Antibody-Free Blood Test Detects Rheumatic Heart Disease Biomarker

Researchers at Ben-Gurion University of the Negev (BGU; Beersheba, Israel) developed a synthetic, antibody-free diagnostic probe for detecting rheumatic heart disease (RHD)-related biomarkers in blood. The polymer-based sensor uses an HPMA backbone modified with specific peptide ligands and near-infrared fluorescent dyes. By eliminating the need for biological antibodies, which are costly to produce and sensitive to heat degradation, the technology aims to support rapid point-of-care screening in rural and underserved communities.

 

The probe functions as an optical switch that generates a fluorescent signal when it encounters E-selectin, an adhesion molecule released into the bloodstream during active valvular inflammation. In its inactive state, the polymer remains tightly clustered, bringing the fluorescent dyes close enough to suppress their light emission. When the targeting peptides bind to E-selectin, the polymer uncoils, separating the dyes and triggering a measurable fluorescent signal detectable using standard microplate readers.

 

In laboratory testing, the probe successfully detected and quantified E-selectin directly in complex serum samples, producing a clear, dose-dependent fluorescent response. Current detection sensitivity is in the microgram range, with further optimization underway to achieve nanogram-level detection for early-stage disease assessment. The findings were published in ACS Sensors, with researchers from BGU, Massachusetts General Hospital, and Harvard Medical School contributing to the study.

 

Although no established blood biomarker currently exists for diagnosing RHD, researchers suggest that combining multiple biomarkers could help distinguish the disease from non-rheumatic valvular conditions and other inflammatory disorders. The same polymer platform could also be adapted to detect biomarkers associated with other vascular and inflammatory diseases by modifying its targeting peptides, potentially expanding its diagnostic applications.