Comparison of three instruments for measuring red blood cell aggregation

Oguz K. Baskurt, Mehmet Uyuklu, Pinar Ulker, Melike Cengiz, Norbert Nemeth, Tamas Alexy, Sehyun Shin, Max R. Hardeman, Herbert J. Meiselman

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


The International Society for Clinical Hemorheology organized a workshop to compare three instruments for measuring RBC aggregation: LORCA, Myrenne Aggregometer and RheoScan-A. The Myrenne Aggregometer provides indices at stasis (M) and at low shear (M1), with four indices obtained with the LORCA and RheoScan-A: amplitude (AMP), half-time (T1/2), surface area (SA) above (LORCA) or below (RheoScan-A) the syllectogram, and the ratio (AI) of the area above (LORCA) or below (RheoScan-A) the syllectogram to total area (AI). Intra-assay reproducibility and biological variability were determined; also studied were RBC in diluted plasma and in 1% 500 kDa dextran, and 0.003% glutaradehyde (GA)-treated cells in plasma. All measurements were performed at 37°C. Standardized difference values were used as a measure of power to detect differences. Salient results were: (1) intra-assay variations below 5% except for RheoScan-A AMP and SA; (2) biological variability greatest for T 1/2 with other indices similar for the three devices; (3) all instruments detected progressive changes with plasma dilution; (4) the Myrenne and LORCA, but not the RheoScan-A, detected differences for cells in dextran; (5) GA-treatment significantly affected the LORCA (AMP, T1/2, SA, AI), the RheoScan-A (AMP, SA, AI) and the Myrenne M parameter. It is concluded that: (a) the LORCA, Myrenne and the RheoScan-A have acceptable precision and suitable power for detecting reduced aggregation due to plasma dilution; (b) greatly enhanced RBC aggregation may not be sensed by the RheoScan-A while the Myrenne M1 index may be insensitive to minor increases of cell rigidity; (c) future studies should define each instrument's useful range for detecting RBC aggregation.

Original languageEnglish (US)
Pages (from-to)283-298
Number of pages16
JournalClinical hemorheology and microcirculation
Issue number4
StatePublished - 2009


  • Erythrocyte aggregation
  • Intrumentation
  • Light reflectance
  • Light transmittance
  • Standardized difference


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