Core Fucosylation of Immunoglobulin G is a Biomarker Candidate for Monitoring Interstitial Pneumonia

Immunoglobulin G (IgG) carries N-glycans at the Asn 297 position of the CH2 domain, and modification of the glycan structure is a potential target for the diagnosis and monitoring of disease.To analyze N-glycan modification, we have developed a monoclonal antibody against IgG that carries a core fucose structure.Using this antibody, we used an enzyme-linked immunosorbent assay (ELISA) to measure the level of core fucosylated IgG in a patient's plasma.The patient underwent surgery for esophageal cancer and was then transferred to the intensive care unit due to respiratory insufficiency.A few days after admission, the patient was diagnosed with interstitial pneumonia.The level of core fucosylated IgG became lower (by approximately 40%) following the onset of interstitial pneumonia, and steroidal pulse therapy temporarily restored it.These results indicated that a low level of core fucosylated IgG would be useful for diagnosing interstitial pneumonia and could be used to monitor the disease state.