Verification of automatic analysers Roller 20PN and iSED for measuring erythrocyte sedimentation rate

Abstract

Automated erythrocyte sedimentation rate (ESR) analysers are based on different methodology than Westergren method. It is questionable whether ESR values obtained from those analysers are comparable with determined values with Westergren method. The aim was verification of the precision, method comparison and accuracy of automated ESR analysers: Roller 20PN (Alifax S.p.A., Polverara, Italy) and iSED (Alcor Scientific, Smithfield, USA). Blood samples (N = 752 for Roller 20PN and N = 213 for iSED) were sampled into K2EDTA (Kima, Italy) tubes for automated and 3.8% Na-citrate tubes (Kima, Italy) for Westergren method. The data was divided into three groups according to the ESR values obtained with the Westergren method: Group Low (L) (ESR ≤ 20 mm), Group Medium (M) (ESR 21-60 mm), and Group High (H) (ESR ≥ 61 mm). Method agreement was assessed by Bland-Altman analysis and Passing-Bablok regression. Analyser iSED has shown better comparability with Westergren method (bias 0.0 (95%Cl -1.4 to 1.5) range than Roller 20 PN (bias = - 6.4 (95%Cl - 7.1 to -5.7) in the whole measuring. For Roller 20 PN, Passing-Bablok regression has shown constant and proportional difference for Groups L and M, and for iSED only for Group H. Roller 20 PN had lower sensitivity (0.51 (95%Cl: 0.45-0.57) than iSED (0.72 (95%Cl: 0.59-0.80) while they had comparable specificity (> 0.90) and accuracy (≥ 0.80) in comparison with the Westergren method. Both analysers are not comparable with the Westergren method and should not be used interchangeably.

Validation of the New MINI-CUBE for Clinic Determination of Erythrocyte Sedimentation Rate

“…However, consistent with previous findings [13,18], sam- ples with low ESR levels correlated better than high ESR levels samples, as can be seen in Figure 1, probably due to the nondilution with sodium citrate of the samples, as in the Westergren test. The high levels of ESR results obtained by MINI-CUBE, through the mathematical calculation of the optical distance of the red blood cell aggregation and the top of the plasma, indicated a slight difference with the high levels of ESR results obtained from the gold standard [11,19,20]; anyhow, despite the larger bias, the lower correlation for high ESR values do not influence the clinical evaluation. It was observed that the ESR high levels were predominantly from samples from cancer patients, due to the inflammatory status generated by the tumor microenvironment.…”

Evaluation of Stability and Accuracy Compared to the Westergren Method of ESR Samples Analyzed at VES-MATIC 5

“…The guidelines for the definition and determination of reference intervals indicate that partitioning should be considered when there are significant differences among subgroups defined by age, sex, and common exposures [ 5 , 21 ]. The ESR increases with age in adults, and at a given age is higher in females than in males [ 5 , 11 , 22 , 23 , 24 ].…”

“…In 2017, the ICSH group published new recommendations, stressing the importance of ensuring that measurements obtained in different laboratories were comparable [ 7 ]. ICSH and CLSI therefore made new recommendations in 2010 and 2011 [ 23 , 26 ]. The ICSH document recognized that automated methods were routinely used in many laboratories, using diluted or undiluted samples.…”

“…The ICSH has recently proposed a classification of commercialized ESR methods [ 7 ] proposed by the companies to shorten the time of the ESR measurement [ 22 ] and increase the laboratory turnaround time (TAT). In addition to the gold standard, two other categories of ESR methods are defined: the modified Westergren method, which is based on Westergren methodology with acceptable modifications, including shorter analysis times and the use of anticoagulants other than citrate, and the alternative method incorporating new technologies for ESR measurement [ 7 , 23 ]. The adoption of these semi-automatic and fully automated systems brings numerous advantages, in addition to the reduction of the analysis times, such as a decrease in the costs of the sampling devices and the blood volume necessary for the test.…”

“…The adoption of these semi-automatic and fully automated systems brings numerous advantages, in addition to the reduction of the analysis times, such as a decrease in the costs of the sampling devices and the blood volume necessary for the test. Moreover, the use of ethylenediaminetetraacetic acid (EDTA) anticoagulant blood improves sample stability [ 24 ], and the introduction of analyzers running these samples makes it possible to employ the whole blood sample withdrawn for other hematology tests [ 22 ], as well as for ESR measurement, providing patient and operator safety, reducing sample handling, and streamlining workflow [ 23 ]. The stability evaluation is a crucial aspect of the preanalytical phase to guarantee the diagnostic quality of laboratory results [ 20 ].…”