The IFN-γ +874T/A polymorphism is associated with retinochoroiditis toxoplasmosis susceptibility

Toxoplasmosis is a worldwide zoonosis that generally produces an asymptomatic infection. In some cases, however, toxoplasmosis infection can lead to ocular damage. The immune system has a crucial role in both the course of the infection and in the evolution of toxoplasmosis disease. In particular, IFN-γ plays an important role in resistance to toxoplasmosis. Polymorphisms in genes encoding cytokines have been shown to have an association with susceptibility to parasitic diseases. The aim of this work was to analyse the occurrence of polymorphisms in the gene encoding IFN-γ (+874T/A) among Toxoplasma gondii seropositive individuals, including those with ocular lesions caused by the parasite, from a rural population of Santa Rita de Cássia, Barra Mansa, state of Rio de Janeiro, Brazil. Further, we verified which of these polymorphisms could be related to susceptibility to the development of ocular toxoplasmosis. This study included 34 individuals with ocular toxoplasmosis (ocular group) and 134 without ocular lesions (control group). The differences between A and T allele distributions were not statistically significant between the two groups. However, we observed that a higher frequency of individuals from the ocular group possessed the A/A genotype, when compared with the control group, suggesting that homozygocity for the A allele could enhance susceptibility to ocular toxoplasmosis in T. gondii infection.

Frequência de lesões sugestivas de toxoplasmose ocular em uma população rural do Estado do Rio de Janeiro / Frequency of lesions suggestive of ocular toxoplasmosis among a rural population in the State of Rio de Janeiro

Para determinar a prevalência da toxoplasmose ocular na população em geral do bairro de Santa Rita de Cássia, Barra Mansa, RJ, foi realizado um estudo seccional no qual 1.071 indivíduos foram submetidos a testes sorológicos (IgG e IgM anti-Toxoplasma) e a exame físico e oftalmológico. O diagnóstico da toxoplasmose ocular presumida foi baseado em critérios clínicos, sorológicos e aspecto da lesão retinocoroidiana. As lesões foram classificadas em três tipos morfológicos: 1. Limites marcados com halo de hiperpigmentação e área de atrofia coriorretiniana central. 2. Halo hipopigmentado e área central hiperpigmentada e 3. Hiperpigmentadas ou hipopigmentadas. A prevalência de lesões cicatrizadas compatíveis com toxoplasmose ocular foi de 3,8 por cento na população em geral e 5,8 por cento entre os indivíduos com sorologia positiva para Toxoplasma gondii (65,9 por cento dos indivíduos analisados), com predominância de: lesões do tipo 1 (41,5 por cento), sexo feminino (68,3 por cento), periféricas (58,5 por cento) e menores que 3 diâmetros de disco (87,8 por cento).

To determine the prevalence of ocular toxoplasmosis among the general population of the district of Santa Rita de Cassia, Barra Mansa, State of Rio de Janeiro, a cross-sectional study on 1,071 individuals was performed. These subjects underwent serological tests (anti-Toxoplasma IgG and IgM) and physical and ophthalmological examinations. The diagnosis of presumed ocular toxoplasmosis was based on clinical and serological criteria and the appearance of the retinochoroidal lesion. The lesions were classified into three morphological types: 1. Limits marked with a halo of hyperpigmentation and an area of central chorioretinal atrophy; 2. Hypopigmented halo and hyperpigmented central area; and 3. Hyperpigmented or hypopigmented. The prevalence of healed lesions compatible with ocular toxoplasmosis was 3.8 percent among the general population and 5.8 percent among individuals who were seropositive for Toxoplasma gondii (65.9 percent of the individuals evaluated). Type-1 lesions (41.5 percent), female sex (68.3 percent), peripheral lesions (58.5 percent) and lesions smaller than three disc diameters predominated.

Postnatal acquired toxoplasmosis patients in an infectious diseases reference center

Infection caused by Toxoplasma gondii, toxoplasmosis, is one of the most frequent zoonoses in the world; it normally affects both genders equally. Humans are one of several possible intermediate hosts, and the disease is oligosymptomatic in most cases. Vertical transmission is an important cause of fetal malformation and sequels in newborns. Approximately 10 percent of postnatal cases present multiple manifestations, ranging from low fever and mild lymphadenopathy to severe encephalitis. In moderate cases, lesions such as retinochoroiditis may emerge during acute infection or even years later. We analyzed 313 cases of toxoplasmosis from 1992 to 2004, including 261 acute cases. Most patients were women (68.1 percent), and 39 percent of these were pregnant. Among acute infection cases, 64.8 percent presented symptomatic disease; the most frequent manifestations were lymphadenomegaly (59.8 percent), fever (27.2 percent), headache (10.7 percent), asthenia (10 percent), weight loss (8.4 percent), myalgia (8 percent), retinochoroiditis (3.4 percent) and hepatosplenomegaly (1.5 percent). Although ocular lesions by T. gondii are well documented as a possible consequence of postnatal infection, two patients developed retinochoroiditis only two years after primary infection. This demonstrates the need for toxoplasmosis case surveillance, even long after acute manifestations.

Análise da confiabilidade da microscopia especular de não-contato-estimativa de densidade celular endotelial e dos parâmetros de área celular / Reliability study of the noncontact specular microscopy - Endothelial cell density estimative and cell area parameters

Objetivos: Avaliar a confiabilidade da estimativa da densidade celular endotelial e dos par6ametros de área celular pela técnica de microscopia especular de não -contato automatizada. Local: Hospital Universitário Clementino Fraga Filho - Universidade Federal do Rio de Janeiro. Material e Métodos: Foram avaliados 140 pacientes (280 olhos), considerados normais, de ambos os sexos e diversas faixas etárias, pela técnica de não-contato com análise computadorizada dos dados. Foram realizadas 3 medidas consecutivas de cada olho, e os dados obtidos comparados entre si, através de um teste estatístico de correlação intraclasse. Os parâmetros estudados foram a densidade celular (CD), a menor área celular (MIN), a maior área celular (MAX) e a área celular média (AVG). Resultados: Os valores de densidade celular variaram entre 1732,8 cel/mm2 e 3655 ce/mm2. Os coeficientes de correlaçào obtidos foram: CD=0,486; MIN=0,401; MAX=0,078 e AVG=0541, com um índice de confiabilidade de 95 por cento. Conclusões: A estimativa da densidade celular endotelial por esta técnica apresenta uma baixa confiabilidade, sendo necessário avaliar em conjunto outros parâmetros de área para aprimorar os resultados.