[Analysis of reference values of serum S100B concentrations of Japanese adults]

S100B is a calcium-binding protein which exists in abundance in glial cells of the central nervous system (CNS). It is reported that the serum S100B level increase with various CNS diseases, such as stroke, head injury, schizophrenia, major depression and Alzheimer's disease. However, there are no reports on its reference values for the Japanese. The purpose of this study is to know the serum S100B concentrations of Japanese adults, free of any CNS diseases, according to sex, age and circadian rhythm. Moreover, the stability and reproducibility of its measurements of S100B in frozen serum over 7 months.

Volunteers were 26 male and 25 female of Japanese adults. Venous blood samples were collected at given times of a day and serum was obtained by centrifugation at 4 degrees C. An automated chemiluminescence analyzer "LIAISON" and exclusive reagent Sangtec 100 (DiaSorin, Italy), was used for measurement of serum S100B concentrations.

The serum S100B concentrations in Japanese adults corresponded well, with the reported values in Asians. Differences by age and sex were not found. S100B did not how circadian variation. The serum S100B concentrations measured in two months and in nine months after venipuncture were almost the same.

The measurement of S100B by "LIAISON" showed excellent reproducibility and reliability. Furthermore, stability of serum S100B stored at -80 degrees C was good.