LAUSR

AIM Our aim was to investigate how bacterial lipopolysaccharide (LPS) is immunoexpressed in periapical lesions. By surprise we detected Rushton bodies (RBs) whose origin has been debatable to be positive for LPS. METHODOLOGY Samples of radicular cysts (N=70) were stained in order to identify variations in LPS immunoexpression indicating bacterial background. For immunostaining, we used an anti-LPS antibody from Escherichia coli, and for visualization Horse Radish Peroxidase labeled polymer as the secondary antibody. RESULTS RBs showed positivity for LPS in radicular cysts. After collection of radicular cyst samples (70 in total), we noted that all RBs (N=25) histologically detected in tissue samples were positive for LPS. Furthermore, calcification in the cyst capsule showed immunopositivity. CONCLUSION We demonstrate for the first time that LPS is present in RBs, indicating that host response to bacteria might be the initial cause of the formation of these hyaline bodies in the cyst epithelium and cyst capsule calcifications.