| Process | Platelet clumping |
| Definition | Presence of platelet clumps (size not specified) on peripheral smear |
| Ddx | In addition to anti-platelet antibodies, platelet clumping may be caused by pre-analytic errors such as over-filled or under-filled EDTA tubes, clotted specimens, or a time delay between sample collection and testing. |
| Conditions associated with the process | Platelet clumping may lead to erroneous platelet count |
| Mechanism | Platelet clumping is most commonly caused by pre-analytic errors such as improper or delayed sample mixing, clotted sample, over-filled or underfilled tubes, and time delay between sample collection and testing. It can also be an ex vivo phenomenon due to EDTA-dependent antibodies. Occasionally this may occur in due to infections, drugs, cold agglutinins or immunoglobulins. |
| History | First reported in 1969 |
| Source/author | William Aird |
| Reviewed and edited by | Parul Bhargava |
| References | J Clin Med 2021;10:594 |
