[Show abstract][Hide abstract] ABSTRACT: ALOX12 is a gene encoding arachidonate 12-lipoxygenase (12-LOX), a member of a non-heme lipoxygenase family of dioxygenases. ALOX12 catalyzes the addition of oxygen onto arachidonic acid producing 12-hydroperoxyeicosatetraenoic acid, 12-HPETE, which can be reduced to eicosanoid, 12-HETE. 12-HETE acts in diverse cellular processes including catecholamine synthesis, vasoconstriction, neuronal function and inflammation. Consistent with effects on these fundamental mechanisms, allelic variants of ALOX12 are associated with diseases including schizophrenia, atherosclerosis and cancers without definition of mechanisms. Toxoplasma gondii is an apicomplexan parasite that causes morbidity and mortality and stimulates an innate and adaptive immune inflammatory reaction. Recently, it has been shown that a gene region known as Toxo1 is critical for susceptibility or resistance to T. gondii infection in rats. An orthologous gene region with ALOX12 centromeric is also present in humans. Herein, we report that the human ALOX12 gene has susceptibility alleles for human congenital toxoplasmosis (rs6502997 [P<0.000309], rs312462 [P<0.028499], rs6502998 [P<0.029794], rs434473 [P<0.038516]). A human monocytic cell line was genetically engineered using lentivirus RNA interference to knockdown ALOX12. In ALOX12 knockdown cells, ALOX12 RNA expression decreased and ALOX12 substrate, arachidonic acid, increased. ALOX12 knockdown attenuated progression of T. gondii infection and resulted in greater parasite burden, but decreased consequent late cell death of the human monocytic cell line. These findings suggest that, ALOX12 influences host responses to T. gondii infection in human cells. ALOX12 has been shown in other studies to be important in numerous diseases. Herein, we now demonstrate the critical role ALOX12 plays in T. gondii infection in humans.
Infection and immunity 03/2014; · 4.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Congenital toxoplasmosis is a severe, life-altering disease in the United States. A recently developed enzyme-linked immunosorbent assay (ELISA) distinguishes Toxoplasma gondii parasite types (II and not exclusively II [NE-II]) by detecting antibodies in human sera that recognize allelic peptide motifs of distinct parasite types.
ELISA determined parasite serotype for 193 congenitally infected infants and their mothers in the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS), 1981-2009. Associations of parasite serotype with demographics, manifestations at birth, and effects of treatment were determined.
Serotypes II and NE-II occurred in the United States with similar proportions during 3 decades. For persons diagnosed before or at birth and treated in infancy, and persons diagnosed after 1 year of age who missed treatment in infancy, proportions were similar (P = .91). NE-II serotype was more common in hot, humid regions (P = .02) but was also present in other regions. NE-II serotype was associated with rural residence (P < .01), lower socioeconomic status (P < .001), and Hispanic ethnicity (P < .001). Prematurity (P = .03) and severe disease at birth (P < .01) were associated with NE-II serotype. Treatment with lower and higher doses of pyrimethamine with sulfadizine improved outcomes relative to those outcomes of persons in the literature who did not receive such treatment.
Type II and NE-II parasites cause congenital toxoplasmosis in North America. NE-II serotype was more prevalent in certain demographics and associated with prematurity and severe disease at birth. Both type II and NE-II infections improved with treatment.
[Show abstract][Hide abstract] ABSTRACT: Neuroimaging studies for persons in the National Collaborative Chicago-Based Congenital Toxoplasmosis Study (NCCCTS) with symptoms and signs referable to the spinal cord were reviewed. Three infants had symptomatic spinal cord lesions, another infant a Chiari malformation, and another infant a symptomatic peri-spinal cord lipoma. One patient had an unusual history of prolonged spinal cord symptoms presenting in middle age. Neuroimaging was used to establish her diagnosis and response to treatment. This 43 year-old woman with congenital toxoplasmosis developed progressive leg spasticity, weakness, numbness, difficulty walking, and decreased visual acuity and color vision without documented re-activation of her chorioretinal disease. At 52 years of age, spinal cord lesions in locations correlating with her symptoms and optic atrophy were diagnosed with 3 Tesla MRI scan. Treatment with pyrimethamine and sulfadiazine decreased her neurologic symptoms, improved her neurologic examination, and resolved her enhancing spinal cord lesions seen on MRI.
[Show abstract][Hide abstract] ABSTRACT: Congenital toxoplasmosis presents as severe, life-altering disease in North America. If mothers of infants with congenital toxoplasmosis could be identified by risks, it would provide strong support for educating pregnant women about risks, to eliminate this disease. Conversely, if not all risks are identifiable, undetectable risks are suggested. A new test detecting antibodies to sporozoites demonstrated that oocysts were the predominant source of Toxoplasma gondii infection in 4 North American epidemics and in mothers of children in the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS). This novel test offered the opportunity to determine whether risk factors or demographic characteristics could identify mothers infected with oocysts.
Acutely infected mothers and their congenitally infected infants were evaluated, including in-person interviews concerning risks and evaluation of perinatal maternal serum samples.
Fifty-nine (78%) of 76 mothers of congenitally infected infants in NCCCTS had primary infection with oocysts. Only 49% of these mothers identified significant risk factors for sporozoite acquisition. Socioeconomic status, hometown size, maternal clinical presentations, and ethnicity were not reliable predictors.
Undetected contamination of food and water by oocysts frequently causes human infections in North America. Risks are often unrecognized by those infected. Demographic characteristics did not identify oocyst infections. Thus, although education programs describing hygienic measures may be beneficial, they will not suffice to prevent the suffering and economic consequences associated with congenital toxoplasmosis. Only a vaccine or implementation of systematic serologic testing of pregnant women and newborns, followed by treatment, will prevent most congenital toxoplasmosis in North America.
[Show abstract][Hide abstract] ABSTRACT: Clinical manifestations of ocular toxoplasmosis are reviewed. Findings of congenital and acute acquired ocular toxoplasmosis include retinal scars, white-appearing lesions in the active phase often associated with vitritis. Complications can include fibrous bands, secondary serous or rhegmatogenous retinal detachments, optic neuritis and neuropathy, cataracts, increased intraocular pressure during active infection, and choroidal neovascular membranes. Recurrences in untreated congenital toxoplasmosis occur in teenage years. Manifestations at birth are less severe, and recurrences are fewer in those who were treated promptly early in the course of their disease in utero and in the first year of life. Severe retinal involvement is common at diagnosis of symptomatic congenital toxoplasmosis in the United States and Brazil. Acute acquired infections also may be complicated by toxoplasmic retinochoroiditis, with recurrences most common close to the time of acquisition. Suppressive treatment can reduce recurrent disease.
Ocular immunology and inflammation 04/2011; 19(2):91-102. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Congenital Toxoplasma gondii infection can result in intracranial calcification, hydrocephalus and retinochoroiditis. Acquired infection is commonly associated with ocular disease. Pathology is characterized by strong proinflammatory responses. Ligation of ATP by purinergic receptor P2X(7), encoded by P2RX7, stimulates proinflammatory cytokines and can lead directly to killing of intracellular pathogens. To determine whether P2X(7) has a role in susceptibility to congenital toxoplasmosis, we examined polymorphisms at P2RX7 in 149 child/parent trios from North America. We found association (FBAT Z-scores +/-2.429; P=0.015) between the derived C(+)G(-) allele (f=0.68; OR=2.06; 95% CI: 1.14-3.75) at single-nucleotide polymorphism (SNP) rs1718119 (1068T>C; Thr-348-Ala), and a second synonymous variant rs1621388 in linkage disequilibrium with it, and clinical signs of disease per se. Analysis of clinical subgroups showed no association with hydrocephalus, with effect sizes for associations with retinal disease and brain calcifications enhanced (OR=3.0-4.25; 0.004<P<0.009) when hydrocephalus was removed from the analysis. Association with toxoplasmic retinochoroiditis was replicated (FBAT Z-scores +/-3.089; P=0.002) in a small family-based study (60 families; 68 affected offspring) of acquired infection in Brazil, where the ancestral T(+) allele (f=0.296) at SNP rs1718119 was strongly protective (OR=0.27; 95% CI: 0.09-0.80).
Genes and immunity 07/2010; 11(5):374-83. · 4.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: AIMS: To determine whether mothers of children with congenital toxoplasmosis have chorioretinal lesions consistent with toxoplasmosis. METHODS: Prospective cohort study. Ophthalmologists in our study have examined 173 children with congenital toxoplasmosis in a hospital outpatient setting. These children were referred to us by their primary care physicians. One hundred and thirty mothers of these children had retina examinations of both eyes at least once. Main outcome measure was lesion(s) consistent with ocular toxoplasmosis. RESULTS: Of 130 mothers examined between 1991-2005, 10 (7.7%, 95% Confidence Interval 3.8%, 13.7%) had chorioretinal lesions which likely represent resolved toxoplasmic chorioretinitis. Most of these were small peripheral chorioretinal lesions. None reactivated between 1991-2005. CONCLUSIONS: Chorioretinal lesions consistent with quiescent ocular toxoplasmosis occur in mothers of children with congenital toxoplasmosis in the United States.
[Show abstract][Hide abstract] ABSTRACT: To determine the incidence of new chorioretinal lesions in children with toxoplasmosis diagnosed after, and therefore not treated during, their first year.
Prospective longitudinal cohort study.
Thirty-eight children were evaluated in Chicago between 1981 and 2005 for new chorioretinal lesions. Thirty-eight children and mothers had serum IgG antibody to Toxoplasma gondii.
Twenty-eight of 38 children had one of the following: diagnosis with serum antibody to T. gondii indicative of chronic infection at age 24 months, central nervous system calcifications, hydrocephalus, illness compatible with congenital toxoplasmosis perinatally but not diagnosed at that time. Twenty-five returned for follow-up during 1981 to 2005. Their mean (range) age at last exam was 10.9 +/- 5.7 (range, 3.5 to 27.2) years and mean follow-up was 5.7 +/- 2.9 years. Eighteen (72%) children developed at least one new lesion. Thirteen (52%) had new central lesions, 11 (44%) had new peripheral lesions, and six (24%) had both. Thirteen (52%) had new lesions diagnosed at age > or =10 years. New lesions were found at more than one visit in four (22%), and bilateral new lesions developed in seven (39%) of 18 children who developed new lesions. Of 10 additional children with eye findings and serologic tests indicative of chronic infection, six returned for follow-up, four (67%) developing new lesions at > or =10 years of age.
More than 70% developed new chorioretinal lesions. New lesions were commonly diagnosed after the first decade of life.
American Journal of Ophthalmology 07/2008; 146(3):375-384. · 4.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine the incidence of new chorioretinal lesions in patients with congenital toxoplasmosis who were treated throughout their first year of life.
Prospective longitudinal observation of a cohort.
One hundred thirty-two children were studied as part of the longitudinal observation.
One hundred thirty-two children were treated during their first year of life with pyrimethamine, sulfadiazine, and leucovorin. They had eye examinations at prespecified intervals.
New chorioretinal lesions on fundus examination and fundus photographs.
The mean age (+/- standard deviation) is 10.8+/-5.1 years (range, 0.2-23). One hundred eight children have been evaluated for new chorioretinal lesions. Thirty-four (31%; 95% confidence interval, 23%-41%) of 108 children developed at least one chorioretinal lesion that was previously undetected. These occurred at varying times during their follow-up course. Fifteen children (14%) developed new central lesions, and 27 (25%) had newly detected lesions peripherally. Ten (9%) had more than one occurrence of new lesions developing, and 13 (12%) had new lesions in both eyes. Of those who developed new lesions, 14 children (41%) did so at age 10 or later.
New central chorioretinal lesions are uncommon in children with congenital toxoplasmosis who are treated during their first year of life. This finding contrasts markedly with earlier reports in the literature for untreated children or those treated for only 1 month near birth, in whom new lesions were much more prevalent (>/=82%). Our observation that 14 (41%) of the 34 children with new chorioretinal lesions had occurrences when they were 10 years or older indicates that long-term follow-up into the second decade of life is important in assessing the efficacy of treating toxoplasmosis during infancy.
[Show abstract][Hide abstract] ABSTRACT: To determine the incidence and natural history of cataracts in children with congenital toxoplasmosis.
Children referred to the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS) between 1981 and 2005 were examined by ophthalmologists at predetermined times according to a specific protocol. The clinical course and treatment of patients who developed cataracts were reviewed.
In the first year of life, 134 of 173 children examined were treated with pyrimethamine, sulfadiazine, and leukovorin, while the remaining 39 were not treated. Cataracts occurred in 27 eyes of 20 patients (11.6%, 95% confidence interval [7.2%, 17.3%]). Fourteen cataracts were present at birth and 13 developed postnatally. Locations of the cataracts included anterior polar (three eyes), anterior subcapsular (six eyes), nuclear (five eyes), posterior subcapsular (seven eyes), and unknown (six eyes). Thirteen cataracts were partial, nine total, and five with unknown complexity. Twelve cataracts remained stable, 12 progressed, and progression was not known for 3. Five of 27 eyes had cataract surgery, with 2 of these developing glaucoma. Sixteen eyes of 11 patients had retinal detachment and cataract. All eyes with cataracts had additional ocular lesions.
In the NCCCTS cohort, 11.6% of patients were diagnosed with cataracts. There was considerable variability in the presentation, morphology, and progression of the cataracts. Associated intraocular pathology was an important cause of morbidity.
Journal of American Association for Pediatric Ophthalmology and Strabismus 01/2008; 11(6):551-4. · 0.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This article describes an unusual case of meningococcal endogenous endophthalmitis presenting as anterior uveitis. This case re-emphasizes the importance of early diagnosis of endogenous endophthalmitis, which can lead to good visual recovery.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this work was to determine whether visual impairment caused by toxoplasmic chorioretinitis is associated with impaired performance of specific tasks on standardized tests of cognitive function. If so, then we worked to determine whether there are patterns in these difficulties that provide a logical basis for development of measures of cognitive function independent of visual impairment and compensatory intervention strategies to facilitate learning for such children.
Sixty-four children with congenital toxoplasmosis with intelligence quotient scores > or = 50 and visual acuity sufficient to cooperate with all of the intelligence quotient subscales had assessments of their vision, appearance of their retinas, and cognitive testing performed between 3.5 and 5 years of age. These evaluations took place between 1981 and 1998 as part of a longitudinal study to determine outcome of congenital toxoplasmosis. Children were evaluated at 3.5 or 5 (37 children) or both 3.5 and 5 (27 children) years of age. Cognitive function was measured using the Wechsler Preschool and Primary Scale of Intelligence-Revised. Wechsler Preschool and Primary Scale of Intelligence-Revised scale scores were compared for children grouped as those children who had normal visual acuity in their best eye (group 1), and those who had impaired vision in their best eye (acuity < 20/40) because of macular disease (group 2). Demographic characteristics were compared for children in the 2 groups. Test scores were compared between groups using all of the 3.5-year-old visits, all of the 5-year-old visits, and using each child's "last" visit (ie, using the 5-year-old test results when a child was tested at both 3.5 and 5 years of age or only at 5 years, otherwise using the 3.5-year-old test results). The results were similar and, therefore, only the results from the last analysis are reported here.
There were 48 children with normal visual acuity in their best eye (group 1) and 16 children with impaired vision because of macular involvement in their best eye (group 2). Ethnicity and socioeconomic scores were similar. There was a significantly greater proportion of males in group 2 compared with group 1 (81% vs 46%). There was no significant diminution in Wechsler Preschool and Primary Scale of Intelligence-Revised test scores between 3.5 and 5 years of age for the 27 children tested at both of these ages. Verbal intelligence quotient, performance intelligence quotient, full-scale intelligence quotient scores, and all of the scaled scores except arithmetic and block design were significantly lower for children in group 2 compared with group 1. The majority of the differences remained statistically significant or borderline significant after adjusting for gender. However, the difference in overall verbal scores does not remain statistically significant. Mean +/- SD verbal (98 +/- 20) and performance (95 +/- 17) intelligence quotients were not significantly different for children in group 1. However, verbal (88 +/- 13) and performance intelligence quotients (78 +/- 17) were significantly different for children in group 2. For children in group 2, their lowest scale scores were in object assembly, geometric design, mazes, and picture completion, all timed tests that involved visual discrimination of linear forms with small intersecting lines. In the 2 scales scored that did not differ between groups 1 and 2, arithmetic and block design, timing and vision but not linear forms were components of the tasks. Children with monocular and binocular normal visual acuity did not differ in verbal, performance, or full-scale intelligence quotients or any of the subscale tests. Difficulty with sight or concomitant neurologic involvement also seemed to impact the ability to acquire information, comprehension skills, and vocabulary and performance in similarities testing. After controlling for gender, however, these differences were diminished, and there were no longer differences in overall verbal scores. As noted above, results were generally similar when all of the tests for 3.5-year-olds or 5-year-olds were analyzed separately. At the 3.5-year visit there were fewer significant differences between the 2 groups for the verbal components than at the 5-year visit.
In children with congenital toxoplasmosis and bilateral macular disease (group 2) because of toxoplasmic chorioretinitis, scaled scores were lowest on timed tests that require discrimination of fine intersecting lines. Although the severity of ocular and neurologic involvement is often congruent in children with congenital toxoplasmosis, ophthalmologic involvement seems to account for certain specific limitations on tests of cognitive function. Children with such visual impairment compensate with higher verbal skills, but their verbal scores are still less than those of children with normal vision, and in some cases significantly so, indicating that vision impairment might affect other aspects of cognitive testing. Patterns of difficulties noted in the subscales indicate that certain compensatory intervention strategies to facilitate learning and performance may be particularly helpful for children with these impairments. These patterns also provide a basis for the development of measures of cognitive function independent of visual impairment.
[Show abstract][Hide abstract] ABSTRACT: Without treatment, congenital toxoplasmosis has recurrent, recrudescent, adverse outcomes. Long-term follow-up of infants with congenital toxoplasmosis treated throughout their first year of life with pyrimethamine and sulfadiazine has not been reported.
Between 1981 and 2004, one hundred twenty infants (current mean age +/- standard deviation, 10.5 +/- 4.8 years) with congenital toxoplasmosis were treated with 1 of 2 doses of pyrimethamine plus sulfadiazine; therapy was initiated shortly after birth and continued for 12 months. Children who received treatment were evaluated at birth and at predetermined intervals; the focus of the evaluations was on prespecified end points: motor abnormalities, cognitive outcome, vision impairment, formation of new eye lesions, and hearing loss.
Treatment of infants without substantial neurologic disease at birth with pyrimethamine and sulfadiazine for 1 year resulted in normal cognitive, neurologic, and auditory outcomes for all patients. Treatment of infants who had moderate or severe neurologic disease (as defined in this article in the Treatments subsection of Methods) at birth resulted in normal neurologic and/or cognitive outcomes for >72% of the patients, and none had sensorineural hearing loss. Ninety-one percent of children without substantial neurologic disease and 64% of those with moderate or severe neurologic disease at birth did not develop new eye lesions. Almost all of these outcomes are markedly better than outcomes reported for children who were untreated or treated for 1 month in earlier decades (P<.01 to P<.001). Sex and severity of disease were comparable in our 2 treatment groups, and no significant differences in efficacy or toxicity were noted between the 2 treatment groups (P > .05).
Although not all children did well with treatment, the favorable outcomes we noted indicate the importance of diagnosis and treatment of infants with congenital toxoplasmosis.
[Show abstract][Hide abstract] ABSTRACT: To report childhood infection with Baylisascaris procyonis (raccoon round worm) manifesting as diffuse unilateral subacute neuroretinitis (DUSN) and choroidal infiltrates in association with neurologic disease (neural larva migrans).
Observational case series, one with eye manifestations of DUSN, the other with choroidal infiltrates, both with severe neurologic degeneration.
Indirect immunofluorescence assays on serum and cerebrospinal fluid were positive for B. procyonis in one and serially positive and increasing in the other. Both children had a history of pica and raccoon exposure.
Baylisascaris procyonis infection is associated with two cases of severe neurologic degeneration with ocular lesions: DUSN and choroidal infiltrates. Although B. procyonis is known to cause DUSN, these cases indicate that concomitant ocular migration may accompany neural larva migrans. These are the third and forth cases in the US literature of neural larva migrans due to B. procyonis with eye findings.
American Journal of Ophthalmology 07/2003; 135(6):888-90. · 4.02 Impact Factor