Increased Levels of Serum Granulocyte-Macrophage Colony-Stimulating Factor Is Associated with Activated Peripheral Dendritic Cells in Type 2 Diabetes Subjects (CURES-99)
Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pro-inflammatory cytokine with
growth factor–like properties for monocytes and dendritic cells (DCs). In the present study, serum GM-CSF
levels and the activation status of DCs were studied in type 2 diabetes mellitus (T2DM) subjects.
Methods: Study subjects were recruited from the Chennai Urban Rural Epidemiology Study. Healthy controls
(n = 45) and T2DM patients (n = 45) were included in the study. Serum levels of GM-CSF, interleukin-1b, interleukin-
6, and tumor necrosis factor-a were measured. Enumeration of circulating DCs (myeloid [m] and plasmocytoid
[p]) and its surface antigen expression were quantified by flow cytometry.
Results: The serum GM-CSF levels were significantly higher among diabetes subjects compared with subjects
without diabetes and showed a positive correlation with glycated hemoglobin (r = 0.208, P = 0.018). The serum
GM-CSF levels were lower in subjects on combined insulin and oral hypoglycemic agents (OHA) treatment
(1.09 pg/mL) compared with those taking OHA alone (1.9 pg/mL). The increased GM-CSF levels were associated
with the activated phenotype of mDCs and pDCs, as determined by up-regulation of the lineage markers.
Conclusion: The activated state of mDCs and pDCs seen among diabetes subjects might be due to the increased
levels of GM-CSF and other pro-inflammatory cytokines
