A-133 iSED PRO: Utilizing Photometric Rheology to Modernize High Throughput Erythrocyte Sedimentation Rate Testing

Abstract Background ESR is a non-specific lab test for assessing or monitoring patients with inflammatory conditions and one of the most common lab tests in the world. Traditional ESR testing is done via the manual Westergren method, but many laboratories have adopted automated ESR analyzers to improve workflow. iSED PRO is the latest analyzer in the iSED ESR analyzer family, specifically designed to maximize efficiency for high-throughput labs. Results are available within 20 seconds with <1 second of hands-on time per sample, significantly reducing time to result and improving patient care. Methods The iSED PRO technology utilizes photometric rheology to assess rouleaux formation, the first step of RBC sedimentation. The degree of RBC aggregation determines the degree of sedimentation. RBCs are pumped into the analyzer’s flow cell which disaggregates the cells. When the pump stops, an optical sensor detects the changes in light transmission through the sample as RBCs aggregate. iSED PRO calculates an ESR value based on light transmission. Results Method Correlation (iSED PRO vs Westergren, n=200) was performed according to CLSI Procedure H02-A5 and yielded a regression equation of y=1.03x+1.58, 95% CI of the slope is 1.000 to 1.093, and 95% CI of intercept is -0.058 to 2.000. CuSum test is >0.05, showing no deviation from linearity. Paired T-Test shows equivalence. Average intrarun precision results are 6.0% for samples 0-30 mm/hr, 2.9% for samples 31-60 mm/hr, 2.4% for samples 61-90 mm/hr, and 2.9% for samples >90 mm/hr. Average interrun precision is 4.3%. Average carryover is 1.83%. Conclusion The iSED PRO’s photometric rheology based ESR measurement correlates with the current ESR reference method, and its modern approach to ESR analysis optimizes laboratory efficiency while rapid reproducible results benefit the patients.