Rheological properties of erythrocytes in patients infected with Clostridium difficile

Clostridium difficile infection (CDI) is a bacterial infection of the digestive tract. Acute infections are accompanied by increased risk for venous thromboembolism (VTE). To date, there have been no studies of the rheological properties of blood during the course of digestive tract infections. The aim of our study was to examine the effects of CDI on red blood cell (RBC) rheology, specifically RBC deformability, RBC aggregation, and plasma viscosity. In addition, the activity of glucose 6 phosphate dehydrogenase (G6PD) and acetylcholinesterase (AChE) in RBC was studied. Our study group included 20 patients with CDI, 20 healthy persons comprised the control group. We examined the effects of CDI on the rheology of RBCs, their deformability and aggregation, using a Laser–assisted Optical Rotational Cell Analyzer (LORCA). Plasma viscosity was determined using a capillary tube plasma viscosymeter. Moreover, we estimated the activity of AChE and G6PD in RBC using spectrophotometric method. A statistically significant increase was found in the aggregation index, viscosity and activity of G6PD whereas the amount of time to reach half of maximum aggregation (t½) and the amplitude of aggregation (AMP) both showed statistically significantly decreases among patients with CDI compared to the control group. We also observed that the Elongation Index (EI) was decreased when shear stress values were low, between 0.3 Pa and 0.58 Pa, whereas EI was increased for shear stress in the range of 1.13 - 59.97 Pa. These observations were statistically significant. We report for the first time that acute infection of the gastrointestinal tract with Clostridium difficile is associated with abnormalities in rheological properties of blood, increased serum viscosity as well as increased aggregation of RBCs, which correlated with severity of inflammation. These abnormalities may be an additional mechanism causing increased incidence of VTE in CDI

The role of VEGF-A and its receptors in angiogenesis

Angiogenesis is essential for the proper development of the organism and repair processes, but also significant in cancer progression and metastasis in solid tumors. A major cytokine that promotes the development of new blood vessels is the vascular endothelial growth factor – VEGF, whereas its soluble receptors (sVEGF-R1 and sVEGF-R2) perform antiangiogenic activity because they capture and neutralize VEGF-A free molecules.Tworzenie naczyń krwionośnych jest niezbędne do prawidłowego rozwoju organizmu i przebiegu procesów naprawczych, ale też kluczowe w progresji choroby nowotworowej i generacji przerzutów odległych w guzach litych. Główną cytokiną promującą rozwój nowych naczyń krwionośnych jest naczyniowo-śródbłonkowy czynnik wzrostu VEGF (vascular endothelial growth factor), natomiast jego rozpuszczalne receptory (sVEGF-R1 i sVEGF-R2), w związku z wychwytywaniem wolnych cząsteczek VEGF-A oraz ich neutralizacją, charakteryzuje aktywność antyangiogenna