Zeta potential and vancomycin-red blood cell interactions.

Area of Science:

• Hematology
• Immunology
• Pharmacology

Background:

• Vancomycin hydrochloride, a polycationic antibiotic, previously shown to induce red blood cell (RBC) aggregation and false-positive direct antiglobulin tests in vitro.
• Ficin pretreatment abolished these reactions, suggesting interaction with RBC sialoglycoproteins.

Purpose of the Study:

• To investigate the mechanism by which vancomycin hydrochloride affects RBCs and direct antiglobulin tests.
• To determine if vancomycin binds to RBC surface proteins or interacts with sialic acid moieties.

Main Methods:

• Testing vancomycin's effect on antibody binding to blood group antigens.
• Ouchterlony assay to assess vancomycin precipitation with sialic acid moieties.
• Flow cytometry to detect vancomycin on RBC surfaces.
• Evaluation of vancomycin's fluorescent properties.

Main Results:

• Vancomycin did not block antibody binding to blood group antigens.
• Vancomycin did not precipitate with sialic acid moieties.
• Vancomycin is fluorescent but not detectable on RBCs via flow cytometry.
• Vancomycin's effects are attributed to its polycationic properties and influence on zeta potential.

Conclusions:

• Vancomycin's interference with RBC serologic reactions is likely due to its polycationic nature affecting zeta potential, not direct protein binding.
• Findings underscore the significance of zeta potential in RBC serology and potential vancomycin-induced interferences.