Human toxocariasis: diagnosis, worldwide seroprevalences and clinical expression of the systemic and ocular forms.

Although human toxocariasis ranks among the most common zoonotic infections worldwide, it remains relatively unknown to the public. The causal agents are the nematode parasites Toxocara canis and T. cati, whose definitive hosts are dogs and cats, respectively. When embryonated eggs are accidentally ingested by humans, larvae hatch in the small intestine, penetrate the intestinal wall and migrate, via the bloodstream, to the liver, lungs, muscles, eye and central nervous system. Although most human infections are asymptomatic, two well-defined clinical syndromes are classically recognised: visceral larva migrans (a systemic disease caused by larval migration through major organs) and ocular larva migrans (a disease limited to the eyes and optic nerves). Two less-severe syndromes have recently been described, one mainly in children (covert toxocariasis) and the other mainly in adults (common toxocariasis). Here, the current laboratory diagnosis, epidemiology and main clinical features of both the systemic and ocular forms of human toxocariasis are reviewed. New developments in serological diagnosis are described, the available seroprevalence data are analysed, and the results of relevant clinical studies that have been published over the last decade are explored, to provide an updated overview of this neglected but highly prevalent human infection.

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.

Eye disease in a patient with rheumatoid arthritis.

We report the case of a 40-year-old woman with diffuse uveitis, sensorineural hearing loss and cerebrospinal fluid pleocytosis as features of Vogt-Koyanagi-Harada syndrome who developed symmetric polyarthritis and stiffness of small and large joints, in addition to rheumatoid arthritis. Although their target tissues are distinct, both diseases have a possible autoimmune origin strongly associated with HLA-DRB4.

HLA-DRB1*0405 is the predominant allele in Brazilian patients with Vogt-Koyanagi-Harada disease.

Vogt-Koyanagi-Harada (VKH) disease is a rare disorder affecting pigmented structures especially the eye and is the main cause of autoimmune non-infectious uveitis in the Brazilian population. The autoimmune target is believed to be the melanocyte. A strong association of VKH disease with HLA-DR4 in the Japanese population is well known. The same association, albeit with lower relative risks has been found in other populations. A secondary association to HLA-DR1 involving a sequence linked with susceptibility to Rheumatoid Arthritis has also been described. VKH disease is more common in non-Caucasian populations. Brazilian patients of varying ethnic origins have been typed for HLA class II antigens. Several of the features found in other population samples are present. Over half of the patients typed HLA-DR4 (20/37) and typing with sequence-specific oligonucleotides disclosed predominance of the DRB1*0405 allele with a relative risk of 11.76 over the general population. In addition, HLA-DR1 and DQ4 were also present, in patients both positive and negative for HLA-DR4. These results suggest that, as in other autoimmune diseases, multiple overlapping susceptibility factors encoded by the MHC complex contribute to the overall susceptibility for the disease, the major factor however, being the presence of the DRB1*0405 allele.

Imunidade celular ao antígeno S empacientes com uveíte endógena / Cellular immune responses to S-antigen in endogenous uveitis

A auto-imunidade retiniana desempenha um papel na etiopatogenia de várias uveítes endógenas. Estudos experimentais e ensaios clínicos têm demonstrado a importância de antígenos retinianos, como o antígeno S (AgS), näo somente na patogenia mas também na elaboraçäo de estratégias de imunoterapia. O presente trabalho visa analisar o perfil da imunidade celular in vitro ao AgS e a dois de seus peptídeos relevantes, denominados M e G, em uma populaçäo brasileira com diagnóstico de uveíte por doença de Behçet (DB) (n=19), doença de Vogt-koyanagi-Harada (DVKH) (n=27) e vasculite da retina (n=5) acompanhados no serviço de uveíte do Hospital das Clínicas da Faculdade de Medicina da USP. Pacientes com DB sem uveíte (n=17) e 16 controles normais foram também analisados ..