[Clinical evaluation of leukocyte differential count in peripheral blood by five-color flow cytometry]

To explore the clinical application values of five-color flow cytometry for leukocyte differential count in peripheral blood.

Leukocyte differentiation in 265 peripheral blood samples collected at Peking University First Hospital from September 2010 to December 2010 was detected by standard microscopic cytology as a reference method. Meanwhile, Beckman-Coulter LH750 hematology analyzer and FC500 flow cytometer were performed. Then the correlations were analyzed between microscopic cytology, hematology analyzer and flow cytometry. Forty blood samples collected at Peking University First Hospital, Beijing Daopei Hospital and General Hospital of Beijing Military Command from August 2010 to November 2010 were analyzed by standard microscopic cytology, Beckman-Coulter LH750 hematology analyzer and NAVIOS flow cytometer. Then the correlations between microscopy, hematology analyzer and flow cytometry were explored to analyze the clinical diagnostic efficiency of flow cytometry.

Correlation of leukocyte differential count between FC500 flow cytometer and standard microscopic cytology was significant (all P < 0.01) . And it was superior in the detection of lymphocytes, neutrophils and eosinophils (r = 0.955, 0.928, 0.876). Moreover, the correlation of leukocyte differential count between NAVIOS flow cytometer via manual gate and standard microscopic cytology was significant (r > 0.700, all P < 0.01) except for basophils. And it was superior in the detection of neutrophils, lymphocytes and blasts (r = 0.950, 0.915, 0.852). When 1% was set as the cut-off value of immature granulocytes on standard microscopic cytology, the sensitivity and specificity of flow cytometry was 87% and 76% respectively. When 0.5% was set as the cut-off value of blasts on standard microscopic cytology, the sensitivity and specificity of flow cytometry stood at 100% and 92% respectively.

Five-color flow cytometry is well-correlated with standard microscopic cytology for leukocyte differential count in peripheral blood with different flow cytometers, and the sensitivity of detecting blasts and immature granulocytes is very excellent.