Combination of Biochemical and Cytological Findings for Better Diagnosis in Pleural Effusions.

Serous pleural effusions result from increased permeability and changed hydrostatic or colloid osmotic pressure. Laboratory biochemical findings provide conclusions about the effusion compositions. Together with the anamnesis and clinical assessment, they enable the evaluation of the effusion nature. The present study retrospectively analyzed combined biochemical and morphological findings in 2307 effusions of patients from two clinical centers: LungenClinic Grosshansdorf in Germany and Duzce University in Turkey. The effusion cytology results of 1771 and 536 patients from the respective centers were combined with clinical/radiological/biochemical findings and counter compared with the final diagnoses. Cytology verified 738 malignant tumors (643 and 95, respectively). Most effusions were benign (n = 1569; 77%) and 367 of them were paramalignant (293 and 74, respectively) and 594 were inflammatory (465 and 129, respectively). There was a distinctly lower number of malignant tumors in transudates than exudates (87 vs. 725; p < 0.0001). Squamous cell carcinoma was more frequent in paramalignant pleura effusions (122 cases out of the 367 effusions) than pleural carcinomatosis (32 cases out of the 780 malignant tumors; p < 0.0001). The cell formula was a suitable marker for malignant mesothelioma, predominantly mesothelial, or neutrophilic characterized by elevated LDH (>500 U/L) in the early stage of empyema or its late manifestation. In conclusion, most effusions are benign. Cytologists, assisted by clinical and biochemical data and microscopic findings, can make significant differential diagnostic contributions beyond the sole detection of malignancy.

Diagnostic Validation of a High-Sensitivity Cardiac Troponin I Assay.

BACKGROUND: Emergency departments worldwide are increasingly adopting rapid diagnosis of patients with suspected myocardial infarction (MI) based on high-sensitivity troponin. We set out to assess the diagnostic accuracy of a high-sensitivity cardiac troponin I (hs-cTnI) assay in a prospective study. METHODS: In a cohort study including 1800 patients presenting with suspected acute MI, we developed and temporally validated a 0/1 h diagnostic algorithm using the Siemens Atellica IM hs-cTnI assay. The algorithm was established in the first 928 patients and validated in the following 872 patients. RESULTS: The derived algorithm consisted of a baseline rule-out of non-ST-segment elevation MI using a cutoff <3 ng/L in patients with symptom onset ≥3 h or an admission troponin I level <6 ng/L with a Δ change of <3 ng/L from 0 h to 1 h. For rule-in, an admission troponin I level ≥120 ng/L or an increase within the first hour ≥12 ng/L was required. Application of the algorithm to the validation cohort showed a negative predictive value of 99.8% (95% CI, 98.7%-100.0%), sensitivity of 99.1% (95% CI, 95.1%-100.0%), and 48.3% of patients ruled out, whereas 15.1% were ruled in with a positive predictive value of 68.0% (95% CI, 59.1%-75.9%) and specificity of 94.4% (95% CI, 92.5%-96.0%). The diagnostic performance was comparable to guideline-recommended application of an established hs-cTnI assay in a rapid 0/1 h strategy. CONCLUSIONS: The Siemens hs-cTnI assay is well suited for application in rapid diagnostic stratification of patients with suspected MI. STUDY REGISTRATION: www.clinicaltrials.gov (NCT02355457).

Development of an artificial synovial fluid useful for studying Staphylococcus epidermidis joint infections.

Staphylococcus epidermidis is a major causative agent of prosthetic joint infections (PJI). The ability to form biofilms supports this highly selective pathogenic potential. In vitro studies essentially relying on phenotypic assays and genetic approaches have provided a detailed picture of the molecular events contributing to biofilm assembly. A major limitation in these studies is the use of synthetic growth media, which significantly differs from the environmental conditions S. epidermidis encounters during host invasion. Building on evidence showing that growth in serum substantially affects S. epidermidis gene expression profiles and phenotypes, the major aim of this study was to develop and characterize a growth medium mimicking synovial fluid, thereby facilitating research addressing specific aspects related to PJI. Using fresh human plasma, a protocol was established allowing for the large-scale production of a medium that by biochemical analysis matches key characteristics of synovial fluid and therefore is referred to as artificial synovial fluid (ASF). By analysis of biofilm-positive, polysaccharide intercellular adhesion (PIA)-producing S. epidermidis 1457 and its isogenic, PIA- and biofilm-negative mutant 1457-M10, evidence is provided that the presence of ASF induces cluster formation in S. epidermidis 1457 and mutant 1457-M10. Consistent with the aggregative properties, both strains formed multilayered biofilms when analyzed by confocal laser scanning microscopy. In parallel to the phenotypic findings, expression analysis after growth in ASF found upregulation of genes encoding for intercellular adhesins (icaA, aap, and embp) as well as atlE, encoding for the major cell wall autolysin being responsible for eDNA release. In contrast, growth in ASF was associated with reduced expression of the master regulator agr. Collectively, these results indicate that ASF induces expression profiles that are able to support intercellular adhesion in both PIA-positive and PIA-negative S. epidermidis. Given the observation that ASF overall induced biofilm formation in a collection of S. epidermidis isolates from PJI, the results strongly support the idea of using growth media mimicking host environments. ASF may play an important role in future studies related to the pathogenesis of S. epidermidis PJI.

Determination of hemolysis thresholds by the use of data loggers in pneumatic tube systems.

BACKGROUND: Pneumatic tube systems (PTSs) for the transport of blood samples are regaining popularity in medical centers after earlier reports that their use could introduce preanalytical distortions such as hemolysis and changes in blood gases. METHODS: We drew duplicate blood samples from 30 volunteers. One sample was hand transported, and the other sample was transported through a PTS together with a mini-data logger that provided continuous measurements of temperature, humidity, pressure, and acceleration. After transport the samples were analyzed at the same time. We looked for possible relationships of the transport method and the parameters measured by the data loggers with differences in hematological parameters, standard clinical chemistry analyses, blood coagulation, erythrocyte sedimentation rate, and blood gas analysis. RESULTS: There were no significant differences in temperature, humidity, and pressure between the methods of transport, but we observed significant differences in 3-axis accelerations. The combined effect of these forces could be described by the right-tailed area under the vector sum acceleration distribution. Our data show that this area correlated with PTS speed and that PTS speed and the area under the curve exhibited a direct relation to the degree of hemolysis. CONCLUSIONS: Assessment of 3-axis acceleration by use of data loggers can be used to identify preanalytical deviations that result from the transportation of blood samples in PTSs. Our approach could be used for the evaluation and regular control of PTSs without the need for repeated blood drawing and laboratory analyses.