REDUCED ACUTE PHASE RESPONSE TO DIFFERENTIATE BETWEEN VIRAL AND BACTERIAL INFECTIONS IN CHILDREN

Quantitative Measurement of Erythrocyte Aggregation as a Systemic Inflammatory Marker by Ultrasound Imaging: A Systematic Review

This systematic review is aimed at answering two questions: (i) Is erythrocyte aggregation a useful biomarker in assessing systemic inflammation? (ii) Does quantitative ultrasound imaging provide the non-invasive option to measure erythrocyte aggregation in real time? The search was executed through bibliographic electronic databases CINAHL, EMB Review, EMBASE, MEDLINE, PubMed and the grey literature. The majority of studies correlated elevated erythrocyte aggregation with inflammatory blood markers for several pathologic states. Some studies used "erythrocyte aggregation" as an established marker of systemic inflammation. There were limited but promising articles regarding the use of quantitative ultrasound spectroscopy to monitor erythrocyte aggregation. Similarly, there were limited studies that used other ultrasound techniques to measure systemic inflammation. The quantitative measurement of erythrocyte aggregation has the potential to be a routine clinical marker of inflammation as it can reflect the cumulative inflammatory dynamics in vivo, is relatively simple to measure, is cost-effective and has a rapid turnaround time. Technologies like quantitative ultrasound spectroscopy that can measure erythrocyte aggregation non-invasively and in real time may offer the advantage of continuous monitoring of the inflammation state and, thus, may help in rapid decision making in a critical care setup.

Automatic 3-dimensional visualization of peripheral blood slides: a new approach for the detection of infection/inflammation at the point of care

CONTEXT

The identification and quantitation of the intensity of the acute-phase response at the point of care might be of clinical relevance.

OBJECTIVE

To report the possibility of automatic screening of unstained peripheral blood slides by using a 3-dimensional image analysis system.

DESIGN

Peripheral venous blood was obtained from children with acute inflammation/infection and examined by an automatic 3-dimensional image analyzer to detect the number of white blood cells as well as to reveal the degree of erythrocyte aggregation, a marker of the humoral phase response.

RESULTS

We included 66 children with acute bacterial infections and 59 with nonbacterial inflammation/infection; mean ages of the 2 groups were 4.3 +/- 3.9 years and 4.2 +/- 3.7 years, respectively (P = .91). The percentages of correct classifications based on discriminant analysis in predicting between bacterial and nonbacterial inflammation/infection were 61.3% by using the white blood cell count, 64.5% by using the percentage of granulocytes, 61.6% by using the degree of erythrocyte aggregation, and 59.2% by using the number of leukocytes counted on the unstained slides. The results of the receiver-operated characteristic curve analysis yielded an area under the curve of 0.714 (P < .001) for the number of granulocytes, 0.699 (P < .001) for the white blood cell count, 0.685 (P < .001) for the number of leukocytes on the slides, and 0.685 (P = .001) for the degree of erythrocyte aggregation. The correlation between the number of leukocytes by the electronic cell analyzer and the number of cells counted on the slides was highly significant (r = 0.85, P < .001).

CONCLUSIONS

It is feasible to use an automatic 3-dimensional image analyzer to reveal the different intensities of the acute-phase response between a group of children with an acute bacterial infection and another with nonbacterial inflammation/infection. These findings might be relevant for potential application at the point of care.