Ethylenediaminetetraacetic Acid-dependent Platelet Aggregation, Satellitism, and Phagocytosis in a Case in Which Aggregation was Resolved using Kanamycin Blood Collection Tubes

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Hiroki Doi
Yuri Seki
Katsuma Sakaizawa
Kaisei Ryu
Michiko Osawa
Seiko Sato
Hideaki Matsuura
Masato Hoshi
Hidehiko Akiyama
Hiroyasu Ito


BACKGROUND: This study aimed to investigate ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia (EDTA-PTCP) a rare but significant phenomenon in clinical laboratories that cause diagnostic errors and unnecessary treatments.

CASE PRESENTATION: Here, we present an 83-year-old male patient with dyspnea and blood sputum and illustrate how EDTA, commonly used in complete blood count testing, causes falsely low platelet counts due to platelet aggregation and phagocytosis. Initially, the patient’s blood tested by the impedance method with a Sysmex XN-3000 analyzer demonstrated abnormally low platelet counts. However, further tests using different assays (fluorescent platelet count) and anticoagulants indicated the presence of EDTA-PTCP. Blood smear revealed platelet aggregation, satellitism, and phagocytosis that predominantly involve neutrophils. Remeasurements demonstrated significant improvement in platelet count and histogram waveform after incorporating K2-EDTA-added blood to K2-EDTA + kanamycin (KM)-containing vacutainer. These results indicate that remeasuring platelet counts after dissociation of platelet aggregation in EDTA-added blood with an additive such as KM is an effective method of handling EDTA-PTCP when platelet aggregation is observed. In addition, in vitro mixing studies were conducted with healthy control using platelet-poor plasma (PPP), prepared from EDTA and EDTA + KM blood collection tubes. It demonstrated that adding PPP from EDTA + KM tubes to whole blood did not decrease platelet count over time, unlike PPP from EDTA tubes. This revealed that KM, an aminoglycoside antibacterial agent, inhibited platelet aggregating factors in the patient’s plasma. The patient’s positive results for anti-ds-DNAIgG antibodies indicated active systemic lupus erythematosus, emphasizing a potential immunological mechanism of EDTA-PTCP in autoimmune diseases.

CONCLUSION: The study reveals that EDTA causes platelet satellitism and phagocytosis by leukocytes, although the exact mechanism of EDTA-induced platelet phagocytosis remains unclear. In conclusion, this case demonstrates that using blood collection tubes other than those containing EDTA salt is a viable option in various laboratories, emphasizing the need for awareness and appropriate management of EDTA-PTCP in clinical practice.


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Doi H, Seki Y, Sakaizawa K, Ryu K, Osawa M, Sato S, Matsuura H, Hoshi M, Akiyama H, Ito H. Ethylenediaminetetraacetic Acid-dependent Platelet Aggregation, Satellitism, and Phagocytosis in a Case in Which Aggregation was Resolved using Kanamycin Blood Collection Tubes. SEE J Immunol [Internet]. 2024 Jan. 30 [cited 2024 Apr. 16];7:33-8. Available from:
Clinical Immunology


Gunawardena D, Jayaweera S, Madhubhashini G, Lokumarakkala DD, Senanayake SJ. Reliability of parameters of complete blood count with different storage conditions. J Clin Lab Anal. 2017;31(2):e22042. PMid:27565129

Chen S, Mao Z, Wang S, Deng J, Liao H, Zheng Q. Micro-red blood cell, fragmented red blood cell, platelet distribution width, mean platelet volume, and platelet-large cell ratio on Sysmex XN series hematology analyzers can be used for the reflex test of impedance platelet count in clinical practice. Arch Pathol Lab Med. 2024;148(1):61-7. PMid:37014982

Takeda MR, Vergara-Lluri ME. Investigating “Leukocytosis” and “Schistocytes” and uncovering hematologic artifacts. J Appl Lab Med. 2021;6(6):1677-82. PMid:34411250.

Lin J, Luo Y, Yao S, Yan M, Li J, Ouyang W, et al. Discovery and correction of spurious low platelet counts due to EDTA- dependent pseudothrombocytopenia. J Clin Lab Anal. 2015;29(5):419-26. PMid:25425098

Yoneyama A, Nakahara K. [EDTA-dependent pseudothrombocytopenia--differentiation from true thrombocytopenia]. Nihon Rinsho 2003;61(4):569-74. PMid:12718077

Ohashi-Fukuda N, Inokuchi R, Sato H, Nakamura K, Iwagami M, Wada T, et al. Poorer prognosis with ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia: A single-center case-control study. Medicine (Baltimore). 2015;94(15):e674. PMid: 25881844

Jing J, Li J, Yu M. Ethylenediaminetetraacetic acid-induced pseudothrombocytopenia in association with graves’ hyperthyroidism. J Coll Physicians Surg Pak. 2022;32(12):SS146-8. PMid:36597320

Lippi G, Plebani M. EDTA-dependent pseudothrombocytopenia: Further insights and recommendations for prevention of a clinically threatening artifact. Clin Chem Lab Med. 2012;50(8):1281-5. PMid:22868791

Kjeldsberg CR, Swanson J. Platelet satellitism. Blood 1974;43(6):831-6.

Ryo R, Sugano W, Goto M, Takada M, Saigo K, Hashimoto M, et al. Platelet release reaction during EDTA-induced platelet agglutinations and inhibition of EDTA-induced platelet agglutination by anti-glycoprotein II b/III a complex monoclonal antibody. Thromb Res. 1994;74(3):265-72. PMid:8042193

Akbayram S, Dogan M, Akgun C, Caksen H, Oner AF. EDTA-dependent pseudothrombocytopenia in a child. Clin Appl Thromb Hemost. 2011;17(5):494-6. https://doi. org/10.1177/1076029610373367 PMid:20530050

Lardinois B, Favresse J, Chatelain B, Lippi G, Mullier F. Pseudothrombocytopenia-a review on causes, occurrence and clinical implications. J Clin Med. 2021;10(4):594. PMid:33557431

Ghariani I, Braham N, Hamzaoui S, Bekir L. Platelet satellitism in autoimmune hemolytic anemia. Curr Res Transl Med. 2017;65(2):61-4. PMid:28619392

John T, Thomas T, Abel B, Wood BR, Chalmers DK, Martin LL. How kanamycin A interacts with bacterial and mammalian mimetic membranes. Biochim Biophys Acta Biomembr. 2017;1859(11):2242-52. PMid:28847502

Tantanate C, Talabthong S, Lamyai P. Kanamycin supplement for the disaggregation of platelet clumps in EDTA- dependent pseudothrombocytopenia specimens. Lab Med. 2022;53(3):e69-73. PMid:34668538

Criswell KA, Breider MA, Bleavins MR. EDTA-dependent platelet phagocytosis. A cytochemical, ultrastructural, and functional characterization. Am J Clin Pathol. 2001;115(3):376-84. PMid:11242794

Lifson MA, Wakui M, Arai T, Mitsuhashi T, Lakos G, Murata M. Alinity hq platelet results are equivalent with the international reference method in thrombocytopenic samples. Int J Lab Hematol. 2021;43(6):1357-62. PMid:34224209

Schoorl M, Schoorl M, Oomes J, van Pelt J. New fluorescent method (PLT-F) on Sysmex xn2000 hematology analyzer achieved higher accuracy in low platelet counting. Am J Clin Pathol. 2013;140(4):495-9. PMid:24045545

Tanaka Y, Tanaka Y, Gondo K, Maruki Y, Kondo T, Asai S, et al. Performance evaluation of platelet counting by novel fluorescent dye staining in the XN-series automated hematology analyzers. J Clin Lab Anal. 2014;28(5):341-8. PMid:24648166

Sakurai S, Shiojima I, Tanigawa T, Nakahara K. Aminoglycosides prevent and dissociate the aggregation of platelets in patients with EDTA-dependent pseudothrombocytopenia. Br J Haematol. 1997;99(4):817-23. PMid:9432027

Knaak C, Nyvlt P, Schuster FS, Spies C, Heeren P, Schenk T, et al. Hemophagocytic lymphohistiocytosis in critically ill patients: Diagnostic reliability of HLH-2004 criteria and HScore. Crit Care. 2020;24(1):244. PMid:32448380

Irisawa A, Kaise S, Kumada Y, Sato Y, Nishimaki T, Kasukawa R, et al. A case of late-onset SLE complicated with EDTA-dependent pseudothrombocytopenia. Ryumachi 1992;32:468-74, discussion 472-3. [Japanese] PMid:1440083

Toishigawa K, Nakagawa H, Furuta T, Fukushima N. Platelet satellitism. Intern Med. 2018;57(13):1949. PMid:29434127

Amouroux I, Lesesve JF. Neutrophilic thrombophagocytosis. Morphologie. 2020;104(344):73-5. PMid:31521508

White LA Jr., Brubaker LH, Aster RH, Henry PH, Adelstein EH. Platelet satellitism and phagocytosis by neutrophils: association with antiplatelet antibodies and lymphoma. Am J Hematol. 1978;4(4):313-23. PMid:717393