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Published on: February 8, 2019
Ethylenediaminetetraacetic acid-dependent pseudomacrocytosis
Jose Manuel Vagace1, Miguel Ángel Rodriguez, María Dolores de la Maya
1Department of Pediatric Hematology, Materno Infantil Hospital, Badajoz, Spain. jvagacev@aehh.org
Abstract:
We investigated the case of a 14-year-old girl with an ethylenediaminetetraacetic acid (EDTA)-dependent haemagglutination detected by macrocytosis, which was only evident by an abnormal red blood cell (RBC) population in the histogram. Investigations included haemograms with different anticoagulants and experimental conditions. Immunohaematological studies were performed using a gel-based technology. At admission, the patient had a low RBC count and an increased mean corpuscular volume with normal haemoglobin. A double population appeared in the RBC histogram. However, the peripheral blood smear was normal and macrocytosis was absent when heparin or citrate was used instead of EDTA. Later studies revealed that the patient's serum was able to induce macrocytosis of control RBC only in the presence of EDTA. An EDTA-dependent panagglutinin was then indentified that produced mixed field agglutination. These findings provide evidence of a haemagglutination induced by EDTA as a source of pseudomacrocytosis.
Insights
An EDTA-dependent panagglutinin caused red blood cell (RBC) agglutination, mimicking macrocytosis in a 14-year-old girl. This pseudomacrocytosis resolved when using heparin or citrate instead of EDTA.
Area of Science:
- Hematology
- Immunology
- Clinical Pathology
Background:
- Investigated a 14-year-old female patient presenting with an abnormal red blood cell (RBC) histogram.
- Observed macrocytosis evident only in histograms using ethylenediaminetetraacetic acid (EDTA) as an anticoagulant.
Observation:
- Peripheral blood smears were normal, and macrocytosis was absent when using heparin or citrate.
- Patient's serum induced macrocytosis in control RBCs exclusively in the presence of EDTA.
Findings:
- Identified an EDTA-dependent panagglutinin responsible for mixed-field agglutination.
- Confirmed ethylenediaminetetraacetic acid (EDTA)-dependent hemagglutination as the cause of pseudomacrocytosis.
Implications:
- Highlights the importance of considering anticoagulant choice in interpreting automated blood counts.
- Underscores the need for specific immunohaematological investigations in cases of unexplained red blood cell abnormalities.
- Provides insight into EDTA-dependent phenomena and their clinical diagnostic challenges.
