Predictors of Viral Pneumonia in Patients with Community-Acquired Pneumonia

<div><p>Background</p><p>Viruses are increasingly recognized as major causes of community-acquired pneumonia (CAP). Few studies have investigated the clinical predictors of viral pneumonia, and the results have been inconsistent. In this study, the clinical predictors of viral pneumonia were investigated in terms of their utility as indicators for viral pneumonia in patients with CAP.</p><p>Methods</p><p>Adult patients (≥18 years old) with CAP, tested by polymerase chain reaction (PCR) for respiratory virus, at two teaching hospitals between October 2010 and May 2013, were identified retrospectively. Demographic and clinical data were collected by reviewing the hospital electronic medical records.</p><p>Results</p><p>During the study period, 456 patients with CAP were identified who met the definition, and 327 (72%) patients were tested using the respiratory virus PCR detection test. Viral pneumonia (n = 60) was associated with rhinorrhea, a higher lymphocyte fraction in the white blood cells, lower serum creatinine and ground-glass opacity (GGO) in radiology results, compared to non-viral pneumonia (n = 250) (p<0.05, each). In a multivariate analysis, rhinorrhea (Odd ratio (OR) 3.52; 95% Confidence interval (CI), 1.58–7.87) and GGO (OR 4.68; 95% CI, 2.48–8.89) were revealed as independent risk factors for viral pneumonia in patients with CAP. The sensitivity, specificity, positive- and negative-predictive values (PPV and NPV) of rhinorrhea were 22, 91, 36 and 83%: the sensitivity, specificity, PPV and NPV of GGO were and 43, 84, 40 and 86%, respectively.</p><p>Conclusion</p><p>Symptom of rhinorrhea and GGO predicted viral pneumonia in patients with CAP. The high specificity of rhinorrhea and GGO suggested that these could be useful indicators for empirical antiviral therapy.</p></div

Receiver operating characteristics (ROC) curves of rhinorrhea and ground glass opacity in chest imaging as a predictor of viral pneumonia in 310 patients with community-acquired pneumonia.

<p>GGO: ground glass opacity. Area under the curve: (a) rhinorrhea, 0.562 (95% CI, 0.477–0.647); (b) GGO, 0.639 (95% CI, 0.555–0.723); (c) GGO or rhinorrhea, 0.672 (95% CI, 0.592–0.751).</p

Laboratory and radiological findings of 310 cases of viral or non-viral community-acquired pneumonia.

<p>Continuous variables were expressed as medians (IQRs)^a and were compared by Mann-Whitney U test^a. GGO: Ground-glass opacity.</p><p>Laboratory and radiological findings of 310 cases of viral or non-viral community-acquired pneumonia.</p

Independently associated factors for viral pneumonia in patients with community-acquired pneumonia.

<p>GGO: ground glass opacity.</p><p>Independently associated factors for viral pneumonia in patients with community-acquired pneumonia.</p

Adjusted 30-day crude and 30-day <i>S. aureus</i>-related mortalities in patients with SCC<i>mec</i> IV/IVa MRSAB or SCC<i>mec</i> I–III MRSAB.

<p>A. Adjusted 30-day mortalities in patients with SCC<i>mec</i> IV/IVa MRSAB or SCC<i>mec</i> I–III MRSAB by multivariate Cox-regression survival analysis. B. Adjusted 30-day <i>S. aureus</i>-related mortalities in patients with SCC<i>mec</i> IV/IVa MRSAB or SCC<i>mec</i> I–III MRSAB by multivariate Cox-regression survival analysis. NOTE. SCC<i>mec</i> IV/IVa MRSAB, bacteremia caused by MRSA possessing SCC<i>mec</i> type IV or IVa; SCC<i>mec</i> type I–III MRSAB, bacteremia caused by MRSA possessing SCC<i>mec</i> types I–III.</p

Increased level and interferon-γ production of circulating natural killer cells in patients with scrub typhus

<div><p>Background</p><p>Natural killer (NK) cells are essential immune cells against several pathogens. Not much is known regarding the roll of NK cells in <i>Orientia tsutsugamushi</i> infection. Thus, this study aims to determine the level, function, and clinical relevance of NK cells in patients with scrub typhus.</p><p>Methodology/Principal findings</p><p>This study enrolled fifty-six scrub typhus patients and 56 health controls (HCs). The patients were divided into subgroups according to their disease severity. A flow cytometry measured NK cell level and function in peripheral blood. Circulating NK cell levels and CD69 expressions were significantly increased in scrub typhus patients. Increased NK cell levels reflected disease severity. In scrub typhus patients, tests showed their NK cells produced higher amounts of interferon (IFN)-γ after stimulation with interleukin (IL)-12 and IL-18 relative to those of HCs. Meanwhile, between scrub typhus patients and HCs, the cytotoxicity and degranulation of NK cells against K562 were comparable. CD69 expressions were recovered to the normal levels in the remission phase.</p><p>Conclusions</p><p>This study shows that circulating NK cells are activated and numerically increased, and they produced more IFN-γ in scrub typhus patients.</p></div

Clinical features of 307 patients with SCC<i>mec</i> IV/IVa MRSAB or SCC<i>mec</i> I–III MRSAB.

<p><b>NOTE</b>. SCC<i>mec</i> IV/IVa MRSAB, bacteremia caused by MRSA possessing SCC<i>mec</i> type IV or IVa; SCC<i>mec</i> I–III MRSAB, bacteremia caused by MRSA possessing SCC<i>mec</i> types I–III; APACHE, acute physiology and chronic health evaluation.</p>a<p>Continuous variables are expressed as means (±SD).</p>b<p>Statistically significant (<i>P</i>≤0.05).</p>c<p>Expressed as number of deaths/number of patients followed up (%).</p

Risk factors for 30-day mortality in 180 patients with <i>Acinetobacter</i> bacteremia.

<p>APACHE, acute physiology and chronic health evaluation; MDR, multidrug resistance.</p>a<p>Continuous variables were expressed as means ± SDs and were compared by the Student’s <i>t</i> test.</p

Cytotoxicity of NK cells in scrub typhus patients.

<p>Panel A and B: NK cytotoxicity. Freshly isolated PBMCs (panel A) or purified NK cells (panel B) from 30 HCs and 20 patients with scrub typhus were cocultured with K562 cells for 4 hours, and then stained with FITC-conjugated anti-CD45 mAb and PI. Cytotoxicity was determined as the percentage of apoptotic K562 cells by flow cytometry. Panel C: CD107a expression in NK cells. PBMCs obtained from 15 HCs and 15 patients with scrub typhus patients were stained with FITC-conjugated anti-CD107a or isotype control mAbs and then incubated with K562 cells. After 1 hour, monensin was added and the cells were incubated for an additional 4 hours. The cells were then stained with PerCP-conjugated anti-CD3 and PE-conjugated anti-CD56 mAbs, and then CD107a expression in NK cells was analyzed by flow cytometry. Symbols represent individual subjects and horizontal lines indicate median values. ns = not significant by the ANCOVA test. Panel D: NK cell cytotoxicity of purified CD69- and CD69+ NK cell subsets in scrub typhus patients. Results are representative of 3 independent experiments.</p

Changes in NK cell levels and CD 69 expression in scrub typhus patients.

<p>The percentages of NK cells (panel A) and CD69-expressing NK cells (panel B) in the peripheral blood of 11 scrub typhus patients during active disease and remission were determined by flow cytometry. Symbols represent individual subjects. *p < 0.005 by the Wilcoxon matched-pairs signed rank test.</p