Procalcitonin Test Research Articles

Decreased antibiotic exposure using a procalcitonin protocol for respiratory infections and sepsis in US community hospitals (ProCommunity)

Objective Antibiotic overuse leading to antimicrobial resistance is a global public health concern. Clinical trials have demonstrated that procalcitonin-based decision-making for antibiotic therapy can safely decrease inappropriate antibiotic use in patients with respiratory infections and sepsis, but real-world data are scarce. This study sought to assess the impact of a procalcitonin-based antibiotic stewardship program (protocol plus education) on antibiotic use in community hospitals. Methods An observational, retrospective, matched cohort study was conducted. Eligible patients treated in hospitals with a procalcitonin-based protocol plus education (Procalcitonin cohort hospitals) were matched to patients admitted to facilities without procalcitonin testing (Control cohort hospitals) using a 1:2 ratio. The Control hospitals were facilities where procalcitonin testing was not available on site. Patient matching was based on: (1) age, (2) gender, (3) admission diagnosis code using groupings of the International Classification of Diseases, 10th Revision, (4) whether patients were admitted to the intensive care unit, and (5) whether a blood culture test was performed. Procalcitonin cohort hospitals implemented a quality improvement initiative, where procalcitonin was available, used regularly, and clinicians (physicians and pharmacists) were educated on its use. Results After adjustment, patients in the Procalcitonin cohort had 1.47 fewer antibiotic days (9.1 vs. 8.5 days, 95%CI: −2.72; −0.22, p = .021). There was no difference in length of stay or adverse clinical outcomes except for increase in acute kidney injury (odds ratio = 1.26, 95%CI: 1.01; 1.58, p = .038). Conclusions Patients with respiratory infections and sepsis in hospitals utilizing a procalcitonin-based protocol coupled with education received fewer days of antibiotic therapy.

P0611 / #1112: ANTIMICROBIAL STEWARDSHIP AND PROCALCITONIN TESTING TO OPTIMIZE SEPSIS CARE IN CRITICALLY ILL PEDIATRIC PATIENTS

Aims & Objectives: We aim to prospectively evaluate an antimicrobial stewardship program (ASP) and Procalcitonin (PCT) testing on septic pediatric intensive care (PICU) patients. Methods: We performed a 30-week baseline collection (Phase 1), and a 30-week evaluation (Phase 2) of ASP and PCT in PICU patients with suspected or confirmed sepsis (inclusion criteria: temperature >38.0 or <36.0 and requiring IV antibiotic). The primary endpoint was in-hospital mortality; secondary endpoints included antimicrobial adequacy, ASP interventions and acceptance, LOS, re-admissions and economic indices, etc. Segmented logistic and linear regression analyses were performed for associations. Results: Each phase had 40 children, mean age of 3.9 (1.8) years; 56.3% male; PRISM III mean was 3.3 and 7.0 (CI:±2.66,p=0.0068) in each phase, respectively. From 104 antibiotic prescriptions, 91 (88%) were guideline-concordant; 103 ASP recommendations were made in 60 assessments, with 83% full acceptance rate; in 12% of patients antimicrobials were not indicated, in 6% narrower spectrum was suggested. PCT was measured at least once in 95% of patients: in 24% initial PCT values were <0.25 ng/mL (stopping rule) while in 71% were >1 ng/mL (continuation rule). Only 1 patient died (phase 1), mortality 1.2%. In phase 2 the mean ICU LOS was shorter (-6.58 days; 95% CI, -14.51, 1.36, p=0.10) and PICU readmissions decreased (12 vs. 4; p=0.048); costs were lower (-$5,830) and QALYs were higher (0.192 vs 0.188). Conclusions: ASP and PCT testing were effectively implemented, well accepted and helpful, albeit mortality did not differ. Implementation was cost effective with fewer re-admissions and resulted in higher quality-adjusted life years.

Use of Procalcitonin in a Febrile Infant Clinical Pathway and Impact on Infants Aged 29 to 60 Days.

Recent evidence suggests that measuring the procalcitonin level may improve identification of low-risk febrile infants who may not need intervention. We describe outcomes after the implementation of a febrile infant clinical pathway recommending measurement of the procalcitonin level for risk stratification. In this single-center retrospective pre-post intervention study of febrile infants aged 29 to 60 days, we used interrupted time series analyses to evaluate outcomes of lumbar puncture (LP), antibiotic administration, hospital admission, and emergency department (ED) length of stay (LOS). A multivariable logistic regression was used to evaluate the odds of LP. Data were analyzed between January 2017 and December 2019 and included 740 participants. Procalcitonin use increased post-pathway implementation (PI). The proportion of low-risk infants receiving an LP decreased significantly post-PI (P = .001). In the adjusted interrupted time series analysis, there was no immediate level change (shift) post-PI for LP (0.98 [95% confidence interval (CI): 0.49-1.97]), antibiotics (1.17 [95% CI: 0.56-2.43]), admission (1.07 [95% CI: 0.59-1.96]), or ED LOS (1.08 [95% CI: 0.92-1.28]), and there was no slope change post-PI versus pre-PI for any measure (LP: 1.01 [95% CI: 0.94-1.08]; antibiotics: 1.00 [95% CI: 0.93-1.08]; admission: 1.03 [95% CI: 0.97-1.09]; ED LOS: 1.01 [95% CI: 0.99-1.02]). More patients were considered high risk, and fewer had incomplete laboratory test results post-PI (P < .001). There were no missed serious bacterial infections. A normal procalcitonin level significantly decreased the odds of LP (P < .001). Clinicians quickly adopted procalcitonin testing. Resource use for low-risk infants decreased; however, there was no change to resource use for the overall population because more infants underwent laboratory evaluation and were classified as high risk post-PI.

Can Procalcitonin Facilitate Antimicrobial Stewardship in Patients with COVID-19?

Although procalcitonin (PCT) testing has been promoted for discriminating bacterial from viral causes of infection, thereby averting unnecessary

Comparing mortality between positive and negative blood culture results: an inverse probability of treatment weighting analysis of a multicenter cohort

BackgroundThe association between blood culture status and mortality among sepsis patients remains controversial hence we conducted a tri-center retrospective cohort study to compare the early and late mortality of culture-negative versus culture-positive sepsis using the inverse probability of treatment weighting (IPTW) method.MethodsAdult patients with suspected sepsis who completed the blood culture and procalcitonin tests in the emergency department or hospital floor were eligible for inclusion. Early mortality was defined as 30-day mortality, and late mortality was defined as 30- to 90-day mortality. IPTW was calculated from propensity score and was employed to create two equal-sized hypothetical cohorts with similar covariates for outcome comparison.ResultsA total of 1405 patients met the inclusion criteria, of which 216 (15.4%) yielded positive culture results and 46 (21.3%) died before hospital discharge. The propensity score model showed that diabetes mellitus, urinary tract infection, and hepatobiliary infection were independently associated with positive blood culture results. There was no significant difference in early mortality between patients with positive or negative blood culture results. However, culture-positive patients had increased late mortality as compared with culture-negative patients in the full cohort (IPTW-OR, 1.95, 95%CI: 1.14–3.32) and in patients with severe sepsis or septic shock (IPTW-OR, 1.92, 95%CI: 1.10–3.33). After excluding Staphylococcal bacteremia patients, late mortality difference became nonsignificant (IPTW-OR, 1.78, 95%CI: 0.87–3.62).ConclusionsCulture-positive sepsis patients had comparable early mortality but worse late mortality than culture-negative sepsis patients in this cohort. Persistent Staphylococcal bacteremia may have contributed to the increased late mortality.

Efficacy of Tocilizumab in the treatment of severe COVID-19 patients with respiratory failure

Objective: This study aimed to investigate the impact of tocilizumab, an IL6R inhibitor, on clinical features and laboratory tests of subjects admitted with severe COVID-19 and respiratory failure.&#x0D; Material and Methods: A total of 30 patients with positive polymerase chain reaction for COVID-19 and respiratory failure were analyzed in a retrospective manner. All patients received 8mg/kg body weight tocilizumab i.v. once in addition to the standard COVID-19 treatment protocol, including Oseltamivir phosphate 75mg twice daily, hydroxychloroquine 200 mg twice daily, and azitromycine 250 mg once daily following a 500 mg loading dose. Demographic characteristics, and clinical features including oxygen saturation, the concentration of oxygen inhalation, body temperature, mean arterial pressure and heart rate, and SpO2, end-tidal CO2, and blood tests including complete blood count, procalcitonin, C-reactive protein (CRP), Troponin-I, D-dimer, and liver and kidney function tests were recorded before and after treatment with tocilizumab.&#x0D; Results: A significant increase occurred in SaO2 on first and third days following treatment with tocilizumab (84.3 % and 90.3%, respectively, p&lt;0.001 for both recordings compared to baseline). There was also a significant increase in end-tidal CO2. The increase in mean SaO2 after tocilizumab was followed by a decline in respiratory rate on the first and third days of treatment. A dramatic decline was observed in body temperature from the first day of treatment with tocilizumab. Lymphocyte count increased following tocilizumab and C-reactive protein and Troponin I levels were reduced.&#x0D; Conclusion: Tocilizumab appears as an effective therapeutic option for improving oxygenation, symptoms and laboratory surrogates of ongoing inflammation in subjects with severe COVID-19.

How does procalcitonin testing affect antibiotic use and other outcomes for people with acute respiratory infection?

How does procalcitonin testing affect antibiotic use and other outcomes for people with acute respiratory infection?

Assessing the Impact of COVID-19 on Antimicrobial Stewardship Activities/Programs in the United Kingdom.

Since first identified in late 2019, the acute respiratory syndrome coronavirus (SARS-CoV2) and the resulting coronavirus disease (COVID-19) pandemic has overwhelmed healthcare systems worldwide, often diverting key resources in a bid to meet unprecedented challenges. To measure its impact on national antimicrobial stewardship (AMS) activities, a questionnaire was designed and disseminated to antimicrobialstewardship leads in the United Kingdom (UK). Most respondents reported a reduction in AMS activity with 64% (61/95) reporting that COVID-19 had a negative impact on routine AMS activities. Activities reported to have been negatively affected by the pandemic include audit, quality improvement initiatives, education, AMS meetings, and multidisciplinary working including ward rounds. However, positive outcomes were also identified, with technology being increasingly used as a tool to facilitate stewardship, e.g., virtual meetings and ward rounds and increased the acceptance of using procalcitonin tests to distinguish between viral and bacterial infections. The COVID-19 pandemic has had a significant impact on the AMS activities undertaken across the UK. The long-term impact of the reduced AMS activities on incidence of AMR are not yet known. The legacy of innovation, use of technology, and increased collaboration from the pandemic could strengthen AMS in the post-pandemic era and presents opportunities for further development of AMS.

Frequency of infectious complications and features of systemic inflammatory response in patients with prolonged disorders of consciousness

Objective: investigate epidemiology of infectious complications, intensity of antibacterial therapy, and features of the systemic inflammatory response in patients with prolonged disorders of consciousness.Materials and methods: retrospective case histories analysis of 102 patients with prolonged disorders of consciousness who were treated in the department of anesthesiology and intensive care of Polenov Neurosurgical Institute from 2010 to 2019.Results: during hospitalization all patients (100%) had signs of tracheobronchitis, 86 patients (84,3%) had urinary tract infection, 34 (33,3%) pneumonia, 10 patients (9,8%) meningoventriculitis, and in 9 (8,8%) cases sepsis was diagnosed. Identified bacterial complications required systemic antibacterial therapy. With an average length of hospital stay of 51±42 days, duration of antibiotic therapy was 37±41 days. One-component therapy was applied in half of the cases (54%), slightly less often (43,2%) treatment consisted of two antibiotics, in some cases patient’s condition required prescription of three antibiotics (2,8%). Even in the absence of a focus of infection, temperature and laboratory markers of inflammation in blood samples of patients with prolonged disorders of consciousness were higher than the reference values. CRP was increased with addition of any bacterial complications. Count of white blood cells significantly increased only in case of pneumonia and sepsis. Procalcitonin test was positive in 16,6% observations of urinary tract infection, 30,4% of pneumonia, and 28% of meningoventriculitis.Conclusion: most informative proinflammatory marker of bacterial complications in patients with prolonged disorders of consciousness was CRP. Mild leukocyte response can be explained by immunosuppression in long-term ill patients. Limited value of procalcitonin test may be due to the insufficiency of the semi-quantitative method sensitivity with a threshold level of 0,5 ng/ml, as well as reduced proinflammatory response to local infection in patients with prolonged disorders of consciousness as a result of massive antibacterial therapy, colonization of opportunistic microflora and presence of sympathicotonia (non-infectious systemic inflammatory reaction).

Clinical outcomes and costs associated with procalcitonin utilization in hospitalized patients with pneumonia, heart failure, viral respiratory infection, or chronic obstructive pulmonary disease

Lower respiratory tract infections (LRTIs) due to bacterial pneumonia are common among hospitalized patients and are frequently treated with antibiotics. Viral illnesses and exacerbations of heart failure or COPD may present with symptoms mimicking a LRTI, resulting in unnecessary antibiotic utilization. Procalcitonin testing may be useful in these clinical scenarios. We attempted to assess the utility of procalcitonin testing versus not testing, and positive versus negative results among hospitalized patients with suspected LRTI. We performed a retrospective cohort study using multivariable analysis comparing clinical outcomes of patients with and without procalcitonin testing. Patients were 18 years or older, hospitalized for pneumonia, heart failure, COPD, or a viral respiratory illness between October 2014 and October 2015 (n = 2353). All patients received at least one dose of antibiotics. Major outcomes were duration of antibiotic therapy, length of hospital stay, C. difficile testing and infections, and normalized total direct costs. Procalcitonin testing occurred in 14.0% of patients and pneumonia (70.6%) was the most common diagnosis. After covariate adjustments, mean length of stay (5.61 vs. 6.67 days, p < 0.001) and duration of antibiotics (3.95 vs. 4.47 days, p < 0.001) were shorter among tested patients. Fewer 30-day readmissions (OR 0.62, 95% CI 0.40-0.95) were observed, and total direct healthcare costs were 34% lower (0.66, 95% CI 0.58-0.74) among tested patients. Negative procalcitonin results were associated with further reductions in some outcomes. In conclusion, procalcitonin testing among hospitalized patients with suspected LRTI is associated with reductions in antibiotic duration, length of stay, 30-day readmission, and healthcare costs.

Clinical utility of procalcitonin in severe odontogenic maxillofacial infection

BackgroundMost of the maxillofacial infections are bacterial infections, and there is a possibility that systemic infections occur by maxillofacial infections. The aim of this study was to investigate the diagnostic value of procalcitonin in patients with odontogenic bacterial infections of the maxillofacial region.MethodsWe enrolled sixty patients, who were admitted with odontogenic maxillofacial infection from September 2018 to March 2020. White blood cell counts, C-reactive protein, and procalcitonin concentrations were evaluated. Sixty patients were classified into two groups, sepsis and non-sepsis groups, based on systemic inflammatory response syndrome. A Student t test was performed to statistically analyze the difference in inflammatory markers between sepsis and non-sepsis groups.ResultsThe mean procalcitonin values on admission were 7.24 ng/mL (range, 0.09–37.15 ng/mL) and 0.40 ng/mL (range, 0.02–4.94 ng/mL) in the sepsis group and non-sepsis group, respectively. The procalcitonin values between the two groups showed a significant difference (P < 0.05). The area under the curve of procalcitonin was 0.927 (P < 0.001), and the cutoff value of procalcitonin that maximizes the area under the curve was calculated to be 0.87 ng/mL.ConclusionsAccording to our study, routine laboratory tests have insufficient accuracy in diagnosing sepsis syndrome. Therefore, it is strongly recommended to perform the procalcitonin test in patients with maxillofacial infection in addition to the conventional laboratory tests to diagnose the systemic inflammatory condition of the patients.

Efficacy and safety of the point-of-care procalcitonin test for determining the antibiotic treatment duration in patients with ventilator-associated pneumonia in the intensive care unit: arandomised controlled trial.

This study was conducted to assess the efficacy of point-of-care (POC) procalcitonin (PCT) serial measurement in determining the antibiotic treatment duration in patients with ventilator-associated pneumonia (VAP). One hundred patients were randomly recruited and then further randomly divided into two groups of 50 patients each. The first group used the POC PCT test along with the standard sepsis parameter monitoring, while the second group had the standard monitoring only (C-reactive protein [CRP] level, total white count, temperature and tracheal aspirate culture). Serial PCT test results and CRP levels were monitored on days 1, 3, 7 and 9. The patients were followed up for 28-day mortality. Eighty-five patients completed the trial, of whom 43 were in the PCT group and 42 were in the control group. The PCT group had asignificantly lower mean (SD) antibiotic treatment duration (10.28 [2.68] days) than the control group (11.52 [3.06]). The mean (SD) difference was -1.25 (95% confidence interval [CI], -2.48 to 0.01; t-statistic [df] = -1.997 [83]; P = 0.049). The PCT group also had ahigher number of antibiotic-free days alive during the 28 days after VAP onset than the control group (mean [SD], 10.79 [7.61] vs. 8.72 [6.41]). The Sequential Organ Failure Assessment score was the sole factor for the decrease in duration after VAP onset (regression coefficient β [95% CI], -0.70 [-1.19 to -0.20]; P = 0.006). The POC procalcitonin test can reduce the antibiotic treatment duration in patients with VAP.

Reference change value and measurement uncertainty of CRP, ferritin, procalcitonin, troponin I and BNP tests in COVID-19 monitoring: how much change matters?

INTRODUCTION: This study was designed to determine the point of clinically significant change in consecutive measurements of high concentrations of C reactive protein (CRP), ferritin, procalcitonin, troponin I, and brain natriuretic peptide (BNP) in patients diagnosed with COVID-19. METHODS: The reference change value (RCV) for each analyte was estimated using the following formula: RCV=21/2xZx(CVa2+CVi2)1/2. The combined RCV was calculated using the mean CV value determined using different concentrations. Measurement uncertainty (MU) was estimated according to NordTest guideline. The root-mean-square (RMS) bias and nominal uncertainty values (uCref) were calculated. Standard uncertainty (ubias) and combined standard uncertainty (u) were calculated using the formula RMSbias2+uCref2 and (uRW2+ubias2)/2, respectively. Expanded uncertainty (U) was obtained by multiplying u by a coverage factor. RESULTS: The lowest RCV values of CRP, ferritin, procalcitonin, BNP, and troponin I tests were 94.57%, 37.16%, 40.55%, 42.01%, and 28.99%, respectively. The combined RCV value was 94.6%, 38.31%, 41.57%, 42.35%, and 29.36% for CRP, ferritin, procalcitonin, troponin I, and BNP, respectively. The U of the CRP test was between 4.70%, and 5.49%. The lowest MU values of ferritin, troponin I, and BNP tests were 48.45%, 48.24%, and 53%, respectively. DISCUSSION AND CONCLUSION: Providing the RCV and MU values with the test results in laboratory reports of these important biomarkers, which are frequently seen in high concentrations in COVID-19 patients, would offer valuable information for more accurate clinical interpretation.

1218. Comparing the Diagnostic Accuracy of Clinician Judgement to a Novel Host Response Diagnostic for Acute Respiratory Illness

BackgroundDiscriminating bacterial and viral infections remains clinically challenging. The resulting antibacterial misuse contributes to antimicrobial resistance. Host gene expression-based tests are a promising strategy to discriminate of bacterial and viral infections, but their potential clinical utility has not yet been evaluated.MethodsA host gene expression biosignature was measured using either qRT-PCR or microarray in 683 ED subjects with suspected infection. Based on chart reviews, we recorded clinical diagnosis as defined both by the provider assessment and by the provider treatment plan. The biosignature, diagnosis, treatment plan, and procalcitonin were compared to clinical adjudication as the reference standard. With this as a baseline, we then calculated average weighted accuracy (AWA) and change in overall net benefit (∆NB), weighting bacterial false negatives four times more seriously than false positives.ResultsGene expression correctly classified the three possible disease etiologies (bacterial, viral, or non-infectious) 76.1% of the time, outperforming provider diagnosis, provider treatment, and procalcitonin (Table 1). Overall accuracy was higher in subjects with bacterial infections (n=278, 83.8% accurate) compared to those with viral (n=234, 76.5%) and non-infectious (n=171, 63.2%) etiologies. Due to a strong sensitivity bias to treat bacterial infections at the expense of diagnostic accuracy and specificity, the provider diagnosis was overall more accurate than the corresponding treatment plan (71.4% accuracy vs. 68.1%), resulting in inappropriate antibiotic use in 41.0% of cases where antibiotics were prescribed. The gene expression test had significantly higher AWA for the diagnosis of bacterial infection than both procalcitonin and provider treatment (82.4% vs. 70.3% and 74.4%, respectively; p < 0.0001). Consequently, the host gene expression test had greater net benefit than provider treatment (∆NBbact = 9.9%), provider diagnosis (∆NBbact = 4.4%), and procalcitonin (∆NBbact = 27.1%).Table 1: Summary of provider, procalcitonin, and host gene expression test performance in a cohort of 683 subjects. ConclusionHost gene expression-based tests to distinguish bacterial and viral infection can facilitate more appropriate treatment, leading to improved patient outcomes and mitigating the antibiotic resistance crisis.Disclosures Geoffrey S. Ginsburg, MD PhD, Predigen, Inc (Shareholder, Other Financial or Material Support) Ephraim L. Tsalik, MD, MHS, PhD, Predigen (Shareholder, Other Financial or Material Support, Founder)

99. Comparison of Procalcitonin Testing to a Targeted Audit-and Feedback Strategy on Prescribed Durations of Therapy for Community-Acquired Pneumonia

BackgroundThe procalcitonin (PCT) assay is FDA-approved to help guide antimicrobial treatment of respiratory tract infections, however, conflicting data exist regarding its impact on shortening durations of therapy. The purpose of this study was to compare the impact of PCT to a targeted audit-and-feedback (TAF) strategy on prescribed antibiotic durations of therapy for community-acquired pneumonia (CAP).MethodsA retrospective cohort study was conducted at two community teaching hospitals, one implementing PCT with routine audit-and-feedback and one implementing a TAF strategy recommending 5 days of therapy for uncomplicated CAP. The primary objective of this study was to compare the impact of PCT implementation to TAF implementation on durations of therapy prescribed for suspected CAP. Secondary objectives included comparing length of stay, 30-day readmission, mortality, and rates of Clostridioides difficile. Adult inpatients with an antibiotic ordered with an indication of pneumonia were eligible for inclusion. Those who were critically ill, immunocompromised, had concurrent infections, were made comfort care, discharged or expired within 48 hours were excluded.Results311 patients were included (Pre-TAF n=80, Pre-PCT n=80, Post-TAF n=80, Post-PCT n=71). Average duration of therapy prescribed for CAP at baseline was similar between groups, Pre-TAF 7.0 days vs. Pre-PCT 7.8 days (p=0.1). After implementation of the respective interventions, there remained no difference in the average duration of therapy between groups, Post-TAF 5.5 days vs. Post-PCT 5.4 days (p=0.8). Both PCT and TAF strategies demonstrated significant improvement in prescribed durations for CAP between their respective Pre- and Post-intervention groups (p< 0.001 and p=0.002, respectively). The PCT protocol was followed 41% of the time in the Post-PCT group. There were no differences in readmission, mortality, or C. difficile between groups.ConclusionPCT and TAF were equally effective antimicrobial stewardship strategies in reducing total days of antibiotic therapy prescribed for CAP with no differences observed in patient outcomes.Disclosures All Authors: No reported disclosures

Use of procalcitonin for antibiotic stewardship in patients with COVID-19: A quality improvement project in a district general hospital

Antibiotic stewardship during the COVID-19 pandemic is an important part of a comprehensive strategy to improve patient outcomes and reduce long-term adverse effects secondary to rising antibiotic resistance. This report describes a quality improvement project which incorporates the use of procalcitonin (PCT) testing to rationalise antibiotic prescribing in patients with suspected or confirmed COVID-19 at Chesterfield Royal Hospital. Data were collected from 118 patients with a total of 127 PCT levels checked over a period of 20 days. Each PCT level was correlated with the subsequent antibiotic outcome as well as the result of the COVID-19 PCR swab. Results indicate that antibiotics were either never started or were stopped within 48 hours in 72% of COVID-confirmed cases with a PCT less than 0.25 μg/L. Our findings suggest that procalcitonin testing, when used in combination with thorough clinical assessment, is a safe, simple and sustainable way of reducing antibiotic use in COVID-19.

Serum Procalcitonin Levels in Patients with Acute Central Nervous System Infections

BACKGROUND: Bacterial infections of the brain are associated with high mortality and neurological sequelae, whereas viral diseases are usually self-limiting. A fast and easy-to-perform biomarker is needed to improve management in these patients.&#x0D; AIM: Procalcitonin (PCT) testing has already been implemented in many laboratories for evaluating septic patients and it is an easily accessible biomarker, so we aimed to examine its role specifically in discriminating acute bacterial from viral infections of the central nervous system (CNS).&#x0D; MATERIALS AND METHODS: This prospective study included 80 patients with both clinical symptoms and laboratory findings suggesting acute CNS infection. The microbiological analysis included direct microscopy, culturing, latex-agglutination test, and multiplex polymerase chain reaction. PCT levels were measured by enzyme-linked fluorescent assay technology.&#x0D; RESULTS: Following the results of the microbiological analysis, the cases were divided into three groups – bacterial 26.3% (n = 21), viral 17.5% (n = 14), and unidentified neuroinfections – 56.2% (n = 45). A statistically significant difference in the median serum PCT was observed between the bacterial and viral neuroinfections (p = 0.004) as well as between bacterial and unidentified infections of the brain (p = 0.000). No significant difference was found (p = 1.000) when comparing viral and unidentified neuroinfection. The area under the receiver operating characteristic curve for serum PCT was 0.823 but could be increased to 0.929 when combining serum PCT and C-reactive protein (CRP).&#x0D; CONCLUSION: Serum PCT levels are significantly higher in patients with acute bacterial infections of the brain. As a stand-alone biomarker, its discriminatory power is not superior to the classical laboratory parameters in the cerebrospinal fluid and serum CRP. However, when combined with serum CRP, excellent discriminatory power is observed.

Procalcitonin Correlates With but Is Not Superior to Other Diagnostic Markers of Bacterial Pneumonia.

Despite extensive research on procalcitonin (PCT)-guided therapy in lower respiratory tract infections, the association between PCT and bacterial pneumonia remains unclear. We evaluated retrospectively the performance of PCT in patients presenting with lower respiratory tract infection symptoms and grouped by seven diagnoses. All patients had microbial testing, chest imaging, and CBC counts within 1 day of PCT testing. Median PCT level in patients diagnosed with bacterial pneumonia was significantly higher than in patients diagnosed with other sources of infections or those not diagnosed with infections. Median PCT levels were not different among patients grouped by type or quantity of pathogen detected. They were significantly higher in patients with higher pathogenicity scores for isolated bacteria, those with abnormal WBC count, and those with chest imaging consistent with bacterial pneumonia. A diagnostic workup that included imaging, WBC count, and Gram stain had an area under the receiver operating characteristic curve of 0.748, and the addition of PCT increased it to 0.778. PCT was higher in patients diagnosed with bacterial pneumonia. Less clear is its diagnostic ability to detect bacterial pneumonia over and above imaging and laboratory data routinely available to clinicians.

Utility of Procalcitonin in Differentiating Acute Chest Syndrome from Vaso-Occlusive Crisis in Sickle Cell Disease

Background: Acute chest syndrome (ACS) frequently complicates sickle cell disease (SCD) and is a leading cause of hospitalization and mortality. Many factors have been implicated in ACS, including infections, thrombosis, fat and pulmonary emboli. However, a clear etiology is not defined in 50% of the cases and ACS is considered a clinical endpoint for different pathogenic processes (Vichinsky et al 2000). The non-specific nature of ACS makes diagnostic tests challenging, and there are no serum tests clinical used to aid diagnosis. Procalcitonin (PCT) is a prohormone of calcitonin and serum PCT rises within hours of an inflammatory stimulus. PCT has clinical utility as a marker of severe systemic inflammation, infection, and sepsis (Becker et al. 2008). Few studies have evaluated PCT as a biomarker for ACS in patients presenting with vaso-occlusive crises (VOC). Two studies have reported no difference in PCT (Biemond et al. 2018 and Stankovic et al 2011), while one study reported higher PCT between ACS and VOC (Patel et al 2014). Methods: We retrospectively reviewed 106 patients with SCD who presented to the emergency department with fever and painful crises during 2015-2019. The patients were divided into two categories based on discharge diagnoses - patients with VOC only (n=88) and patients with ACS (n=18). Inclusion criteria for both groups were patients with SCD, 17 years and older and PCT measurement on presentation. Exclusion criteria were defined as patients who had received empiric antibiotics prior to PCT testing. Data collected on presentation included genotype, age, gender, complete blood count, PCT, creatinine, total bilirubin and hydroxyurea use. Length of stay was recorded. Data was analyzed between the two groups using descriptive statistics and accounting for unequal variances, withp-value set at 0.05 for significance. Results: Demographics and clinical characteristics are summarized in Table 1 (Figure). The sample included primarily adult males (77%), with about two-thirds on hydroxyurea. Genotype HbSS (73.6%) was most prevalent followed by HbSC (22.6%) and HbSβ (3.8%). The ACS group had a higher percentage of HbSS, lower use of hydroxyurea and higher mean bilirubin. Mean PCT for the ACS group was 0.52 ng/mL (range, 0.05-2.04), compared to 0.31 ng/mL (range, 0.02-6.82) in the VOC group; withp=0.084. ROC analysis showed a PCT&amp;gt;0.5ng/mL had 39% sensitivity and 85% specificity for ACS in this sample. Conclusion: In this sample, PCT on presentation was higher in those with ACS compared to VOC, but this difference did not achieve statistical significance. Further study in a larger population would be useful to evaluate this finding. Disclosures No relevant conflicts of interest to declare.

Diagnostic Accuracy of Immunologic Biomarkers for Accurate Diagnosis of Bloodstream Infection in Patients with Malignancy: Procalcitonin in Comparison with C-Reactive Protein.

Purpose To calculate the diagnostic value of C-reactive protein (CRP) and serum procalcitonin (PCT) levels for the pathologic presence of microbes in the bloodstream of patients with malignancy, in comparison with blood culture. Methodology. Blood culture (by reference method) and assay results of PCT and CRP of febrile patients, with clinical suspicion to blood infections, were collected. Statistical aspects of PCT and CRP tests were evaluated. Results Data from 255 cases were gathered. The area under the curve for differentiating bacteremia from nonbacteremia for PCT (0.741) was superior to that of CRP (0.612). Amongst the different cutoffs of PCT and CRP, the cutoff of ≥1.17 ng/ml and >47 mg/l had the sensitivity of 75 and 58.3%, the best NPV of 91.5% and 81.3%, and the best specificity of 79.9% and 72.8%, respectively. Discussion. Despite statistically nonsignificant results, PCT seems to be a superior indicator to CRP for rejecting the presence of microorganism in bloodstream. For PCT, the cutoff value of 1.17 ng/ml (bacteremia from nonbacteremia) had the highest NPV value of 91.5% in malignant patients, suspicion of sepsis.