammation.

Development and validation of machine learning-based models for predicting healthcare-associated bacterial/fungal infections among COVID-19 inpatients: a retrospective cohort study

BACKGROUND

COVID-19 and bacterial/fungal coinfections have posed significant challenges to human health. However, there is a lack of good tools for predicting coinfection risk to aid clinical work.

OBJECTIVE

We aimed to investigate the risk factors for bacterial/fungal coinfection among COVID-19 patients and to develop machine learning models to estimate the risk of coinfection.

METHODS

In this retrospective cohort study, we enrolled adult inpatients confirmed with COVID-19 in a tertiary hospital between January 1 and July 31, 2023, in China and collected baseline information at admission. All the data were randomly divided into a training set and a testing set at a ratio of 7:3. We developed the generalized linear and random forest models for coinfections in the training set and assessed the performance of the models in the testing set. Decision curve analysis was performed to evaluate the clinical applicability.

RESULTS

A total of 1244 patients were included in the training cohort with 62 healthcare-associated bacterial/fungal infections, while 534 were included in the testing cohort with 22 infections. We found that patients with comorbidities (diabetes, neurological disease) were at greater risk for coinfections than were those without comorbidities (OR = 2.78, 95%CI = 1.61-4.86; OR = 1.93, 95%CI = 1.11-3.35). An indwelling central venous catheter or urinary catheter was also associated with an increased risk (OR = 2.53, 95%CI = 1.39-4.64; OR = 2.28, 95%CI = 1.24-4.27) of coinfections. Patients with PCT > 0.5 ng/ml were 2.03 times (95%CI = 1.41-3.82) more likely to be infected. Interestingly, the risk of coinfection was also greater in patients with an IL-6 concentration < 10 pg/ml (OR = 1.69, 95%CI = 0.97-2.94). Patients with low baseline creatinine levels had a decreased risk of bacterial/fungal coinfections(OR = 0.40, 95%CI = 0.22-0.71). The generalized linear and random forest models demonstrated favorable receiver operating characteristic curves (ROC = 0.87, 95%CI = 0.80-0.94; ROC = 0.88, 95%CI = 0.82-0.93) with high accuracy, sensitivity and specificity of 0.86vs0.75, 0.82vs0.86, 0.87vs0.74, respectively. The corresponding calibration evaluation P statistics were 0.883 and 0.769.

CONCLUSIONS

Our machine learning models achieved strong predictive ability and may be effective clinical decision-support tools for identifying COVID-19 patients at risk for bacterial/fungal coinfection and guiding antibiotic administration. The levels of cytokines, such as IL-6, may affect the status of bacterial/fungal coinfection.

Clinical utility of procalcitonin in implementation of procalcitonin-guided antibiotic stewardship in the South-East Asia and India: evidence and consensus-based recommendations

INTRODUCTION

The South-East Asian (SEA) region and India are highly susceptible to antibiotic resistance, which is caused due to lack of antimicrobial stewardship (AMS) knowledge, uncontrolled use of antibiotics, and poor infection control. Nonadherence to national/local guidelines, developed to combat antimicrobial resistance, is a major concern. A virtual advisory board was conducted to understand the current AMS standards and challenges in its implementation in these regions.

AREAS COVERED

Procalcitonin (PCT)-guided antibiotic use was discussed in various clinical conditions across initiation, management, and discontinuation stages. Most experts strongly recommended using PCT-driven antibiotic therapy among patients with lower respiratory tract infections, sepsis, and COVID-19. However, additional research is required to understand the optimal use of PCT in patients with organ transplantation and cancer patients with febrile neutropenia. Implementation of the solutions discussed in this review can help improve PCT utilization in guiding AMS in these regions and reducing challenges.

EXPERT OPINION

Experts strongly support the inclusion of PCT in AMS. They believe that PCT in combination with other clinical data to guide antibiotic therapy may result in more personalized and precise targeted antibiotic treatment. The future of PCT in antibiotic treatment is promising and may result in effective utilization of this biomarker.

Procalcitonin and Risk Prediction for Diagnosing Bacteremia in Hospitalized Patients: A Retrospective, National Observational Study

Bacteremia is associated with significant morbidity and mortality. Timely, appropriate therapy may improve clinical outcomes, and therefore, determining which patients benefit from more comprehensive diagnostic strategies (i.e., direct specimen testing) could be of value. We performed an assessment of procalcitonin (PCT) and clinical characteristics in the discrimination of bacteremic hospitalizations. We analyzed 71,105 encounters and 14,846 visits of patients with bacteremia alongside 56,259 without an admission. The area under the receiver-operating characteristic (AUROC) curve for the prediction of bacteremia via procalcitonin was 0.782 (95% CI 0.779-0.787). The prediction modeling of clinical factors with or without PCT resulted in a similar performance to PCT alone. However, the clinically predicted risk of bacteremia stratified by PCT thresholds allowed the targeting of high-incidence bacteremia groups (e.g., ≥50% positivity). The combined use of PCT and clinical characteristics could be useful in diagnostic stewardship by targeting further advanced diagnostic testing in patients with a high predicted probability of bacteremia.

One biomarker does not fit all: tailoring anti-infective therapy through utilization of procalcitonin and other specific biomarkers

INTRODUCTION

Considering the ongoing increase in antibiotic resistance, the importance of judicious use of antibiotics through reduction of exposure is crucial. Adding procalcitonin (PCT) and other biomarkers to pathogen-specific tests may help to further improve antibiotic therapy algorithms and advance antibiotic stewardship programs to achieve these goals.

AREAS COVERED

In recent years, several trials have investigated the inclusion of biomarkers such as PCT into clinical decision-making algorithms. For adult patients, findings demonstrated improvements in the individualization of antibiotic treatment, particularly for patients with respiratory tract infections and sepsis. While most trials were performed in hospitals with central laboratories, point-of-care testing might further advance the field by providing a cost-effective and rapid diagnostic tool in upcoming years. Furthermore, novel biomarkers including CD-64, presepsin, Pancreatic stone and sTREM-1, have all shown promising results for increased accuracy of sepsis diagnosis. Availability of these markers however is currently still limited and there is insufficient evidence for their routine use in clinical care.

EXPERT OPINION

In addition to new host-response markers, combining such biomarkers with pathogen-directed diagnostics present a promising strategy to increase algorithm accuracy in differentiating between bacterial and viral infections. Recent advances in microbiologic testing using PCR or nucleic amplification tests may further improve the diagnostic yield and promote more targeted pathogen-specific antibiotic therapy.

COVID-19 association with multidrug-resistant bacteria superinfections: Lessons for future challenges

The future waves of COVID 19 infections will continue to raise serious problems in patients with severe forms of the disease. Bacterial infections associated with SARS-CoV-2 disease may complicate the progress of hospitalized patients with COVID-19. The present study aimed to evaluate the etiological spectrum of superinfection in adult patients with COVID-19 and to investigate the correlation between superinfection with multidrug-resistant (MDR) bacteria and serum procalcitonin (PCT). A total of 82 COVID-19 hospitalized patients with COVID-19 and bacterial superinfection were included. The superinfections were classified into early infections (3-7 days from admission) and late infections (>7 days from admission). Bacterial superinfection etiological spectrum, MDR bacteria profile and levels of serum PCT were studied. The most frequently isolated bacteria were Klebsiella pneumoniae, Acinetobacter baumannii and Enterococcus spp. MDR bacteria were involved in 73.17% of COVID-19 patients with bacterial superinfections. Most MDR bacteria superinfections (73.52%) occurred in the late infection period. Klebsiella pneumoniae, Enterococcus spp. and Methicillin-resistant Staphylococcus aureus were the most common MDR bacteria identified in late infections after hospitalization in 20.43, 4.30 and 4.30% of all infections, respectively. Serum PCT values were significantly higher in patients with MDR bacteria superinfection compared with patients with sensitive bacteria superinfection (P=0.009). The principal findings of the present study were the high prevalence of superinfection with MDR bacteria among the COVID-19 patients with bacterial superinfections and the presence of a statistically significant association between serum PCT levels and the presence of superinfection with MDR bacteria. The most effective way to fight against microbial resistance to antibiotics, whether it occurs independently or overlaps with viral infections, is to pursue a national policy for the rational use of antibiotics.

Ultrasensitive Photoelectrochemical Immunoassay Strategy Based on Bi2S3/Ag2S for the Detection of the Inflammation Marker Procalcitonin

As an inflammatory marker, procalcitonin (PCT) is more representative than other traditional inflammatory markers. In this work, a highly efficient photoelectrochemical (PEC) immunosensor was constructed based on the photoactive material Bi₂S₃/Ag₂S to realize the sensitive detection of PCT. Bi₂S₃ was prepared by a hydrothermal method, and Ag₂S quantum dots were deposited on the ITO/Bi₂S₃ surface via in situ reduction. Bi₂S₃ is a kind of admirable photoelectric semiconductor nanomaterial on account of its moderate bandgap width and low binding rate of photogenerated electron holes, which can effectively convert light energy into electrical energy. Therefore, based on the energy level matching principle of Bi₂S₃ and Ag₂S, a labeled Bi₂S₃/Ag₂S PEC immunosensor was constructed, and the sensitive detection of PCT was successfully established. The linear detection range of the PEC immunosensor was 0.50 pg∙mL^-1 to 50 ng∙mL^-1, and the minimum detection limit was 0.18 pg∙mL^-1. Compared with the traditional PEC strategy, the proposed PEC immunosensor is simple, convenient, and has good anti-interference, sensitivity, and specificity, which could provide a meaningful theoretical basis and reference value for the clinical detection of PCT.

SARS-CoV-2 infection and multi-organ system damage: A review

The SARS-CoV-2 infection causes COVID-19, which has affected approximately six hundred million people globally as of August 2022. Organs and cells harboring angiotensin-converting enzyme 2 (ACE2) surface receptors are the primary targets of the virus. However, once it enters the body through the respiratory system, the virus can spread hematogenously to infect other body organs. Therefore, COVID-19 affects many organs, causing severe and long-term complications, even after the disease has ended, thus worsening the quality of life. Although it is known that the respiratory system is most affected by the SARS-CoV-2 infection, many organs/systems are affected in the short and long term. Since the COVID-19 disease simultaneously affects many organs, redesigning diagnostic and therapy policies to fit the damaged organs is strongly recommended. Even though the pathophysiology of many problems the infection causes is unknown, the frequency of COVID-19 cases rises with age and the existence of preexisting symptoms. This study aims to update our knowledge of SARS-CoV-2 infection and multi-organ dysfunction interaction based on clinical and theoretical evidence. For this purpose, the study comprehensively elucidates the most recent studies on the effects of SARS-CoV-2 infection on multiple organs and systems, including respiratory, cardiovascular, gastrointestinal, renal, nervous, endocrine, reproductive, immune, and parts of the integumentary system. Understanding the range of atypical COVID-19 symptoms could improve disease surveillance, limit transmission, and avoid additional multi-organ-system problems.

The Role of COVID-19 in Antibiotic Resistance in Pediatric Population

There is data on the irrational use of antimicrobial drugs in pediatric population during the COVID-19 pandemic. This could lead to potential development of antibiotic resistance and increased morbidity and mortality among this vulnerable population group. The aim of this review is to study the role of COVID-19 in antimicrobial drugs administration and antibiotic resistance development, as well as to determine a set of measures for its prevention. Recent studies results have shown that COVID-19 pandemic had both direct and indirect impact on antibiotic resistance development in pediatric population. The COVID-19 outbreak has revealed weaknesses in health systems around the world. Antibiotics administration in patients with coronavirus infection during this period exceeded the number of cases with bacterial co-infection or other diseases. Thus, it indicates irrational antibiotic treatment. There were cases of inappropriate antibiotics administration during the crisis caused by the COVID-19 pandemic even in regions with long-term rational antibiotic treatment programs. One of the most viable methods to combat antibiotic resistance is to improve approaches in health care and to increase preparedness to infectious outbreaks. Increasing clinical competence of medical workers, accessibility of medical facilities, permanent supply of high-quality and cheap antibiotics, vaccines, reducing COVID-19 testing time, and adequate administration of antibacterial agents are the measures that can prevent diseases caused by drug resistance. All stakeholders (health authorities, regulating authorities, politicians, scientific community, pharmaceutical companies) have to collaborate and achieve results to implement all the mentioned above protection measures.

Procalcitonin-guided antibiotic therapy for pediatrics with infective disease: A updated meta-analyses and trial sequential analysis

Objective

We aimed to evaluate the effect of procalcitonin (PCT) guided therapy on antibiotic exposure in pediatric patients with infectious disease.

Methods

We performed an updated systematic review and meta-analysis of randomized controlled trials (RCTs) identified in systematic searches of MEDLINE, Embase, the Cochrane Database, Google Scholar, and SinoMed (through July 2021). The primary outcome was the length of the antibiotic therapy. Required information size (RIS) was calculated using trial sequential analysis (TSA).

Results

Four RCTs with 1,313 patients with infectious disease were included. Overall, after a mean 22-day follow-up, PCT-guided antibiotic therapy was associated with a significantly shorter length of antibiotic therapy compared with the control group (WMD, −2.22 days; 95% CI, −3.41 to −1.03; P <0.001) and a decreased rate of antibiotic adverse events (RR, 0.25; 95% CI, 0.11–0.58; P <0.001). However, the length of hospital stay (WMD, −0.39 days; 95% CI, −0.84 to 0.07; P = 0.094), rates of antibiotic prescription (RR, 1.10; 95% CI, 0.97–1.25; P = 0.122), hospital readmission (RR, 1.03; 95% CI, 0.92–1.16; P = 0.613) and mortality (RR, 0.73; 95% CI, 0.17–3.19; P = 0.674) were comparable between the PCT-guided antibiotic and control groups. TSA showed that the RIS was 2,340, indicating a statistically significantly shorter length of antibiotic therapy between PCT-guided antibiotic and control groups (P <0.05).

Conclusions

PCT-guided management seems to be able to decrease antibiotic exposure in patients with infectious disease. However, much larger prospective clinical studies are warranted to confirm these findings.

Impact of COVID-19 on Antimicrobial Resistance in Paediatric Population: a Narrative Review

Purpose of Review

Irrational use of antimicrobials has been reported in paediatric population during the COVID-19 time period. This may lead to potential development of antimicrobial resistance and increased morbidity and mortality among this vulnerable population. The purpose of this review is to ascertain the impact of COVID-19 pandemic on antimicrobial resistance among paediatrics and the possible strategies to minimize the menace of antimicrobial resistance.

Recent Findings

Recent findings indicate that the COVID-19 pandemic has direct as well as indirect impact on the development of antimicrobial resistance among paediatric population.

Summary

This review article shows the impact of COVID-19 on the development of antimicrobial resistance and strategies to prevent it with special reference to antimicrobial stewardship programmes among paediatric population.