AB0171 Experimental Blood Perfusion Through Dnase I- Containing Magnetic Beads: Preliminary Short-Term Examination Using Rat Model

BackgroundDNA, nucleosomes, and other deoxyribonucleoproteins (DNP) are currently believed to be the key autoantigens in SLE. However, these extracellular DNP itself appear to be just a cellular debris without any essential physiological function. This contradiction could open up a potential for diminishing anti-dsDNA pathogenic effect by degradation of the autoantigen and ICs.ObjectivesTo evaluate efficacy and safety of experimental in vivo blood perfusion through DNase I-containing magnetic beads under preliminary short-term examination using rat model of SLE-like alterations of DNP elimination.MethodsIn the experiments we used 20 female Wistar rats (50-54 weeks), randomized in 2 groups. All the experimental protocols fulfilled both the national ethical requirements and ETS 123. The SLE-like disorders of DNP elimination were simulated by method of N. Jiang et al [1] which was followed by intravenous injection of anti-dsDNA (1 mg/kg). Magnetic beads were synthesized using technique described by A.B. Zborovsky et al [2]. In the experimental group after preliminary heparinization blood was perfused through mini column with DNase I-containing magnetic beads (0.2 ml) at 1 ml/min until overall perfusion volume 100 ml/kg had been reached. Beads for the placebo group didn't contain any active substance. Titers of IgG deposited in rat kidneys (IgGf) were measured by direct IF on kidney cryoslices, serum circulating immune complexes (CIC) by PEG precipitation assay, serum anti-dsDNA IgG by ELISA, and plasma DNA by fluorimetry with PicoGreen. CBC, total plasma protein, plasma creatinine, ALT, AST, and coagulation time were determined using conventional methods. All these measurements except IgGf were performed before and immediately after perfusion.ResultsWe didn't observed animal death as well as hemodynamic instability during perfusion. There was no significant differences between experimental and placebo groups in the initial marker means. We revealed distinct differences between the experimental and placebo control groups in DNA (p