Altered interferon-γ response in patients with Q-fever fatigue syndrome. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: Keijmel, Stephan P.; Raijmakers, Ruud P.H.; Bleeker-Rovers, Chantal P.; van der Meer, Jos W.M.; Netea, Mihai G.; Schoffelen, Teske; van Deuren, Marcel
• Is Part Of: Journal of infection. Volume 72:Issue 4(2016)
• Page Start: 478
• Page End: 485
• Publication Date: 2016-04
• Subjects: Cell-mediated immunity -- Coxiella burnetii -- Cytokines -- Diagnosis -- Interferon-gamma -- IFNγ -- Q-fever -- Q-fever fatigue syndrome -- QFS; Infection -- Periodicals; Bacterial Infections -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.905
• DOI: 10.1016/j.jinf.2016.01.004
• Languages: English
• ISSNs: 0163-4453

Abstract

Summary: Objectives: Whether immunological mechanisms underlie Q-fever fatigue syndrome (QFS) remains unclear. For acute Q-fever, the antigen-specific interferon-γ (IFNγ) response may be a useful tool for diagnosis, and the IFNγ/interleukin(IL)-2 production ratio may be a marker for chronic Q-fever and treatment monitoring. Here we explored the specific IFNγ production and IFNγ/IL-2 ratio in QFS patients. Methods: IFNγ and IL-2 production were tested in ex-vivo stimulated whole blood of QFS patients (n = 20), and compared to those previously determined in seropositive controls (n = 135), and chronic Q-fever patients (n = 28). Also, the correlation between patient characteristics and IFNγ, IL-2, and IFNγ/IL-2 ratio was determined. Results: QFS patients were younger (p < 0.001), but gender distribution was similar to seropositive controls and chronic Q-fever patients. Coxiella burnetii Nine Mile stimulation revealed a higher IFNγ production in QFS (median 319.5 pg/ml) than in seropositive controls (120 pg/ml, p < 0.01), but comparable to chronic Q-fever (2846 pg/ml). The IFNγ/IL-2 ratio was similar to that in seropositive controls, but lower than in chronic Q-fever patients (p < 0.01). Symptom duration was positively correlated with IL-2 production, and negatively correlated with the IFNγ/IL-2 ratio. Conclusions: These results point to an altered cell-mediated immunity in QFS, and suggest a different immune response than in chronic Q-fever. Highlights: We explored the specific IFNγ production, and the IFNγ/IL-2 ratio in QFS patients. QFS patients have a significant higher IFNγ production than seropositive controls. The IFNγ/IL-2 ratio is significantly lower in QFS than in chronic Q-fever patients. These results point to an altered cell-mediated immunity in QFS.