Today there are no tests that allow to make a precise differential diagnosis between uveitis from presumed tuberculous origin and uveitis by sarcoidosis. Therefore, with this study, investigators aim to identify, in the aqueous humor and in the blood of participants (patients that suffering from one of these two forms of uveitis) the presence of immunologic markers that distinguish between uveitis of tuberculous etiology and uveitis by sarcoidosis.

Both tuberculosis and sarcoidosis are chronic, multi-systemic and granulomatous pathologies that have very similar pulmonary and extra-pulmonary manifestations, and even in the case of ocular involvement it has been shown that many features of intraocular TB can also be found in participants with ocular sarcoidosis.

In this monocentric observational study investigators are asking to the participants with granulomatous uveitis, in which a tuberculosis or sarcoidosis origin is suspected and who will have undergo paracentesis of the anterior chamber, to grant part of the aqueous humor and a blood sample for this study.

The collected samples will be analyzed as follow:

1. Determination of the concentration of various cytokines, chemokines and growth factors in aqueous humor and in the plasma.
2. Analysis of the mononuclear cells ( T helper lymphocytes CD3+ (CD3 is the acronym of cluster of differentiation 3: a glycoprotein found on the surface of immune cells) and CD4+ ((CD4 is the acronym of cluster of differentiation 4), T cytotoxic lymphocytes CD3+ CD8+ (CD8 is the acronym of cluster of differentiation 8) , B lymphocytes CD19+ (CD19 is the acronym of cluster of differentiation 19), Natural killer lymphocytes CD56+ (CD56 is the acronym of cluster of differentiation 56) and CD3- and monocytes CD14+ (CD14 is the acronym of cluster of differentiation 14) present in the aqueous humor by cytofluorimetry.
3. Evaluation of the presence of anti-human HSP70 antibodies in plasma samples by Western blot immunoprecipitation assays.
4. Whenever possible (adequate number of cells), in vitro stimulation of mononuclear cells in aqueous humor with epitopes of tuberculosis mycobacterium antigens and the analysis of cytokines production in the supernatants.

Inclusion Criteria:

• Patients with diagnosis of uveitis of tuberculous etiology or patients with diagnosis of uveitis of suspect sarcoidosis or patients with diagnosis of uveitis of undifferentiated origin (tuberculosis/sarcoidosis)

Exclusion Criteria:

• Patients suffering from non-granulomatous uveitis.

The population will be composed of patients who come at the Simple Dipartiental Structure of Ocular Immunology of the Reggio Emilia Hospital with diagnosis of granulomatous uveiti and to whom are diagnosed a uveitis of tuberculous etiology or uveitis of suspect sarcoidosis or uveitis of undifferentiated origin (tuberculosis/sarcoidosis).