Rapid accurate absolute granulocyte count determination during severe leukopenia using the flow cytometer

Area of Science:

• Hematology
• Clinical Pathology
• Laboratory Medicine

Background:

• Accurate determination of absolute granulocyte count (AGC) is crucial for managing leukopenic patients.
• Traditional methods like manual smear differentials can be time-consuming and labor-intensive.
• Existing automated methods may lack comprehensive validation for severely leukopenic samples.

Purpose of the Study:

• To compare the accuracy and efficiency of three methods for estimating AGC in patients with low white blood cell counts.
• To evaluate flow cytometry as a rapid and reliable alternative to manual methods for AGC determination.

Main Methods:

• Absolute granulocyte count (AGC) was estimated in 125 leukopenic blood samples using three techniques: Wright's-stained smear differential, WBC counting chamber estimates, and flow cytometry (light-scatter characteristics).
• Data from counting chamber and flow cytometry methods were compared to the smear differential standard using linear regression.
• Outliers were identified to assess method concordance.

Main Results:

• Excellent correlation was observed between the flow cytometry method and the smear differential standard (correlation coefficient = 0.970).
• Good correlation was found between the WBC counting chamber method and the smear differential (correlation coefficient = 0.911).
• The flow cytometry method required minimal sample preparation and yielded results within 60 seconds per sample.

Conclusions:

• Flow cytometry is a statistically reliable, rapid, and efficient method for determining AGC in leukopenic patients.
• The ease of sample preparation and speed of results make flow cytometry an attractive alternative to stained blood smear differentials.
• This automated approach can enhance laboratory workflow and diagnostic turnaround time for critical patient populations.