Arch Hellen Med, 27(1), January-February 2010, 72-77
Comparison of LSRB in children measured by the Westergren method and by the Test-1 analyzer
E. PAPAKONSTANTINOU, E. YFANTIS, P. GEORGOUTSOU, A. LAVDA,
OBJECTIVE The erythrocyte sedimentation rate (ESR), now more appropriately referred to as the length of sedimentation reaction in blood (LSRB), continues to be the most widely used laboratory test for monitoring the course of infections, inflammatory diseases and some types of cancer. The Westergren method of measuring the LSRB has remained essentially unchanged since its inception and it was recommended as the method of choice by the International Council for Standardization in Hematology (ICSH) in 1973 and 1977. Over the last few years there have been a number of technical innovations, and many automated and semi-automated instruments have been introduced, aimed at eliminating or decreasing the risk of exposure of laboratory workers to potentially infectious material, i.e., blood. The newer procedures are considered less hazardous, primarily because they are either self-contained or use disposable materials, or both. There is a need to examine these innovations, both for comparability of results with those of previously employed methods and to ensure, on an ongoing basis, the quality of the results. This study was undertaken to evaluate the comparability of the LSRB as measured by the Westergren method and by the Test-1 analyzer.
METHOD Samples of blood from 89 children were analyzed by both the Westergren method and the Test-1 analyzer. The non-parametric Wilcoxon test was used for statistical comparison between the results derived from the two methods.
RESULTS Analysis of the comparison between uncorrected LRSB measured by the Westergren method and Test-1 analyzer showed that the results derived from the two methods do not show correlation (P<0.005). In comparison of the LRSB values corrected according to the hematocrit (Ht) (Ht <35%) no statistical difference was demonstrated between the two methods (P=0.249).
CONCLUSIONS The differences in LSRB measured by the two methods, Westergren and Test-1 analyzer, must be investigated with further studies in order to provide accuracy in daily clinical practice.
Key words: Length of sedimentation reaction in blood, Test-1 analyzer, Westergren method.