Removal of Non-specific Reactions of LABScreen Single Antigen Class II Assay by Fetal Bovine Serum Treatment.

Recently, the removal of false reaction from beads 10 (DRB1*04:04), 30 (DRB1*16:01), and 31 (DRB1*16:02) by fetal bovine serum (FBS) treatment in LABScreen Single Antigen Class II Assay was reported. We aimed to confirm the reaction in many cases. Fifty-nine sera showed positivity on at least two among beads 10, 30 and 31 from Nov 2017 to Oct 2018 in Seoul National University Hospital were included. FBS treatment was performed on 59 sera, and Single Antigen Class II Assay was repeated. Among 59 cases, the negative conversion rates of DR16 (57/59, 96.6%), DR4 (37/39, 94.9%), and accompanied other antibodies, e.g.) DP19 (39/45, 86.7%) were very high. The prior use of intravenous immunoglobulin in a non-specific binding group was significantly higher than the sex, age-matched control group (P=0.005).