Epigenetic CD4+ T-Cell Quantification from Dried Blood Spots Using a qPCR-Based Assay

Despite the clinical importance of CD4 testing for identifying advanced HIV disease, access to conventional flow cytometry remains limited in many settings. Epigenetic quantitative PCR (qPCR)–based immune cell quantification represents a molecular alternative that may be compatible with simplified sample types such as dried blood spots (DBS). This study evaluated the analytical performance of an epigenetic CD4+ T-cell qPCR assay (Epimune diagnostics) using DBS samples.Residual EDTA whole blood specimens (n = 150) from HIV patients were applied to Whatman 903 DBS cards and tested following manual DNA extraction and qPCR using the iMune CD4 assay.