[Analysis of anti HMW.MAA antibodies in sera of melanoma patients using antiidiotypic monoclonal antibodies].

The immunogenicity in patients with melanoma of three high molecular weight melanoma associated antigens (HMW.MAA) defined by murine monoclonal antibodies (MoAb) was investigated. For this end sera from patients with melanoma (stage I, IV) and normal individuals were tested by inhibition assay and sandwich assay using antiidiotypic MoAb to anti HMW.MAA MoAb. In inhibition assay, sera were tested for their ability to inhibit the binding of murine antiidiotypic MoAbs to biotin conjugated anti HMW.MAA MoAbs. Some of the sera from patients with melanoma significantly inhibited the binding of antiidiotypic MoAb to anti HMW.MAA MoAb in comparison with that from normal individuals. In sandwich assay, sera were tested for their ability to bind to precoated murine antiidiotypic MoAb and to biotin conjugated anti HMW.MAA MoAbs. Positive findings suggest the existence of anti HMW.MAA antibodies in sera were showed in several sera from the patients, which were less in frequency than that in inhibition assay. These results suggest that HMW.MAA could elicit the immune response in some melanoma patients and also suggest that the assay anti HMW.MAA MoAb in sera will help us to understand the prognosis of the patients and to evaluate the usefulness of treatment with antiidiotypic MoAb as vaccine therapy.