Human endothelial cell proliferation inhibiting activity in the sera of patients suffering from 'shock' or 'sepsis'.

The response of DNA-synthesis of human endothelial cells to sera derived from twenty-five patients suffering from 'sepsis' or 'shock' was measured by autoradiographic methods. In eight cases a constant decrease in proliferative response was found compared to that of sera from healthy donors. These proliferation values were shown to lie below the '60%-of-control-line'. The difference between the means of control and of corresponding 'low-response' values was significant (P less than 0.05). In three cases a diminished response was caused only by some of several serum samples taken at different times. These results correlated well with the clinical state and outcome of patients but not with any of the over sixty clinical, therapeutic, laboratory and post-mortem parameters of investigation. Evidence is presented for a proliferation inhibiting activity in sera of patients in clinically poor states, and some physico-chemical properties of this 'factor' are described. Lethal injury to the cells or an impairment of cellular migration could not be observed within the observation periods used in this study.