Alloantibodies, autoantibodies, and immune complexes in patients with lung cancer

The sera of patients with lung cancer, nonmalignant lung disease, and blood donors were subjected to various immunologic assays. Nine assays, based on immunoradiometric (IRMA) and immunoenzymatic (ELISA) principles, included 3 types of fetal cell antibodies, 2 established lung cancer cell antibodies, anti-DNA, anti-IgG autoantibodies, and immune complex assays based on C1q binding and anti-C3 activity. Antitumor cell antibody level was significantly lower in patients with lung cancer compared to blood donors. In the remaining 7 assays, the lung cancer patients tended towards higher median values compared to both control patients and blood donors, but without statistical significance, with the exception of anti-DNA antibodies. Statistical analysis of all 9 assays taken together has shown significant differences between the 3 groups. When only 5 assays were used to assess 3 types of fetal cell antibodies, anti-DNA antibodies, and immune complexes by means of ELISA anti-C3, the margins between groups increased. A range of values for the selected assays was established that may discriminate 70% of tested individuals of the 3 groups. These results suggest the existence of a characteristic profile of deranged humoral immunity in lung cancer patients.