The analysis of bone microstructure provides useful information about many aspects of bone biology. Histological examination of bone material gives valuable information about life and diseases in studies of archeological human and animal bone remains. The study aimed to analyze the microstructure of Latvian historic bone specimens, collected from Riga city regions. Nine humerus and four ulna were selected from skeletal collection dated from Middle Ages till the Late Modern Period, that was obtained by archaeological excavation from the St. George’s Church in Riga. To evaluate age-related changes in bone samples two approaches were used: i) micro-CT - for measurements and calculations of such parameters as bone volume/trabecular volume (BV/TV), cortical bone and trabecular thickness, and trabecular pore diameter; ii) immunohistochemistry (IHC) was performed to detect Runx2, OPG, OC, MMP2, TIMP2, BFGF, IL-1, IL-10, OPN, defensin-2, BMP 2/4, TGFβ factor presence in bone cells – osteocytes. For statistical tests, SPSS was used. Comparative analysis between groups revealed significantly higher BV/TV values (p=0,012) in the control group, whereas values of the diameter of pores were higher (p=0,014) in the patient bones. Within the control group, the measurements of cortical bone thickness had statistically significant difference to other parameters (p<0,05), the same observation was obtained within the patient group .
Runx2, OPG, OC, MMP2, TIMP2, BFGF, IL-1, IL-10, OPN, defensin-2, BMP 2/4, TGFβ positive cells were found in all samples. Comparison of groups revealed a higher value of TIMP2 (p=0,047) in samples of the control group, while the value of IL-1 was higher (p=0,036) in the patient group. All factors had a quantitative superiority over the Runx2 within patient bone samples, but no significant difference was found in the control group. A lower BV/TV, higher pore diameter, along with an increased number of IL-1 positive cells may indicate some ancient bone disease.