Standardisation of platelet counting accuracy in blood banks by reference to an automated immunoplatelet procedure: comparative evaluation of Cell-Dyn CD4000 impedance and optical platelet counts

摘要: Prophylactic and therapeutic platelet transfusions are increasingly used for patients with conditions associated thrombocytopenia in order to prevent the development of potentially life threatening bleeding. These clinical strategies have led a significant expansion unit manufacture, this now represents major resource cost commitment blood banks. As part manufacturing process, banks required implement control procedures, determination counts particular is necessary confirm that quality production meets standards defined by national or international guidelines. Apart from linearity analysis comparisons given different instruments, there has been no systematic standardisation counting methods bank practice because date suitable reference method platelets citrate anticoagulants. The recent introduction an automated immunoplatelet procedure on Cell-Dyn CD4000 provides means determining true count unaffected changes induced either storage anticoagulant. its routine configuration also simultaneous impedance optical study was therefore undertaken compare all three parallel representative series units. Platelet determined after sub-sampling units into EDTA vs plain non-anticoagulated tubes revealed differences but generally lower when aliquoted did not contain EDTA. This routinely sub-samples. Comparative results buffy coat (n = 36) indicated higher than mean factor 1.25 while 0.87. degree overestimation particularly consistent underestimation more variable. Linearity studies 10 fresh showed deviation range 0-2305 x 10(9) l(-1) 0 1420 counts, relative numerical relationships between were conserved throughout dilutions tested. In analysis, samples anticoagulated distinctive elliptical population distribution fell within system thresholds. contrast, pattern observed (in CPD) ACD-anticoagulated venous wider 90 degrees scatter events above upper discriminator. these excluded (but still identified as method) it meant citrate-based anticoagulants systematically counts. 15) analysed daily over seven day period greatest decline measurement most stable value obtained analysis. further suggested progressive increase small increasing time. use standardised examine question analyser suitability counts/yields thus provided number important findings. An utilised great majority haematology instruments current use, common analyser, correction employed take account RBC/platelet coincidence. found such RBC-free, inappropriate applied. Consequently, will provide reliable irrespective storage, applied system-reported result. By comparison, likely be affected subtle morphological may result limitations documented well affect many other analysers implementation process statistics related less previously assumed. It could much better achieved if some form cross-calibration referenced independent assay. proposed type should extended wide assessment accuracy standardise data organisations. If inter-instrument factors those here can identified, would considerably relevance processes.