Melanoma-inhibitory activity protein concentrations in blood of melanoma patients treated with immunotherapy.

Melanoma inhibitory activity protein (MIA) has been detected in patients with advanced melanoma. The present study measured the variations in blood concentrations of MIA in 84 patients with AJCC stage II to IV melanoma by ELISA. Patients treated with repeated injections of a polyvalent melanoma vaccine (PMV), interferon-alpha-2b (IFN-alpha2b), or interleukin-2 (IL-2) were followed during treatment duration. Before treatment, patients treated with PMV or IFN-alpha2b had comparable low MIA concentrations, whereas most IL-2-treated patients had higher MIA levels. At the end of treatment, MIA concentrations were higher in patients with progressive disease (PD) than in patients with no clinical evidence of melanoma (NPD) for PMV, IFN-alpha2b, or IL-2 therapy (3.7+/-0.2 vs. 11.5+/-5.4 ng/ml, 3.8+/-0.2 vs. 8.3+/-1.7 ng/ml, and 2.3+/-0.7 vs. 20.2+/-7.4 ng/ml, respectively, P<0.05). In contrast to stable MIA concentrations measured in NPD patients, significant increase in MIA levels were observed in PD patients over time regardless of treatment (P<0.05). In 20 of the 27 patients who had melanoma recurrence or progression, MIA concentrations were above 4.5 ng/ml. Finally, in these 20 patients, MIA concentrations above 4.5 ng/ml were observed prior to clinical evidence of progression (P<0.01).