Is human pre-alpha-inhibitor a positive acute-phase protein that is more susceptible than inter-alpha-inhibitor to proteolysis by stimulated neutrophils?
During inflammatory diseases plasma PalphaI levels may be dependent on increased synthesis in combination with enhanced catabolism, perhaps implicating neutrophil or other proteinases.
In patients with frequent syncopal episodes, especially clustered shortly before performing HUTT, in whom symptoms are very suggestive of VVS, a simple point-score system based on medical history accurately predicts HUTT results. Thus, HUTT may not be necessary for establishing diagnosis in this group of patients.