Terminal complement complex in blood of patients with neurological diseases.

The local involvement of complement (C) in the pathophysiology of tissue lesions in several neurological diseases is known, but it has never been studied whether or not in neurological disorders the C activity in the circulation is altered as well. This was the aim of the present investigations. We measured in blood plasma, with an automatic device for analysis and quantitation of the haemolytic activity of the terminal complement complex, the variables T1, T2 and T3 which define the latter quantitatively. We did this, on the one hand, in 100 patients who had 46 neurological disorders systematized in 16 nosological groups, and, on the other hand, in a control group of 40 healthy blood-donors. The mean values of all variables found in the patients have not been statistically different from those found in the controls. This demonstrates that in neurological disorders possible activations of C remain restricted to the local tissue lesions and do not occur in blood, probably due to the opposition against C activation of the known inhibitor system.