Sézary syndrome (SS) is an aggressive type of cutaneous T-cell lymphoma. Diagnosing SS can be challenging, especially in early stages of disease. Previously, in a genome-wide study, we showed that promoter hypermethylation of PROM1, G0S2, CMTM2, PAM, GNMT and NEXN is frequently observed in late stages of disease, but is neither found in healthy donors nor in benign erythrodermic inflammatory dermatoses (EID) patients. In this study, we evaluated the diagnostic value of these biomarkers in early stages of disease. Furthermore, we aimed to improve the accuracy, sensitivity and straightforwardness of biomarker detection by developing and testing novel digital PCR-based assays. Digital PCR (dPCR) is the third generation of PCR and enables sensitive, precise and reproducible absolute quantification of nuclei acid molecules. We collected peripheral blood from 15 early SS and 15 EID patients. The early SS patients had progressive disease and fulfilled disease-specific WHO criteria during follow-up. The methylation status of our biomarker panel was analyzed in DNA extracted from whole blood and enriched cell fractions by using Methylation Specific – Melting Curve Analysis (MS-MCA) and Methylation Sensitive Restriction Enzyme – digital PCR (MSRE-dPCR). In 87% of early SS patient samples, one or more of the biomarkers was hypermethylated as detected by MS-MCA. Moreover, with MSRE-dPCR we could accurately and sensitively quantify methylation of these markers, even in less enriched cell fractions. These data show that analyzing the DNA methylation status of biomarkers is useful in the early diagnosis of SS. Implementation of this finding in daily practice can shorten the delayed diagnosis of SS which can have beneficial effects on treatment and quality of life. Furthermore, applying MSRE-dPCR allows precise threshold calling which results in more accurate, sensitive and straightforward diagnosis.

ESDR454 - Digital quantitative detection of methylated DNA biomarkers: A helpful tool in the early diagnosis of Sézary syndrome.

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.