Pseudothrombocytopenia masking true thrombocytopenia.

Area of Science:

• Hematology
• Clinical Pathology
• Immunology

Background:

• Pseudothrombocytopenia is a common laboratory finding often caused by platelet clumping in ethylenediaminetetraacetic acid (EDTA) anticoagulated blood.
• Cold agglutinins, particularly IgM antibodies, can also induce pseudothrombocytopenia when blood samples are processed at room temperature.

Observation:

• A patient presented with pseudothrombocytopenia that was not associated with EDTA or cold agglutinins.
• This unique agglutinin was temperature-independent and EDTA-independent, complicating diagnosis.
• The pseudothrombocytopenia was masking a concurrent true thrombocytopenia.

Findings:

• The study reports a rare case of pseudothrombocytopenia caused by a novel temperature-independent, EDTA-independent platelet agglutinin.
• This agglutinin led to significant underestimation of platelet counts, mimicking true thrombocytopenia.
• A specific blood collection technique was developed to accurately assess platelet counts in this challenging case.

Implications:

• Accurate platelet count determination is critical for diagnosing and managing hematological disorders.
• This case underscores the importance of recognizing non-standard causes of pseudothrombocytopenia.
• The described blood collection method offers a valuable tool for similar clinical scenarios, improving diagnostic accuracy.