EDTA-induced pseudothrombocytopenia in association with bladder cancer

Transient EDTA-dependent pseudothrombocytopenia and ulcerative colitis recurrence during chemotherapy: A case of misleading platelet count results attributable to a laboratory artifact

Key Clinical Message

EDTA-dependent pseudothrombocytopenia as well as myelosuppression should be suspected when thrombocytopenia occurs in patients with autoimmune disease during chemotherapy.

Abstract

A patient with pancreatic cancer and ulcerative colitis developed transient ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia with exacerbation of ulcerative colitis during chemotherapy. Unfortunately, pseudothrombocytopenia could not be immediately detected because thrombocytopenia was masked by a reasonable time course of adverse events associated with chemotherapy and ulcerative colitis recurrence. When thrombocytopenia occurs during chemotherapy, especially in patients with autoimmune diseases, EDTA-dependent pseudothrombocytopenia and bone marrow suppression caused by anti-cancer agents should be suspected.

Ethylene Diamine Tetra Acetate-Induced Pseudo Thrombocytopenia (EDTA-PTCP) in an Adolescent: A Case Report

Ethylene diamine tetra acetate-induced pseudo thrombocytopenia (EDTA-PTCP) is a fictitious laboratory condition that is associated with platelet clumping, leading to falsely low platelet counts. This fictitious occurrence can lead to expensive, time-consuming, and invasive diagnostic procedures. It may also result in the application of unnecessary therapies, although it is not linked to any hemorrhagic symptoms or platelet malfunction. This emphasizes the necessity of verifying laboratory results from automated analyzers in every patient with thrombocytopenia with a peripheral smear, particularly when they are out of proportion when compared to the clinical features. When using hematology analyzers, EDTA-induced pseudo thrombocytopenia can be missed. In cases of isolated thrombocytopenia, this can be easily avoided by performing a simple visual peripheral blood smear check, hence making it an important differential for thrombocytopenia on an automatic analyzer report, which has to be ruled out. Here, we present the case of an adolescent who presented to us with low platelet counts and was diagnosed with EDTA-PTCP after proper evaluation.

Generalized Edema and Pseudothrombocytopenia After ChAdOx1 nCoV-19 COVID-19 Vaccination: A Case Report

Reports of side effects of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasing worldwide. Capillary leak syndrome and vaccine-induced immune thrombotic thrombocytopenia are very rare but life-threatening adverse events that should be identified early and treated. However, isolated thrombocytopenia can indicate pseudothrombocytopenia. In certain people, ethylenediaminetetraacetic acid (EDTA) induces an in vitro platelet aggregation, resulting in misleading underestimation of platelet counts. It is essential to recognize pseudothrombocytopenia to prevent diagnostic errors, overtreatment, anxiety, and unnecessary invasive procedures. We present a case who developed generalized edema and persistent pseudothrombocytopenia after the first dose of the ChAdOx1 nCoV-19 vaccine (AstraZeneca).

Efficacy of point-of-care thromboelastography 6s to evaluate platelet function in a patient with pseudothrombocytopenia undergoing cardiopulmonary bypass: a case report

BACKGROUND

Pseudothrombocytopenia is a phenomenon caused by in vitro platelet aggregation induced by anticoagulants contained in blood sampling tubes. Thromboelastography (TEG) 6s is a common point-of-care viscoelastic test to assess intraoperative coagulation status, which may reduce the need for blood transfusions. The reliability and usefulness of TEG6s for patients with pseudothrombocytopenia has not been established.

CASE PRESENTATION

We present a patient with pseudothrombocytopenia, who underwent suprarenal abdominal aortic aneurysm repair under cardiopulmonary bypass. At the beginning of surgery, TEG6s with citrated blood sampling showed that the results were unaffected by the disease. After completion of the aortic repair and the administration of protamine, maximum amplitude of TEG6s and adequate hemostasis were achieved without platelet transfusions, while standard laboratory tests showed thrombocytopenia.

CONCLUSIONS

In the present patient who underwent cardiopulmonary bypass, TEG6s may have contributed to a reliable and useful assessment of coagulation and hemostatic status avoiding unnecessary platelet transfusions.

Pseudothrombocytopenia-A Review on Causes, Occurrence and Clinical Implications

Pseudothrombocytopenia (PTCP), a relative common finding in clinical laboratories, can lead to diagnostic errors, overtreatment, and further (even invasive) unnecessary testing. Clinical consequences with potential life-threatening events (e.g., unnecessary platelet transfusion, inappropriate treatment including splenectomy or corticosteroids) are still observed when PTCP is not readily detected. The phenomenon is even more complex when occurring with different anticoagulants. In this review we present a case of multi-anticoagulant PTCP, where we studied different parameters including temperature, amikacin supplementation, measurement methods, and type of anticoagulant. Prevalence, clinical risk factors, pre-analytical and analytical factors, along with clinical implications, will be discussed. The detection of an anticoagulant-dependent PTCP does not necessarily imply the presence of specific disorders. Conversely, the incidence of PTCP seems higher in patients receiving low molecular weight heparin, during hospitalization, or in men aged 50 years or older. New analytical technologies, such as fluorescence or optical platelet counting, will be soon overturning traditional algorithms and represent valuable diagnostic aids. A practical laboratory approach, based on current knowledge of PTCP, is finally proposed for overcoming spuriously low platelet counts.

An Episode of Pseudothrombocytopenia during Pembrolizumab Therapy in NSCLC Patient

Immunotherapy with immune checkpoint inhibitors (ICI) is a new option of treatment in a growing range of neoplasms. In addition to an antitumor effect, ICI are associated with autoimmune reactions resulting in a wide spectrum of toxicities that have not been seen in patients receiving chemotherapy. In this article, we present a case of a patient with advanced lung adenocarcinoma who developed an EDTA-dependent pseudothrombocytopenia (PTCP) during pembrolizumab therapy. To the best of our knowledge, this is the first reported case of EDTA-dependent PTCP occurring during immunotherapy treatment of nonsmall lung cell cancer with ICI. The phenomenon of EDTA-dependent PTCP may prompt clinical decisions, as unnecessary transfusions or even exclusion from pembrolizumab therapy. Therefore, it is important to be aware of PTCP as a possible side effect of this therapy.

Pseudothrombocytopenia in Patients with Scrub Typhus Infection

Pseudothrombocytopenia is an ex vivo EDTA-dependent artefactual thrombocytopenia, that has been described in association with several conditions. When EDTA-blood samples are drawn from patients with pseudothrombocytopenia and analysed by automated cell counters, low platelet counts are obtained (often below 50,000/mm³). However, simultaneous heparinised samples show normal platelet counts, and peripheral smears show no reduction in numbers of platelets. We report a series of 12 patients with scrub typhus infections and pseudothrombocytopenia. An association between these two entities has only recently been appreciated. It appears that pseudothrombocytopenia may sometimes accompany acute scrub typhus infections. The distinction between pseudothrombocytopenia and true thrombocytopenia is of great clinical relevance, as the former is merely a laboratory artefact, and does not require blood product transfusions despite apparently severe reductions in platelet counts. It is therefore important to recognise that apparent thrombocytopenia, especially in patients with an acute febrile illness due to scrub typhus, is not always true thrombocytopenia.

Spurious Thrombocytopenia in Automated Platelet Count

Spurious thrombocytopenia is a well-known phenomenon observed with the widespread use of hematology analyzers (HAs). In this study, 355 specimens with pseudo-thrombocytopenia (PTCP) were evaluated via epidemiology, identification, remedies, and platelet (PLT) count. Data showed that anticoagulants such as citrate and/or heparin-dependent PTCP (16.0%) became increasingly common, whereas ethylenediaminetetraacetic acid (EDTA)-induced PTCP (49.1%) remained the most frequent. We note that that nearly half of the patients with PTCP had veritable decreased PLT counts, even after PLT levels had been corrected. Our findings suggest that there were seasonal changes in patients with PTCP: PLT levels were higher in spring, compared with other seasons, with winter levels being the lowest. There were higher risks of PTCP for individuals with malignant neoplasms, liver diseases, infection, and hematologic disease, compared with other conditions. PTCP is related to diseases, rather than being a simple phenomenon, and thus demands careful attention.

Transient appearance of EDTA-dependent pseudothrombocytopenia in a postoperative patient with sepsis: A case report

RATIONALE

Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia (EDTA-PTCP) is a rare phenomenon characterized by spuriously low platelet counts when EDTA reacts with harvested blood. However, to the best of our knowledge, only two cases involving EDTA-PTCP in postoperative patients with sepsis have been reported. Here, we describe a case of EDTA-PTCP that appeared transiently in a postoperative patient with sepsis.

PATIENT CONCERNS

A 68-year-old female patient underwent laparoscopic tension-free hernioplasty for incisional hernia. Postoperatively, the patient developed very low platelet counts. The number of platelets in this patient had not improved following treatment with fresh-frozen plasma and platelet transfusions.

DIAGNOSES

The diagnosis of EDTA-PTCP was confirmed from the discovery of platelet aggregation in peripheral blood smears.

INTERVENTIONS

We used sodium citrate-anticoagulated blood samples for platelet counting.

OUTCOMES

The patient's platelet counts returned to normal with the use of sodium citrate-anticoagulated blood samples. Furthermore, the phenomenon of EDTA-PTCP disappeared when the patient was cured.

LESSONS

The phenomenon of low platelet counts in postoperative patients with sepsis should be considered as possible EDTA-PTCP. In addition, peripheral blood smears and the use of sodium citrate anticoagulant are effective and valuable methods that can help identify EDTA-PTCP.