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This abstract is assigned to session OB Free papers 5 - Miscellaneous

Title

FRO - Study of the immune response in patients with uveitis and latent tuberculosis

Purpose	In this work, we would like to investigate the usefulness of different methods of tuberculosis immunity testing in a series of patients with intraocular inflammation. The production of IFN-γ by mononuclear cells in response to purified proteins derivatives and other mycobacterium antigen like native heparin-binding hemagglutinin (nHBHA) has been measured by ELISA.
Methods	In this prospective study, patients with uveitis of unknown origin suspected to be related to tuberculosis or to autoimmune disease have been recruited and underwent a standard diagnosis procedure, including TST, chest Xray and a QuantiFERON-Gold. The production of IFN-γ by mononuclear cells in response to purified proteins derivatives and the other mycobacterium antigen heparin-binding hemagglutinin (nHBHA) has also been measured by ELISA.
Results	With the help of the FRO 2009, we recruited 46 patients. Twenty six patients were TST and QuantiFERON- TB negative. When we analyse the IFN gamma release in response to PPD in this concordant negative group, 88,5 % did not, as expected, respond to PPD. Similarly, IFN gamma’s response to HBHA was negative in 92 % of the cases. In 15 patients QuantiFERON-TB Gold and TST were positive. In this positive group, IFN response to PPD and nHBHA stimulation was found in respectively, 80 and 47 % of the cases. Discordant results between QuantiFERON-TB Gold and TST were observed in 5 patients (13%). Among them, only one had a positive QuantiFERON-TB Gold and a negative TST. Four patients had thus a positive TST and a negative QuantiFERON-TB Gold. In this discordant group, no patients had any release of IFN in response to PPD or HBHA, which strongly argue in favour of false positive.
Conclusion	Analysis of the IFNγ production in response to PPD and nHBHA seem to add important information in both concordant and discordant group. However, more patients need to be included in order to make definitive conclusions.

Author 1

Last name	MAKHOUL
Initials	D
City	Brussels