Monocyte entropy in type 2 diabetic patients

Major evidence points towards a link between inflammation and type 2 diabetes, insulin resistance and diabetic complications, where monocytes are deeply involved. Entropy (information dimension) of pericellular membrane of monocytes was evaluated in diabetic patients and in control subjects. Monocytes were collected from normal healthy volunteers (n=6) and from type 2 diabetic patients (n=10). To reproduce in vitro an activated status of the monocytes, monocytes from healthy volunteers were stimulated in vitro with the calcium ionophore A23187 or with the oligopeptide FMLP. Monocytes, obtained by Ficoll-Paque, were examined by transmission electron microscopy. The cell contour was extracted, resized to a standard dimension and converted to a single pixel outline. Box-counting method was then applied to determine the entropy of the monocytic surface. Entropy of monocytes appeared statistically higher in diabetic patients, compared with sexand agematched controls (p<0.01). The mechanism underlying the observed increased complexity of pericellular membrane may be explained by the in vivo activation of the circulating monocyte in diabetes. In effect, fractal analysis of stimulated in vitro monocytes (healthy subjects) showed a significant increase of entropy of pericellular membrane, compared with their controls (p<0.001). Our approach was able to assess and quantitatively evaluate in diabetic patients morphological modifications of the monocyte linked to its activation, offering new parameters useful to follow the effects of therapeutic procedures.