Prospection of plasma proteins as biomarkers for diabetes mellitus monitoring

Purpose This prospective study aimed to detect and identify plasma proteins differentially expressed between groups of Brazilian diagnosed with type 1 (T1DM), type 2 (T2DM) diabetes with good and poor glycemic control and the non-diabetic group denominated control group (CG). Methods Patients with T1DM and T2DM were subdivided according to their glycated haemoglobin (HbA 1c ) level: ≥ 53 mmol/mol and < 53 mmol/mol. Each subgroup was composed of ten subjects ( n = 10). The plasma from each subgroup was pooled and depleted of albumin and IgG. The reminiscent proteins were quantified and separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). The relative volume of protein bands was determined by densitometry analysis, and those with differential abundance were identified by MALDI-TOF mass spectrometry. Results Alpha 2 - Macroglobulin (AMG) was 1.3-fold more abundant in T1DM with HbA 1c ≥ 53 mmol/mol and < 53 mmol/mol and 1.4-fold more abundant in T2DM with HbA 1c ≥ 53 mmol/mol compared to CG. Ceruloplasmin (Cp) and Haptoglobin (Hp) were overexpressed above 1.5-fold in all DM subgroups. Cp in T1DM and Hp in both types of DM were more expressed in HbA 1c ≥ 53 mmol/mol than <53 mmol/mol. Apolipoprotein A-I (Apo A-I) was upregulated only in T2DM subgroups. Conclusion In summary, three positive acute-phase proteins, AMG, Cp and Hp were more abundant in diabetic individuals regardless of the diabetes type. The highest Hp abundance in both types of DM with HbA 1c ≥ 53 mmol/mol, reinforces Hp as a possible biomarker associated with diabetic complications.