Treatment Response in Kawasaki Disease Is Associated with Sialylation Levels of Endogenous but Not Therapeutic Intravenous Immunoglobulin G

Abstract

ObjectivesAlthough intravenous immunoglobulin (IVIG) is highly effective in Kawasaki disease (KD), mechanisms are not understood and 10-20% of patients are treatment-resistant, manifesting a higher rate of coronary artery aneurysms. Murine models suggest that α2-6-linked sialic acid (α2-6Sia) content of IVIG is critical for suppressing inflammation. However, pro-inflammatory states also up-regulate endogenous levels of β-galactoside:α2-6 sialyltransferase-I (ST6Gal-I), the enzyme that catalyzes addition of α2-6Sias to N-glycans. We asked whether IVIG failures correlated with levels of α2-6Sia on infused IVIG or on the patient’s own endogenous IgG.MethodsWe quantified levels of α2-6Sia in infused IVIG and endogenous IgG from 10 IVIG-responsive and 10 resistant KD subjects using multiple approaches. Transcript levels of ST6GAL1, in patient whole blood and B cell lines were evaluated by RT-PCR. Plasma soluble (s)ST6Gal-I levels were measured by ELISA.ResultsThere was no consistent difference in median sialylation levels of infused IVIG between groups. However, α2-6Sia levels in endogenous IgG, ST6GAL1 transcript levels, and ST6Gal-I protein in serum from IVIG-resistant KD subjects were lower than in responsive subjects at both pre-treatment and one-year time points (p <0.001, respectively). ConclusionsOur data indicate sialylation levels of therapeutic IVIG are unrelated to treatment response in KD. Rather, lower sialylation of endogenous IgG and lower blood levels of ST6GALI mRNA and ST6Gal-I enzyme predict therapy resistance. These differences were stable over time, suggesting a genetic basis. Because IVIG-resistance increases risk of coronary artery aneurysms, our findings have important implications for the identification and treatment of such individuals.

Controlled tetra-Fc sialylation of IVIg results in a drug candidate with consistent enhanced anti-inflammatory activity

“…For example, in patients with Kawasaki disease treated with IVIg, increased levels of endogenous human IgG sialylation decreased the likelihood of IVIg treatment resistance (defined as persistent or recrudescent fever at least 36 h after the completion of IVIg infusion) (21). Similarly, in patients with Guillain-Barré syndrome, those with more severe forms of the disorder showed a lower level of IgG sialylation, despite IVIg treatment (22).…”

Inhibition of FcγR-mediated phagocytosis by IVIg is independent of IgG-Fc sialylation and FcγRIIb in human macrophages

“…The lack of support for this theory from our data in human macrophages is in line with multiple recent studies challenging the concept of Fc sialylation and/or FcgRIIb being important for IVIg efficacy in various diseases, as studied in murine models 25,26,39,44 or with human material. 37,45,46 Therefore, the importance of IgG Fc sialylation and upregulation of FcgRIIb in IVIg treatment need to be reconsidered.…”

ENHANCED p53-DEPENDENT GROWTH INHIBITION OF HUMAN GLIOBLASTOMA CELLS BY COMBINATORIAL TREATMENT OF TEMOZOLOMIDE AND NOVEL PURIFIED NATURAL CARBOHYDRATE OF PLEUROTUS FLORIDA

“…Mannitol and monosaccharides were further confirmed by GC-MS of trimethylsilyl (TMS) derivatization of the active fraction [27]. Finally, the TMS derivative of Fr-II and standard reference samples were dissolved in Hexane and GC-MS analysis was performed using Agilent 5820A GC system equipped with 5975 Series MSD detector.…”

“…Linkage analysis was performed on purified Fr-II by GC-MS of per-Omethylated alditol acetate (PMAA) derivative [27]. PMAA analysis was done byGC-MS using Restek-5ms capillary column (30m x0.25 mm).…”

“…1 mg/ml sample was mixed with saturated DHB in 1:1 ratio and subjected to analysis for mass fragmentation by MALDI [27]. The data was interpreted using Bruker Daltronics flex analysis ® software.…”