Multicenter study of an erythro-aggregometer: quality control and standardization

Area of Science:

• Hemorheology and clinical diagnostics
• Biomedical engineering and instrumentation

Background:

• Quality assurance is essential for hemorheology, particularly in clinical and pharmacological studies.
• Standardized methods and calibrated instruments are needed for interpretable and comparable hemorheological data.
• Previous work involved preparing standardized red blood cells (RBC) and optimizing storage conditions.

Purpose of the Study:

• To compare erythro-aggregometers (EA) from the same brand across multiple laboratories.
• To evaluate a newly developed protocol for the standardization of EA measurements.
• To assess the precision and accuracy of EA measurements using standardized conditions.

Main Methods:

• Six laboratories participated, using identical standardized RBC and suspending media (SM).
• Erythro-aggregometers were calibrated and tested using laser backscattering to measure aggregation time (AT), partial dissociation threshold (PDT), and aggregation index (AI).
• Within-assay precision (WAP) and between-assay precision (BAP) were assessed over several days and months, respectively. Accuracy was evaluated using RBCs of unknown aggregability.

Main Results:

• Good agreement was observed between 5 out of 6 centers for all three EA parameters.
• Within-assay precision was good, with low coefficients of variation (CV) for AT (1.4–2.5%).
• Between-assay precision showed slightly lower values than WAP but demonstrated no significant drift, with better precision observed using hyperaggregable HS than normal NS suspending media.

Conclusions:

• A protocol for the standardization of erythro-aggregometry has been successfully developed and evaluated.
• This standardized protocol enables effective quality control for EA techniques.
• The study highlights the importance of RBC parameters in rheological data and provides a foundation for reliable hemorheological measurements.