Analysis of the temperature affects on leukocyte surface antigen expression

Area of Science:

• Immunology
• Clinical Pathology

Background:

• Flow cytometry is crucial for analyzing leukocyte surface antigens in infectious and septic conditions.
• Standardization of pre-analytical variables is essential for reliable immunophenotyping results.

Purpose of the Study:

• To evaluate the impact of sampling temperature, anticoagulant type, and storage duration on leukocyte immunophenotyping.
• To determine optimal conditions for preserving leukocyte surface antigen expression for flow cytometry.

Main Methods:

• Blood samples from sepsis patients and healthy volunteers were collected using heparin or acid citrate dextrose.
• Samples were processed at +4°C or room temperature (RT) and analyzed immediately, or after 6 or 24 hours of storage.
• Expression levels of key surface antigens (e.g., CD11b, CD64, CD14, HLA-DR, CD69) on neutrophils, monocytes, and lymphocytes were quantified.

Main Results:

• Higher fluorescence intensities were observed at RT compared to +4°C.
• Storage at RT led to increased fluorescence intensities, while +4°C resulted in minimal changes.
• The effects of temperature and storage were consistent regardless of the anticoagulant used.

Conclusions:

• Flow cytometric analysis of leukocyte surface antigens is significantly influenced by pre-analytical conditions.
• +4°C temperature throughout the process and analysis within 6 hours are recommended for optimal and reliable results.