Hyaluronic acid (HA) is present in many tissues; its presence in serum may be related to certain inflammatory conditions, tissue damage, sepsis, liver malfunction and some malignancies. In the present work, our goal was to investigate the significance of hyaluronic acid effect on erythrocyte flow properties. Therefore we performed in vitro experiments incubating red blood cells (RBCs) with several HA concentrations. Afterwards, in order to corroborate the pathophysiological significance of the results obtained, we replicated the in vitro. | Luquita et al. Journal of Biomedical Science 2010 17 8 http content 17 1 8 I NSC The cost of publication in Journal of Biomedical Science is bourne by the National Science Council Taiwan. JOURNAL OF BIOMEDICAL SCIENCE RESEARCH Open Access In vitro and ex vivo effect of hyaluronic acid on erythrocyte flow properties A Luquita 1 L Urli1 MJ Svetaz2 AM Gennaro3 ME Giorgetti1 G Pistone1 R Volpintesta4 S Palatnik4 and M Rasia1 Abstract Background Hyaluronic acid HA is present in many tissues its presence in serum may be related to certain inflammatory conditions tissue damage sepsis liver malfunction and some malignancies. In the present work our goal was to investigate the significance of hyaluronic acid effect on erythrocyte flow properties. Therefore we performed in vitro experiments incubating red blood cells RBCs with several HA concentrations. Afterwards in order to corroborate the pathophysiological significance of the results obtained we replicated the in vitro experiment with ex vivo RBCs from diagnosed rheumatoid arthritis RA patients a serum HA-increasing pathology. Methods Erythrocyte deformability by filtration through nucleopore membranes and erythrocyte aggregability EA were tested on blood from healthy donors additioned with purified HA. EA was measured by transmitted light and analyzed with a mathematical model yielding two parameters the aggregation rate and the size of the aggregates. Conformational changes of cytoskeleton proteins were estimated by electron paramagnetic resonance spectroscopy EPR . Results In vitro erythrocytes treated with HA showed increased rigidity index RI and reduced aggregability situation strongly related to the rigidization of the membrane cytoskeleton triggered by HA as shown by EPR results. Also a significant correlation r p was found between RI and serum HA in RA patients. Conclusions Our results lead us to postulate the hypothesis that HA interacts with the erythrocyte surface leading to .
