Abstract
Bone metabolism markers play an important role in evaluating the therapeutic effects of osteoporosis treatment. TRACP-5b (tartrate-resistant acid phosphatase 5b) has been considered a reliable bone metabolism marker since it is not susceptible to diurnal and day-to-day variation, and is unaffected by renal dysfunction. Also TRACP-5b has higher sensitivity to change in its blood level during osteoporosis treatment than other bone resorption markers. In our research however, some differences were found in TRACP-5b values between the analytical laboratories. We came to the conclusion that this interlaboratory variation is caused by the differences in handling the analytical samples, i.e., the time for exposure to the room temperature and the frequency of freezing and thawing. TRACP-5b is an acid phosphatase, so its activity may be sensitive to pH, temperature and exposure time. Therefore, more careful handling of TRACP-5b samples at each analytical laboratory is crucial for achieving more accurate analysis and reducing interlaboratory variation on this marker.
