Five cases of ocular toxocariasis confirmed by serology

Park, Sung-Pyo; Park, Inwon; Park, Hyun-Young; Lee, Soo-Ung; Huh, Sun; Magnaval, Jean-François

doi:10.3347/kjp.2000.38.4.267

Cited by 43 publications

(29 citation statements)

References 7 publications

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“…Previous reports showed that the low-molecular-mass bands (24 to 35 kDa) were more specific for toxocariasis, while higher-molecular-mass bands showed reactivity with sera from patients with various helminth infections (11,17). These findings are thus consistent with the pattern of specificities obtained in the present study, namely, rTES-26 Ͼ rTES-30USM Ͼ rTES-120.…”

Section: Discussionsupporting

confidence: 82%

“…These differences may be due to the fact that native antigen was employed in their study whereas recombinant antigens were used in our study. The result of the present study, however, is in agreement with other (17) previous studies that reported a significant increase in the specificity for detection of toxocariasis when an IgG4 assay (instead of an IgG assay) was used (15,16,26). In terms of specificity, all three recombinant antigens displayed high specificities.…”

Section: Discussionsupporting

confidence: 76%

“…Furthermore previous studies have shown that lowmolecular-mass bands (24 to 35 kDa) of native TES antigen were more specific for toxocariasis, while the high-molecularweight TES antigen bands showed reactivity with sera from various helminth infections (11,17). Therefore, we hypothesized that rTES-26 might be useful as a serodiagnostic marker for toxocariasis.…”

Section: Discussionmentioning

confidence: 99%

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Development and Evaluation of a Sensitive and Specific Assay for Diagnosis of Human Toxocariasis by Use of Three Recombinant Antigens (TES-26, TES-30USM, and TES-120)

2009

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Diagnosis of human toxocariasis currently relies on serologic tests that use Toxocara excretory-secretory (TES) antigen to detect immunoglobulin G (IgG) antibodies to the larvae. In general, however, these assays do not have adequate specificity for use in countries in which other soil-transmitted helminths are endemic. The use of recombinant antigens in these assays, however, is promising for improving the specificity of the diagnosis of toxocariasis. Toward this goal, we developed an IgG4 enzyme-linked immunosorbent assay (ELISA) involving three recombinant antigens: rTES-30USM (previously produced), rTES-26, and rTES-120. The latter two antigens were produced by reverse transcription-PCR cloning; subcloned into glutathione S-transferase (GST)-tagged and His-tagged prokaryotic expression vectors, respectively; and expressed in Escherichia coli. The recombinant proteins were subsequently purified by affinity chromatography using GST and His-Trap resins. The diagnostic potential of each purified recombinant antigen was tested with various immunoglobulin classes (IgG, IgM, and IgE) and IgG subclasses. The IgG4 ELISA was determined to have the highest specificity and was further evaluated using a panel of serum samples. The rTES-26 IgG4 ELISA showed 80.0% (24/30 samples positive) sensitivity, and both the rTES-30USM IgG4 ELISA and rTES-120 IgG4 ELISA had 93.0% (28/30) sensitivity. Combined use of rTES-120 and rTES-30 IgG4 ELISA for the diagnosis of toxocariasis provided 100% sensitivity. The specificities of rTES-26, rTES-30USM, and rTES-120 antigens were 96.2%, 93.9%, and 92.0%, respectively. These results indicate that the development of a diagnostic test using the three recombinant antigens will allow for more-accurate detection of toxocariasis.Human toxocariasis is a worldwide parasitic zoonosis, caused most commonly by the intestinal parasites the dog roundworm (Toxocara canis) and also the cat roundworm (Toxocara cati) (2). It commonly manifests as visceral larva migrans, ocular larva migrans, and covert toxocariasis. Toxocariasis is probably one of the most common zoonotic helminthiases in temperate climates and developed countries (20). In Malaysia, the seroprevalence rate is approximately 20% (6).Definitive diagnosis of toxocariasis is based on the detection of Toxocara larvae from biopsy tissues, but this test is timeconsuming and difficult to perform. Therefore, diagnosis is commonly based on clinical and serologic diagnosis. Currently, common routine serology tests are applied for detection, such as commercial immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) kits in which Toxocara excretorysecretory (TES) antigens obtained from culture of T. canis second-stage (L2) larvae are used (22). The use of the native TES antigen for serodiagnosis of human toxocariasis is a laborious and time-consuming technique, and the production capacity is limited by the culture volume (22). Further, the specificity is often low, especially in developing countries, where infections with helminths that cause c...

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Section: Discussionsupporting

confidence: 82%

Section: Discussionsupporting

confidence: 76%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Development and Evaluation of a Sensitive and Specific Assay for Diagnosis of Human Toxocariasis by Use of Three Recombinant Antigens (TES-26, TES-30USM, and TES-120)

2009

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“…Moreover, there was no hepatic or pulmonary involvement in children with a localized form of ocular infection, and similarly VLM cases have not demonstrated any ophthalmological problems. In case of a series of ocular toxocarosis in adults published by Park et al [13], there were no hepatobiliary symptoms or increase in liver enzymes. One of the patients, who complained of decreased visual acuity with tractional retinal detachment and inflammatory exudates had highly elevated titres of total and anti-Toxocara specific immunoglobulin E antibodies (3116 IU/ml and 34,000 TU, respectively), and hypereosinophilia in the peripheral blood (3,340 eosinophils per µl) [17].…”

Section: Discussionmentioning

confidence: 99%

The co-occurrence of Toxocaraocular and visceral larva migrans syndrome: a case series

et al. 2009

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Introduction: Ocular toxocarosis associated with high peripheral eosinophilia and together with systemic signs of visceral damage has been reported sporadically. Eye infections caused by numerous migrating larvae of Toxocara parasites, probably due to re-invasion or delayed reactivation, and leading to a progressive loss of vision is relatively rare. We report three atypical cases of toxocarosis with the co-existence of ocular larva migrans syndrome and generalized signs of Toxocara infection in schoolboys.

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“…The patient had clinical complaints of visual impairment along with floating or bubbling sensation [11]. For a secondary antibody, goat anti-human IgG ( γ -chain specific) coupled with 5 nm colloidal gold particle (Sigma, St. Louis, Missouri, USA) was used.…”

mentioning

confidence: 99%

Ultrastructural Localization of Toxocara canis Larval Antigen Reacted with a Seropositive Human Serum

Lee

Huh

2009

Korean J Parasitol

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Human toxocariasis is one of the most commonly reported zoonotic helminthic infections in the world. In Korea, out of 97 healthy people with over 10% eosinophilia, 60% was positive to Toxocara larvae excretory-secretory (TES) antigen by both immunoblot and ELISA [1]. Also, there was a 0.9% egg positive rate of Toxocara canis out of 662 dogs in a rural area, Korea [2]. Three modes of pathogenesis occur in human toxocariasis. First, T. canis larvae can cause destructive lesions that are characterized by hemorrhage and necrosis during their migration to the eye, liver, lung, brain, and heart [3]. Second, the host immune response against migrating larvae induces inflammation and granuloma formation that is directed to the TES antigen. Third, the TES has been associated with allergy-related syndromes such as chronic urticaria, reactive arthritis, and angioderma, which suggest an allergic reaction to the TES [4]. The excretory-secretory (ES) products of T. canis larvae have been considered as a functional antigen in immune responses against toxocariasis because the excretory cells of the larvae contain many ES products [5]. Then, in most immunological tests, ES recombinant antigens from T. canis second-stage larvae have been conventionally used because the infective Toxocara larvae are extremely difficult to detect in biopsy specimens [6]. Some components of the TES are known to be released from the esophageal gland and lumen, i.e., midbody secretory column, which opens onto the cuticle at a secretory pore, and epicuticle under immunogold electron microscopy [7,8]. Although several studies on the secretory anatomy have been performed in parasitic nematode species [5,9,10], there are no data on the origin of the TES itself in relation to structure and function of the excretory system. We attempted to elucidate the ultrastructural localization of the TES antigen from T. canis second-stage larvae using a human serum that is seropositive against the TES. Determining the distribution sites of the TES will help elucidate the physiologic nature of the TES antigen.For the primary antibody, a human serum that was serologically positive to TES by ELISA and immunoblotting analysis was used. The patient had clinical complaints of visual impairment along with floating or bubbling sensation [11]. For a secondary antibody, goat anti-human IgG ( γ -chain specific) coupled with 5 nm colloidal gold particle (Sigma, St. Louis, Missouri, USA) was used. T. canis larvae from culture media [12] were fixed in 2% paraformaldehyde and 0.4% glutaraldehyde in 0.2 M phosphate buffer (PB, pH 7.4) for 2 hr at room temperature, and washed with 0.2 M PB for 30 min at room temperature. The samples were dehydrated in a graded series of ethanol at 4℃ and embedded in LR gold resin (Electron Microscopy Sciences, Fort Washington, Pennsylvania, USA). The resin was polymerized at -20℃ for 2 days. An ultrathin section (90 nm) was cut and mounted on a 300-mesh nickel grid for labeling (Electron Microscopy Sciences). Sectioned specimens were incubated with drop...

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Five cases of ocular toxocariasis confirmed by serology

Cited by 43 publications

References 7 publications

Development and Evaluation of a Sensitive and Specific Assay for Diagnosis of Human Toxocariasis by Use of Three Recombinant Antigens (TES-26, TES-30USM, and TES-120)

Development and Evaluation of a Sensitive and Specific Assay for Diagnosis of Human Toxocariasis by Use of Three Recombinant Antigens (TES-26, TES-30USM, and TES-120)

The co-occurrence of Toxocaraocular and visceral larva migrans syndrome: a case series

Ultrastructural Localization of Toxocara canis Larval Antigen Reacted with a Seropositive Human Serum

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