A conserved immune dysregulation signature is associated with infection severity, risk factors prior to infection, and treatment response.

Older age, being male, obesity, smoking, and comorbidities (e.g., diabetes, asthma) are associated with an increased risk for severe infections. We hypothesized that there is a conserved common immune dysregulation across these risk factors. We integrated single-cell and bulk transcriptomic data and proteomic data from 12,026 blood samples across 68 cohorts to test this hypothesis. We found that our previously described 42-gene Severe-or-Mild (SoM) signature was associated with each of these risk factors prior to infection. Furthermore, this conserved immune signature was modifiable using immunomodulatory drugs and lifestyle changes. The SoM score predicted the individuals with sepsis who would be harmed by hydrocortisone treatment and individuals with asthma who would not respond to monoclonal antibody treatment. Finally, the SoM score was associated with all-cause mortality. The SoM signature has the potential to redefine the immunologic framing of the baseline immune state and response to chronic, subacute, and acute illnesses.