*Purpose: Differential glycosylation of Immunoglobulin G (IgG) is known to affect its effector functions by modulating interactions with its binding partners, such as C1q or Fc receptors. Our research aim is to detect variable glycosylation profiles of anti-HLA antibodies and donor specific antibodies (DSA) using conventional simple single antigen bead technology, and to analyze the impact of the differential glycosylations of kidney transplant patients on the allograft outcomes

*Methods: Deglycosylated Class I single antigen beads were prepared by enzymatic digestion using enzymatic glycoengineering. The positive control sera and the patients’ sera are pretreated to remove excess non-specific binding proteins with glycans. Glycans of the antibodies bound to the beads were detected with biotinylated lectins known to specifically bind sialic acid, galactose, or fructose residues, complexed with neutravidin-PE as MFI reporter. Data acquisition was performed using a LABScan 3D.

*Results: In-house positive control sera contain mixtures of high PRA patients’ sera with varying degrees of glycosylation profiles, which imply the differential levels of glycosylations in different patients (data not shown). This prediction is demonstrated with the differential levels glycosylations in different post-transplant patients’ sera (figure: serum #1 with high detectable glycans, serum #2 with low detectable glycans) who developed DSA.

*Conclusions: We have developed a simple assay for detecting glycans on anti-HLA antibodies using modified single antigen beads technology. Using this new assay, it is demonstrated that the presence of variable levels of glycosylations in anti-HLA antibodies of the post-transplant patients, which might result in differential effector functions of DSA. Further research is in progress to assess the clinical validity of the assay and to assess the predictive value of glycosylation profiles of DSA on the outcome of kidney transplant recipients.

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