[Immunogenicity of allogeneic freezing periosteum and bone marrow].

Objective: To investigate the immunogenicity of freezing periosteum and bone marrow during allogeneic joint transplantation, and to explore proper pretreatment of allogeneic joint.

Methods: The allogeneic periosteum and bone marrow were harvested from knee joints of 5 New Zealand white rabbits (aged, 6 months; weighing, 2.6-3.0 kg). After gradient cooling, the tissue was cryopreserved for 1 month. The freezing periosteum and bone marrow were grinded to pieces after rewarming to prepare the suspension of periosteum and bone marrow. Eighteen Chinchilla rabbits (aged, 6 months; weighing, 2.1-2.8 kg) were divided into 3 groups randomly: normal saline injection group (group A, n = 6), periosteum injection group (group B, n = 6), and bone marrow injection group (group C, n=6). The normal saline, periosteum suspension, and bone marrow suspension were injected into the peritoneal cavity in groups A, B, and C, respectively. The concentrations of interleukin 2 (IL-2), IL-6, and tumor necrosis factor alpha (TNF-alpha) in serum and the ratio of CD4' T cell/CD8+ T cell in venous blood were measured before injection, at 1 week and 2 weeks after injection.

Results: There was no significant difference in the concentration of IL-2 between before and after injection in the same group (P=0.241), and between groups (P = 0.055). The concentration of IL-6 after injection was significantly lower than that before injection in the same group (P = 0.040), but no significant difference was found between groups (P = 0.357). The concentration of TNF-a showed no significant difference between before and after injection in the same group (P = 0.925), but the concentration of TNF-a in group B was significantly higher than that in groups A and C (P < 0.05). The ratio of CD4+ T cell/CD8+ T cell of venous blood had no significant difference between before and after operation in the same group (P = 0.248), and between groups (P=0.646).

Conclusion: The freezing periosteum and bone marrow are lowly immunogenic. In order to decrease the immunogenicity of the joint, preserving the periosteum and removing the marrow cavity are recommended.