Assessing immune function by profiling cytokine release from stimulated blood leukocytes and the risk of infection in rheumatoid arthritis

Persons with rheumatoid arthritis (RA) suffer a high burden of infections, but currently no biomarkers are available to identify individuals at greatest risk. A prospective longitudinal study was therefore conducted to determine the association between the responsiveness of ex vivo cytokine production and 6-month risk of infections. Infections were identified by billing codes and validated by medical record review. At baseline, the release of 17 cytokines by peripheral blood mononuclear cells in response to stimulation, or media alone, was measured using multiplexed cytokine analysis. Production of IL-2, IL-8, IL-10, IL-17, TNF-α, IFN-γ, and GM-CSF, induced by various conditions, was significantly associated with the occurrence of infections. A multivariable prediction model based on these data provided new information on the risk of infection beyond standard assessments of disease activity, severity, and treatment. Future studies could utilize this information to devise new biomarkers for the prediction of infection in patients with RA.

► We studied immune profiles as infection predictors in rheumatoid arthritis patients. ► Profiles were defined by measuring cytokine production from stimulated leukocytes. ► A cytokine profile was predictive of incident infection at 6-months of follow-up. ► The profile conveyed new information on infection risk beyond standard predictors.