Impact of pre-analytical variables - temperature, agitation, storage duration, and blood-to-anticoagulant ratio - on complete blood count test reliability.
Author(s): Al-Najdawi MA, Fararjeh AS, Khataibeh M
Publication: Med Pharm Rep, 2025, Vol. 98, Page 452-460
PubMed ID: 41221466 PubMed Review Paper? No
Purpose of Paper
This paper compared complete blood count (CBC) parameters in case-matched blood specimens from optimally and suboptimally (50%) filled tubes that were transported with or without agitation and then stored at 4°C or room temperature for up to 24 h.
Conclusion of Paper
The measured uncertainty margins of the instrument were ±1.5% for counts of red blood cells (RBC) and white blood cells (WBC), ±1.2% for hemoglobin (Hb) levels , ±2.0% for platelet counts, ±1.8% for red cell distribution width (RDW), and ±1.5% for mean platelet volume (MPV). The authors report (data not shown) that agitation did not impact counts of WBC, RBC, neutrophils, lymphocytes or platelets , hemoglobin levels, mean corpuscular volume (MCV), MPV, packed cell volume (PCV) or red cell distribution width (RDW). The authors report that specimens with optimal fill volumes showed slightly more stable platelet and neutrophil counts than tubes filled suboptimally (50% fill), but the effect size was small and no effect was observed for the remaining parameters investigated. WBC declined progressively with storage at either 4°C or room temperature, with a greater decrease observed when tubes were stored at room temperature than 4°C. The WBC decrease exceeded the uncertainty margin (±1.5%) when tubes were stored at either temperature for ≥12 h, and decreased by 6% and 5.7% after 24 h at room temperature and 4°C, respectively. While RBC counts and hemoglobin levels declined when blood was stored at either temperature, the declines only exceed the measurement uncertainty when blood was stored at room temperature for 24 and ≥12 h, respectively (RBC -2.21%, P<0.05 at 24 h and hemoglobin -1.5%, P<0.05 at 12 h and -2.28%, P<0.05 at 24 h). Platelet count declined with storage, declining more rapidly when blood was stored at 4°C than room temperature; the first declines in platelet count that exceeded measurement uncertainty occurred after storage for 12 h at either temperature, with declines of 8.1% and 5.2% (P<0.001, both) observed after 24 h of storage at 4°C and room temperature, respectively. The authors report that MPV remained stable during the storage timecourse, but that lymphocyte and neutrophil counts declined more rapidly when blood was stored at room temperature compared to 4°C. MCV and RDW increased with blood storage, but only exceeded the measurement uncertainty threshold when stored at room temperature for 24 h (P<0.001, both). Based on their findings, the authors identify the maximum acceptable delay for each parameter; however, they note that blood storage at 4°C for ≤12 h is suitable for all of the analytes evaluated.
Studies
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Study Purpose
This study compared complete blood count (CBC) parameters in case-matched blood specimens from optimally and suboptimally (50%) filled tubes that were transported with or without agitation and then stored at 4°C or room temperature for up to 24 h. Blood was collected from eight healthy volunteers into four different K₂EDTA Vacutainer tubes. Two tubes were properly filled with 2 mL of blood and two were filled with 1 mL. One properly filled and one improperly filled tube from each volunteer were subjected to agitation (1–5 Hz and 25–80 mm/s² Root Mean Square acceleration) during transport, while the matched tubes were transported without agitation. Blood specimens were then split and stored at 4°C and room temperature for 0, 4, 12 and 24 h before complete blood count using a DIAGON D-Cell 60 hematology analyzer.
Summary of Findings:
The measured uncertainty margins of the instrument were ±1.5% for counts of red blood cells (RBC) and white blood cells (WBC), ±1.2% for hemoglobin (Hb) levels, ±2.0% for platelet counts, ±1.8% for red cell distribution width (RDW), and ±1.5% for mean platelet volume (MPV). The authors report (data not shown) that agitation did not impact counts of WBC, RBC, neutrophils, lymphocytes or platelets, hemoglobin levels, mean corpuscular volume (MCV), MPV, packed cell volume (PCV) or red cell distribution width (RDW). The authors report that specimens with optimal fill volumes showed slightly more stable platelet and neutrophil counts than tubes filled suboptimally (50% fill), but the effect size was small and no effect was observed for the remaining parameters investigated. WBC declined progressively with storage at either 4°C or room temperature, with a greater decrease observed when tubes were stored at room temperature than 4°C. The WBC decrease exceeded the uncertainty margin (±1.5%) when tubes were stored at either temperature for ≥12 h, and decreased by 6% and 5.7% after 24 h at room temperature and 4°C, respectively. While RBC counts and hemoglobin levels declined when blood was stored at either temperature, the declines only exceed the measurement uncertainty when blood was stored at room temperature for 24 and ≥12 h, respectively (RBC -2.21%, P<0.05 at 24 h and hemoglobin -1.5%, P<0.05 at 12 h and -2.28%, P<0.05 at 24 h). Platelet count declined with storage, declining more rapidly when blood was stored at 4°C than room temperature; the first declines in platelet count that exceeded measurement uncertainty occurred after storage for 12 h at either temperature, with declines of 8.1% and 5.2% (P<0.001, both) observed after 24 h of storage at 4°C and room temperature, respectively. The authors report that MPV remained stable during the storage timecourse, but that lymphocyte and neutrophil counts declined more rapidly when blood was stored at room temperature compared to 4°C. MCV and RDW increased with blood storage, but only exceeded the measurement uncertainty threshold when stored at room temperature for 24 h (P<0.001, both). Based on their findings, the authors identify the maximum acceptable delay for each parameter; however, they note that blood storage at 4°C for ≤12 h is suitable for all of the analytes evaluated.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Cell count/volume Hematology/ auto analyzer Protein Hematology/ auto analyzer Morphology Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Specimen transport duration/condition With agitation
No agitation
Biospecimen Aliquots and Components Aliquot size/volume 1 ml (50% fill)
2 ml (100% fill)
Storage Storage duration 0 h
4 h
12 h
24 h
Storage Storage temperature 4°C
Room temperature