T-lymphocyte subsets in the aqueous humor and peripheral blood of patients with acute untreated uveitis

The number of CD8+ T cells and NKT cells increases in the aqueous humor of patients with Behçet's uveitis

To determine whether there are differences in the immunopathogenesis of different endogenous uveitis syndromes, the phenotypic characteristics of immune cells were analysed among patients with endogenous uveitis. The aetiology of the uveitis included idiopathic recurrent acute anterior uveitis (18 patients), idiopathic intermediate uveitis (13 patients), Behçet's uveitis (17 patients), Vogt-Koyanagi-Harada syndrome (7 patients), and so on. Flow cytometric analysis was performed using immune cells of the aqueous humor and the peripheral blood during the active phase of intraocular inflammation, and monoclonal antibodies to CD3, CD4, CD8, CD14, CD19, CD56, TCR gammadelta, pan TCR alphabeta and Valpha24. CD8+ T cells were predominant in the aqueous humor of the patients with Behçet's uveitis, whereas CD4+ T cells were mainly found in the aqueous humor of patients other than those with Behçet's uveitis. The number of NKT (CD3+CD56+) cells was significantly higher both in the aqueous humor and the peripheral blood of the patients with Behçet's uveitis compared with the other groups (P < 0.05). CD8+CD56+ cells were the predominant subtype of the increased NKT cells in patients with Behçet's uveitis. In addition, intraocular infiltration of CD14+ cells significantly differed among the uveitis patients (P < 0.05). These results suggest that the immunopathogenesis of endogenous uveitis can vary between syndromes, and that CD8+CD56+ NKT cells may play an important role in the immunopathogenesis of Behçet's uveitis.

Diagnosis of intraocular lymphoma by flow cytometry

PURPOSE

To evaluate flow cytometry of vitreous cellular specimens as a means of diagnosing intraocular lymphoma and ocular inflammatory disease.

METHODS

We undertook a retrospective, observational study of hematopoietic cell-surface markers in 20 patients with vitreous cellular infiltration in whom lymphoma was considered in the differential diagnosis. Immunophenotyping of vitreous cells obtained by vitrectomy was performed by flow cytometry using antibodies directed against specific cell-surface antigens, including ones associated with B-lymphocyte and T-lymphocyte lymphomas and activated inflammatory cells. Smears were examined cytologically. Cytofluorography was compared with the cytopathologic diagnosis and with final diagnosis.

RESULTS

With flow cytometry, a diagnosis of intraocular lymphoma was confirmed in two of four patients with known lymphoma, one of whom had recurrent disease after radiation, and not confirmed in two patients who had had prior treatment with radiation or corticosteroids. In six patients with no prior diagnosis of lymphoma, five were diagnosed with lymphoma on the basis of cytofluorography. Thus, seven (70%) of 10 patients with intraocular lymphoma were diagnosed by cytofluorography compared with three (30%) of 10 with lymphoma diagnosed by cytology. With flow cytometry, 10 patients with uveitis or intraocular infections were distinguishable from patients with lymphoma by lack of a monotypic population and, in some cases, by elevated CD4:CD8 ratios and a high percentage of activated cells.

CONCLUSIONS

Cytofluorography of vitreous cells is an effective alternative or adjunct to cytology. Information can be gained from specimens that are uninterpretable by routine cytology. The optimal technique for diagnosis may vary among institutions.

Apoptosis-related fas antigen on memory T cells in aqueous humor of uveitis patients

To investigate the role of lymphocytes in the pathogenesis of uveitis, we analyzed the expression of memory markers, CD29 and CD45RO antigens, and apoptosis-related Fas antigen on T lymphocytes in the aqueous humor (AH) and peripheral blood (PB) from patients with uveitis. Using three-color flow cytometry, we assessed the number of T lymphocyte subsets that stained with fluorescence-conjugated anti-CD3, CD4, CD8, CD29, CD45RA, CD45RO, HLA-DR, and Fas monoclonal antibodies in the AH and PB from 19 patients with active uveitis who were diagnosed as having sarcoidosis, Vogt-Koyanagi-Harada disease, HLA-B27+ uveitis, or idiopathic uveitis. Cells from AH and PB were evaluated by light and electron microscopy before and after 6 h of incubation. The majority of lymphocytes in AH but not in PB, were CD3+HLA-DR+ (activated) T cells. The percentage of CD4+ lymphocytes was significantly higher in uveitic AH than in PBL (P < 0.01). While the percentage of CD4+ CD45RA+ (naive) cells within T cells was much lower in uveitic AH than in PB, the percentage of CD4+CD29+ or CD4+CD45RO+ (memory) cells was significantly higher in uveitic AH than in PBL (P < 0.01). Fas antigen was expressed preferentially on memory cells in uveitic AH. Apoptosis of cells in the AH was observed by microscopically following after incubation with no stimulation. Lymphocytes from the AH of patients with uveitis were more activated than those from PB. The majority of T lymphocytes from uveitic AH expressed memory markers and Fas antigen. Results suggest that an increase in the number of Fas+ memory T lymphocytes in AH is involved in the pathogenesis of uveitis.

Etiology and clinical features of anterior uveitis in southern croatia (dalmatia)

Patients with endogenous uveitis represent 6.5+ of patients in University Hospital Split, which serves most of South Croatia. Within a four-year period 208 patients were treated for endogenous uveitis. Results of clinical-laboratory examinations and treatment of 112 subjects suffering from anterior uveitis are presented and compared. Acute anterior uveitis (AAU) was the commonest form of uveal inflammation. It was present in 49+ of all uveitis cases and in 91.1+ of all anterior uveitis cases (AU). 67.6+ of the subjects with AAU had and 32.4+ did not have the HLA B(27) antigen. The inflammatory pattern in B(27)(+) patients was typical of B(27)(+) AAU. Patients with B(27)(+) AAU exhibited the same inflammatory pattern as those with B(7)(+) AAU. B(27)(+) AAU patients had significantly more systemic/rheumatic diseases (p>0.05), while patients with B(27)(-) AAU had significantly more infectious diseases (p>0.05). Forty percent of the patients with chronic anterior uveitis suffered from juvenile rheumatoid arthritis. The authors observed the rise in peripheral blood IgG, IgA, IgM, CD(2)(+), CD(4)(+) and B cells during the acute phase of AAU. Normalization of B cells (CD(20)(+)) was observed in early remission of anterior uveitis, about eight weeks after the onset of the disease.

Two-color flow cytometric analysis of activated T lymphocytes in aqueous humor of patients with endogenous vs. exogenous uveitis

To investigate the immunopathologic role of lymphocytes in aqueous humor of patients with uveitis, we assessed activated T lymphocyte subsets stained with fluorescein isothiocyanate-labeled and phycoerythrin-labeled monoclonal antibodies in aqueous humor and in peripheral blood, using two-color flow cytometry. We divided our 25 patients into those with endogenous or exogenous uveitis. The percentages of activated T lymphocytes in uveitic aqueous humor significantly exceeded those in peripheral blood lymphocytes from patients with either disease form. CD4+HLA-DR+ lymphocytes were predominant in endogenous uveitic aqueous humor, whereas CD8+HLA-DR+ lymphocytes predominated in exogenous uveitic aqueous humor in the early stage of the disease. The percentages of CD4+HLA-DR+ lymphocytes tended to increase while those of CD8+HLA-DR+ cells tended to decrease in aqueous humor from patients in the late phase of exogenous uveitis. Our results may contribute to increasing diagnostic accuracy in patients with uveitis and to developing more rational methods of treatment.

Analysis of aqueous humour in uveitis by high performance liquid chromatography and sodium dodecyl sulphate-polyacrylamide gel electrophoresis

Aqueous humour from patients with Fuchs' heterochromic cyclitis (FHC) and other types of uveitis was analysed by high performance liquid chromatography (HPLC) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Using HPLC, the number of peaks and their respective elution times were similar for the FHC, uveitis and control groups. SDS-PAGE and silver staining showed immunoglobulin G migrating as two to four distinct bands in all non-reduced samples. In the reduced state, 1-5 unidentified low MW bands (10-19 kD) were seen. Two bands at 19 and 10 kD appeared to be specific for the uveitis group, and a band at 11 kD was present in 76% of uveitis and 19% of FHC patients. None of these three bands were detected in any of the control group. As yet the identity of these low MW proteins and their possible significance in the pathogenesis of intraocular inflammation are unknown.

Arachidonic acid cascade and platelet-activating factor in the network of eye inflammatory mediators: therapeutic implications in uveitis

The cellular and biochemical events triggered by uveitis involve a complex array of cells and a heterogeneous network of mediators of intraocular inflammation. Resident cells are activated and inflammatory cells are recruited. Chemical mediators from the arachidonic acid cascade, prostaglandins, hydroxyeicosatetraenoic acids, and leukotrienes, are formed. Several of these metabolites are modulators of cellular functions, but when generated in sustained, excessive amounts, they contribute to enhanced vascular permeability and to the onset of pathophysiological responses. Another very active membrane-derived mediator is platelet-activating factor. This important mediator of immune and inflammatory responses may play a central role in uveitis due to cell priming, since interleukin-1, tumor necrosis factor, and other as yet unidentified mediators are also being generated. The concomitant accumulation of these networks of mediators in various parts of the uveal tract leads to spreading of the intraocular inflammatory response and cellular damage. At both early and late stages of uveitis, the generation of free radicals is also a major contributor to the impairment of function. Free radicals are generated in two distinct sites: in the oxidative burst of recruited white cells and in free radical formation and lipid peroxidation in resident cells. The identification of the cellular events that lead to the accumulation of networks of mediators of inflammation and their effects has important therapeutic implications in uveitis.