• type 1 diabetes;
  • hyperglycemia;
  • properdin

Hyperglycemia associated with type 1 diabetes (T1D) alters the host immune system, resulting in a predisposition to infectious diseases. The high risk of infection in the diabetic population may lead to life-threatening situations. The early proteins of the alternative complement system pathway, constituting factors P, B, and D, have been shown to play an important role in preventing infection because they form a membrane attack complex (MAC)-C5-9, which debilitates the target microbes and/or molecules via cytotoxic and cytolytic reactions. Patients who are devoid of or contain low levels of these proteins may be susceptible to developing chronic infections. We have observed striking differences in partially fractionated serum proteins in diabetic patients (type 2) relative to controls, through single and two-dimensional gel electrophoresis. Our data, obtained from 50 diabetic patients in the age group of 25–45 years, who had the disease for fewer than 5 years, indicated patterns in low- and high-molecular-weight proteins, which could be grouped into five different categories with minor differences in their respective levels of protein expression. Immunoblot assay could barely detect the presence of properdin expression in diabetic patients. Quantization by ELISA in 99 patients indicated low levels of properdin expression in 70% of 50 diabetic patients (6.5 ± 3 μg/mL) when compared to nondiabetic controls (19.5 ± 8.5 μg/mL). This study concluded that patients with low expression of properdin should be advised to take extensive preventive measures and seek early management with appropriate treatments against infection.