Expression of phagocyte Fcg receptors in HIV infected patients with tuberculosis
Abstract number: 1733_1508
Escobar M.A., Garcia-Egido A.A., Bernal J.A., Fernandez F.J., Rosety M., Ruiz P., Rivera C., Gomez F.
Phagocyte receptors for IgG (FcgRs) are important in host defence against infection.
Objectives: We have studied the expression of FcgRs by peripheral blood monocytes (M), monocytes cultured for 72 hours (M/Mø), and granulocytes (G) in HIV infected patients with active Tuberculosis (TB), during anti-tuberculous therapy (anti-TB-Rx) and, after completition of anti-TB-Rx.
Methods: The expression of FcgRI, FcgRII and FcgRIII, on M, M/Mø and G (resting and cultured with IFNg) were analysed by flow cytometry in 68 HIV infected patients with active TB (45 men and 6 women), at diagnosis of TB, and monthly thereafter until completition of anti-TB-Rx.
Results: The expression of FcgRI and FcgRIII by M, M/Mø and G was enhanced in HIV infected patients with active TB by: 34±4% and 19±3% for M, respectively (p < 0.001), 43±6% and 29±3% for M/Mø, respectively (p < 0.001) and, 54±6% and 21±3% for G, respectively (p < 0.001). The expression of FcgRIIB by M, M/Mø and G was decreased by -24±3% (p = 0.02), -33±4% and -19±2% (p < 0.005), respectively. These alterations of FcgRs expression normalised from week 12th until the end of effective anti-TB-Rx. The expression FcgRI, FcgRIIA and FcgRIII by M, M/Mø and G from HIV patients with TB was significantly enhanced by culture with IFNg (p < 0.005). Setting a cut-off value =25% of the mean fluorescence intensity over controls for FcgRs surface expression and, assuming a prevalence range of active TB between 25 and 80% among HIV patients undergoing confirmatory tests, results in a range of sensitivity, specificity, positive and, negative predictive values of: 6186%, 5896%, 6489%, and 5790%, respectively for M-FcgRIIA, 5684%, 6391%, 5879% and 6897%, respectively for M-FcgRIII, 6188%, 5487%, 4487% and 6991%, respectively for G-FcgRI and, 4275%, 8898%, 4977% and 8698%, respectively for G-FcgRIIB.
Conclusions: Our results suggest that, the alterations of Mø and G Fcg receptors expression in HIV infected patients with active TB can be used to predict the response to anti-tuberculous therapy.
|Session name:||European Society of Clinical Microbiology and Infectious Diseases|
|Location:||ICC, Munich, Germany|
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