Host immune response gene expression signature (HIGS)

A host immune response gene expression signature is a coordinated pattern of messenger RNA (mRNA) transcripts that reflects the physiological state of the host's immune system in response to a stimulus (Sweeney et al., 2016 [1]). These signatures are typically identified through transcriptomic profiling of peripheral blood and are used to distinguish between bacterial and viral infections or to predict the severity of conditions like sepsis (McHugh et al., 2015 [2]). While not a single therapeutic target such as a receptor or enzyme, these signatures serve as high-dimensional biomarkers that capture the complexity of the immune response across multiple biological pathways (Davenport et al., 2016 [3]). In drug development, they are utilized as pharmacodynamic markers to assess how immunomodulatory drugs, such as corticosteroids or biologics, influence the overall immune landscape (Inflammatix [4]). By providing a holistic view of the host's reaction, these signatures offer superior diagnostic and prognostic value compared to traditional single-analyte markers like C-reactive protein (SeptiCyte [5]). They are increasingly integrated into clinical trials for patient stratification, helping to identify individuals most likely to benefit from specific anti-inflammatory or antimicrobial interventions. However, the clinical implementation of these signatures requires robust validation across diverse patient populations and standardized technological platforms to ensure diagnostic accuracy.

Other names

Host response signatureHost gene expression profileImmune transcriptomic signatureHost-based diagnostic signatureTranscriptomic host response

Drugs do not target the signature itself; rather, they modulate the underlying immune signaling pathways and cellular activities that the signature measures, leading to a change in the transcriptomic profile.