Procalcitonin, a valuable biomarker assisting clinical decision-making in the management of community-acquired pneumonia

Antibiotic stewardship: Early discontinuation of antibiotics based on procalcitonin level in COVID-19 pneumonia

WHAT IS KNOWN AND OBJECTIVE

Procalcitonin (PCT) levels rise in systemic inflammation, especially if bacterial in origin. COVID-19, caused by the novel coronavirus SARS-CoV-2, presents with acute respiratory distress syndrome. Elevated procalcitonin in COVID-19 is considered as a marker for severity of disease. There is no study available that indicates whether elevated PCT in COVID-19 is associated with inflammation or superimposed bacterial infection. The objective of this study is to evaluate the association between PCT levels and superadded bacterial infection, and the effect of discontinuation of antibiotic in the low PCT (<0.25 ng/ml) group on patients' outcomes.

METHODS

A retrospective chart review of patients admitted with COVID-19 pneumonia at a single tertiary care centre. We collected information on demographics, co-morbidities, PCT level, antibiotic use, culture results for bacterial infection, hospital length of stay (LOS) and mortality.

STATISTICAL ANALYSIS

Continuous variables were summarized with the sample median, interquartile range, mean and range. Categorical variables were summarized with number and percentage of patients.

RESULTS AND DISCUSSION

We studied a total of 147 patients with COVID-19 pneumonia. 101 (69%) patients had a low PCT level (< 0.25 ng/ml). Bacterial culture results were negative for all patients, except 1 who had a markedly elevated PCT level (141.ng/ml). In patients with low PCT, 42% received no antibiotics, 59% received antibiotics initially, 32 (57%) patients antibiotic discontinued early (within 24 hours) and their culture remained negative for bacterial infections during hospitalizations. LOS was shorter (6 days in low PCT group compared to 9 days) in high PCT group. LOS was 1 day shorter (5 days vs 6 days) in no antibiotic group compared to antibiotic group. Our study examines the association between PCT level and superadded bacterial infection in COVID-19 pneumonia. Our results demonstrate that most patients admitted with COVID-19 have a low PCT (<0.25 ng/ml), which suggests no superadded bacterial infection and supports the previously published literature regarding low PCT in viral pneumonia.

WHAT IS NEW AND CONCLUSION

Procalcitonin level remains low in the absence of bacterial infection. Early de-escalation/discontinuation of antibiotics is safe without adverse outcomes in COVID-19 pneumonia. Early de-escalation/discontinuation of antibiotics is associated with lower LOS.

Seeking diagnostic and prognostic biomarkers for childhood bacterial pneumonia in sub-Saharan Africa: study protocol for an observational study

INTRODUCTION

Clinically diagnosed pneumonia in children is a leading cause of paediatric hospitalisation and mortality. The aetiology is usually bacterial or viral, but malaria can cause a syndrome indistinguishable from clinical pneumonia. There is no method with high sensitivity to detect a bacterial infection in these patients and, as result, antibiotics are frequently overprescribed. Conversely, unrecognised concomitant bacterial infection in patients with malarial infections occur with omission of antibiotic therapy from patients with bacterial infections. Previously, we identified two combinations of blood proteins with 96% sensitivity and 86% specificity for detecting bacterial disease. The current project aimed to validate and improve these combinations by evaluating additional biomarkers in paediatric patients with clinical pneumonia. Our goal was to describe combinations of a limited number of proteins with high sensitivity and specificity for bacterial infection to be incorporated in future point-of-care tests. Furthermore, we seek to explore signatures to prognosticate clinical pneumonia.

METHODS AND ANALYSIS

Patients (n=900) aged 2-59 months presenting with clinical pneumonia at two Gambian hospitals will be enrolled and classified according to criteria for definitive bacterial aetiology (based on microbiological tests and chest radiographs). We will measure proteins at admission using Luminex-based immunoassays in 90 children with definitive and 160 with probable bacterial aetiology, and 160 children classified according to the prognosis of their disease. Previously identified diagnostic signatures will be assessed through accuracy measures. Moreover, we will seek new diagnostic and prognostic signatures through machine learning methods, including support vector machine, penalised regression and classification trees.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Gambia Government/Medical Research Council Unit The Gambia Joint Ethics Committee (protocol 1616) and the institutional review board of Boston University Medical Centre (STUDY00000958). Study results will be disseminated to the staff of the study hospitals, in scientific seminars and meetings, and in publications.

TRIAL REGISTRATION NUMBER

H-38462.

Admission lysophosphatidylethanolamine acyltransferase level predicts the severity and prognosis of community-acquired pneumonia

PURPOSE

Early diagnosis and prognosis of patients with community-acquired pneumonia (CAP) are still difficult clinical challenges. This study aimed to investigate the role of lysophosphatidylethanolamine acyltransferase (LPEAT) in CAP and to evaluate the effectiveness of this enzyme as an indicator of disease severity and risk of death in CAP.

METHODS

This retrospective, multi-center study was conducted in 2017. A total of 267 patients with CAP were included. Of these 267 patients, 175 patients had non-severe CAP (non-SCAP) and 92 patients had severe CAP (SCAP). In addition, we recruited 15 healthy volunteers and 42 hospitalized disease controls in our study. The demographic and clinical characteristics were recorded for all participants. Admission levels of LPEAT were determined by quantitative enzyme-linked immunosorbent assay.

RESULTS

Admission levels of LPEAT in patients with SCAP were significantly higher, particularly in non-survivors and were not affected by the causative etiology. Furthermore, when the patients were stratified according to PSI and CURB-65 scores, the patients with high severity scores had higher LPEAT levels upon admission than patients with low severity scores. LPEAT also performed well in predicting SCAP in patients with CAP. Moreover, LPEAT could predict the 30-day mortality rate of patients with CAP, and combining LPEAT with the clinical severity score further improved the accuracy of mortality prediction.

CONCLUSION

Elevated LPEAT levels can reliably predict the severity of illness in patients with CAP at the time of admission. Adding LPEAT to clinical scoring methods could improve prognostic accuracy. Trial registration ClinicalTrials.gov, NCT03093220. Registered on March 28th, 2017.

Association of serum procalcitonin and C-reactive protein levels with CURB-65 criteria among patients with community-acquired pneumonia

Background

The concentration of diagnostic markers such as inflammatory biomarkers including procalcitonin (PCT) and C-reactive protein (CRP) increases in bacterial infections. The aim of this study was to compare serum PCT and CRP levels with CURB-65 ranking, in the patients with community-acquired pneumonia (CAP).

Patients and methods

In a cross-sectional study, 93 hospitalized patients with a definite diagnosis of CAP, considering inclusion and exclusion criteria, were enrolled. Serum PCT and CRP levels and their relations with CURB-65 criteria were assessed.

Results

The mean serum levels of PCT and CRP were 3.64±12.32 ng/mL and 75.01±51.93 mg/L, respectively. There was a statistically significant association between CURB-65 criteria and serum levels of PCT (P=0.0001) and CRP (P=0.007), which means that the concentration of these two inflammatory biomarkers increased with an increase in the score of CURB-65 criteria. Moreover, there was a statistically significant association between the serum level of PCT and the outcomes of the disease (P<0.001).

Conclusion

According to the results, the serum level of PCT or CRP is a strong prognostic factor for evaluating severity of CAP and is a suitable factor for the CURB-65 criteria in the decision making of whether a patient with CAP in the ICU should be admitted.

Procalcitonin as Biomarker of Infection: Implications for Evaluation and Treatment

Procalcitonin (PCT) is a quickly measurable marker, assumed to have high sensitivity and specificity for sepsis and infection. A literature search was conducted to evaluate PCT ability as a diagnostic and prognostic tool in infectious processes and its ability to monitor the antibiotic therapy. PCT level is increased in bacterial and fungal infections, but not in viral infections, with a significantly higher level in patients with bacteremia compared with uninfected patients (2.5 vs. 0.3 ng/mL; P < 0.0001). A PCT value of ≤0.1 ng/mL discards bacteremia and microbiological tests (negative predictive value of 96.3%), >0.1 ng/mL needs microbiological tests, and >1.0 ng/mL is indicative of bacteremia. Antibiotic treatment algorithms guided by PCT decreased the need for antibiotic treatment in approximately 50%. PCT is a promising test in clinical practice to decide the introduction of antibiotic therapy in addition to the existing tools, without neglecting the clinical assessment, with a significant decrease in costs.

The prognostic and risk-stratified value of neutrophil–lymphocyte count ratio in Chinese patients with community-acquired pneumonia

Community-acquired pneumonia is a common disease associated with high mortality. This retrospective study examined whether the neutrophil–lymphocyte count ratio (NLR), already widely used as an index of inflammation, can be used to predict in-hospital mortality of adults with community-acquired pneumonia. Clinical characteristics, CURB-65 and pneumonia severity index score of pneumonia severity, NLR, serum levels of C-reactive protein and procalcitonin, and in-hospital mortality were analyzed for 318 consecutive adults with community-acquired pneumonia admitted to West China Hospital between July 2012 and December 2013. The ability of NLR and other parameters to predict in-hospital mortality was assessed using receiver operating characteristic (ROC) curves. Results showed that NLR increased with increasing CURB-65 ( P < 0.05) and pneumonia severity index ( P < 0.05), and NLR correlated positively with serum levels of C-reactive protein (r = 0.239, P < 0.05) and procalcitonin (r = 0.211, P < 0.05). The median value of NLR was significantly higher among patients who died in hospital (11.96) than among those who were alive at the end of hospitalization (4.19, P < 0.05). Based on a cut-off NLR of 7.12, this index predicted in-hospital mortality with a sensitivity of 82.61% and specificity of 72.20% (area under ROC curve, 0.799). Predictive power was greater for the combination of NLR and serum levels of C-reactive protein and procalcitonin. These results suggest that NLR may be useful for predicting prognosis in Chinese adults with community-acquired pneumonia, and it may work better in combination with traditional markers.

Biomarker-based diagnosis of pacemaker and implantable cardioverter defibrillator pocket infections: A prospective, multicentre, case-control evaluation

Background

The use of cardiac implantable electronic devices (CIED) has risen steadily, yet the rate of cardiac device infections (CDI) has disproportionately increased. Amongst all cardiac device infections, the pocket infection is the most challenging diagnosis. Therefore, we aimed to improve diagnosis of such pocket infection by identifying relevant biomarkers.

Methods

We enrolled 25 consecutive patients with invasively and microbiologically confirmed pocket infection. None of the patients had any confounding conditions. Pre-operative levels of 14 biomarkers were compared in infected and control (n = 50) patients. Our selected biomarkers included white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), lipopolysaccharide binding protein, high-sensitivity C-reactive protein (HS-CRP), polymorphonuclear-elastase, presepsin, various interleukins, tumor necrosis factor α (TNF-α), and granulocyte macrophage colony-stimulating factor (GM-CSF).

Results

Of the 25 patients with isolated pocket infection (70±13years, 76% male, 40% ICDs), none presented with leukocytosis. In contrast, they had higher serum levels of HS-CRP (p = 0.019) and PCT (p = 0.010) than control patients. Median PCT-level was 0.06 ng/mL (IQR 0.03–0.07 ng/mL) in the study group versus 0.03 ng/mL (IQR 0.02–0.04 ng/mL) in controls. An optimized PCT cut-off value of 0.05 ng/mL suggests pocket infection with a sensitivity of 60% and specificity of 82%. In addition TNF-α- and GM-CSF-levels were lower in the study group. Other biomarkers did not differ between groups.

Conclusion

Diagnosis of isolated pocket infections requires clinical awareness, physical examination, evaluation of blood cultures and echocardiography assessment. Nevertheless, measurement of PCT- and HS-CRP-levels can aid diagnosis. However, no conclusion can be drawn from normal WBC-values.

Clinical trial registration

clinicaltrials.gov identifier: NCT01619267

Antibiotic Utilization and Opportunities for Stewardship Among Hospitalized Patients With Influenza Respiratory Tract Infection

OBJECTIVE

Hospitalized influenza patients are often treated with antibiotics empirically while awaiting final diagnosis. The goal of this study was to describe the inappropriate continuation of antibiotics for influenza respiratory tract infections (RTIs).

DESIGN

We retrospectively studied adults admitted to our institution over 2 respiratory flu seasons with positive influenza RTIs. Inappropriate antibiotic duration (IAD) was defined as antibiotic use for >24 hours after a positive influenza test in patients presenting with <72 hours of RTI symptoms and with no other indications of bacterial infection.

RESULTS

During the study period, 322 patients included in this study were admitted for influenza RTI. Respiratory cultures were ordered for 50 of these patients (15.5%) and 71 patients (22%) had a positive chest x-ray, but antibiotics were prescribed to 211 patients (65.5%) on admission. Antibiotics were inappropriately continued in 73 patients (34.5%). Patients receiving IAD had a longer length of stay (LOS) (median, 6 days; range, 4-9 days) compared with those whose antibiotics were discontinued appropriately (median, 5 days; range, 3-8 days) and those who were not treated with antibiotics (median, 4 days; range, 3-6 days; P<.001). However, mortality was similar among these 3 groups: 3 patients (4.1%) from the IAD cohort died; 6 patients (4.3%) from the group with an appropriate antibiotic duration died; and 2 patients [1.8%] from the group given no antibiotics died (P=.510). The 30-day readmission rates were similar as well: 9 patients (12.3%) from the IAD group were readmitted within 30 days; 21 patients (15.2%) from the group with appropriate antibiotic duration were readmitted; and 11 patients (9.9%) from the group given no antibiotics were readmitted (P=.455). Total hospital costs were greater in patients treated with IAD ($10,645; range, $6,485-$18,035) compared with the group treated with appropriate antibiotic duration ($7,479; range, $4,866-$12,922) and the group given no antibiotics $5,961 (range, $4,711-$9,575). Thus, the hospital experienced a median loss in net hospital revenue of $2,076 per IAD patient compared with a patient for which antibiotic duration was appropriate.

CONCLUSION

The majority of patients with influenza RTI received antibiotics on admission, and 34.5% were inappropriately continued on antibiotics without evidence of bacterial infection, which led to increased LOS, loss of net revenue, and no improvement in outcome. Thus, stewardship initiatives aimed at this population are warranted.