OBJECTIVETo study the clinical value of the expression of neutrophil surface CD64 in the diagnosis of community acquired pneumonia in children.

METHODSNinety-eight children with community acquired pneumonia were recruited into the study and were classified into three groups according to pathogene: bacterial pneumonia (n=48), viral pneumonia (n=29) and Mycoplasmal pneumonia (n=21). Twenty healthy children were enrolled as controls. The bacterial infection group was subdivided into mild infection (n=36) and severe infection groups (n=12). The levels of peripheral blood neutrophil CD64 were measured using flow cytometry. Dynamic changes of C-reactive protein were also detected for each patient.

RESULTSThe CD64 index and CRP levels in the bacterial pneumonia group were significantly higher than in the other three groups (P<0.05). The CD64 index in the severe bacterial infection group was significantly higher than in the mild group (P<0.05). After antibiotic treatment, expression of CD64 in the severe bacterial infection group decreased significantly (P<0.05). The CD64 index was positively correlated with CRP value (r=0.545, P<0.01). ROC curve analysis showed that the threshold of CD64 and CRP was 2.8 and 8 mg/L respectively. Specificity of CD64 index (90%) was much higher than CRP (74%).

CONCLUSIONSThe determination of peripheral blood neutrophil CD64 contributes to the early diagnosis of pulmonary bacterial infection and the evaluation of anti-infection effect.

C-Reactive Protein ; analysis ; Child ; Child, Preschool ; Community-Acquired Infections ; blood ; diagnosis ; Female ; Humans ; Male ; Neutrophils ; chemistry ; Pneumonia, Bacterial ; blood ; diagnosis ; ROC Curve ; Receptors, IgG ; blood

BACKGROUND/AIMS: We investigated the utility of serum C-reactive protein (CRP) and procalcitonin (PCT) for differentiating pulmonary tuberculosis (TB) from bacterial community-acquired pneumonia (CAP) in South Korea, a country with an intermediate TB burden. METHODS: We conducted a prospective study, enrolling 87 participants with suspected CAP in a community-based referral hospital. A clinical assessment was performed before treatment, and serum CRP and PCT were measured. The test results were compared to the final diagnoses. RESULTS: Of the 87 patients, 57 had bacterial CAP and 30 had pulmonary TB. The median CRP concentration was 14.58 mg/dL (range, 0.30 to 36.61) in patients with bacterial CAP and 5.27 mg/dL (range, 0.24 to 13.22) in those with pulmonary TB (p<0.001). The median PCT level was 0.514 ng/mL (range, 0.01 to 27.75) with bacterial CAP and 0.029 ng/mL (range, 0.01 to 0.87) with pulmonary TB (p<0.001). No difference was detected in the discriminative values of CRP and PCT (p=0.733). CONCLUSIONS: The concentrations of CRP and PCT differed significantly in patients with pulmonary TB and bacterial CAP. The high sensitivity and negative predictive value for differentiating pulmonary TB from bacterial CAP suggest a supplementary role of CRP and PCT in the diagnostic exclusion of pulmonary TB from bacterial CAP in areas with an intermediate prevalence of pulmonary TB.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; C-Reactive Protein/*analysis ; Calcitonin/*blood ; Community-Acquired Infections/blood/*diagnosis ; Diagnosis, Differential ; Female ; Humans ; Male ; Middle Aged ; Pneumonia, Bacterial/blood/*diagnosis ; Prospective Studies ; Protein Precursors/*blood ; Severity of Illness Index ; Tuberculosis, Pulmonary/blood/*diagnosis

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R² = 0.033; P = 0.018), followed by acute kidney injury (AKI; R² = 0.032; P = 0.011) and plasma MIP-1β level (R² = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.
Acute Kidney Injury/complications* ; Bacteria/classification* ; Chemokine CCL4/blood* ; Community-Acquired Infections/microbiology* ; Humans ; Lung ; Microbiota/genetics* ; Pneumonia, Bacterial/diagnosis* ; Prognosis ; RNA, Ribosomal, 16S/genetics*

BACKGROUND: Community-acquired pneumonia (CAP) is a common respiratory disorder in children, which necessitates hospitalization. Bacterial pneumonia, especially lobar pneumonia and parapneumonic effusions, is associated with considerably severe clinical course and extensive alveolar infiltrates. Serum procalcitonin (PCT) level has been used to distinguish bacterial from viral infections, but its usefulness is disputed. The diagnostic accuracy and usefulness of PCT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count were determined by comparing their values in the patients with CAP with those in healthy controls. METHODS: The serum PCT levels, as well as CRP level, ESR, and WBC counts, were measured in 76 hospitalized patients with CAP (lobar pneumonia, 16; bronchopneumonia, 60) and 18 healthy controls. Serum PCT level was measured using VIDAS(R) BRAHMS PCT (Biomerieux, France), and ROC curve analysis was performed to evaluate its diagnostic accuracy. RESULTS: Serum PCT levels were higher in the patients with CAP than in healthy controls, especially in the patients with lobar pneumonia than in those with bronchopneumonia. Serum CRP level was also significantly elevated in the patients with CAP, especially in those with lobar pneumonia. The diagnostic accuracy of serum PCT level for the diagnosis of lobar pneumonia was better than those of serum CRP level and ESR. The serum PCT level was significantly correlated with the CRP level, ESR, and WBC count. CONCLUSIONS: Serum PCT level was a better marker than CRP level or ESR for the diagnosis of lobar pneumonia in children with CAP.
Adolescent ; Biological Markers/blood ; Blood Sedimentation ; Bronchopneumonia/complications ; C-Reactive Protein/analysis ; Calcitonin/*blood ; Child ; Child, Preschool ; Community-Acquired Infections/complications/*diagnosis ; Female ; Humans ; Infant ; Infant, Newborn ; Leukocyte Count ; Male ; Pneumonia/complications/*diagnosis ; Protein Precursors/*blood ; ROC Curve

INTRODUCTIONRoutine blood cultures have been recommended for all patients in treatment guidelines for community-acquired pneumonia (CAP). This practice has become a major area of resource utilisation, despite the lack of evidence in its clinical utility. Calls for abandoning the practice is balanced by the occasions of uncovering an unexpected pathogen or an unusual antimicrobial resistance pattern. The aim of this study is to identify factors that predict positive blood cultures among patients hospitalised for pneumonia upon presentation at the Emergency Department (ED).

MATERIALS AND METHODSA case control study was carried out on patients treated for pneumonia in the ED who had routine blood cultures performed as part of their management. The pneumonia severity index (PSI) was used to categorize patients into low- and high-risk for 30-day mortality. Logistic regression was carried out to determine factors significantly associated with positive blood cultures, from which a predictive probability equation was used to identify patients whose blood cultures were negative at a pre-determined cut-off, with minimum number of culture positive misclassification. A scoring system was devised, with scores predicting which patients would be likely to have a positive or negative blood culture.

RESULTSA total of 1407 patients with pneumonia were treated at ED from May to December 2006, from whom 1800 blood cultures were performed. Of these, 140 cultures (7.8%) grew organisms, comprising 96 (5.3%) true positive cultures and 44 (2.4%) contaminated cultures. Logistic regression analysis identified ill patients with higher PSI classes, smokers and Malay patients to be more likely to have positive blood cultures. Patients who had prior treatment with antibiotics, chronic obstructive pulmonary disease and cough were less likely to have positive blood cultures. An index to predict a negative blood culture resulted in the accurate classification of all but 4 positive patients while still correctly classifying 27.8% of blood culture negative patients. The area under the ROC curve was 0.71 (95% CI, 0.65-0.76). A simplified scoring system was devised based on the predictive model had a sensitivity of 82% and specificity of 38.2% for a positive blood culture.

CONCLUSIONRoutine blood cultures yielded negative results in 94% of patients presenting with pneumonia. The development of the clinical scoring system is a first step towards selecting patients for whom blood cultures is performed and improve cost-effectiveness.

Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Community-Acquired Infections ; blood ; diagnosis ; Culture Techniques ; Emergency Service, Hospital ; Female ; Forecasting ; Gram-Negative Bacteria ; isolation & purification ; Gram-Positive Bacteria ; isolation & purification ; Humans ; Male ; Middle Aged ; Pneumonia ; blood ; diagnosis ; Regression Analysis ; Singapore ; Young Adult