Total hemolytic complement (CH50) and its fractions C3 and C4 in the sera of patients with localized juvenile periodontitis.

The total hemolytic complement activity (CH50) and its fractions C3 and C4 levels were determined in the sera of 21 subjects with localized juvenile periodontitis (LJP). Total hemolytic complement activity was expressed as number of CH50 units per ml of blood, while C3 and C4 levels were assessed by radial immunodiffusion and expressed as mg%. The values were compared with an equal number of age- and sex-matched periodontally healthy controls. The results indicate a significant increase in CH50, C3, and C4 levels in the sera of patients with LJP. The study reveals the participation of complement system in the pathogenesis of LJP, and its assessment may assist in understanding the relative importance of complement activities in the disease process.