Immunotherapy Responsiveness and Risk of Relapse in Down Syndrome Regression Disorder (S34.003)

Abstract

<h3>Objective:</h3> This study evaluated the clinical effectiveness of IVIg and evaluated clinical characteristics associated with relapse after therapy discontinuation in persons with Down Syndrome Regression Disorder (DSRD). <h3>Background:</h3> Down syndrome regression disorder (DSRD) is a clinical symptom cluster consisting of neuropsychiatric regression without an identifiable cause. Although presumably polyfactorial, a minority of individuals with this condition have been found to have inflammatory biomarkers and are immunotherapy responsive. This study evaluated the clinical effectiveness of IVIg and evaluated clinical characteristics associated with relapse after therapy discontinuation. <h3>Design/Methods:</h3> A prospective, multi-center, non-randomized, observational study was performed. Patients met criteria for DSRD and were treated with IVIg. All patients underwent a standardized wean off therapy after 9–12 months of treatment. Baseline, on therapy, and relapse scores of the Neuropsychiatric Inventory Total Score (NPITS), Clinical Global Impression-Severity (CGI-S), and the Bush-Francis Catatonia Rating Scale (BFCRS) were used to track clinical symptoms. <h3>Results:</h3> Eighty-two individuals were enrolled in this study. Patients had lower BFCRS (MD: −6.68; 95% CI: −8.23, −5.14), CGI-S (MD: −1.27; 95% CI: −1.73, −0.81), and NPITS scores (MD: −6.50; 95% CI: −7.53, −5.47) while they were on therapy compared to baseline. Approximately 46% of the patients (n = 38) experienced neurologic relapse with wean of IVIg. Patients with neurologic relapse were more likely to have any abnormal neurodiagnostic study (χ2 = 11.82, p = 0.001), abnormal MRI (χ2 = 7.78, p = 0.005), and abnormal LP (χ2 = 5.45, p = 0.02), and a personal history of autoimmunity (OR: 6.11, p&lt;0.001) compared to patients without relapse. <h3>Conclusions:</h3> IVIg was highly effective in the treatment of DSRD. Individuals with a history of personal autoimmunity or neurodiagnostic abnormalities were more likely to relapse following weaning of immunotherapy, indicating the potential for, a chronic autoimmune etiology in some cases of DSRD. <b>Disclosure:</b> Dr. Santoro has received personal compensation for serving as an employee of UCB. Dr. Santoro has received personal compensation for serving as an employee of Cycle Pharma. Dr. Spinazzi has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for Zalkin Law Firm. The institution of Dr. Spinazzi has received research support from Konica Minolta. The institution of an immediate family member of Dr. Filipink has received research support from NIH . Dr. Filipink has received personal compensation in the range of $0-$499 for serving as a Author with Medlink. Dr. Hayati Rezvan has nothing to disclose. The institution of Dr. Kammeyer has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. The institution of Dr. Kammeyer has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi-Genzyme. Dr. Kammeyer has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Ogborn-Mihm Trial Lawyers. The institution of Dr. Kammeyer has received research support from Rocky Mountain Multiple Sclerosis Center. Dr. Patel has nothing to disclose. The institution of Dr. Sannar has received research support from Colorado Department of Public Health and Environment. The institution of Dr. Sannar has received research support from National Institute of Health. Dr. Dwyer has nothing to disclose. Dr. Banerjee has nothing to disclose. Dr. Khoshnood has nothing to disclose. Dr. Jafarpour has nothing to disclose. Ms. Boyd has nothing to disclose. Dr. Partridge has nothing to disclose. The institution of Dr. Gombolay has received research support from CDC. The institution of Dr. Gombolay has received research support from NIH. Dr. Christy has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for SAGE Publishing. Dr. Christy has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for The Becker Law Firm . The institution of Dr. Christy has received research support from Biohaven. Dr. ORTEGA BERNARDO has nothing to disclose. Dr. Manning has nothing to disclose. Dr. Van Mater has nothing to disclose. Dr. Worley has nothing to disclose. Dr. Franklin has nothing to disclose. The institution of Dr. Stanley has received research support from NIH. The institution of Dr. Stanley has received research support from NIH. Dr. Brown has nothing to disclose. The institution of George Capone has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for ACImmune. The institution of George Capone has received research support from LuMind. Dr. Quinn has nothing to disclose. Dr. Rafii has received personal compensation in the range of $500-$4,999 for serving as a Consultant for AC Immune. Dr. Rafii has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Keystone Bio. Dr. Rafii has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alzheon.