IMMUNOLOGICAL AND VIROLOGICAL CHARACTERIZATION OF THE PRIMARY INFILTRATING CELLS IN THE AQUEOUS HUNTER OF HUMAN T-CELL LEUKEMIA-VIRUS TYPE-1 UVEITIS - ACCUMULATION OF THE HUMAN T-CELL LEUKEMIA-VIRUS TYPE-1-INFECTED CELLS AND CONSTITUTIVE EXPRESSION OF VIRAL AND INTERLEUKIN-6 MESSENGER RIBONUCLEIC-ACIDS

Purpose. To characterize immunologically and virologically the infiltr ating cells in the aqueous humor of patients with human T-cell leukemi a virus type-1 (HTLV-1) uveitis (HU). Methods. With their informed con sent, patients had 0.1 ml of the aqueous humor in the anterior chamber collected with a needle under an operating microscope. An aliquot of the collected sample from patients without steroid therapy was examine d by May-Giemsa staining and immunocytochemically. The presence of the HTLV-1-infected cells was investigated by polymerase chain reaction ( PCR) using the gag and pol regions of the provirus genome. Tile popula tion of tile infected cells was compared by PCR testing the amplificat ion of the virus genome frost 60 cells, or determining the endpoint of successful amplification of die twofold dilution series of the sample s, collected from the aqueous humor and peripheral blood mononuclear c ells (PBMCs), which were obtained at the same time. Expression of vira l and cytokine genes was studied by reverse transcriptase-PCR (RT-PCR) . The interleukin-6 (IL-6) level in the aqueous humor of patients with HU and control subjects was measured by a high-sensitivity enzyme-lin ked immunosorbent assay kit. Results: The number of the infiltrating c ells ranged from 475 to 3563 (mean = 2111) per 0.1 ml of aqueous humor , and all the identifiable cells were lymphocytes. Most of them were C D3-positive T cells (mean = 78%), whereas CD4-positive cells constitut ed less than half (mean = 35.3%). HTLV-1 provirus was detected by PCR in the infiltrating cells of 36 of 38 patients with HU tested, whereas it was detected by PCR in the infiltrating cells of 36 of 38 patients with HU tested, whereas it was detected in 1 of 4 seropositive patien ts with other entities of uveitis. A higher population of the infected cells in the aqueous humor than in the PBMC was found in seven of nin e patients with HU by two independent approaches. Expression of HTLV-1 env or pX genes or both was shown in all 12 patients with HU tested b y RT-PCR. IL-6 messenger ribonucleic acid (mRNA) was detected by RT-PC R in 10 of these 12 patients, whereas those of interleukin-1 alpha, in terleukin-2, interleukin-4, and tumor-necrosis factor-alpha were not, and that of interferon-gamma was detected in only 1 patient. The IL-6 level was elevated significantly in the aqueous humor of nine patients with HU compared with that of five control subjects (520.2 +/- 841 pg /ml versus 2.77 +/- 1.59 pg/ml, P < 0.01 by Mann-Whitney test). Conclu sions. HU is characterized by lymphocytic infiltration with a predomin ance of T cells and by the presence and probable accumulation of HTLV- 1-infected lymphocytes in the affected eye. Production of viral antige ns and IL-6 by the infiltrating cells could be responsible for the dev elopment of HU.