1987 Volume 49 Issue 6 Pages 949-955
Levels of serum immunoglobulins, complement and macrophage activity were compared between plaque-susceptible (SUS) and plaque-resistant (RES, control) rats. SUS rats with pregingivitis showed the significant lower levels in serum immunoglobulins than those in RES rats, especially at early months of age. C3 level and complement hemolytic activity in SUS rats were also lower than those of RES rats at the same age. IgA level and complement hemolytic activity in SUS rats remained at low levels throughout the observed period although the levels of the other immunoglobulins increased gradually thereafter. C3 levels in SUS rats aged 2 to 7 months were higher than that in RES control, while complement hemolytic activity was always lower than that in RES rats. Antibody response against sheep red blood cells (SRBC) was depressed in young SUS rats. The observations suggest that some abnormalities of immaturities in the humoral immune system are present in young SUS rats before occurrence of gingivitis. The susceptibility to periodontal lesions may be based on these abnormalities.
