Circulating immune complexes in human malignant melanoma.

The sera from 34 patients with malignant melanoma at various clinical stages of the disease were examined for the presence of circulating immune complexes (CIC) by the C1q solid-phase assay. Their urine and serum samples had been previously examined for the presence of an urinary melanoma-specific protein (MSP) and the corresponding serum antibody. Low levels of CIC (only in the third stage of the disease) and no positive correlation with the presence of MSP were found. The discordance between our and other author's data stresses again the fact that the different laboratory methods for CIC evaluation reveal in a different way the various CIC populations occurring in several diseases.