Serial determinations of melanoma tumor-associated antigen and antibody in patients with stage I melanoma
J. H. Wong, R. K. Gupta and D. L. Morton
The correlation of circulating immune complexes (CICs) and the clinical
course of malignant melanoma has not been consistent when using nonspecific
assays for CIC. To improve predictability, serial serum samples from
patients with pathologic stage I melanoma were analyzed for the presence of
antimelanoma tumor-associated antigen (TAA) antibody by direct
radioimmunoassay and for the presence of melanoma TAA in CIC by the antigen
competition method. Immunochemically characterized TAA was isolated from
the spent culture medium of a melanoma cell line. Seventy-five percent of
patients with melanoma TAA-specific immune complex (IC) had recurrences,
while 71% of patients without melanoma TAA-specific IC remained free of
disease for prolonged periods (up to 14 years of follow-up). Anti-TAA
antibody titers did not correlate with disease recurrence. Our results
demonstrate a correlation with melanoma TAA-specific IC and disease
recurrence. The absence of melanoma TAA-specific IC is associated with a
low risk of recurrence. Fluctuations in melanoma TAA-specific IC levels
indicate a dynamic tumor host immunobiology and the need for serial
follow-up.