Circulating Immune Complexes, Immunoglobulin Classes (IgG, IgA and IgM) and Complement Components (C3c, C4 and Factor B) in Diabetic Nigerians

Objective: To evaluate serum levels of circulating immune complexes (CICs), immunoglobulin classes (IgG, IgA and IgM) and Complement Components (C3c, C4 and Factor B) in Nigerians with Type 1 or Type 2 diabetes mellitus.

Design: Case control study.

Setting: University College Hospital, Ibadan, Oyo State, Nigeria.

Subjects: Forty-two subjects with diabetic mellitus (17 Type 1 D. M. and 25 Type 2 D. M.) and 21 apparently healthy control subjects.

Intervention: Serum level of CICs was measured by polyethylene glycol precipitation method while single radial immunodiffusion method was used to measure serum levels of immunoglobulins and complement components.

Results: Only CICs were significantly higher in Type 1 diabetic subjects compared with the controls whereas CICs C3c, C4 and IgM were significantly increased in Type 2 diabetic subjects compared with the controls. The levels of CICs, C3c and IgM were significantly elevated in Type 2 diabetics compared with Type 1 diabetics.

Conclusion: CIC concentrations may serve as a useful index of depressed host defences usually associated with diabetics mellitus and that humoral immunity is deranged more in Type 2 diabetics compared with Type 1 diabetics. Probably as a result of hyperinsulinaemia associated with insulin resistance.