[Humoral and cellular immunity investigation in idiopathic uveitis]

There is an amount of controversy regarding the patho-physiology of uveitis. Due to the fact that the eye (and especially the highly vascular tissues such as the uvea and the conjunctiva) is considered a special "target" for the immunopathologic reactions, the goal of our study is to contribute to the understanding of the causal role of the immune reactions in the development of idiopathic uveitis.

We have studied 48 patients with idiopathic uveitis and 20 control subjects (with no ocular symptomatology) for the following humoral and cellular immune markers: IgM and IgG, the C3 complement fraction, circulating immune complexes, autoantibodies (antinuclear autoantibodies, anti-double stranded DNA autoantibodies, anti-smooth muscle autoantibodies, anti-neutrophilic cytoplasm autoantibodies, anti-cardiolipin autoantibodies, anti-parietal cell autoantibodies), and lymphocyte subtypes.

Changes in the serum levels of the immune humoral and cellular markers have been noted in 39 (81.25%) of the patients studied. C3 was decreased in 12 (30%) of all cases; the immune complex level was increased over 50 U/mL in 20 patients (51.28%). The presence of the above-mentioned autoantibodies was seen in 19 patients (48.71%), with different incidence. By flow cytometry the percentage of CD4+ (T helper lymphocytes) has been found to be decreased, and the percentage of CD8+ was found to be increased in 8 cases (20.51%). The opposite, the increase in the percentage of CD4+ lymphocytes, and the decrease in the percentage of CD8+ cells was seen in 25 (64.10%) of the studied patients. Taking into consideration the clinical symptoms and the level of the immune humoral and cellular parameters, the cases included in the study have been included in two groups: anterior uveitis (acute and chronic), and posterior uveitis.

By comparing the results, we conclude that the autoimmunity and the immediate hypersensitivity mediated by immune complexes may be involved in the appearance and the development of the intraocular inflammation in certain cases of idiopathic uveitis.