Activa tion of the complement system by the classical and alternative pathways in prolonged type 2 diabetes mellitus

Abstract

The study was undertaken to assess the functional activity of the classical and alternative pathways of complement activation in type 2 diabetes mellitus (DM-2) at late stages of the disease. For this purpose, the total hemolytic activity of the classical and alternative pathways of complement activation and the hemolytic activities of the complement components C1, C2, C3, and C4 were determined in the blood of patients with DM-2 and healthy individuals. According to the data obtained, patients with DM-2 at late stages of the disease have statistically significant increases in both the total hemolylical activity of the classical pathway of complement activation (by 1.5 times; p < 0 01; t = 2.54) and the hemolytic activities of individual complement components - C1 and C3 by 2.2 times (t - 2.05;p < 0 046 and t = 3.9; p < 0 0004, respectively) and C4 by 1.8 times (t - 2.05; p < 0.046) whereas the total hemolytic activity of the alternative pathway and the hemolytic activity of the complement component C2 remain in the normal range (p > 0 5). The findings suggest that the alternative pathway of complement activation is most likely to make no contribution to the activation of C3-convertase and the subsequent generation of C3d, and the further formation of the cytolytic and membrane-attacking complex.