An unusual case of sodium citrate-dependent artifactual platelet count

Abstract

Background Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia is a rare phenomenon. Spurious pseudothrombocytopenia has also been described in other circumstances, while artifactual platelet count in whole blood samples anticoagulated with sodium citrate is an exceptional occurrence. Case report In this study, we describe the case of a 44-year-old ostensibly healthy woman who attended the local outpatient clinic for routine laboratory testing, including platelet count in EDTA and sodium citrate, for suspected artifactual pseudothrombocytopenia previously identified in another center. The results of hematological testing on both specimens were essentially normal, except for mild anemia. Nevertheless, the platelet number was 425 × 109/L in K2EDTA and 266 × 109/L (293 × 109/L after correcting for sample dilution) in sodium citrate, respectively. Microscopic revision of blood smears revealed the presence of platelet aggregates and satellitism only in the sodium citrate specimen. Conclusion Unlike previous occasional reports of concomitant EDTA- and sodium citrate-dependent pseudothrombocytopenia, we first describe a paradigmatic case of artifactual platelet count attributable to platelet clumping and satellitism, exclusively developing in blood anticoagulated with sodium citrate.

Influence of different methods and anticoagulants on platelet parameter measurement

“…For example, EDTA, the standard anticoagulant for platelet counting, causes a time-dependent platelet shape change with consecutive spontaneous platelet activation, and, in rare cases, the EDTA-dependent PTCP can lead to misdiagnosis. Since this phenomenon has also been described for citrate and heparin [29,30,32], a reliable alternative for the correct estimation of platelet counts in suspected PTCP is MgSO 4 [34].…”

“…The basis of an EDTA-dependent PTCP is auto-antibodies directed against the platelet fibrinogen receptor GpIIb/IIIa, which is unmasked by EDTA [14]. Since such a phenomenon has also been described for other in vitro anticoagulants [29], partial combined incompatibilities occur [30][31][32][33], and the in vitro agglutination does not necessarily lead to a platelet count that defines as thrombocytopenia [34], the correct term should be "anticoagulant-induced platelet agglutination. "…”

Variation in Parameters of Complete Blood Count Using Ethylene Diamine Tetra Acetic Acid (EDTA), Sodium Citrate and Lithium Heparin: A Cross-Sectional Study

“…When comparing PLT levels between blood samples treated with K2EDTA, sodium citrate, and lithium heparin, a notable decrease in PLT counts in samples observed treated with sodium citrate and lithium heparin compared to those treated with EDTA. In other studies that involved patients with pseudo thrombocytopenia, PLT was found to be higher among those treated with sodium citrate than EDTA [13][14][15]. According to a study, reduced PLT count might result from the potent activation of platelets by citrate in ill animals, forming small platelet aggregates.…”

Variations in the full blood count parameters among apparently healthy humans in the Ho municipality using ethylenediamine tetraacetic acid (EDTA), sodium citrate and lithium heparin anticoagulants: A laboratory-based cross-sectional analytical study

“…Considering EDTA as the most widely used anticoagulant in the estimation of FBC particularly because of its ability to irreversibly sequester ionized calcium (Ca 2+ ), thus permanently inhibiting blood coagulation and enabling a better stability of anticoagulated blood for purposes of cell enumeration and sizing [ 5 , 28 , 29 ], this study further assessed the agreement of heparin and citrate anticoagulants using K 3 EDTA as the reference standard. Surprisingly, heparin produced almost perfect agreement only in the assessment of RBC while a substantial agreement was observed in the assessment of HGB, HCT and MCH.…”