Sustained silencing peanut allergy by xanthopurpurin is associated with suppression of peripheral and bone marrow IgE-producing B cell.

Introduction: Peanut allergy is an immunoglobulin E (IgE) mediated food allergy. Rubia cordifolia L. (R. cordifolia), a Chinese herbal medicine, protects against peanut-induced anaphylaxis by suppressing IgE production in vivo. This study aims to identify IgE-inhibitory compounds from the water extract of R. cordifolia and investigate the underlying mechanisms using in vitro and in vivo models. Methods: Compounds were isolated from R. cordifolia water extract and their bioactivity on IgE production was assessed using a human myeloma U266 cell line. The purified active compound, xanthopurpurin (XPP), was identified by LC-MS and NMR. Peanut-allergic C3H/HeJ mice were orally administered with or without XPP at 200µg or 400µg per mouse per day for 4 weeks. Serum peanut-specific IgE levels, symptom scores, body temperatures, and plasma histamine levels were measured at challenge. Cytokines in splenocyte cultures were determined by ELISA, and IgE + B cells were analyzed by flow cytometry. Acute and sub-chronic toxicity were evaluated. IL-4 promoter DNA methylation, RNA-Seq, and qPCR analysis were performed to determine the regulatory mechanisms of XPP. Results: XPP significantly and dose-dependently suppressed the IgE production in U266 cells. XPP significantly reduced peanut-specific IgE (>80%, p <0.01), and plasma histamine levels and protected the mice against peanut-allergic reactions in both early and late treatment experiments (p < 0.05, n=9). XPP showed a strong protective effect even 5 weeks after discontinuing the treatment. XPP significantly reduced the IL-4 level without affecting IgG or IgA and IFN-γ production. Flow cytometry data showed that XPP reduced peripheral and bone marrow IgE + B cells compared to the untreated group. XPP increased IL-4 promoter methylation. RNA-Seq and RT-PCR experiments revealed that XPP regulated the gene expression of CCND1, DUSP4, SDC1, ETS1, PTPRC, and IL6R, which are related to plasma cell IgE production. All safety testing results were in the normal range. Conclusions: XPP successfully protected peanut-allergic mice against peanut anaphylaxis by suppressing IgE production. XPP suppresses murine IgE-producing B cell numbers and inhibits IgE production and associated genes in human plasma cells. XPP may be a potential therapy for IgE-mediated food allergy.

Age-related macular degeneration: is polypoidal choroidal vasculopathy recognized and treated?

OBJECTIVE: To assess how polypoidal choroidal vasculopathy (PCV) is recognized and treated, and to assess whether treatment outcomes are different between Chinese and Caucasian Canadian patients with age-related macular degeneration (AMD). DESIGN: Retrospective chart review. PARTICIPANTS: 154 eyes from 135 Chinese patients and 2291 eyes from 1792 Caucasian patients who were newly diagnosed with either AMD or PCV and had more than 1 year of follow-up were included. METHODS: All newly diagnosed AMD patients presenting to the Retina Service of 3 Toronto University Hospitals, between March 25, 2008, to September 30, 2014, were reviewed. RESULTS: 10/154 eyes (6.5%) in Chinese Canadians and 16/2291 eyes (0.7%) in Caucasian Canadians were diagnosed as having PCV. Indocyanine green angiography (ICGA) was used to diagnose PCV in 20% of Chinese Canadians and 8.8% of Caucasian Canadians. Clinical practices with a larger percentage of Chinese patients were more likely to diagnose PCV in both Chinese (p = 0.004) and Caucasian patients (p = 0.03), were more likely to use photodynamic therapy (PDT) (p < 0.01), and had significantly greater central retinal thickness decrease (p < 0.001). CONCLUSION: Our study has shown that PCV is under-recognized in a Canadian population, and ICGA is underutilized. In clinical practices with a greater portion of Chinese patients, PCV is more often recognized and PDT is used more liberally.

LGI1 antibody encephalopathy overlapping with sporadic Creutzfeldt-Jakob disease.

OBJECTIVE: To report a rare case of leucine-rich, glioma inactivated 1 (LGI1) antibody-mediated autoimmune encephalopathy clinically overlapping with pathologically confirmed sporadic Creutzfeldt-Jakob disease (CJD). METHODS: The patient was investigated with repeated brain MRI, EEG, CSF examination, whole-body fluorodeoxy-glucose positron emission tomography, genetic analysis of the prion protein gene (PRNP), and extensive serologic screening for paraneoplastic and autoimmune encephalopathy markers. Written informed consent was obtained from the patient's next of kin for access to clinical files for research purposes and for publication. RESULTS: The patient was a 77-year-old man who presented with faciobrachial dystonic seizures (FBDS) secondary to LGI1 antibody-mediated autoimmune encephalopathy, with suggestive MRI findings and a complete response to treatment with combinatorial immunosuppression. Stereotactic biopsy of a nonenhancing T1 hyperintense basal ganglia lesion during the initial FBDS phase, albeit following immunosuppression, did not disclose evidence of lymphocytic inflammation. Following full remission of the FBDS, the patient manifested a rapidly progressive dementia associated with gross motor decline confirmed to be CJD at autopsy (molecular subtype VV3), with no evidence of a pathogenic PRNP mutation. CONCLUSIONS: Our patient highlights that these rare diseases are not invariably mutually exclusive and underscores the benefits of comprehensive neuropathologic examination of the brain to achieve an accurate diagnosis, especially in complex cases when the clinical trajectory dramatically deviates and a concomitant disease may need to be conscientiously considered to best explain the new clinical course.