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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: 61–86%, 58–96%, 64–89%, and 57–90%, respectively for M-FcgRIIA, 56–84%, 63–91%, 58–79% and 68–97%, respectively for M-FcgRIII, 61–88%, 54–87%, 44–87% and 69–91%, respectively for G-FcgRI and, 42–75%, 88–98%, 49–77% and 86–98%, 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 Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Subject:
Location: ICC, Munich, Germany
Presentation type:
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