A study of correlation of osteoblasts from peripheral blood with related bone turnover markers.

The bone remodeling process called osteoblasts has an important role in bone formation working together with osteoclasts of which the cells are responsible for bone resorption. In addition, these bone turnover markers are used to follow-up the conditions of bone remodeling in the patients. Recently, osteoblastic lineage cells have been found that they exist in the human peripheral blood. However there has been no report about the amount of circulating osteoblastic lineage cells that have the relationship with the samples of bone turnover markers showing the bone remodeling condition. In the present study, circulating osteoblasts were quantified in 43 subjects aged between 25-90 years. They were classified by age into 3 groups: A) lower than 60 years old (n = 9), B) from 60 to 79 years old (n = 22) and C) equal and over 80 years old (n = 12). All were studied by the flow cytometry method using an antibody to osteocalcin and bone turnover markers beta-CrossLab (betaCTx), PINP and NMID. These markers including parathyroid hormone were analyzed. The result showed the best positive correlation between the percentage of circulating osteoblasts and bone turnover markers of the equal and over 80-year-old group. While another result exhibited the negative correlation of circulating osteocalcin positive cells with the bone turnover markers in the group of lower than 60 years old. As circulating osteoblasts had the correlation with bone turnover markers in the group aged 80 years old, this could be used as the markers to follow up the bone turnover situation of the patients in this age group. However, this is a pilot study. Further analysis of more amounts of subjects should be done for a better result.