PLASTIC-EMBEDDED UNDECALCIFIED BONE BIOPSIES - AN IMMUNOHISTOCHEMICALMETHOD FOR ROUTINE STUDY OF BONE-MARROW EXTRACELLULAR-MATRIX

The immunohistological staining with polyclonal antibodies of bone bio psies from patients with osteitis fibrosa due to secondary hyperparath yroidism was tested in methyl methacrylate embedded bone samples. The embedding medium preserved the expression of several antigens. Type I collagen was lightly stained in the bone marrow fibrous tissue and sta ined intensely in non-mineralized osteoid seams and in woven bone. Typ e III collagen stained throughout the fibrous tissue of the bone marro w as well as in non-mineralized osteoid matrix. Intense immunostaining for basement membrane type IV collagen was evident within the fibrous marrow tissue next to capillaries and sinusoids. Non-collagenous glyc oproteins, such as fibronectin and laminin, appeared evenly distribute d throughout the fibrous bone marrow tissue. After decalcification, mi neralized trabecular bone matrix became strongly positive for type I c ollagen and fibronectin. Light, patchly distributed immunostaining was observed for tenascin. The results from the present study provide ins ight into the routine utilization of immunohistochemical staining in p lastic embedded bone biopsies as a reliable procedure in the investiga tion of several components of the bone and bone marrow in normal and p athological conditions.