Substance P and NK‐1R in Dengue: A First Serological Investigation

ABSTRACT Background Dengue fever lacks reliable biomarkers to explain its complex pathophysiology. Substance P (SP) and its receptor, the Neurokinin‐1 receptor (NK1R), known regulators of inflammation and vascular permeability in viral infections, may play a role in dengue but remain unexplored. Aim/Objective To investigate the levels of SP and NK1R in serum samples of diagnosed dengue patients. Methods Participants were selected from a pool of diagnosed dengue fever patients using a convenience sampling technique ( n  = 40), along with a control group of healthy individuals ( n  = 12). Serum samples were collected, and SP and NK1R levels were measured using enzyme‐linked immunosorbent assay (ELISA). Complete blood count (CBC) parameters were also evaluated. Results The mean NK1R levels in the control and case groups were 2.681 ± 3.147 and 0.57 ± 0.131, respectively. NK1R levels were significantly lower in dengue patients compared with controls ( p  < 0.0001). SP levels did not differ significantly between male and female dengue patients (Mann–Whitney U  = 85, p  = 0.899). Conclusion NK1R may be associated with dengue pathogenesis through its potential involvement in vascular permeability, immune activation, and cytokine responses. These findings suggest a possible connection between NK1R and the pathophysiological mechanisms underlying dengue infection.