Related Experiment Video
Updated: Mar 26, 2026

Application of Long-term cultured Interferon-γ Enzyme-linked Immunospot Assay for Assessing Effector and Memory T Cell Responses in Cattle
Published on: July 11, 2015
Altered interferon-γ response in patients with Q-fever fatigue syndrome
Stephan P Keijmel1, Ruud P H Raijmakers1, Chantal P Bleeker-Rovers1
1Radboud Expertise Centre for Q Fever, Department of Internal Medicine, Division of Infectious Diseases, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands; Department of Internal Medicine, Radboud university medical center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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.
Related Concept Videos
Inhibitors of Viral Protein Synthesis
Methods of reducing fever
Pharmacological Methods of Reducing Fever:
Fatigue
Myocarditis II: Clinical Features and Diagnostic Tests

