Abstract
In our previous report, we demonstrated that complements such as β1-C/A-globulin (C3) and β1- E-globulin (C4) increased significantly in the serum of patients with diabetes mellitus.
In this study, we analyzed the hemolytic activity of the serum complement. We also measured various components of the whole complement system and the complement-inhibitor in the serum of the diabetics.
CHSO was measured by Mayer's original method in 95 adult-onset diabetics and Ciq, C1s, C3a, C3A, C5, and C9, as well as C1s-INH were measured quantitatively by the single radial immunodiffusion method using Behringwerke's Partigens in 32 adult-onset diabetics. The serum of 20 healthy adults served as the control. All of the diabetics (group DM) were divided into three groups; group D diabetics without clinical manifestations of microangiopathy, group R: diabetics with retinopathy, and group N: diabetics with nephropathy.
The following results were summarized. (1) CH5O increased in all diabetic groups. Its increase was more predominant in group R than in group D. In group N, CHSO showed changes: both increase and decrease. (2) Among the early-acting components, increase of C1q was minimum but Cis showed significant increase in group DM, and R. (3) C1s-INH showed a significant increase in all diabetic groups. Increase of C1s-INH became more pronounced as involvement of microangiopathy progressed. (4) Among the complements related with an alternative pathway, C3a did not show any remarkable change and C3A showed minimal increase in the diabetic groups. (5) Among the late-acting components, C5 showed remarkable increases in all diabetic groups and C9 showed moderate increase along with the progression of microangiopathy.
From our previous and present studies, it is thus clearly confirmed that hemolytic activity of the complement, almost all components of the complement system as well as complementinhibitor were generally increased in diabetics, particularly in those with microangiopathy. Although the pathophysiological nature of the increase of the serum complement system in diabetics is still obscure, it is suggested that there are possibilities that these changes of the complement system might be reflecting the presence of insidious inflammatory process of the slightest degree in the diabetics, and also that changes of the complement system might be playing a very important role in the development of microangiopathy as the complement system is recently found to be closely related to the coagulation and fibrinolysis systems as well as the kinin system in the blood.
