{Reference Type}: Journal Article
{Title}: Methylomic Biomarkers of Lithium Response in Bipolar Disorder: A Proof of Transferability Study.
{Author}: Marie-Claire C;Courtin C;Bellivier F;Scott J;Etain B;Marie-Claire C;Courtin C;Bellivier F;Scott J;Etain B;Marie-Claire C;Courtin C;Bellivier F;Scott J;Etain B;
{Journal}: Pharmaceuticals (Basel)
{Volume}: 15
{Issue}: 2
{Year}: Jan 2022 23
{Factor}: 5.215
{DOI}: 10.3390/ph15020133
{Abstract}: Response to lithium (Li) is highly variable in bipolar disorders (BD) and no clinical or biological predictors of long-term response have been validated to date. Using a genome-wide methylomic approach (SeqCapEpi), we previously identified seven differentially methylated regions (DMRs) that discriminated good from non-responders (prophylactic response phenotype defined using the "Alda" scale). This study is a proof of transferability from bench to bedside of this epigenetic signature. For this purpose, we used Methylation Specific High-Resolution Melting (MS-HRM), a PCR based method that can be implemented in any medical laboratory at low cost and with minimal equipment. In 23 individuals with BD, MS-HRM measures of three out of seven DMRs were technically feasible and consistencies between SeqCapEpi and MS-HRM-measures were moderate to high. In an extended sample of individuals with BD (n = 70), the three MS-HRM-measured DMRs mainly predicted nonresponse, with AUC between 0.70-0.80 according to different definitions of the phenotype (Alda- or machine-learning-based definitions). Classification tree analyses further suggested that the MS-HRM-measured DMRs correctly classified up to 84% of individuals as good or non-responders. This study suggested that epigenetic biomarkers, identified in a retrospective sample, accurately discriminate non-responders from responders to Li and may be transferrable to routine practice.