Procalcitonin-guided antibiotic therapy in AECOPD patients: Overview of systematic reviews

BACKGROUND

Procalcitonin (PCT)-guided antibiotic therapy has emerged as mainstream treatment for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and has been studied in many systematic reviews (SRs), but robust conclusion has not been drawn. Thus, this overview aims to summarize and critically evaluate the methodological and evidence quality of SRs on this topic.

METHODS

PubMed, EMBASE, Cochrane library, and Web of science were searched for SRs regarding on PCT-guided antibiotic therapy on AECOPD. Two reviewers assessed the quality of SRs in line with AMSTAR-2 tool and evaluated the strength of evidence quality with the grading of recommendations, assessment, development, and evaluation (GRADE) system for concerned outcomes independently.

RESULTS

Six SRs were published from Jun 2011 to Aug 2019, with from 4 (556 patients) to 15 (2571 patients) randomized controlled trials (RCTs) and retrospective studies. All the included SRs were classified as critical low methodology quality according to A MeaSurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) tool. Most of SRs were absented a list of excluded studies (item 7), and adequate investigation of publication bias and discuss its likely impact on the results (item 15). The PCT-guided antibiotic therapy may reduce antibiotic exposure days and antibiotic prescription rate in patients with AECOPD without affecting treatment success rate or causing adverse events (all-cause mortality, re-admission, re-exacerbation), but the results should be study deeper for the low or moderate evidence quality.

CONCLUSION

Current SRs show that PCT-guided antibiotic therapy could be employed by clinicians in treatment of AECOPD. However, the high-quality evidence of outcomes is lacking, further intensive exploration should be carried out on the precise role of PCT-guided antibiotic therapy on AECOPD.

Procalcitonin Monitoring as a Guide for Antimicrobial Therapy: A Review of Current Literature

Effective antimicrobial stewardship practices are increasingly essential to best utilize the current arsenal of antimicrobials for the shortest necessary duration to minimize the development of antimicrobial resistance, secondary infections, and health care costs. Monitoring of serum procalcitonin (PCT) levels represents an effective antimicrobial stewardship strategy to differentiate bacterial infections from viral infections and noninfectious inflammatory conditions. Current literature illustrates the merits of PCT monitoring in reducing duration of antibiotic therapy without detrimental effects on mortality or infection relapses. However, the interpretation of PCT levels can be challenging, especially in light of comorbid disease states that can elevate PCT levels. This review sheds light on the utility of PCT monitoring, as well as providing insight into the practical interpretation of PCT levels. Much of the current literature surrounding PCT monitoring consists of use among patients with lower respiratory tract infections or in the critically ill. Overall, studies have demonstrated shorter antibiotic therapy durations when PCT monitoring is utilized. No studies to date have found increased rates of mortality or infection relapses, suggesting that PCT monitoring is not only effective, but also safe when used as a guide for antimicrobial therapy. Nonetheless, many conditions were shown to elevate PCT serum concentrations, even in the absence of bacterial infections, which can make interpretation of PCT concentrations challenging. Two common conditions that affect the accurate interpretation of PCT levels are renal dysfunction and congestive heart failure. Limited studies have been performed in these populations, but current available data propose the need for higher PCT thresholds in those with renal dysfunction or congestive heart failure and support utilizing PCT trends to monitor clinical improvement from bacterial infections. Evidence also suggests that PCT monitoring is cost-effective, as long as the test is ordered judiciously. In summary, PCT monitoring represents a promising antimicrobial stewardship strategy to limit exposure to unnecessary antimicrobial therapy.

Procalcitonin Biomarker Algorithm Reduces Antibiotic Prescriptions, Duration of Therapy, and Costs in Chronic Obstructive Pulmonary Disease: A Comparison in the Netherlands, Germany, and the United Kingdom

Antibiotics are often recommended as treatment for patients with chronic obstructive pulmonary disease (COPD) exacerbations. However, not all COPD exacerbations are caused by bacterial infections and there is consequently considerable misuse and overuse of antibiotics among patients with COPD. This poses a severe burden on healthcare resources such as increased risk of developing antibiotic resistance. The biomarker procalcitonin (PCT) displays specificity to distinguish bacterial inflammations from nonbacterial inflammations and may therefore help to rationalize antibiotic prescriptions. We report in this study, a three-country comparison of the health and economic consequences of a PCT biomarker-guided prescription and clinical decision-making strategy compared to current practice in hospitalized patients with COPD exacerbations. A decision tree was developed, comparing the expected costs and effects of the PCT algorithm to current practice in the Netherlands, Germany, and the United Kingdom. The time horizon of the model captured the length of hospital stay and a societal perspective was also adopted. The primary health outcome was the duration of antibiotic therapy. The incremental cost-effectiveness ratio was defined as the incremental costs per antibiotic day avoided. The incremental cost savings per day on antibiotic therapy avoided were (in Euros) €90 in the Netherlands, €125 in Germany, and €52 in the United Kingdom. Probabilistic sensitivity analyses showed that in the majority of simulations, the PCT biomarker strategy was superior to current practice (the Netherlands: 58%, Germany: 58%, and the United Kingdom: 57%). In conclusion, the PCT biomarker algorithm to optimize antibiotic prescriptions in COPD is likely to be cost-effective compared to current practice. Both the percentage of patients who start with antibiotic treatment as well as the duration of antibiotic therapy are reduced with the PCT decision algorithm, leading to a decrease in total costs per patient. Economic analysis based on real-life data is recommended for further research. Biomarker-driven prescription algorithms are important instruments for personalized medicine in COPD. This also attests to the emerging convergence of biomarker innovations and the broader field of Health Technology Assessment (HTA).

Specific networks of plasma acute phase reactants are associated with the severity of chronic obstructive pulmonary disease: a case-control study

Objectives. A detailed understanding of the intricate relationships between different acute phase reactants (APRs) in chronic obstructive pulmonary disease (COPD) can shed new light on its clinical course. In this case-control study, we sought to identify the interaction networks of a number of plasma APRs in COPD, with a special focus on their association with disease severity. Methods. COPD cases and healthy smoking controls (3:1 ratio) were recruited in our outpatient pulmonary clinic. Cardiopulmonary exercise testing was used to rule out the presence of ischemic heart disease. All subjects were males as per protocol. Multiple plasma APRs - including α-2-macroglobulin, C-reactive protein (CRP), ferritin, fibrinogen, haptoglobin, procalcitonin (PCT), serum amyloid A (SAA), serum amyloid P, and tissue plasminogen activator (tPA) - were measured using commercial Acute Phase Bio-Plex Pro Assays and analyzed on the Bio-Plex manager software. Correlations between different APRs were investigated using a heat map. Network visualization and analyses were performed with the Cytoscape software platform. Results. A total of 96 COPD cases and 33 controls were included in the study. Plasma A2M, CRP, and SAP levels were higher in COPD patients than in controls. Circulating concentrations of haptoglobin and tPA were found to increase in parallel with the severity of the disease. Increasing disease severity was associated with distinct intricate networks of APRs, which were especially evident in advanced stages. Conclusions. We identified different networks of APRs in COPD, which were significantly associated with disease severity.

[Respiratory infections in Emergencies]

Respiratory infections account for 63.8% of infections met. Of which a quarter are lower respiratory tract: acute bronchitis, exacerbation of COPD or bronchiectasis and pneumonia. Acute bronchitis usually of viral etiology and in immunocompetent patients without comorbidity treatment is symptomatic with analgesics and anti-inflammatories. The main cause of exacerbation of COPD is the respiratory infection. The indication of empirical antibiotic choice and it is based on clinical criteria, the severity of the underlying disease, the severity of the exacerbation and the presence of risk factors for infection with Pseudomonas aeruginosa. The community-acquired pneumonia (CAP) is the leading cause of death by infection. The use of prognostic severity scales (PSI or CURB-65) is recommended for deciding where treatment is started, the tests to be performed for the etiological diagnosis and the recommended empirical antibiotic therapy. Patients with Healthcare Associated Pneumonia (HCAP) and nosocomial pneumonia (NP) have a higher risk of infection by multiresistant microorganisms (MMR) and increased morbidity and mortality. It requires specific empirical treatment depending on the severity of disease and risk factors for infection MMR.

Personalizing and targeting therapy for COPD: the role of molecular and clinical biomarkers

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by persistent airflow limitation. It is the third leading cause of death worldwide, and there are currently no curative strategies for this disease. Many factors contribute to COPD susceptibility, progression and exacerbations. These include cigarette smoking, environmental and occupational pollutants, respiratory infections and comorbidities. As the clinical phenotypes of COPD are so variable, it has been difficult to devise an individualized treatment plan for patients with this complex chronic disease. This review will highlight how potential clinical, inflammatory, genomic and epigenomic biomarkers for COPD could be used to personalize treatment, leading to improved disease management and prevention for our patients.

[Alveolar epithelial cell injury as an etiopathogenic factor in pulmonary fibrosis]

Idiopathic pulmonary fibrosis (IPF) is characterized by a progressive accumulation of extracellular matrix and an imbalance between profibrotic and antifibrotic mediators. In the last few years, understanding of the mechanisms of the biology of IPF has increased. One of the most significant discoveries is the finding that alveolar epithelial cell injury plays an important role in the pathogenesis of this disease. In this review, we describe some of the mechanisms involved in alveolar cell injury and their contribution to the development of IPF.

The role of biomarkers in low respiratory tract infections

Low respiratory tract infections (LRTI) represent the leading infectious cause of death worldwide and account for substantial use of healthcare resources. Physicians must adopt practices focused on improving outcomes and serum biomarker can help them in the management of patients with LRTI. Several studies have been carried out or are currently ongoing to evaluate the role of various biomarkers for the differential diagnosis, definition of prognosis, treatment and duration of antibiotic therapy in respiratory infections. The objective of this position paper of the Italian Society of Respiratory Diseases (SIMER) is to provide evidence-based recommendations for the use of biomarkers in routine clinical practice in the management of adult patients with LRTI. These guidelines capture the use of biomarkers both outside and inside the hospital, focused on community-acquired pneumonia, acute exacerbations of chronic obstructive pulmonary disease, hospital-acquired and ventilator-acquired pneumonia.