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) level: ≥ 53 mmol/mol and < 53 mmol/mol. Each subgroup was composed of ten subjects ( = 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 ≥ 53 mmol/mol and < 53 mmol/mol and 1.4-fold more abundant in T2DM with HbA ≥ 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 ≥ 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 ≥ 53 mmol/mol, reinforces Hp as a possible biomarker associated with diabetic complications.