Rheological consequences of acute infections: the rheodifference between viral and bacterial infections

The aim of the present study was to explore the difference between viral and bacterial infections regarding the intensity of erythrocyte aggregation in the peripheral venous blood. Although a rheodifference in terms of erythrocyte aggregation between viral and bacterial infections has been shown by us in the past, the time from onset of disease was not included. We have presently included the time from the onset of disease in a group of 133 patients with an acute bacterial infection who showed a significantly enhanced erythrocyte aggregation as opposed to a group of 23 with viral ones and no increased erythrocyte aggregation despite of there being no significant difference in the time from onset of disease (55.7+/-55.6 hours in the bacterial group versus 50+/-35.2 in the viral one). In addition, we could match 22 patients with viral infections who presented the same fibrinogen concentrations (338+/-78 mg/dl) as those with acute bacterial ones (338+/-79 mg/dl). Although of borderline (p=0.06) significance, patients with an acute bacterial infection presented enhanced (vacuum radius=12.6+/-6.4 microns) erythrocyte aggregation as opposed to their isofibrinogenemic counterparts (vacuum radius=9.4+/-6.5 microns). Again, both groups presented no difference regarding the time from onset of disease. We conclude therefore that patients with acute bacterial infections present higher levels of erythrocyte aggregation. This is not a result of a shorter time interval from disease onset of the viral group. The known detrimental effects of increased erythrocyte aggregation regarding capillary slow flow, endothelial dysfunction and reduced tissue oxygenation might be therefore relevant in the context of patients with an acute infection, especially the bacterial ones.