Human T-cell lymphotropic virus type 1 infection and ocular manifestations in São Paulo, Brazil.

OBJECTIVES: Although human T-cell lymphotropic virus type 1 (HTLV-1)-associated uveitis has been well recognized in Japan, related studies in Brazil are scarce. We performed a serologic survey for HTLV-1 infection among patients with uveitis and investigated the ocular findings in HTLV-1-asymptomatic carriers. METHODS: One hundred ninety serum samples from patients with uveitis of determined (n = 137) and undetermined origins (n = 53) being examined at the Uveitis Service, University of São Paulo, São Paulo, Brazil, underwent testing using HTLV enzyme-linked immunosorbent assay and discriminatory Western blots. One hundred five asymptomatic blood donors and/or their relatives who were seropositive for HTLV-1 (carrier group) and 105 age- and sex-paired blood donors who were seronegative for HTLV-1 (control group) underwent ocular evaluation. For the statistical analysis, chi2 test was used. RESULTS: Only 1 patient with uveitis was seropositive for HTLV- 1, and she belonged to the group with uveitis of undetermined origin. Results of tear films were evaluated in 52 carriers. The prevalence of a decreased tear break-up time was significantly higher in the carrier compared with the control group (P = .02). Two carriers had keratoconjunctivitis sicca. Three of the 105 carriers exhibited mild uveitis (cells in the vitreous, retinal and choroidal infiltrates, retinal vasculitis, and bilateral pars planitis). Retinal pigmentary changes were found in both groups (no statistical difference). CONCLUSIONS: Early tear abnormalities may be present in asymptomatic carriers, and mild uveitis may be found among them. The relatively low seroprevalence of HTLV-1 in the Brazilian population made it difficult to establish the real importance of HTLV-1-associated uveitis among our patients with uveitis.

Effects of the immunosuppressant FK506 on a penetrating keratoplasty rejection model in the rat.

PURPOSE: The immunosuppressive effects of FK506 on allogeneic corneal transplantation were tested in a rat model. METHODS: Inbred-strain Lewis rats were used as recipients, and Fisher rats were used as donors. Intraperitoneal injection of FK506 (0.3, 1.0, and 3.0 mg/kg per day) was administered for 2 weeks, and the grafts were inspected by clinical evaluation. Mixed lymphocyte culture assay, using lymphocytes from recipients of penetrating keratoplasty as responder cells and irradiated splenocytes from naive Fisher or Brown Norway as stimulator cells, was used to identify allogeneic stimulation. The rejection process was studied by histology and immunohistochemistry. RESULTS: The rat strain combination developed 100% graft rejection in about 2 weeks after the penetrating keratoplasty. FK506 prolonged the graft survival in a dose-dependent manner, as observed by clinical evaluation. In mixed lymphocyte culture assay, Lewis rats that had been primed to allogeneic stimulation at the time of cornea transplantation presented significant proliferation to Fisher stimulator splenocytes. FK506 suppressed this primed lymphocyte proliferation. Immunohistochemical and histologic studies confirmed the clinical evaluations. Untreated rat corneas, at the second postoperative week, presented a large number of helper/inducer T cells, macrophages, IL-2 receptor-expressing cells, and Ia-antigen-expressing cells. In the same period, FK506-treated rats appeared normal and had no cellular infiltration. Corneas rejected after FK506 cessation had less intense cell infiltration than the control corneas. CONCLUSIONS: These data indicate that FK506 prolonged the corneal graft survival and can be a potentially useful drug in the immunotherapeutic arsenal to suppress corneal graft rejection.

Polymerase chain reaction for the detection of the varicella-zoster genome in ocular samples from patients with acute retinal necrosis.

We used the polymerase chain reaction to detect the virus genome in ocular samples from patients with clinically diagnosed acute retinal necrosis. Four samples from four patients with acute retinal necrosis, and five samples from three patients with other ocular diseases (sarcoidosis, rhegmatogenous retinal detachment, and epiretinal membrane of unknown origin) were evaluated. The samples consisted of aqueous humor, vitreous, or subretinal fluid. Primers were specific for varicella-zoster virus, herpes simplex virus, or cytomegalovirus. The varicella-zoster virus genome was detected in three of the four samples from patients with acute retinal necrosis. Among these three positive samples, two had PstI-site-less point mutation, strains that have been described only in Japan and of low prevalence. Samples from patients with diagnoses other than acute retinal necrosis yielded negative results when varicella-zoster virus primer was used. No sample was positive for herpes simplex virus or cytomegalovirus primers.