Evaluation of the Goldmann-Witmer coefficient in the immunological diagnosis of ocular toxocariasis

Mycobacterium tuberculosis transcriptome in intraocular tuberculosis

Introduction. Intraocular tuberculosis (IOTB) is a significant cause of visual morbidity in tuberculosis (TB)-endemic countries. Although Mycobacterium tuberculosis (M. tb) has been detected in both the retinal pigment epithelial (RPE) cells and in the intraocular fluid (IOF) in some cases, IOTB is paucibacillary in the vast majority of patients. As a result, M. tb pathogenesis in the ocular compartment is poorly defined.Hypothesis. The transcriptional profile of M. tb in the ocular compartment will differ from those of M. tb in environments that represent earlier stages of infection.Aim. Our aim is to shed light on the pathogenesis of M. tb in a clinically relevant but challenging environment to study.Methodology. Whole-genome microarray analysis was performed on M. tb grown in an IOF model (artificial IOF; AIOF) over 6 days against reference log phase bacteria grown in 7H9. Results were compared to published M. tb transcriptomes in other physiologically relevant environments, e.g. RPE cell line.Results. M. tb replicates slowly in AIOF. Genes involved in active replication and aerobic respiration as well as lipid metabolism were either downregulated or not differentially expressed. Yet, M. tb in AIOF downregulated genes of the DosR regulon, indicating the suppression of dormancy, similar to M. tb in RPE cells. This transcriptional profile is distinct from the active and virulent transcriptomes of M. tb in alveolar epithelial cells and blood.Conclusion. M. tb likely acquires a non-invasive and quiescent phenotype, between active infection and dormancy, upon reaching an extrapulmonary niche, i.e. the ocular environment.

Cytokine Profile in Aqueous Humor of Patients With Ocular Toxocariasis

Purpose

Ocular toxocariasis (OT) is a vision-threatening disease with a largely unknown intraocular pathogenesis. Herein, we determined the cytokine expression profile in aqueous humor (AH) of patients with OT.

Methods

This is a retrospective case-control study of cytokine levels in AH of patients with OT and uveitis and control subjects. Thirty samples from eyes with OT, 23 from eyes with non-OT uveitis, and 25 from eyes with age-related cataract were analyzed using a multiplexed magnetic bead immunoassay. Thirty-one cytokines were detected and classified into 5 categories: T-helper type 1 (Th1) -associated cytokines, Th2-associated cytokines, Th17 cytokine, proinflammatory mediators, and growth factors.

Results

In the 31 cytokines, 9 cytokines were undetectable, including IL-1a, IL-1b, IL-2, IL-3, IL-12p70, IL-17A, TGF-a, TNF-β, and IFN-g. From the 22 cytokines, 13 exhibited significantly increased expression in the OT group than in the control group, including TNF-a, IFN-a2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, sCD40L, PDGF-AA, PDGF-AB/BB, FLT3l, and EGF. There were 5 cytokines exhibited significantly increased expression in the OT group than in non-OT group, including IL-5, IL-9, IL-10, IL-13, and PDGF-AA. There was no significantly decreased expression in any cytokines in the OT group when compared with control or non-OT groups. To the 5 cytokines that showed significant difference in OT group alone, IL-10 and IL-13 exhibited more than 13-fold increase, and IL-5 showed the most obvious as 27-fold increase in OT patients, when compared with that in control group.

Conclusion

The cytokine profile expression in aqueous humor from patients with ocular toxocariasis was investigated, and our findings suggest that Th1 and Th17 cytokine responses are not enhanced, whereas the cytokine status was polarized toward a Th2 response. Our findings also suggest the involvement of IL-5, IL-10, and IL-13 in the immunopathogenesis of ocular toxocariasis.

The Value of the Antibody Detection in the Diagnosis of Ocular Toxocariasis and the Aqueous Cytokine Profile Associated With the Condition

Introduction

To evaluate and compare the specificity of Toxocara canis-specific antibody detection in the serum and aqueous samples for the diagnosis of ocular toxocariasis (OT) and explore the cytokine profiles associated with the condition in children.

Materials and Methods

This is a prospective cohort study. The inclusion criteria were the clinical presentations of OT, which included unilateral vision reduction, typical peripheral or posterior pole granuloma with variable degrees of vitritis, and exclusion of other diagnoses. The titer of antibody against the excretory-secretory antigen of Toxocara canis [T-immunoglobulin G (IgG)] was measured in serum and aqueous samples that were taken from the affected eyes. The diagnosis of OT was made upon positive detection of T-IgG either in the serum or aqueous. The rest with typical clinical presentations as described above but a positive serum or aqueous T-IgG could not be confirmed were diagnosed as suspected OT. Cytokines were measured using multiplexed cytometric bead array system.

Results

Two hundred and eleven eyes of 211 patients had participated in the study. One hundred and twenty-eight eyes were diagnosed as OT. The median age of the cohort was 7.7 years with a male to female ratio of 2.5:1. Major initial symptoms were decreased vision (74%) and strabismus (22%). The percentages of eyes with peripheral granuloma, posterior granuloma, and endophthalmitis were 40, 18, and 41%, respectively. Vitritis (100%), vitreous strands (64%), retinal fibrotic bands (57%), and retinal detachment (42%) were the most common signs. T-IgG was positive in 66.7% of the aqueous and 57.2% of the serum samples. Forty-four patients were diagnosed T-IgG negative in both serum and aqueous of the affected eyes. Interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-8, eosinophil chemotactic protein (Eotaxin), MCP-1β, and vascular endothelial growth factor (VEGF) were higher in T-IgG negative eyes when compared to controls and further increased in T-IgG positive eyes. However, only T-IgG positive eyes showed increased IL-5, IL-13, and IL-10. IL-1β, tumor necrosis factor-alpha (TNF-α), IL-12, IL-2, interferon-gamma (IFN-γ), and IL-4 were undetectable in all eyes.

Conclusions

Pediatric OT is often present with severe retinal complications. Polarized intraocular Th2 response was only found in aqueous T-IgG positive eyes. Our results supported an aqueous sample-based antibody test for the more specific diagnosis of OT.

Non-invasive diagnostic strategy of ocular toxocariasis based on clinical features

PURPOSE

To develop a non-invasive diagnostic strategy based on the clinical manifestations of ocular toxocariasis (OT), and evaluate its sensitivity and specificity.

METHODS

Patients with unilateral OT-like lesions were enrolled retrospectively and classified into OT and non-OT groups according to the immunologic diagnosis criterion of anti-OT IgG. Nine clinical manifestations were recorded and compared between groups. Among them, the retrolental membrane (RM), branch-like vitreous strands (BVS), and retinal granulomas (RG) were the most common, which were further classified into three categories, including at least 1 out of 3 signs, at least 2 out of 3 signs, and all 3 signs positive. Diagnostic sensitivity and specificity were calculated for each strategy.

RESULTS

There were 105 immunologically confirmed patients with OT and 70 patients with non-OT uveitis/vitreoretinopathy. RG, RM, and BVS were significantly more frequent in OT patients than in non-OT patients. At least 1 of 3 signs positive strategy showed the highest sensitivity (100.0%) but the lowest specificity (62.0%). At least 2 out of 3 signs positive strategies showed 80.0% sensitivity and 94.3% specificity. All 3 signs positive strategies had the lowest sensitivity (46.7%) and the highest specificity (100.0%). The cutoff point of this revealed an area under the curve of 0.85 and a 95% confidence interval of 0.79 to 0.91.

CONCLUSION

A comprehensive strategy based on at least 2 out of 3 positive signs showed excellent sensitivity and specificity, and could serve as a non-invasive and fast screening strategy for the clinical diagnosis of OT.

Uveitis in Children and Adolescents

Childhood noninfectious uveitis leads to sight-threatening complications. Idiopathic chronic anterior uveitis and juvenile idiopathic arthritis-associated uveitis are most common. Inflammation arises from an immune response against antigens within the eye. Ophthalmic work-up evaluates anatomic involvement, disease activity, ocular complications, and disease course. Local and/or systemic glucocorticoids are initial treatment, but not as long-term sole therapy to avoid glucocorticoids-induced toxicity or persistent ocular inflammation. Children with recurrent, refractory, or severe disease require systemic immunosuppression with methotrexate and/or anti-tumor necrosis factor monoclonal antibody medications (adalimumab, infliximab). Goals of early detection and treatment are to optimize vision in childhood uveitis.

Diagnosis of Ocular Toxocariasis by Serum and Aqueous Humor IgG ELISA

Purpose

Ocular toxocariasis (OT) is a worldwide ocular parasitic infection and is especially sight-threatening in children. Because of the clinical manifestation diversity, OT has frequently been misdiagnosed. The purpose of this study was to evaluate the diagnostic value of anti-toxocara immunoglobulin G (IgG) in intraocular fluid (IF) and serum in OT.

Methods

IF and serum were collected from patients with clinically diagnosed OT and non-OT uveitis. The level of anti-toxocara IgG was detected by enzyme-linked immunosorbent assay. The data were statistically analyzed in anti-toxocara IgG and the Goldmann–Witmer coefficient (GWC) between groups. The area under the receiver operating characteristic curve (AUC ROC) was performed to assess the diagnostic value of serum and IF anti-toxocara IgG and the GWC.

Results

A total of 290 participants, 128 (44.1%) with OT and 162 (55.9%) with non-OT uveitis, were included in this study. The default serum anti-toxocara IgG cutoff value of 11 U had 72.1% sensitivity and 95.5% specificity. With the optimized cutoff value of 8.2 U, the AUC was 0.886 (95% confidence interval [CI] = 0.830–0.929, P < 0.0001), sensitivity increased to 80.2%, and specificity was 94.0%. With an IF anti-toxocara IgG cutoff value of 1.8 U, the AUC was 0.934 (95% CI = 0.892–0.963, P < 0.0001), sensitivity was as high as 88.4%, and specificity was 96.4%.

Conclusions

Our study proposes novel diagnostic cutoff values of serum and IF anti-toxocara IgG for OT, which are 8.2 U and 1.8 U, respectively.

Translational Relevance

This study will improve the accuracy of diagnosis in patients with OT.

Multimodality Image Analysis in a Cohort of Patients with Atypical Juvenile Ocular Toxocariasis

Purpose

To analysis the multimodal imaging of a group of patients diagnosed clinically with atypical juvenile ocular toxocariasis (OT).

Methods

In this case series study, we examined 9 young patients diagnosed with atypical OT. Routine ophthalmological examinations, fundus photography, optical-coherence tomography (OCT), fluorescein angiography (FFA), and B-mode ultrasound were performed. A questionnaire was used to record whether the patients were newly diagnosed and whether they had a history of exposure to a cat and dog. Aqueous humor and serum samples were taken for serological tests.

Results

In all the patients, yellow-and-white dot-shaped lesions and perivascular white sheath were seen in the fundus. Heterogeneous changes including hyper-reflection in the disrupted neuroretina, hyper-reflection in the outer retinal layer, high-reflection mass on the surface of the neuroretina accompanied with reflective attenuation, and high-reflection mass involving the entire neuroretina or high-reflection mass in the vitreous body were noticed in OCT images. On FFA, seven of these patients (77.8%) showed leakage of fluorescein in the small- and medium-branch veins of the retina, and a “bristle-like” change indicated increased permeability of the vessels. B-mode ultrasound showed proliferative membranes and proliferative bands (33.3%), as well as spotted opacity in the vitreous (66.7%). The antibodies to Toxocara canis in the aqueous humor and serum were positive, and the Goldmann–Witmer coefficient was significantly increased in 6 out of 7 patients.

Conclusions

Multimodality images are useful in the diagnosis of atypical juvenile OT, which could be easily overlooked and misdiagnosed.

Pathobiology and treatment of viral keratitis

Keratitis is one of the most prevalent ocular diseases manifested by partial or total loss of vision. Amongst infectious (viz., microbes including bacteria, fungi, amebae, and viruses) and non-infectious (viz., eye trauma, chemical exposure, and ultraviolet exposure, contact lens) risk factors, viral keratitis has been demonstrated as one of the leading causes of corneal opacity. While many viruses have been shown to cause keratitis (such as rhabdoviruses, coxsackieviruses, etc.), herpesviruses are the predominant etiologic agent of viral keratitis. This chapter will summarize current knowledge on the prevalence, diagnosis, and pathobiology of viral keratitis. Virus-mediated immunomodulation of host innate and adaptive immune components is critical for viral persistence, and dysfunctional immune responses may cause destruction of ocular tissues leading to keratitis. Immunosuppressed or immunocompromised individuals may display recurring disease with pronounced severity. Early diagnosis of viral keratitis is beneficial for disease management and response to treatment. Finally, we have discussed current and emerging therapies to treat viral keratitis.

Clinical features of ocular toxocariasis: a comparison between ultra-wide-field and conventional camera imaging

PURPOSE

The purpose of this study is to compare the lesion detection rates of ocular toxocariasis (OT) between ultra-wide-field scanning laser ophthalmoscopy (UWF-SLO) and conventional fundus photography (CFP), and to evaluate the potential diagnostic ability of UWF-SLO in OT.

METHODS

A total of 56 patients with serological/immunological confirmed unilateral OT were enrolled. The presence of OT characteristic features included the posterior granuloma (postG), peripheral granuloma (periG), tractional retinal detachment (TRD), retinal folds (RF), and vitreous strands (VS) and was analyzed in 36 patients with UWF-SLO and 56 patients with CFP. Diagnostic tests were employed using the clinical examination as gold standard.

RESULTS

In total of the 56 OT eyes, granulomas were identified in 91.1% (51/56) of eyes, including postG in 46.4% (26/56) of eyes, periG in 41.1% (23/56) of eyes, and combined granulomas in 3.6% (2/56) of eyes. TRD, RF, and VS were found in 28.6% (16/56), 51.8% (29/56), and 83.9% (47/56) of patients, respectively. Although the specificities of the diagnosis in clinical features were similar by the diagnostic tests, the sensitivities of postG, periG, TRD, RF, and VS using UWF-SLO were 100%, 100%, 66.7%, 95%, and 81.8%, respectively, which were significantly higher those of CFP (72.2%, 31.3%, 11.1%, 55%, and 48.5%). Additionally, the extent of vitreous haze was milder graded by UWF-SLO compared to CFP (p = 0.0099).

CONCLUSIONS

The diagnostic ability of UWF-SLO was superior to CFP using clinical examination as gold standard for the ascertainment of the characteristic manifestations of OT, especially for granulomas and RF.

Ocular Toxocariasis: Long-Term Follow-Up and Prognosis of Patients following Vitrectomy

Purpose: To investigate the outcomes of surgical treatment in patients with ocular toxocariasis and identify prognostic factors.Methods: We retrospectively reviewed the medical records of 56 consecutive patients who underwent vitrectomy.Results: The mean follow-up was 20.7 months. Visual acuity (VA) improved in 70.4% of patients by the final visit, but VA was better than Snellen 20/70 in only 31.5% of patients. Preoperative VA was closely correlated with final VA (P = 0.001). Macular involvement was associated with final VA worse than 20/70 (P = 0.03). The most common postoperative complications were ocular hypertension (19.6%) and retinal detachment (12.5%). Seven patients (12.5%) experienced recurrent inflammation postoperatively, but no preoperative factors were associated with recurrent inflammation.Conclusion: Surgical treatment could rescue visual function in patients with ocular toxocariasis but their prognosis was unfavorable. Preoperative VA was associated with final VA, whereas macular involvement was associated with poor visual outcomes.

Diagnosis of ocular toxocariasis by detecting antibodies in the vitreous humor

OBJECTIVES

To demonstrate the production of the local toxocara antibodies in the vitreous of patients with negative serology.

MATERIAL AND METHODS

Retrospective review of the medical records of patients seen in a Tertiary Referral Hospital, and at an Eye Institute, with an ocular diagnosis of toxocariasis who had a negative serology and positive titres in the vitreous.

RESULTS

After reviewing the medical records of 40 patients with a diagnosis of ocular toxocariasis, a total of six cases (15%) were found with a negative serology and a positive vitreous titre for toxocara antibody, both of them performed using an ELISA procedure. The mean age was 18 years, there were no differences observed between males and females. A peripheral granuloma was the most common clinic finding, and all patients underwent vitrectomy either to remove epiretinal membranes or to repair retinal detachments.

CONCLUSION

A negative serology does not rule out a diagnosis of ocular toxocariasis. Vitreous samples may be necessary to confirm a clinical diagnosis.