CD34+ and CD133+ Primitive Stem Cell Expression in Peripheral Blood: Considering Gender, Age, and Smoking.

BACKGROUND: The number of primitive progenitor cells (pPC) in healthy individuals, in correlation to age, gender, and smoking status, has not yet been thoroughly elucidated. MATERIAL AND METHODS: The pPC from a collective of 168 healthy blood donors aged 18-61 years was investigated using flow cytometric analysis. In addition, the pPC of 20 subjects were studied once a month for half a year to determine the extent of physiological variation of pPC within a single individual. RESULTS: We demonstrated a statistically significant difference (p = 0.005) in the numbers of pPC in men (836,100/l) versus women (583,850/l). No statistical difference was found between younger and older donors or between smokers and non-smokers, both overall and within a single gender. The extent of physiological variation in pPC was lower than 20% in 2 individuals, 18 individuals exhibited amplitudes greater than 20%. CONCLUSION: We conclude that the number of pPC in healthy individuals was primarily determined by gender as an operative factor. It seems that age and smoking status are of minor importance. Furthermore, our data demonstrate strong variability in the expression of pPC within a single individual. This may be influenced by varying physiological and environmental factors.