Morphometric changes in C57BL/6 mice retina infected by Toxoplasma gondii ME 49 strain.

This study evaluated the morphometric implications in C57BL/6 mouse retina infected by Toxoplasma gondii, ME 49 strain. Twenty C57BL/6 female mice were divided into group 1 (n=8, intraperitoneally infected with 30 cysts of T. gondii ME 49 strain) and group 2 (n=12 non-infected controls). The eyes were enucleated on the 60th day after infection, fixed and processed for light microscopy. Changes in retinal thickness and in the perimeter/area ratio (P/A) of the retinal layers were analyzed by digital morphometry. We considered that P/A was the measurement of retinal architecture distortion induced by toxoplasmosis. This study considered the ganglion cells and nerve fiber layers as a monolayer, thus six layers of retina were evaluated: photoreceptors (PRL), outer nuclear (ONL), outer plexiform (OPL), inner nuclear (INL), inner plexiform (IPL) and ganglion cells/nerve fiber monolayer (GNL). Histological analysis of infected mouse retina showed inflammatory infiltrate, necrosis, glial reaction and distortion of the retina architecture. It also presented increased thickness (167.8±24.9µm versus 121.1±15.4µm, in controls) and increased retinal thickness within the retinitis foci (187.7±16.6µm versus 147.9±12.2µm out of the retinitis foci). A statistically significant difference in P/A was observed between infected and uninfected mouse retinas. The same was observed in PRL, OPL, INL and GNL. Retinal morphometry may be used to demonstrate differences between infected and uninfected mouse retinas.

Cat-scratch disease: ocular manifestations and visual outcome.

To describe the intra-ocular manifestations of cat-scratch disease (CSD) found at two uveitis reference centers in Brazil. Retrospective case series study. Review of clinical records of patients diagnosed with CSD in the Uveitis Department of São Geraldo Hospital and the Ophthalmology Department of the Instituto de Pesquisa Clínica Evandro Chagas-FIOCRUZ, from 2001 to 2008. In the 8-year period, 24 patients with the diagnosis of CSD were identified. Twelve patients were male and 12 female. The mean age was 27.04 years (range 7-56). Sixteen patients (66.6%) presented with a history of a cat scratch and all patients reported cat exposure. Visual acuity ranged from counting fingers to 1.0 in the affected eye. Thirteen patients presented with bilateral disease. Sixteen (66.6%) patients complained of systemic symptoms, including fever, lymphadenopathy, liver and spleen enlargement and rash. All patients presented with serum antibodies (IgG) to Bartonella henselae. Thirty-seven eyes were affected. The most common findings were small areas of retinal infiltrates which occurred in 11 eyes (29.7%) and angiomatous lesions which occurred in nine eyes (24.3%). Neuroretinitis occurred in only six eyes (16.2%). The most common findings of CSD in our study were retinal infiltrates and angiomatous lesions. CSD patients may present with significant visual loss. Patients may benefit from systemic treatment with antibiotics.

Epidemic of unilateral panuveitis in children from Brazilian Amazonia: clinical and etiological aspects in seven patients.

OBJECTIVES: To describe clinical presentation and results of diagnostic and therapeutic procedures in seven children from an epidemic of panuveitis in the Brazilian Amazonia, as well as environmental analysis and etiological aspects involved. METHODS: Patients underwent full pediatric and ophthalmic examinations, B-scan, ultrasound biomicroscopy, and serological tests. Ocular samples were thoroughly analyzed, including two enucleation specimens. Environmental investigation encompassed water, soil, and river fauna. RESULTS: All patients had bathed in the waters of a regional river, the Araguaia. Six of them presented with intermediate uveitis, with snowbanking. Five had cataract and four showed inferior endothelial opacity, with localized anterior synechiae. One showed total leukoma, with flat anterior chamber. Only two had active uveitis, one of them with anterior chamber nodule. Serology revealed high prevalence of anti-Toxocara canis immunoglobulin G (IgG) antibodies. In three cases, vitreous and lens samples disclosed spicules of freshwater sponges Drulia uruguayensis and D. ctenosclera, also detected in the waters of the river. CONCLUSION: Freshwater sponge spicules could be potential new etiological agents of ocular pathology, but further studies are needed, considering the heterogeneity of the ocular lesions and results of serological and environmental studies.

Congenital toxoplasmosis in southeastern Brazil: results of early ophthalmologic examination of a large cohort of neonates.

OBJECTIVE: To report results of early ophthalmologic examinations in a large cohort of newborns with congenital toxoplasmosis (CT) after neonatal screening. DESIGN: Cross-sectional analysis of a cohort. PARTICIPANTS: A total of 178 newborns with confirmed CT from 146,307 screened babies (95% of live births) from Minas Gerais state, southeastern Brazil. METHODS: From November 2006 to May 2007, newborns underwent neonatal screening by immunoglobulin (Ig)M capture of dried blood samples. On all positive or suspected cases, confirmative serology was performed on babies and their mothers. Congenital toxoplasmosis was confirmed in newborns who had IgM and/or IgA and IgG, or IgG associated with suggestive ocular lesions (with IgM and IgG in the mother). Ophthalmologic evaluation consisted of indirect ophthalmoscopy with a lid speculum. Pediatric examination and radiologic studies of the central nervous system were also performed. In selected cases, biomicroscopy of the anterior segment, fundus photographs, or ultrasonography (B-scan) was performed. MAIN OUTCOME MEASURES: Prevalence of retinochoroidal lesions, either cicatricial or active, and their location and associated findings, such as vascular sheathing, hemorrhage, vitreous opacities, and retinal detachment, were evaluated. The occurrence of cataract, microphthalmia, microcephaly, intracranial calcification, and hydrocephalus was also recorded. RESULTS: Of 146,307 neonates screened, 190 had CT, yielding a prevalence of 1 in 770 live births, of whom 178 (93.7%) underwent standardized ophthalmologic examination at an average age of 55.6+/-16.6 days. Of these 178 infants, 142 (79.8%) had retinochoroidal lesions consistent with CT in at least 1 eye. Bilateral involvement was noted in 113 patients (63.5%). Macular involvement was seen in 165 eyes (46.3%) of 111 patients (62.4%). Active lesions were observed in 142 eyes (39.9%) of 85 patients (47.8%). These lesions were located in the macula of 75 eyes (21.1%) and were associated with retinal vascular sheathing in 44 eyes (12.4%). CONCLUSIONS: A high prevalence of CT was encountered (1/770) with high rates of early retinochoroidal involvement ( approximately 80%) and many active lesions (in approximately 50%), indicating a possibly more severe ocular involvement by CT in Brazil than in other parts of the world. The hypotheses of higher parasite virulence and increased individual susceptibility are being currently investigated.

Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA.

Toxoplasma gondii causes posterior uveitis and the specific diagnosis is based on clinical criteria. The presence of anti-T. gondii secretory IgA (sIgA) antibodies in patients' tears has been reported and an association was found between ocular toxoplasmosis and the anti-T. gondii sIgA isotype in Brazilian patients. The purpose of this study was to provide an objective validation of the published ELISA test for determining the presence of anti-T. gondii sIgA in the tears of individuals with ocular toxoplasmosis. Tears from 156 patients with active posterior uveitis were analysed; 82 of them presented characteristics of ocular toxoplasmosis (standard lesion) and 74 patients presented uveitis due to other aetiologies. Cases of active posterior uveitis were considered standard when a new inflammatory focus satellite to old retinochoroidal scars was observed. The determination of anti-T. gondii sIgA was made using an ELISA test with crude tachyzoite antigenic extracts. Tears were collected without previous stimulation. Detection of sIgA showed 65.9% sensitivity (95% CI = 54.5-74.4), 71.6% specificity (95% CI = 59.8-81.2), a positive predictive value of 72% (95% CI = 60.3-81.5) and a negative predictive value of 65.4% (95% CI = 54.0-75.4). sIgA reactivity was higher in the tears of patients with active posterior uveitis due to T. gondii (p < 0.05). The test is useful for differentiating active posterior uveitis due to toxoplasmosis from uveitis caused by other diseases.

Interleukin-10 gene polymorphism (-1082G/A) is associated with toxoplasmic retinochoroiditis.

PURPOSE: Experimental data have demonstrated a relevant role for IL-10, an anti-inflammatory cytokine, in the modulation of acute ocular toxoplasmosis. Therefore, this study was conducted to investigate the possible association between an IL10 gene polymorphism at position -1082 and toxoplasmic retinochoroiditis (TR) in humans. METHODS: One hundred patients with diagnosed TR were recruited from the Uveitis Section, Federal University of Minas Gerais. For comparison, one hundred healthy blood donors with positive serology for toxoplasmosis and without retinal signs of previous TR were included in the study. Genomic DNA was obtained from oral swabs of individuals and amplified using polymerase chain reaction (PCR) with specific primers flanking the locus -1082 of IL10 (-1082G/A). PCR products were subjected to restriction endonuclease digestion and analyzed by polyacrylamide gel electrophoresis, to distinguish allele G and A of the IL-10 gene, allowing the detection of the polymorphism and determination of genotypes. RESULTS: There was a significant difference in the genotype distribution between TR patients and control subjects (chi(2) = 6.33, P = 0.04). Carriers of the IL10 -1082 A allele (AA+AG genotypes) were more often patients with TR than control subjects (chi(2) = 5.97, P = 0.01, OR, 2.55; 95% CI, 1.11 < OR < 5.55). In a subgroup analysis, there was no significant difference in genotypes and allele carriage regarding visual acuity, involvement of both eyes and TR recurrence. CONCLUSIONS: This study suggests that the genotypes related with a low production of IL-10 may be associated with the occurrence of TR.

Interleukin-1 gene polymorphisms and toxoplasmic retinochoroiditis.

PURPOSE: It has been proposed that cytokine gene polymorphisms can predispose individuals to disease by enhancing inflammatory processes. Considering the relevance of interleukin-1 (IL-1) in the pathogenesis of toxoplasmic retinochoroiditis (TR), we investigated whether IL1A -889 C/T and IL1B +3954C/T promoter polymorphisms are associated with TR in humans. METHODS: We performed a cross-sectional study that involved 100 Brazilian TR patients and 100 age- and gender-matched control subjects. Genomic DNA was obtained from oral swabs of all participants and amplified using polymerase chain reaction (PCR) with specific primers flanking the locus -889 of IL1A and +3954 of IL1B. PCR products were submitted to digestion and analyzed by PAGE to distinguish C and T alleles. RESULTS: There was no significant difference in the genotype or allele distributions of the IL1A -889 C/T and IL1B +3954C/T polymorphisms in patients with TR when compared with controls. However, in a subgroup analysis, the frequency of genotype and allele distributions of IL1A -889 C/T differed significantly between TR patients with and without recurrent episodes. CONCLUSION: This study suggests that the genotypes related with a high production of IL-1a may be associated with the recurrence of TR.

[Imunogenetics in the uveítes]. / Imunogenética das uveítes.

Cytokines are molecules involved in intercellular communication in immune and inflammatory responses, playing an important role in uveitis. Genetic polymorphisms responsible for the production of certain cytokines have been associated with the occurrence and the severity of uveitis. Therefore, the present study has the purpose of describing these possible associations, pointing out the individual genetic background in the prognosis of uveitis.

[Clinical characteristics of 64 individuals carrying active posterior presumptively toxoplasmic uveitis, in Pernambuco]. / Características clínicas de 64 indivíduos portadores de uveítis posterior activa presumiblemente toxoplásmica en Pernambuco.

PURPOSE: To describe clinical characteristics of posterior active uveitis presumptively by Toxoplasma gondii (PAUPT) in patients with typical lesion. Tranversal study. METHODS: Sixty-four patients with retinochoroiditis scatter and active satellite lesions examined in Pernambuco, Brazil. All were older than 10 years and immunocompetent. Gender, age, skin color, and residence were recorded. Previous uveitis, visual accuracy, intraocular pressure (IOP), and ocular examination were analyzed. RESULTS: 52% were males, most of them with white skin (68.8%). Mean age 29 years (+/-10.87). Eighty-four percent of the patients lived in the metropolitan area. 56.2% were having the first episode of uveitis. In the damaged eye, visual accuracy mean was 20/200, IOP mean 14.5 mmHg (+/-64). Hyperemia of the conjunctiva was observed in 29.7% of the patients and alterations of the cornea in 51.6%. There were cells in the aqueous humor in 62.7%. 6.2% had posterior synechiae. All had vitreous damage and 45.3% retinal vasculitis. In 42.2% of the patients, lesions were located in zone I of Holland and 90.6% had the size of one discus diameter or greater. Neuritis was observed in 28.2%. Uveitis was more frequent in the right eye (54.7%). CONCLUSION: PAUPT affects young people and the main symptom was reduction of visual acuity. IOP mean was normal. Alterations of the vitreous were observed in all cases. Injuries were equal to one discus diameter or greater and located in zone I of Holland.

Vitreoretinal morphology in active ocular toxoplasmosis: a prospective study by optical coherence tomography.

AIM: To investigate the third generation optical coherence tomography (OCT3) findings in patients with active ocular toxoplasmosis. METHODS: A prospective observational case series, including 15 patients with active ocular toxoplasmosis in at least one eye evaluated at a single centre. Vitreoretinal morphological features at baseline and changes within a 24-week follow-up interval on OCT3 were evaluated. RESULTS: The active ocular toxoplasmosis lesion was classified clinically as punctate (n = 6), focal (n = 6) or satellite (n = 3). Retinal layers were hyper-reflective at the active lesion site, and some degree of retinal pigment epithelium-choriocapillaris/choroidal optical shadowing was seen in all patients. In general, the retina was thinned at the active lesion site in eyes with punctate lesions and thickened in eyes with focal and satellite lesions. When detected by OCT3, the posterior hyaloid appeared thickened. While focally detached over punctate lesions, the posterior hyaloid was partially detached, but still attached to the lesion in focal and satellite lesions. Additional findings (not detected on clinical examination) include diffuse macular oedema (n = 6), vitreomacular traction (n = 3) and maculoschisis (n = 1). During follow-up, a decrease in retinal thickness and focal choriocapillaris/choroidal relative hyper-reflectivity were observed at the former lesion site, and posterior vitreous detachment progressed/occurred in all patients. CONCLUSION: OCT3 enabled identification of morphological features underestimated on clinical examination in patients with ocular toxoplasmosis, which may expand the clinical spectrum of the disease. Further studies are needed to verify the relevance of OCT3 in assisting with the diagnosis and management of ocular toxoplasmosis.

Increased serum levels of CXCL8 chemokine in acute toxoplasmic retinochoroiditis.

PURPOSE: Chemokines have been implicated in the control of leucocyte infiltration in uveitis and in modulating angiogenesis in several ocular conditions. Toxoplasmic retinochoroiditis is a common cause of posterior uveitis. This study aimed to evaluate the serum concentrations of CC and CXC chemokines in patients with acute toxoplasmic retinochoroiditis. METHODS: The levels of five chemokines (CCL2, CCL11, CXCL9, CXCL8 and CXCL10) were evaluated in the serum of patients with active toxoplasmic retinochoroiditis (n = 55) and control subjects (n = 40). In a subset of patients (n = 18), a second measure of serum levels of chemokines was performed after the completion of oral treatment with pyrimethamine (25 mg/day), sulphadiazine (1 g, four times per day), folinic acid (7.5 mg/day) and prednisone (initial dose: 1 mg/kg/day) for approximately 30 days. RESULTS: Patients with toxoplasmic retinochoroiditis, notably those presenting with vasculitis, had increased serum levels of CXCL8 (mean +/- standard error of the mean [SEM] 35.1 +/- 6.5 pg/ml) compared with control subjects (mean +/- SEM 16.0 +/- 2.3 pg/ml; p = 0.01). There were no differences between patients and controls in serum levels of the other chemokines measured. The size of ocular lesions correlated significantly with serum levels of CXCL8 and CXCL9. After treatment, there was a significant reduction in serum levels of CXCL8. Severity of vitreous opacities did not correlate with serum levels of these chemokines. CONCLUSIONS: These data suggest a role for CXCL8 in the inflammatory process of acute toxoplasmic retinochoroiditis. Furthermore, CXCL8 may be a useful marker for patient follow-up.

[The role of chemokines in uveitis]. / O papel das quimiocinas nas uveítes.

Inflammation is part of the physiological process that aims at repairing the damage produced by different causes such as infection, trauma, and autoimmune disease. However, when this physiological process is not regulated, it can contribute to the increase in tissue damage. Chemokines and their receptors are major factors involved in the process of cell migration into inflamed tissues. In the ocular diseases, mainly in uveitis, such proteins have been identified as important mediators of the inflammation process. This review discusses the role of chemokines in several ocular diseases, with emphasis on the uveitic process.

[Cornea verticillata - a clinical marker of Fabry disease: case report]. / Córnea verticilata - marcador clínico da doença de Fabry: relato de caso.

Fabry's disease is a rare X-linked lysosomal storage disorder of glycosphingolipid (GL) metabolism, caused by a deficiency of alpha-galactosidase A activity. The progressive accumulation of GL in tissues results in the clinical manifestations of the disease, that are more evident in hemizygous males, and include angiokeratomas, acroparesthesia, cornea verticillata, cardiac and kidney involvement, cerebrovascular manifestations. A family with Fabry's disease including 2 female patients and 3 male patients is reported. The patients were submitted to complete medical history, ophthalmological examination and alpha-galactosidase activity test. Cornea verticillata was a constant finding in all patients. This demonstrates the important role of the ophtalmological examination for the diagnosis of Fabry's disease since the eye findings are so characteristic of the disease.

[Fractal analysis of retinal vascular tree: segmentation and estimation methods]. / Análise fractal da vasculatura retínica: métodos de segmentação e de cálculo dimensional.

PURPOSE: Although it has been proposed that retinal vasculature is fractal, no method of standardization has been performed for vascular segmentation or for dimension calculation, thus resulting in great variability among values of fractal dimensions. The present study was designed to determine if estimation of retinal vessel fractal dimensions is dependent on vascular segmentation and dimensional calculation methods. METHODS: Ten eye fundus images were segmented to extract their vascular trees by four computational methods ("multi-threshold", "scale-space", "pixel classification" and "ridge based detection"). Their information, mass-radius and box counting fractal dimensions were calculated and compared with those of the same vascular trees manually segmented (gold standard). RESULTS: The mean vascular tree dimension varied among the groups of different segmentation methods, from 1.39 to 1.47 for box counting, from 1.47 to 1.52 for information and from 1.48 to 1.57 for mass-radius dimensions. The utilization of different vascular segmentation methods and different dimension calculation methods introduced significant difference among fractal dimension of vessels. CONCLUSION: Estimation of retinal vessel fractal dimensions was dependent on both vascular segmentation and dimension calculation methods.

Serum levels of neurotrophic factors in active toxoplasmic retinochoroiditis.

Toxoplasmic retinochoroiditis (TR) is the most common identifiable cause of posterior uveitis in Brazil. Response to treatment and clinical presentation may vary significantly. We assessed serum levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), neurotrophin (NT)-3, and NT-4/5 in patients with active TR, before and after TR treatment. METHODS: Twenty patients with active lesion and 15 healthy controls were enrolled in the study. Serum concentration of neurotrophic factors was determined by enzyme-linked immunosorbent assay. RESULTS: BDNF levels were significantly higher in patients before treatment when compared with controls (p=0.0015). There was no significant difference in pro-BDNF, NGF, GDNF, NT-3, and NT-4/5 levels between TR patients and controls. Treatment did not affect the levels of these factors. CONCLUSION: BDNF may be released in the context of the active TR inflammatory response.

T cell immunoregulation in active ocular toxoplasmosis.

Toxoplasma gondii infection is an important cause of infectious ocular disease. The physiopathology of retinochoroidal lesions associated with this infection is not completely understood. The present study was undertaken to investigate cytokine production by T cells from individuals with active toxoplasmic retinochoroiditis (TR) comparing with controls. Eighteen patients with active TR and 15 healthy controls (6 controls IgG+ to Toxoplasma and 9 negative controls) were included in the study. Peripheral blood mononuclear cells were incubated in the presence or absence of T. gondii antigen (STAg), and stained against CD4, CD8, TNF, IL-10 and IFN-γ. Baseline expression of cytokines was higher in TR/IgG+ patients in comparison with controls. Cytokine expression was not increased by STAg in vitro stimulation in controls. After stimulation, TR/IgG+ patients' lymphocytes increased cytokine as compared to cultures from both controls. While T cells were the main source of IL-10, but also IFN-γ and TNF, other lymphocyte populations were relevant source of inflammatory cytokines. Interestingly, it was observed a negative correlation between ocular lesion size and IL-10 expression by CD4+ lymphocytes. This study showed that T cells are the main lymphocyte populations expressing IL-10 in patients with TR. Moreover, expression of IL-10 plays a protective role in active TR.

Ocular manifestation of cat-scratch disease in HIV-positive patients.

PURPOSE: To characterize ocular manifestations of cat-scratch disease in HIV-positive patients. DESIGN: Retrospective case series study. METHODS: Records and photography of patients with the diagnosis of cat-scratch disease and HIV were reviewed. RESULTS: From 2001 and 2004 three patients with cat-scratch disease and HIV were identified. All patients presented with subretinal mass associated with an abnormal vascular network. Fluorescein angiography revealed this abnormal vascular network more clearly. All patients were treated with antibiotics alone with good response. CONCLUSIONS: Subretinal mass associated with abnormal vascular network is characteristic of cat-scratch disease in HIV-positive patients. Fluorescein angiography is important to characterize this vascular pattern, and patients may benefit from systemic treatment.

Third-generation optical coherence tomography findings in punctate retinal toxoplasmosis.

PURPOSE: To investigate optical coherence tomography (OCT) findings in patients with punctate retinal toxoplasmosis (PRT). DESIGN: Observational case series. SETTING: Tertiary ophthalmic referral center. STUDY POPULATION: Four patients with PRT consecutively evaluated between July 2004 and June 2005. OBSERVATION PROCEDURES: Clinical examination and OCT. MAIN OUTCOME MEASURES: Morphologic features at baseline and changes within a 24-week follow-up interval. RESULTS: Retinal layers were abnormally hyperreflective at the active lesion site and associated with some degree of retinal pigment epithelium-choriocapillaris/choroidal optical shadowing in all patients. The posterior hyaloid was thickened and focally detached (over the lesion). Additional findings include tractional maculopathy (n = 2) and diffuse macular edema (n = 1). During follow-up, focal choriocapillaris/choroidal relative hyperreflectivity was observed at the former lesion site, and posterior vitreous detachment progressed in all patients. CONCLUSIONS: Our findings suggest that OCT may enable identification of subtle morphologic features previously underappreciated in patients with PRT, which may provide new insights about the disease pathophysiologic mechanisms.

[The relationship between the length of ciliary processes as measured by ultrasound biomicroscopy and the duration, localization and severity of uveitis]. / A relação entre o comprimento dos processos ciliares medidos pela biomicroscopia ultra-sônica e a duração, localização e gravidade das uveítes.

PURPOSE: To determine the relationship between the length of ciliary processes as measured by ultrasound biomicroscopy and the duration, localization and severity of uveitis. METHODS: We analyzed in this prospective study, 58 individuals including patients with different stages of uveitis and normal patients (112 eyes including 18 normal), between August 2001 and August 2002, at the Cleveland Clinic Foundation, Ohio, USA. All patients were referred to ultrasound biomicroscopy by the Uveitis Department, after a complete ophthalmological examination. A 50 MHz-transducer UBM model 840 (Zeiss-Humphrey) was used under topical anesthesia and immersion technique. RESULTS: The most frequent etiology was idiophatic uveitis (27.8%). Recurrent, aggressive and diffuse uveitis lead to significant damage of the ciliary processes. The most significant loss of the ciliary processes was found in the inferior quadrant and the highest in normal patients and in the temporal quadrant. Hypotonic eyes have their ciliary processes reduced. CONCLUSIONS: Ultrasound biomicroscopy has proved to be useful in evaluating anatomical changes of ciliary processes in uveitis and in ocular hypotony, and provides a basis to, make recommendations regarding baseline screening of uveitis patients. Patients who are found to have atrophy of the ciliary processes may need a more aggressive treatment for any signs of inflammation to prevent further damage and eventual hypotony.