Sensitive New Assay System for Serum Wisteria floribunda Agglutinin-Reactive Ceruloplasmin
That Distinguishes Ovarian Clear Cell Carcinoma from Endometrioma
Wisteria floribunda agglutinin (WFA)-reactive
ceruloplasmin (CP) is a candidate marker for ovarian clear cell carcinoma
(CCC) reported in our previous paper. Herein, a new measurement system
was developed to investigate its potential as a serum marker for CCC.
Site-specific glycome analysis using liquid chromatography/mass spectrometry
showed that WFA-CP from CCC binds to WFA via the GalNAcβ1,4GlcNAc
(LDN) structure. We used mutant recombinant WFA (rWFA), which has
a high specificity to the LDN structure, instead of native WFA, to
increase the specificity of the serum sample measurement. To improve
the sensitivity, we used a surface plasmon field-enhanced fluorescence
spectroscopy immunoassay system, which is approximately 100 times
more sensitive than the conventional sandwich enzyme-linked immunosorbent
assay system. With these two improvements, the specificity and sensitivity
of the serum rWFA-CP measurement were dramatically improved, clearly
distinguishing CCC from endometrioma, from which CCC originates. This
rWFA-CP assay can be used clinically for the serodiagnosis of early-stage
CCC, which is difficult to detect with existing serum markers.