Establishment of a method for measuring leukocyte phagocytosis based on 16S rDNA.

The goal of this study was to develop a method for measuring leukocyte phagocytosis based on 16S rDNA, and to investigate its clinical significance. Whole blood was collected and incubated with bacteria. Free bacteria were removed using differential centrifugation. Bacteria phagocytosed by leukocytes were measured using real-time PCR technology based on universal primers of 16S rDNA. The change rate of bacterial DNA (CRD) was considered as a criterion of phagocyte function. In the test, the CRD of whole blood leukocytes from a healthy volunteer was repeatedly measured (five times) by the new method in order to document the repeatability. The CRD from the new method and the rate of phagocytosis measured using traditional microscopy were compared in a young healthy group and an aged group of volunteers to observe the relationship between the new method and traditional microscopy and to assess the clinical value of the new method. There was a significant correlation between real-time PCR technology and traditional microscopy (r = 0.82, P < 0.01). The coefficient of variation (CV) was 2.7% for the new method. The CRD was statistically significantly lower in the aged group than in the healthy young group (P < 0.05). The real-time PCR method established for measuring leukocyte phagocytosis was accurate and reliable, and has potential clinical application.