Mixed cryoglobulinemia and platelet counts

 Q: Mixed cryoglobulinemia may give false? (select one) 

A) thrombocytosis 

B) thrombocytopenia

Answer: A

The objective of this question is to highlight the importance of blood smears. In many conditions, automated counter machines may give erroneous values. One example is mixed cryoglobulinemia. When a blood sample is tested at a temperature ≤30°C, precipitated cryoglobulin particles get falsely counted as platelets. To obtain true platelet count in a patient with mixed cryoglobulinemia the blood sample needs to be maintained at body temperature until the testing. 

Other conditions which may cause pseudothrombocytosis by the automated counter machine are leukemia or lymphoma cells, hemolysis, or burns where circulating cytoplasmic fragments or fragmented red cells may be falsely read as platelets.

#hematology

#lab-medicine

References:

1. Hutchinson CV, Stelfox P, Rees-Unwin KS. Needle-like cryoglobulin crystals presenting as spurious thrombocytosis. Br J Haematol 2006; 135:280. 

2. Ballard HS, Sidhu G. Cytoplasmic fragments causing spurious platelet counts in hairy cell leukemia: ultrastructural characterization. Arch Intern Med 1981; 141:942. 

3. Berkessy S. [Cytoplasm fragmentation of malignant lymphoma cells]. Folia Haematol Int Mag Klin Morphol Blutforsch 1983; 110:651. 

4. Lawrence C, Atac B. Hematologic changes in massive burn injury. Crit Care Med 1992; 20:1284.