Poor Glycemic Control Is Associated With Lower Interleukin-2 (IL-2) Levels and Low Macrophage Viability in Chronic Diabetic Foot Ulcers (DFUs)

Abstract

Low macrophage viability in chronic diabetic foot ulcers (DFUs) may lead to inadequate interleukin (IL) expression and the persistence of infection. This study evaluates the association between macrophage function, IL-2 expression, and wound microflora in chronic DFUs. Diabetic patients with DFUs (group 1, n = 40) and without DFUs (group 2, n = 40) were compared for macrophage function in serum by viability testing. Immunological response was measured by serum IL-1β, IL-2β, and IL-10 levels. The aerobic and anaerobic microflora of the DFUs were assessed by culture and molecular methods. Demographic, clinical, and biochemical factors were statistically analyzed by χ2 test and Student t test. Multiple correspondence analysis (MCA) was used to detect the pattern of association between glycosylated hemoglobin (hemoglobin A1c), serum IL-2 levels, and macrophage viability. Of the total DFU cases, 22 (55%) showed the presence of polymicrobial microflora. Low macrophage viability with predominant Gram-negative flora was seen in 10 (25%) cases in group 1. Serum IL-2 levels were significantly lower ( P = .004) in patients in group 1 along with elevated levels of hemoglobin A1c ( P = .038). MCA showed an association between low viability of macrophages and lower IL-2 levels and elevated hemoglobin A1c levels with lower serum IL-2 levels. As compared to group 2, the low viability of macrophages was significantly associated ( P = .007) with lower IL-2 levels in group 1. Elevated hemoglobin A1c levels are strongly associated with lower IL-2 levels and low macrophage viability. This might be a contributing factor to the persistence of infections in chronic DFUs.