Disease diagnosis via sperm motility variations induced by body fluids in bioassay

Precise diagnosis of high-risk conditions such as cardiovascular and cerebrovascular diseases still remains a challenge. We previously developed a microfluidic chip for sperm selection and observed that sperm motility is highly sensitive to environmental changes. Building on this finding, we hypothesized that motility traits of sperm could be differentially modulated by body fluids from healthy versus diseased individuals, thereby serving as potential biomarkers for disease diagnosis. To test this hypothesis, we designed a diagnostic system in which mouse sperm were co-incubated with serum samples from patients with myocardial infarction, cerebral infarction, and pancreatitis, along with matched healthy controls. Key kinematic parameters--including motility rate (MR), curvilinear velocity (VCL), straight-line velocity (VSL), linearity (LIN), and amplitude of lateral head displacement (ALH)--were analyzed using a multiparameter sperm quality analysis system. The results revealed that disease-specific serum induced distinct and reproducible changes in sperm motility patterns, enabling accurate discrimination between healthy and pathological conditions. Evaluation of these motility parameters demonstrated high diagnostic performance, with area under the receiver operating characteristic curve (AUC) values ranging from 0.719 to 0.888. This sperm-based bioassay offers a non-invasive, rapid, and cost-effective platform for disease detection and personalized health assessment, with the potential to complement existing diagnostic approaches.