Lectin reactivity of alpha-fetoprotein in a case of renal cell carcinoma

The increased serum level of alpha-fetoprotein (AFP) in a case of renal cell carcinoma, a rare condition of AFP production by mesoderm-derived cells, was evaluated for its lectin reactivity by affinity electrophoresis, followed by the antibody-affinity transfer to nitrocellulose membranes for visualization of separated AFP bands. The AFP of this case was characterized by relative increases of concanavalin A-nonreactive AFP-C1 (60.4%), erythroagglutinating phytohemagglutinin-reactive AFP-P4 (37.8%) and AFP-P5 (46.3%) and Allomyrina dichotoma lectin-nonreactive AFP-A1s (66.7%), and by the total absence of lentil lectin-reactive components, AFP-L2 and AFP-L3. Thus, the lectin-reactive pattern of AFP markedly deviated not only from that of cord serum, but also from those of other malignancies and of fetal kidney cells in culture.