[Serum-complement factors in the pseudo-LE syndrome (author's transl)].

In contrast to the situation in disseminated lupus erythematodes, in pseudo-LE syndrome the serum-complement factors C'3 and C'4 are elevated and not decreased in the active stage of the disease. Although both diseases are defined and easily distinguished by the demonstration of the specific pathognomonic autoantibodies, at least in the active stage, they can also be distinguished by determining these two complement factors. The finding also demonstrates a different pathogenesis of the two diseases. The serum concentration of C'3 activator is elevated both in LE and pseudo-LE. In the former, determining C'4 is a more sensitive test than that of C'3.