[Detection of circulating immune complexes in lupus erythematosus by precipitation test with polyethylene glycol and complement consumption test (author's transl)].

Immune complexe-like materials have been detected by a precipitation test with polyethylene glycol (PEG test) in the sera of 14 (93.3 p. 100) of 15 patients with active SLE, in 11 (44.0 p. 100) of 25 patients with inactive SLE, in 5 (83.3 p. 100) of 6 patients with widespread DLE and 3 (42.9 p. 100) of 7 patients with localized DLE. A good correlation was demonstrated between the value of PEG test and the complement consumption activity measured by an anticomplementary method in the cases of SLE, but it was not clear in the cases of DLE. The anticomplementary activity has been observed in the macromolecular fractions obtained by gel filtration on Sephadex G-200 of serum samples from one patient with active SLE and one patient with widespread DLE. As the value of PEG test had shown a tendency to increase with the antinuclear antibody titer if the titer was higher than 1 : 128, it is probable that the antinuclear factors were the important elements of the composition of circulating immune complexes in the cases of SLE. Contrarily, in several DLE patients, PEG test was positive despite lacking antinuclear antibody. In most cases, no significant decrease of PEG titers after DNase action was recorded, suggesting the participation of complexes containing antigens different from DNA.