Effects of Blood Storage Time and Temperature on Döhle Body or Döhle Body-like Inclusions in Feline Neutrophils

Background: Detecting Döhle body inclusions in cat neutrophils is one of the most relevant toxic changes with clinical significance. It is necessary to study pre-analytical factors such as temperature and blood storage time on the formation of these toxic changes. Objectives: The present study sought to investigate the impact of blood storage time and temperature on Döhle or Döhle-like inclusions in cat neutrophils. Methods: Ethylenediaminetetraacetic acid (EDTA) blood samples were obtained from 8 cats without evidence of Döhle inclusions on fresh blood smears (T0). Samples were stored at room temperature (RT) and 4°C as routine storage temperatures of samples in the laboratory. Smears were prepared 2 (T2), 4 (T4), 8 (T8), and 24 (T24) hours following the blood draw for each storage condition. Döhle or Döhle-like inclusions were assessed on each smear randomly selected. Results: The percentages of neutrophils with Döhle or Döhle-like inclusions in T8 and T24 increased significantly at RT and 4°C, respectively (P<0.001) compared to T0. The smears prepared from blood samples stored at RT contained more neutrophils with Döhle or Döhle-like inclusions than 4°C. A significant difference was not found in the percentages of neutrophils with these inclusions between the two temperatures at any storage times. Conclusion: The development of Döhle body-like in cat neutrophils occurs when the analysis is delayed, especially at higher storage temperatures. This condition may affect diagnosis and clinical decisions. Therefore, the blood smears should be prepared as soon as the blood is drawn to reduce pre-analytical changes.