Complement Component 3 (C 3) and Diabetes Mellitus

Abstract

Complement factor 3 (C3) phenotype and allele frequencies were defined in 312 patients with Type 1 diabetes (IDDM), 256 patients with Type 2 diabetes mellitus (NIDDM), 114 apparently healthy first-degree relatives of Type 1 diabetics, in 10 families (29 members) with a familial history of Type 1 or Type 2 diabetes, and 512 controls (blood donors). All persons investigated were Europeans. There is no evidence to suggest that genes linked to C3 influence susceptibility to Type 1 and Type 2 diabetes and to their late complications. C3 levels in blood plasma were found to be slightly elevated in both types of diabetes. But the C3 concentrations varied considerably within the groups. C3 split products were demonstrable in a high percentage in the blood plasma of freshly manifested Type 1 diabetic persons as well as in Type 1 diabetics with a duration of the disease of 1 to 3 years. C3 proteolysis could also be found in plasma of Type 2 diabetics (26%).

Serum Adipocytokines, Metabolic and Immunological Correlations in Type 1 Diabetes mellitus (T1DM) Children

“…Complement C3 and C4 are the major plasma proteins of the immune system complement pathways. The synthesis of serum complement protein C3 increased in response to inflammation and metabolic disorders, diabetes C3 levels elevated in T1DM Table 3 [ 60,61]. Zhain et al [62] reported that serum C3 and C4 of T1DM patients is significantly lower than corresponding value of healthy subjects and the lowest value of C3 was observed in patients with HbA1c >11%.…”

Genetic variants in the complement system and their potential link in the aetiology of type 1 diabetes

“…Of these genes, C3 alleles and phenotypes have been evaluated in 312 individuals with type 1 diabetes, 114 healthy first-degree relatives, and 512 controls of European ancestry. 45 While there was no statistically significant evidence of association of C3 variants with type 1 diabetes risk, C3 levels in blood were highly elevated in recent-onset cases but only slightly elevated overall. More recently, the TEDDY study assessed 15 SNPs in the complement system in 5474 participants with follow-up that identified 413 with islet autoimmunity and 115 who developed type 1 diabetes.…”

“…There are many other complement genes, including C1QC (complement C1q C chain, chr1p36.12), C5 (complement component 5, chr9q33.2), ITGAM (Integrin Subunit Alpha M, previously CD11B , CR3A , chr16p11.2), and C3 (Complement Component 3, chr19p13.3). Of these genes, C3 alleles and phenotypes have been evaluated in 312 individuals with type 1 diabetes, 114 healthy first‐degree relatives, and 512 controls of European ancestry 45 . While there was no statistically significant evidence of association of C3 variants with type 1 diabetes risk, C3 levels in blood were highly elevated in recent‐onset cases but only slightly elevated overall.…”