Excretory-secretory products of Toxocara canis larvae have been considered as a major functional antigen in immune responses against toxocariasis. We studied ultrastructural localization of T. canis second-stage larval antigen using a seropositive human serum under immunogold electron microscopy. High-density gold particles were observed in the secretory cells, excretory duct, intestinal epithelium, and cuticle of the larval worm sections. The distribution of the positive reactions in the larval worms suggests that the nature of the antigen is excretory-secretory antigen including waste metabolites and secretory enzymes.
Animals ; Antigens, Helminth/*immunology/ultrastructure ; Humans ; Larva/*immunology/ultrastructure ; Toxocara canis/*immunology/ultrastructure ; Toxocariasis/*immunology

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.
Animals ; Brain/*pathology ; Disease Models, Animal ; Female ; Gene Expression Profiling ; Histocytochemistry ; *Immunocompromised Host ; Immunohistochemistry ; Interleukin-5/genetics ; Male ; Mice ; Parasite Load ; Toxocara canis/*immunology ; Toxocariasis/*immunology/*pathology

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.
Animals ; Brain/*pathology ; Disease Models, Animal ; Female ; Gene Expression Profiling ; Histocytochemistry ; *Immunocompromised Host ; Immunohistochemistry ; Interleukin-5/genetics ; Male ; Mice ; Parasite Load ; Toxocara canis/*immunology ; Toxocariasis/*immunology/*pathology

Roundworms of Toxocara canis and Toxascaris leonina are common gastrointestinal helminths of canids over the world. Humans are infected with T. canis larvae through ingestion of infective eggs in contaminated environments or larvae by consumption of raw or uncooked meat or livers. Recently, patients of clinically diagnosed toxocariasis are increasing and require correct diagnosis in Korea. The present study investigated serological cross-reactivity between crude antigens of T. canis (TCLA) and T. leonina (TLLA) larvae. We collected serum specimens from 177 toxocariasis patients who were clinically suspected in the Seoul National University Hospital and 115 healthy controls. An ELISA method for toxocariasis was used to evaluate diagnostic efficacy of TLLA for serodiagnosis of human toxocariasis. The IgG ELISA using TLLA gave 14 (14.3%) positives of 98 TCLA positive specimens among 177 suspected toxocariasis patients. Most of them showed high absorbances with TCLA. In conclusion, there is a partial cross reaction between serum specimens of toxocariasis and TLLA.
Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/*immunology ; Cross Reactions ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G/blood ; Larva/immunology/metabolism ; Toxascaris/growth & development/*immunology/isolation & purification ; Toxocara canis/growth & development/*immunology/isolation & purification ; Toxocariasis/*diagnosis/parasitology

Toxocariasis is a worldwide zoonosis caused by larvae of ascarid nematodes of dogs or cats, Toxocara canis or T. cati. Diagnosis of human toxocariasis currently relies on serology that uses T. canis excretory-secretory antigen to detect specific IgG antibodies by ELISA. We investigated the serodiagnostic efficacy of ELISA using crude antigen of T. canis larvae (TCLA). Serum specimens of 64 clinically confirmed toxocariasis, 115 healthy controls, and 119 other tissue-invading helminthiases were screened by ELISA using TCLA. The ELISA using TCLA showed 92.2% (59/64 patient samples) sensitivity and 86.6% (103/119) specificity. Its positive diagnostic predictivity was 78.7% and negative predictivity was 97.8%. No serum of healthy controls reacted but that of anisakiasis (45.5%), gnathostomiasis (19.2%), clonorchiasis (15.8%), sparganosis (11.1%), and cysticercosis (6.3%) cross-reacted. Immunoblot analysis on TCLA recognized antigenic proteins of 28- and 30-kDa bands in their dominant protein quantity and strong blotting reactivity. The present results indicate that the ELISA using our TCLA antigen is acceptable by the sensitivity and specificity for serodiagnosis of human toxocariasis. ELISA with TCLA is recommended to make differential diagnosis for patients with any sign of organ infiltration and eosinophilia.
Adolescent ; Adult ; Aged ; Animals ; Antigens, Helminth/chemistry/*diagnostic use/immunology/isolation & purification ; Cats ; Dogs ; Enzyme-Linked Immunosorbent Assay/*methods ; Female ; Humans ; Larva/chemistry/immunology ; Male ; Middle Aged ; Serologic Tests ; Toxocara canis/chemistry/*immunology ; Toxocariasis/*diagnosis/immunology/parasitology ; Young Adult

Recently reports on toxocariasis are increasing by serodiagnosis in Korea. A previously healthy 17-yr-old boy complained of headache, fever, dyspnea, and anorexia. He showed symptoms and signs of eosinophilic meningitis with involvement of the lungs and liver. Specific IgG antibody to Toxocara canis larval antigen was positive in serum and cerebrospinal fluid by ELISA. He took raw ostrich liver with his parents 4 weeks before the symptom onset. His parents were seropositive for T. canis antigen but had no symptoms or signs suggesting toxocariasis. This is the first report of toxocariasis in a family due to ingestion of raw ostrich liver in Korea.
Adolescent ; Animals ; Antibodies, Helminth/blood/cerebrospinal fluid ; Eating ; Humans ; Larva/immunology ; Liver/parasitology ; Male ; Meningitis/*diagnosis/parasitology ; Struthioniformes ; Tomography, X-Ray Computed ; Toxocara canis/growth & development/*immunology/isolation & purification ; Toxocariasis/*diagnosis/parasitology/transmission

Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzymelinked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p< 0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow- up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged.
Adult ; Aged ; Animals ; Case-Control Studies ; Female ; Humans ; Immunoglobulin E/blood ; Korea ; Leukocyte Count ; Liver/parasitology ; Male ; Middle Aged ; Pulmonary Eosinophilia/diagnosis/*etiology/immunology ; Seroepidemiologic Studies ; Tomography, X-Ray Computed ; Toxocara/immunology ; Toxocariasis/*complications/diagnosis/epidemiology

PURPOSE: Since few reports had been published on the prevalence of toxocariasis in ankylosing spondylitis (AS) patients with acute non-granulomatous anterior uveitis (ANGAU), the aim of this work was to determine the presence of antibodies against Toxocara canis in AS patients with ANGAU. METHODS: Thirty-six patients (14 female and 22 male) with AS were enrolled in the study. The history of ANGAU was accepted only if diagnosed by an ophthalmologist. The detection of IgG antibodies to T. canis was determined by enzyme-linked immunosorbent assay. In addition, antibodies to Ascaris lumbricoides were also tested to verify non-specific reactions. RESULTS: The prevalence of ANGAU in the AS patients was 58% (21 / 36), and 38% (8 / 21) of the patients with ANGAU were positive for antibodies to Toxocara, while 7% (1 / 15) of AS patients without ANGAU were positive for T. canis (p = 0.038, two tails; mid-p exact). No antibodies were detected to A. lumbricoides antigens in the serum samples of patients with AS. CONCLUSIONS: These data suggest that the seroprevalence of antibodies to T. canis is high in Mexican patients with AS-associated uveitis, suggesting a chronic asymptomatic toxocariosis, which could be associated with the pathogenesis of ANGAU; however, further larger-scale studies are needed to confirm this observation.
Acute Disease ; Adult ; Aged ; Animals ; Antibodies, Anti-Idiotypic/*isolation & purification ; Enzyme-Linked Immunosorbent Assay ; Eye Infections, Parasitic/complications/*immunology/parasitology ; Female ; Humans ; Immunoglobulin G/*immunology ; Male ; Middle Aged ; Seroepidemiologic Studies ; Spondylitis, Ankylosing/*complications/immunology/parasitology ; Toxocara canis/*immunology/isolation & purification ; Toxocariasis/complications/*immunology/parasitology ; Uveitis, Anterior/complications/*immunology/parasitology ; Young Adult

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis.
Adult ; Albendazole/therapeutic use ; Animals ; Anthelmintics/therapeutic use ; Antibodies, Helminth/blood/immunology ; Humans ; Immunoglobulin E/blood/immunology ; Magnetic Resonance Imaging ; Middle Aged ; Myelitis/drug therapy/*etiology/*immunology/pathology ; Retrospective Studies ; Toxocara/*immunology ; Toxocariasis/*complications/drug therapy/*immunology/pathology ; Treatment Outcome ; Young Adult

PURPOSE: To investigate the seroprevalence of toxocariasis in patients diagnosed as schizophrenia. PATIENTS AND METHODS: Ninety-eight schizophrenic patients hospitalized at The Elazig Psychiatric Hospital were included in the study. Anti-Toxocara IgG and/or IgM antibodies were determined by using commercial Toxocara canis IgG and/or IgM ELISA kit. RESULTS: Seropositivity for T. canis was detected in 45 (45.9%) of 98 patients and 2 (2.0%) of 100 control subjects the difference was statistically significant (p < 0.001). The seroprevalence was 40.4% (19 cases) and 51.0% (26 cases) for female and male subjects, respectively (p=0.3). When the seropositive and seronegative schizophrenic patients were compared with respect to the age group environment they were living in, occupation period of follow up and number of hospitalizations, there were no differences between the two groups (all, p > 0.05). CONCLUSION: In conclusion, the schizophrenic state seems to present a high risk for Toxocara infection in Turkey.
Adolescent ; Adult ; Animals ; Antibodies, Helminth/blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Male ; Middle Aged ; Schizophrenia/*blood/parasitology ; Seroepidemiologic Studies ; Toxocara/*growth & development/immunology ; Toxocariasis/*blood/epidemiology ; Turkey/epidemiology