Razi Journal of Medical Sciences

Background: Cold antibody induced platelet clumping is a rare in-vitro phenomenon that causes EDTA independent pseudo thrombocytopenia. This pre-analytical problem leads to a challenge in the clinical laboratory. In such a case platelets tend to easily aggregate in vitro, giving rise to lower platelet counts. The error is detected simply by examining peripheral blood smear. This report describes a 77 year old man with colon cancer who has received 10 units of random donor platelets due to an analytical error.

Case report: Blood sample was collected on EDTA and sodium citrate anticoagulants and counted in different times and various temperatures by cell counter to detecting the cause of thrombocytopenia. The patient had no signs of bleeding. Platelet count was 164000/µl immediately after sampling but declined sharply after 5 minutes. Platelet clumps was seen at the end of peripheral blood smear. We conclude that cold agglutination induced pseudothrombocytopeniais rare phenomenon which resulting in misleading laboratory results.

Conclusion: This condition should be considered in severe thrombocytopenia without abnormal bleeding manifestation. Since the cold coantibodies did not affect platelet function, this patients will not suffer complications from their platelet cold agglutinin, but it could pose a problem under circumstances such as extensive surgery with associated with hypothermia