To explore the diagnosis results of peripheral blood neutrophil CD64 on the surface of a bacterial infection in patients with leukemia.

The clinical data of 30 cases of leukemia complicated with bacterial infection (A group), 30 patients with non-bacterial infection of leukemia (B group) and 30 cases of healthy volunteers (healthy control group) were selected in our hospital from January 2013 to January 2014 by immune turbidity detection of patients in each group of C-reactive protein (CRP) and calcitonin peptide (PCT) level by flow cytometry and CD4/CD8 and CD64 expression and the resistance impedance method was applied detect neutrophils (NEU%).

The levels of CRP, PCT and NEU% of patients in A group of were 3.27 (0.14-4.41) ng/ml, 2.4 (1.7-3.1) ng/ml and 89 (80-90)%, respectively. The levels of CRP, PCT and NEU% of patients in B group were were 0.10 (0.10-0.10) ng/ml, 0.4 (0.2-0.6) ng/ml and70 (68-75)%, respectively. The levels of CRP, PCT and NEU% of patients in healthy control group were 0.06 (0.04-0.08) ng/ml, 0.2 (0.1-0.5) ng/ml and 62 (50-70)%, respectively. The levels of CRP, PCT and NEU% in healthy control group and leukemia non-bacterial infection group were all significantly lower than those of patients of leukemia complicated with bacterial infection. The levels of CRP, PCT and NEU% of patients in A group and B group were compared with significant differences (P = 0.024, 0.021, 0.029; LSD-t = 8.390, 8.511, 8.153). The levels of CRP, PCT and NEU% of patients in A group and C group were compared with significant differences (P = 0.037, 0.033, 0.039; LSD-t = 7.315, 7.672, 7.123). The expression of CD64 index and CD4/CD8 index in A group were (95.52±0.31) and (0.64±0.03), respectively; the CD64 index and CD4/CD8 expression in the B group were (38.33±0.22) and (0.97±0.12), respectively; the CD64 index and CD4/CD8 expression in the C group were (5.11±0.43) and (1.64±0.23), healthy control group and patients with non leukemia CD64 expression in bacterial infection group were lower than those of patients with leukemia complicated with bacterial infection group, healthy control group and non leukemia CD4/CD8 in bacterial infection group were significantly higher than that of patients of leukemia complicated with bacterial infection group (χ² = 2.274, P = 0.035). The sensitivity and specificity of PCT detection were 67% and 89%, the sensitivity and specificity of CRP detecting were 85% and 76%, the sensitivity and specificity of CD64 detecting were 71% and 90%, the sensitivity and specificity of NEU% detecting were 58% and 86.0% , respectively.

The diagnosis of leukemia CD64 to bacterial infection was specific for early diagnosis of leukemia with bacterial infection, with important diagnostic value.