Biomarkers for iron metabolism among patients hospitalized with community-acquired pneumonia caused by infection with SARS-CoV-2, bacteria, and influenza.

Ferritin, the central iron storage protein, has attracted attention as a biomarker of severe COVID-19. Few studies have investigated regulators of iron metabolism in the context of COVID-19. The aim was to evaluate biomarkers for iron metabolism in the acute phase response to community-acquired pneumonia (CAP) caused by SARS-CoV-2 compared with CAP caused by bacteria or influenza virus in hospitalized patients. A cross-sectional study of 164 patients from the Surviving Pneumonia Cohort recruited between January 8, 2019 and May 26, 2020. Blood samples were collected at admission and analyzed for levels of C-reactive protein (CRP), ferritin, soluble transferrin receptor, erythroferrone, and hepcidin. Median (IQR) hepcidin was higher in SARS-CoV-2 with 143.8 (100.7-180.7) ng/mL compared with bacterial and influenza infection with 78.8 (40.1-125.4) and 53.5 (25.2-125.8) ng/mL, respectively. The median ferritin level was more than 2-fold higher in patients with SARS-CoV-2 compared with the other etiologies (p < 0.001). Patients with SARS-CoV-2 had lower levels of erythroferrone and CRP compared with those infected with bacteria. Higher levels of hepcidin and lower levels of erythroferrone despite lower CRP levels among patients with SARS-CoV-2 compared with those infected with bacteria indicate alterations in iron metabolism in patients with SARS-CoV-2 infection.

Behavior of clinical and humoral variables on admission as predictors of death in patients with community-acquired pneumonia. Comparative study between adults and older adults. / Comportamiento de variables clínicas y humorales al ingreso, como predictores de fallecimiento en pacientes con neumonía adquirida en la comunidad. Estudio comparativo entre adultos y adultos mayores

Community-acquired pneumonia is recognized as one of the main infectious health problems worldwide. The objective was to determine the condition of predictors of death for a group of selected clinical conditions, and for laboratory variables frequently used in practice. Study with descriptive design, which included 967 patients with pneumonia hospitalized between 2016 and 2019, and whose information was obtained from clinical records. Statistical treatment included bivariate and multivariate analysis (logistic regression); it was used the ratio of crossed products (odds ratio) and its 95% confidence interval. Several manifestations were significantly more frequent in older adults: dyspnea (OR 1.5[1.07,2.1]), absence of productive cough (OR 1.7 [1.3, 2.4]), neuropsychological manifestations (OR 2 [1.4,2.8]), tachypnea (OR 1.5 [1.1,2.1]), arterial hypotension (OR 2.1 [1.2,3.6]), anemia (OR 1.6[1.2,2.2]), elevated creatinine (OR 1.6[1.2,2.3]) and hypoproteinemia (OR 3.3[1.9,5.7]); showed a significant association with death: absence of productive cough, neuropsychological manifestations, temperature below 36 degrees Celsius, blood pressure below 110/70 mmHg, respiratory rate above 20 per minute, hemoglobin below 100 g/L, erythrosedimentation greater than 20 mm/L, leukopenia less than 5 x 109/L and serum creatinine above 130 micromol/L. As conclusions certain clinical and laboratory conditions present in the patient at the time of hospital admission, of routine exploration in the comprehensive assessment of the patient, were predictors of death. Additionally, the existence of evident differences in the number of conditions with a predictive nature of death between the population with pneumonia under 60 years of age and the elderly, as well as in the frequency of these conditions in both subgroups, is verified.

La neumonía adquirida en la comunidad está reconocida como uno de los principales problemas de salud de tipo infeccioso al nivel mundial. La investigación tuvo como objetivo determinar el carácter de predictores de fallecimiento de un grupo de condiciones clínicas seleccionadas, y de variables de laboratorio de uso frecuente en la práctica. Se realizó un estudio con diseño descriptivo, que incluyó a 967 pacientes con neumonía hospitalizados entre 2016 y 2019, y cuya información se obtuvo de los expedientes clínicos. El tratamiento estadístico incluyó análisis bivariante y multivariado (regresión logística); como estadígrafo se utilizó la razón de productos cruzados (odds ratio) y su intervalo de confianza de 95%. Entre los resultados se destacan los siguientes: varias manifestaciones fueron significativamente más frecuentes en los adultos mayores: disnea (OR 1,5[1,07;2,1]), ausencia de tos productiva (OR 1,7[1,3;2,4]), manifestaciones neuropsicológicas (OR 2[1,4;2,8]), taquipnea (OR 1,5[1,1;2,1]), hipotensión arterial (OR 2,1[1,2;3,6]), anemia (OR 1,6[1,2;2,2]), creatinina elevada (OR 1,6[1,2;2,3]) e hipoproteinemia (OR 3,3[1,9;5,7]); mostraron asociación significativa con el fallecimiento: ausencia de tos productiva, manifestaciones neuropsicológicas, temperatura por debajo de 36 grados Celsius, tensión arterial inferior a 110/70 mmHg, frecuencia respiratoria por encima de 20 por minuto, hemoglobina inferior a 100 g/L, velocidad de sedimentación eritrocitaria superior a 20 mm/L, leucopenia inferior a 5 x 109/L y creatinina sérica por encima de 130 micromol/L. Se concluye que ciertas condiciones clínicas y de laboratorio presentes en el paciente al momento del ingreso hospitalario, de exploración habitual en la valoración integral del enfermo, constituyeron predictores de fallecimiento. Adicionalmente, se comprueba la existencia de evidentes diferencias en el número de condiciones con carácter predictor de muerte entre la población con neumonía menor de 60 años y los adultos mayores, así como en la frecuencia de estas condiciones en ambos subgrupos.

The Role of Red Blood Cell Distribution Width in the Severity and Prognosis of Community-Acquired Pneumonia.

Objectives: The objective of this study is to unravel the correlation between RDW and the severity and prognosis of CAP, as well as exploring RDW with the inflammatory markers white blood cells (WBC), C-reactive protein (CRP), and procalcitonin (PCT). Methods: According to the data characteristics, appropriate statistical methods were selected to analyze the relationship between RDW and the severity and prognosis of CAP patients and to determine whether RDW is associated with the inflammatory markers WBC, CRP, and PCT. Results: The results show that with the increase of PSI and CURB-65 values, the proportion of patients with RDW ≥ 12.987% is significantly higher than that of RDW < 12.987% (P < 0.01). When RDW is combined with PSI or CURB-65 to predict the 90-day mortality of CAP patients, the area under the receiver operating characteristic (ROC) curve increased prominently, and if RDW, PSI, and CURB-65 are combined, the area under the ROC curve is maximized. Conclusions: Our findings suggest that the higher RDW value is associated with short-term adverse outcomes in CAP patients. We also find that when RDW, PSI, and CURB-65 are combined, the best performance is achieved to predict CAP 90-day mortality risk.

Serum levels of SIRT3 and other inflammatory factors are associated with clinical outcomes and prognosis in severe community-acquired pneumonia in adults: A prospective study.

ABSTRACT: The aim of this study was to investigate clinical significance of SIRT3 in severe community-acquired pneumonia (CAP) patients.This prospective observational research enrolled a total of 114 severe CAP patients who went to our hospital during January 2018 to December 2019. Serum SIRT3 and IL-1ß, IL-6, and tumor necrosis factor (TNF)-α levels were determined using the enzyme-linked immunosorbent assay (ELISA) method. Demographic data, including age, sex, and body mass index (BMI), as well as clinical symptoms, SOFA and SMART-COP scores were collected. The routine blood test was conducted for all patients and white blood cell (WBC) amount, as well as serum levels of C-reactive protein (CRP), D-Dimer, and procalcitonin (PCT).Among all patients, 55 cases died during the study period. The serum levels of CRP, PCT, IL-1ß, and IL-6, as well as SOFA and SMART-COP scores were markedly higher in deceased patients than in the survival patients. The expression of SIRT3 was significantly decreased in severe CAP patients compared with the healthy, especially in the deceased patients. SIRT3 levels were negatively correlated with levels of CRP, PCT, IL-1ß, and IL-6. Patients with SIRT3 low expression showed remarkably higher expression of CRP, PCT, IL-1ß, and IL-6, as well as high SMART-COP scores, higher 1-month mortality rate, and shorter survival. Only SIRT3 and IL-1ß were independent risk factors for 1-month mortality in severe CAP patients.Lower serum SIRT3 level predicts poor clinical outcomes and prognosis in severe CAP patients.

C-reactive protein predicts persistent bacteremia caused by community-acquired methicillin-resistant Staphylococcus aureus strain.

There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S. aureus bacteremia were prospectively investigated from August 2008 to December 2018. Patients with ST72 MRSA bacteremia were included in the study. Patients were stratified into the PB group (defined as positive blood cultures for ≥ 3 days) and short bacteremia (SB) group. A total of 291 patients were included, comprising 115 (39.5%) with PB and 176 (60.5%) with SB. Although the 30-day mortality did not differ between PB and SB, recurrent bacteremia within 12 weeks was significantly more common in PB (8.7% vs 1.7%; P = 0.01). Multivariate analysis showed risk factors of PB were liver cirrhosis (adjusted odds ratio [aOR], 3.27; 95% confidence interval [CI], 1.50-7.12), infective endocarditis (aOR, 7.13; 95% CI, 1.37-37.12), bone and joint infections (aOR, 3.76; 95% CI, 1.62-8.77), C-reactive protein ≥ 10 mg/dL (aOR, 2.20; 95% CI, 1.22-3.95), metastatic infection (aOR, 7.35; 95% CI, 3.53-15.29), and agr dysfunction (aOR, 2.47; 95% CI, 1.05-5.81). PB occurred in approximately 40% of bacteremia caused by ST72 MRSA with a significantly higher recurrence rate. Patients with risk factors of PB, including liver cirrhosis, high initial CRP, infective endocarditis, or bone and joint infections, might require early aggressive treatment.

Soluble form of suppression of tumorigenicity-2 predicts clinical stability of inpatients with community-acquired pneumonia.

The soluble form of the suppression of tumorigenicity-2 (sST2) is a biomarker for risk classification and prognosis of heart failure, and its production and secretion in the alveolar epithelium are significantly correlated with the inflammation-inducing in pulmonary diseases. However, the predictive value of sST2 in pulmonary disease had not been widely studied. This study investigated the potential value in prognosis and risk classification of sST2 in patients with community-acquired pneumonia. Clinical data of ninety-three CAP inpatients were retrieved and their sST2 and other clinical indices were studied. Cox regression models were constructed to probe the sST2's predictive value for patients' restoring clinical stability and its additive effect on pneumonia severity index and CURB-65 scores. Patients who did not reach clinical stability within the defined time (30 days from hospitalization) have had significantly higher levels of sST2 at admission (P < 0.05). In univariate and multivariate Cox regression analysis, a high sST2 level (≥72.8 ng/mL) was an independent reverse predictor of clinical stability (P < 0.05). The Cox regression model combined with sST2 and CURB-65 (AUC: 0.96) provided a more accurate risk classification than CURB-65 (AUC:0.89) alone (NRI: 1.18, IDI: 0.16, P < 0.05). The Cox regression model combined with sST2 and pneumonia severity index (AUC: 0.96) also provided a more accurate risk classification than pneumonia severity index (AUC:0.93) alone (NRI: 0.06; IDI: 0.06, P < 0.05). sST2 at admission can be used as an independent early prognostic indicator for CAP patients. Moreover, it can improve the predictive power of CURB-65 and pneumonia severity index score.

Sex-specific differences in plasma levels of FXII, HK, and FXIIa-C1-esterase inhibitor complexes in community-acquired pneumonia.

Sex-dependent differences in immunity and coagulation play an active role in the outcome of community-acquired pneumonia (CAP). Contact phase proteins act at the crossroads between inflammation and coagulation thus representing a point of convergence in host defense against infection. Here, we measured the levels of factor XII (FXII), FXIIa-C1 esterase inhibitor (C1INH) complexes, and high-molecular-weight kininogen (HK) in plasma of patients with CAP and correlated them to clinical disease severity. Levels of FXIIa-C1INH/albumin ratio were elevated, irrespective of sex, in plasma of patients with CAP (n = 139) as compared with age-matched donors (n = 58). No simultaneous decrease in FXII levels, indicating its consumption, was observed. Stratification by sex revealed augmented FXII levels in plasma of women with CAP as compared with sex-matched donors yet no apparent differences in men. This sex-specific effect was, however, attributable to lower FXII levels in female donors relative to men donors. Plasma estradiol levels mirrored those for FXII. Levels of HK/albumin ratio were decreased in CAP plasma as compared with donors, however, after stratification by sex, this difference was only observed in women and was related to higher HK/albumin values in female donors as opposed to male donors. Finally, strong negative correlation between plasma levels of HK/albumin ratio and CAP severity, as assessed by CRB65 score, in males and females was observed. Our study identifies sex-dependent differences in plasma levels of the contact phase proteins in elderly subjects that may contribute to specific clinical outcomes in CAP between men and women.

Serum MCP-1 and NGAL Play an Important Role in the Acute Inflammatory Event of Chronic Obstructive Pulmonary Disease.

NGAL is mainly secreted by neutrophils which play the core role in AECOPD. MCP-1 is secreted specifically by monocytes and macrophages. Both biomarkers are involved in the core process of acute inflammatory reaction in COPD. So We analyzed serum NGAL and MCP-1levels to explore their potential clinical values in the chronic obstructive pulmonary disease (COPD) .This study enrolled 97 COPD patients and 50 healthy controls. All participants received blood collection and lung function test and arterial blood gas measurements. The expression levels of serum NGAL and MCP-1 were measured by ELISA. The serum NGAL and MCP-1 levels of COPD with community-acquired pneumonia (COPD-CAP) patients were significantly higher than those of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients and healthy adults. The NGAL levels of the GOLD III and IV groups were significantly higher than those of the GOLD II group. Spearman correlation analysis showed a negative correlation between NGAL and FEV1%pred, FVC% pred. ROC curves indicated that NGAL has a high diagnostic value for both AECOPD and COPD-CAP. NGAL has the value of distinguishing GOLD I and II from GOLD III and IV. MCP-1 have moderate diagnostic value for COPD-CAP and can differentiate COPD-CAP from AECOPD. This study shows NGAL has certain diagnostic value for AECOPD and COPD-CAP, but can not distinguish the two. NGAL is closely related to airway remodeling and can be used as a potential indicator to distinguish the higher GOLD degree. MCP-1 can be used as potential indicator for the diagnosis of COPD-CAP.

Plasma Ferritin as Marker of Macrophage Activation-Like Syndrome in Critically Ill Patients With Community-Acquired Pneumonia.

OBJECTIVES: Plasma ferritin levels above 4,420 ng/mL have been proposed as a diagnostic marker for macrophage activation-like syndrome in sepsis and used for selection of sepsis patients for anti-inflammatory therapy. We here sought to determine the frequency, presentation, outcome, and host response aberrations of macrophage activation-like syndrome, as defined by admission ferritin levels above 4,420 ng/mL, in critically ill patients with community-acquired pneumonia. DESIGN: A prospective observational cohort study. SETTING: ICUs in two tertiary hospitals in the Netherlands. PATIENTS: One hundred fifty-three patients admitted with community-acquired pneumonia. MEASUREMENTS AND MAIN RESULTS: Patients were stratified in community-acquired pneumonia-macrophage activation-like syndrome (n = 15; 9.8%) and community-acquired pneumonia-control groups (n = 138; 90.2%) based on an admission plasma ferritin level above or below 4,420 ng/mL, respectively. Community-acquired pneumonia-macrophage activation-like syndrome patients presented with a higher disease severity and had a higher ICU mortality (46.7% vs 12.3% in community-acquired pneumonia-controls; p = 0.002). Twenty-three plasma biomarkers indicative of dysregulation of key host response pathways implicated in sepsis pathogenesis (systemic inflammation, cytokine responses, endothelial cell activation, and barrier function, coagulation activation) were more disturbed in community-acquired pneumonia-macrophage activation-like syndrome patients. Hematologic malignancies were overrepresented in community-acquired pneumonia-macrophage activation-like syndrome patients (33.3% vs 5.1% in community-acquired pneumonia-controls; p = 0.001). In a subgroup analysis excluding patients with hematologic malignancies (n = 141), differences in mortality were not present anymore, but the exaggerated host response abnormalities in community-acquired pneumonia-macrophage activation-like syndrome patients remained. CONCLUSIONS: Macrophage activation-like syndrome in critically ill patients with community-acquired pneumonia occurs more often in patients with hematologic malignancies and is associated with deregulation of multiple host response pathways.

Knockdown of circ-UQCRC2 ameliorated lipopolysaccharide-induced injury in MRC-5 cells by the miR-326/PDCD4/NF-κB pathway.

BACKGROUND: Circular RNAs (circRNAs) have been shown as important modulators in the pathogenesis of pediatric pneumonia. In this paper, we focused on the molecular basis of circRNA ubiquinol-cytochrome c reductase core protein 2 (circ-UQCRC2, circ_0038467) in lipopolysaccharide (LPS)-induced cell injury. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to gauge the levels of circ-UQCRC2, microRNA (miR)-326 and programmed cell death 4 (PDCD4) mRNA. PDCD4 protein expression and the activation of the NF-κB signaling pathway were evaluated by western blot. Ribonuclease R (RNase R) assay was performed to assess the stability of circ-UQCRC2. Cell viability and apoptosis were detected by the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. The levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and IL-6 were measured by the enzyme-linked immunosorbent assay (ELISA). Targeted relationship between miR-326 and circ-UQCRC2 or PDCD4 was confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. RESULTS: Our data showed the up-regulation of circ-UQCRC2 level in pneumonia serum and LPS-treated MRC-5 cells. The silencing of circ-UQCRC2 attenuated LPS-induced MRC-5 cell injury. Mechanistically, circ-UQCRC2 directly targeted miR-326, and circ-UQCRC2 regulated PDCD4 expression through miR-326. MiR-326 was a downstream effector of circ-UQCRC2 function, and PDCD4 was a functional target of miR-326 in regulating LPS-induced MRC-5 cell injury. Additionally, circ-UQCRC2 knockdown inactivated the NF-κB signaling pathway by regulating the miR-326/PDCD4 axis. CONCLUSION: Our findings demonstrated a novel regulatory network, the miR-326/PDCD4/NF-κB pathway, for the function of circ-UQCRC2 in LPS-induced cell injury in MRC-5 cells.

Establishing Classifiers With Clinical Laboratory Indicators to Distinguish COVID-19 From Community-Acquired Pneumonia: Retrospective Cohort Study.

BACKGROUND: The initial symptoms of patients with COVID-19 are very much like those of patients with community-acquired pneumonia (CAP); it is difficult to distinguish COVID-19 from CAP with clinical symptoms and imaging examination. OBJECTIVE: The objective of our study was to construct an effective model for the early identification of COVID-19 that would also distinguish it from CAP. METHODS: The clinical laboratory indicators (CLIs) of 61 COVID-19 patients and 60 CAP patients were analyzed retrospectively. Random combinations of various CLIs (ie, CLI combinations) were utilized to establish COVID-19 versus CAP classifiers with machine learning algorithms, including random forest classifier (RFC), logistic regression classifier, and gradient boosting classifier (GBC). The performance of the classifiers was assessed by calculating the area under the receiver operating characteristic curve (AUROC) and recall rate in COVID-19 prediction using the test data set. RESULTS: The classifiers that were constructed with three algorithms from 43 CLI combinations showed high performance (recall rate >0.9 and AUROC >0.85) in COVID-19 prediction for the test data set. Among the high-performance classifiers, several CLIs showed a high usage rate; these included procalcitonin (PCT), mean corpuscular hemoglobin concentration (MCHC), uric acid, albumin, albumin to globulin ratio (AGR), neutrophil count, red blood cell (RBC) count, monocyte count, basophil count, and white blood cell (WBC) count. They also had high feature importance except for basophil count. The feature combination (FC) of PCT, AGR, uric acid, WBC count, neutrophil count, basophil count, RBC count, and MCHC was the representative one among the nine FCs used to construct the classifiers with an AUROC equal to 1.0 when using the RFC or GBC algorithms. Replacing any CLI in these FCs would lead to a significant reduction in the performance of the classifiers that were built with them. CONCLUSIONS: The classifiers constructed with only a few specific CLIs could efficiently distinguish COVID-19 from CAP, which could help clinicians perform early isolation and centralized management of COVID-19 patients.

The value of PCT, IL-6, and CRP in the early diagnosis and evaluation of COVID-19.

OBJECTIVE: The aim of the present study was to assess the value of inflammatory factors procalcitonin (PCT), interleukin 6 (IL-6), and C-reactive protein (CRP) in the early diagnosis and evaluation of novel coronavirus pneumonia (COVID-19). MATERIALS AND METHODS: The data of 140 patients with pneumonia in our hospital, including 70 who had COVID-19 and 70 who had community-acquired pneumonia (CAP), were statistically analyzed. The levels of PCT, IL-6, and CRP were measured and statistically analyzed to determine the differences between the two groups. The differences in the COVID-19 group were analyzed after subgrouping into the ordinary type, severe type, and critical type. RESULTS: The PCT and CRP levels in the COVID-19 group were statistically lower than those in the CAP group (p < 0.05), but IL-6 was not statistically different between the two groups (p > 0.05). Statistically significant differences existed in IL-6 and CRP when comparing the COVID-19 subgroups of the critical type, severe type, and ordinary type (p < 0.05). However, there was no clinical meaning in the evaluation of the difference in PCT levels among the three subgroups with COVID-19. CONCLUSIONS: PCT and CRP could be used as indicators in the differentiation between COVID-19 and CAP, but IL-6 was of little significance in the differentiation. The higher the IL-6 and CRP, the more severe the condition of COVID-19 might be.

Activation and Functional Alteration of Mucosal-Associated Invariant T Cells in Adult Patients With Community-Acquired Pneumonia.

Community-acquired pneumonia (CAP) remains the significant infectious cause of morbidity and mortality worldwide. Although mucosal-associated invariant T cells (MAIT) play roles in the pathogenesis of children CAP and ICU-associated pneumonia, their roles in adult CAP are largely unexplored. In this study, we investigated the frequency, phenotype, and function of MAIT cells in peripheral blood and bronchoalveolar lavage fluid (BALF) of adult CAP patients. Our data indicate that MAIT-cell frequency is profoundly lower in the peripheral blood of CAP patients compared to that in healthy individuals. Furthermore, the circulatory MAIT cells express higher levels of CD69 and PD-1 compared to those in healthy individuals. In BALF of CAP patients, MAIT-cell frequency is higher and MAIT cells express higher levels of CD69 and PD-1 compared to their matched blood counterparts. Levels of IL-17A and IFN-γ are increased in BALF of CAP patients compared to those in BALF of patients with pulmonary small nodules. The IL-17A/IFN-γ ratio is significantly positively correlated with MAIT frequency in BALF of CAP patients, suggesting a pathogenic role of MAIT-17 cells in CAP. Of note, blood MAIT-cell frequency in CAP patients is strongly negatively correlated with high-sensitivity C-reactive protein (hsCRP) and neutrophil count percentage in blood. The ability of circulating MAIT cells in CAP patients to produce IFN-γ is significantly impaired compared to those in healthy individuals. In summary, our findings suggest the possible involvement of MAIT cells in the immunopathogenesis of adult CAP.

Effects of age and comorbidities on serum levels of inflammatory markers in community-acquired pneumonia.

INTRODUCTION: Studies have suggested that an inappropriate inflammatory response is a major cause of treatment failure and mortality in patients with community-acquired pneumonia (CAP). We aimed to determine the effect of age and comorbidities on serum inflammatory markers in CAP. METHODS: We performed a prospective cohort study of adults hospitalized with CAP. For the purposes of this study, we compared patients according to comorbidities and age. Inflammatory markers were measured at hospital admission, focusing on acute phase proteins, cytokines and monocyte human leucocyte antigen DR (mHLA-DR) expression. RESULTS: In patients with chronic pulmonary disease (COPD), serum cytokines had significantly decreased levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6 and mHLA-DR expression, as well as the C-reactive protein (CRP), compared with patients who had no comorbidities. Similarly, patients with chronic heart disease had a significantly reduced CRP levels and mHLA-DR expression, whereas patients with chronic kidney disease had significantly higher serum levels of procalcitonin and TNF-α. Lower procalcitonin, IL-6 and IL-10 levels, as well as mHLA-DR expression, were documented in older patients, but with no significant differences compared to younger patients. Multimorbidity in older patients was associated with significant lower levels of CRP and mHLA-DR expression. CONCLUSIONS: The circulating inflammatory markers to CAP have profiles that differ with age and underlying comorbidities. Multimorbidity in the elderly is also associated with lower serum levels of some inflammatory markers. Our findings suggest that inflammatory markers in CAP should be interpreted after considering age and comorbid conditions.

High ratio of C-reactive protein/procalcitonin predicts Mycoplasma pneumoniae infection among adults hospitalized with community acquired pneumonia.

There is limited data on serum biomarkers in distinguishing Mycoplasma pneumoniae (MP) from Streptococcus pneumoniae (SP) and viral pneumoniae (VP) etiologies of community-acquired pneumonia (CAP). A retrospective study of inpatients diagnosed with CAP at the First Affiliated Hospital of Dali University (Dali, Yunnan, China) between January 2018 and June 2020 was conducted. The demographic, clinical and laboratory data of the patients with CAP were analyzed. Univariate analyses identified predictors for MP infections. The discriminative power of C-reactive protein (CRP), procalcitonin (PCT), CRP/PCT and CRP/PCT >350 µg/ng was assessed by area under the curve (AUC) of the receiver operating characteristic (ROC) curves. A total of 552 CAP patients, including 247 (44.7%) with MP, 152 (27.6%) with SP and 153 (27.7%) with influenza A and B viruses, were enrolled. When comparing MP with SP, cough and CRP/PCT >350 µg/ng (odds ratio [OR]) 2.88, p < .001) were predictors for MP. CRP/PCT >350 µg/ng had 76% sensitivity and 100% specificity (AUC = 0.89, p < .001, 95% confidence interval [CI]:0.81-0.94) to predict MP infections. Furthermore, similar results were again obtained when comparing MP with VP. CRP/PCT >350 µg/ng present better information (OR: 4.70; AUC = 0.92, p < .001, 87% sensitivity and 100% specificity). In addition, comparing MP and non-MP (SP and VP combined), CRP/PCT >350 µg/ng exhibited excellent performance (AUC = 0.90, 95%CI 0.83-0.95, p < .001, 76% sensitivity and 100% specificity). CRP/PCT ratio may be a potential index to distinguish MP-CAP from non-MP-CAP.

Dynamics of cytokines, immune cell counts and disease severity in patients with community-acquired pneumonia - Unravelling potential causal relationships.

BACKGROUND: Community acquired pneumonia (CAP) is a severe and often rapidly deteriorating disease. To better understand its dynamics and potential causal relationships, we analyzed time series data of cytokines, blood and clinical parameters in hospitalized CAP patients. METHODS: Time series data of 10 circulating cytokines, blood counts and clinical parameters were related to baseline characteristics of 403 CAP patients using univariate mixed models. Bivariate mixed models were applied to analyze correlations between the time series. To identify potential causal relationships, we inferred cross-lagged relationships between pairs of parameters using latent curve models with structured residuals. RESULTS: IL-6 levels decreased faster over time in younger patients (Padj = 0.06). IL-8, VCAM-1, and IL-6 correlated strongly with disease severity as assessed by the sequential organ failure assessment (SOFA) score (r = 0.49, 0.48, 0.46, respectively; all Padj < 0.001). IL-6 and bilirubin correlated with respect to their mean levels and slopes over time (r = 0.36 and r = 0.46, respectively; Padj < 0.001). A number of potential causal relationships were identified, e.g., a negative effect of ICAM-1 on MCP-1, or a positive effect of the level of creatinine on the subsequent VCAM-1 concentration (P < 0.001). CONCLUSIONS: These results suggest that IL-6 trajectories of CAP patients are associated with age and run parallel to bilirubin levels. The time series analysis also unraveled directed, potentially causal relationships between cytokines, blood parameters and clinical outcomes. This will facilitate the development of mechanistic models of CAP, and with it, improvements in treatment or surveillance strategies for this disease. TRIAL REGISTRATION: clinicaltrials.gov NCT02782013, May 25, 2016, retrospectively registered.

Serum Procalcitonin, White Blood Cell and Hypersensitive C-reactive Protein Combined with Age Established a New Prediction Model in Predicting ICU Admission in Adult Community-Acquired Pneumonia (CAP) Patients.

BACKGROUND: CAP is the most common cause of death in infectious diseases in developing countries, while also an important cause of death and morbidity in developed countries. In recent years, CURB-65 (or CRB-65) and pneumonia severity index (PSI) scoring systems have been widely used in the prognosis scoring system of CAP. However, each of them has some shortcomings in predicting ICU admission in CAP patients. The aim of this study is to analyze serum inflammatory biomarkers combined age to established a new prediction model in predicting ICU admission in CAP patients. METHODS: This is a retrospective study. The enrolled CAP patients received serum inflammatory biomarker tests, including procalcitonin (PCT), white blood cell count (WBC), hypersensitive C-reactive protein (hs-CRP), and erythrocyte sedimentation rate (ESR). Body temperature and age were also recorded. The main outcome measures were ICU admission. Univariate analysis and binary logistic regression analysis were used to explore the in-dependent risk factors which could be components of a new predicting model for ICU admission in CAP patients. Receiver operating characteristic curves (ROC) were used to evaluate the sensitivity and specificity of the new model, which consisted of the combination of all independent risk factors in predicting the main outcomes. RESULTS: Initially, 246 CAP patients were admitted to general wards, 61 of whom were subsequently transferred to ICU (61/246). Age, PCT, WBC, and hs-CRP were independent risk factors for subsequent admission to ICU for CAP patients in general wards. The AUC of the ROC curve of new prediction model (the joint model consists of age, PCT, WBC, and hs-CRP) was 0.93 (95% CI 0.85 - 0.96), the sensitivity and specificity were 85.2% and 88.1%, respectively. CONCLUSIONS: Serum inflammatory biomarkers combined age have high specificity and sensitivity in predicting ICU admission in adult CAP patients.

Accuracy of Biomarkers for the Diagnosis of Adult Community-acquired Pneumonia: A Meta-analysis.

BACKGROUND: Biomarkers such as C-reactive protein (CRP) and procalcitonin may help distinguish community-acquired pneumonia (CAP) from other causes of lower respiratory tract infection. METHODS: We performed a systematic review of the literature to identify prospective studies evaluating the accuracy of a biomarker in patients with acute cough or suspected CAP. We performed parallel abstraction of data regarding study inclusion, characteristics, quality, and test accuracy. Study quality was evaluated using QUADAS-2. Bivariate meta-analysis was performed using the mada package in R, and summary receiver operating characteristic (ROC) curves were created. RESULTS: Fourteen studies met our inclusion and exclusion criteria; three were at low risk of bias and four at moderate risk of bias, largely due to failure to prespecify diagnostic thresholds. Considering all studies regardless of the cutoff used, CRP was most accurate (area under the ROC curve = 0.802), followed by leukocytosis (0.777) and procalcitonin (0.771). Lipopolysaccharide-binding protein and fibrinogen are promising, but were only studied in a single report. For CRP and procalcitonin, the positive and negative likelihood ratios (LR+ and LR-, respectively) varied inversely based on the cutoff. For CRP, LR+ and LR- were 2.08 and 0.32 for a cutoff of 20 mg/L, 3.64 and 0.36 for a cutoff of 50 mg/L, and 5.89 and 0.47 for a cutoff of 100 mg/L. For procalcitonin, LR+ and LR- were 2.50 and 0.39 for a cutoff of 0.10 µg/L, 5.43 and 0.62 for a cutoff of 0.25 µg/L, and 8.25 and 0.76 for a cutoff of 0.50 µg/L. The combination of CRP >49.5 mg/L and procalcitonin >0.1 µg/L had LR+ of 2.24 and LR- of 0.44. CONCLUSIONS: The best evidence supports CRP as the preferred biomarker for diagnosis of outpatient CAP given its accuracy, low cost, and point-of-care availability.

The utility of serial procalcitonin measurements in addition to pneumonia severity scores in hospitalised community-acquired pneumonia: A multicentre, prospective study.

OBJECTIVES: The usefulness of serial procalcitonin (PCT) measurements for predicting the prognosis and treatment efficacy for hospitalised community-acquired pneumonia (CAP) patients was investigated. METHODS: This prospective, multicentre, cohort study enrolled consecutive CAP patients who were hospitalised at 10 hospitals in western Japan from September 2013 to September 2016. PCT and C-reactive protein (CRP) were measured on admission (PCT D1 and CRP D1), within 48-72 h after admission (PCT D3 and CRP D3), and within 144-192 h after admission. CURB-65 and the Pneumonia Severity Index (PSI) were assessed on admission. The primary outcome was 30-day mortality; secondary outcomes were early and late treatment failure rates. RESULTS: A total of 710 patients were included. The 30-day mortality rate was 3.1%. On multivariate analysis, only PCT D3/D1 ratio >1 [odds ratio (95% confidence interval): 4.33 (1.46-12.82),P = 0.008] and PSI [odds ratio (95% confidence interval): 2.32 (1.07-5.03), P = 0.03] were significant prognostic factors. Regarding treatment efficacy, PCT D3/D1 >1 was a significant predictor of early treatment failure on multivariate analysis. PCT D3/D1 with the PSI significantly improved the prognostic accuracy over that of the PSI alone. CONCLUSIONS: PCT should be measured consecutively, not only on admission, to predict the prognosis and treatment efficacy in CAP.