Real-Time Multiplex PCR Analysis in Infectious Uveitis

Diagnostic and therapeutic results of aqueous real-time polymerase chain reaction in infectious uveitis

OBJECTIVE

This study was aimed primarily at describing the results of aqueous real-time polymerase chain reaction (RT-PCR) and reporting the rate of therapeutic modifications directly attributable to this procedure (profitability). Our secondary outcome was to compare demographic and clinical characteristics between patients with RT-PCR positivity and those with RT-PCR negative results.

DESIGN

Retrospective observational study conducted at the Uveitis Service of San Raffaele Hospital (Milan, Italy) between November 2016 and July 2022.

PARTICIPANTS

Patients with infectious uveitis suspect (anterior, intermediate, posterior uveitis, or panuveitis).

METHODS

Patients with suspected infectious uveitis underwent aqueous RT-PCR for detection of herpes simplex 1 (HSV-1), herpes simplex 2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), and Toxoplasma gondii.

RESULTS

Sixty-five eyes of 61 patients (60 ±16 years of age; 54% males) were included. Aqueous RT-PCR tested positive in 58% and negative in 42% of patients. CMV and HSV-1 were the most frequently detected pathogens. RT-PCR confirmed clinical suspicion in 38% of patients and altered the presumed etiologic diagnosis and treatment in 20% of patients. Profitability was associated with CMV positivity. HSV-1 positivity was related to iris atrophy. CMV positivity was correlated with keratic precipitates. Vitritis and retinitis were related to VZV, CMV, and T. gondii detection. Synechiae, retinitis, and neuritis were related to positive tests regardless of the pathogen investigated. Early complications related to paracentesis were rarely reported.

CONCLUSION

Aqueous RT-PCR was a safe semi-invasive tool to confirm a presumptive diagnosis and to change initial suspicion in ambiguous cases of herpetic uveitis. Thus aqueous RT-PCR may alter therapeutic management.

Long Vax in the Eye: Long Post-COVID Vaccination Syndrome Presenting with Frosted Branch Angiitis

mRNA COVID-19 vaccines have been reported as protecting against COVID-19 and reducing its severity, and we have recognized post-vaccination symptoms recently. This research investigates the clinical trajectories of ocular disorders in a 51-year-old female who received a second dose of the BNT162b2 (Pfizer-BioNTech) mRNA COVID-19 vaccine. Exhibiting fever and blurred vision within 24 h post-vaccination, with progressive blurry vision over two months, she underwent in-depth ophthalmologic examinations, revealing intraocular cellular infiltration in anterior chamber, vitreous opacity, and frosted branch angiitis in both eyes. Comprehensive evaluations, including systemic workups as well as ocular and blood specimen analyses, excluded autoimmune and infectious etiologies, consolidating the diagnosis of vaccine-induced ocular inflammation. Despite adherence to prevailing therapeutic protocols, her condition showed no significant improvement over 18 months, pointing to a possible long post-COVID vaccination syndrome. Such persistent sequelae underscore the need for detailed studies to discern the interactions between vaccine-induced immune responses and the development of post-vaccination sequelae. Continual documentation of patients with long post-COVID vaccination syndrome is now essential to better understand the vaccine's immunological effects, aiding in improving global vaccination strategies.

Multiplex Detection of RNA Viruses Based on Ligation Reaction and Universal PCR Amplification

To detect several RNA viruses simultaneously, a method based on multiplex ligation reaction combined with multiplex qPCR or multiplex PCR+capillary electrophoresis was established to detect four RNA viruses: human immunodeficiency virus (HIV), hepatitis C (HCV), influenza A virus (IAV) H1N1 and H5N1. The experimental conditions including ligation probe concentration, annealing procedure, ligation temperature and ligase dosage were optimized intensively. We found that the specificity of the ligation reaction was affected by the probe concentration predominantly, high-probe concentration (100 nM) resulted in splint-independent ligation with efficiency comparable to that with RNA splint. The sensitivity of the ligation reaction was affected by the annealing mode apparently as the sensitivity of the step-down annealing mode was 100 times higher than that of the isothermal annealing at 37 °C. Under the optimized condition, this assay could detect virus RNA as low as 16 viral copies per reaction in doubleplex and triplex real-time quantitative PCR detection with satisfactory specificity and precision. By multiplex PCR+capillary electrophoresis, four RNA viruses could be detected in one tube with the sensitivity of 10 copies per reaction.

Infectious Uveitis in Horses and New Insights in Its Leptospiral Biofilm-Related Pathogenesis

Uveitis is a sight-threatening eye disease in equids known worldwide that leads to considerable pain and suffering. By far the most common type of uveitis in Germany and neighboring countries is classical equine recurrent uveitis (ERU), which is caused by chronic intraocular leptospiral infection and is the main cause of infectious uveitis in horses. Other infectious causes are extremely rare and are usually clinically distinguishable from ERU. ERU can be treated very effectively by vitreous cavity lavage (vitrectomy). For proper indications of this demanding surgery, it is necessary to differentiate ERU from other types of uveitis in which vitrectomy is not helpful. This can be conducted on the basis of anamnesis in combination with ophthalmologic findings and by aqueous humor examination. During vitrectomy, vitreous material is obtained. These vitreous samples have historically been used for numerous etiologic studies. In this way, a chronic intraocular leptospiral infection has been shown to be the cause of typical ERU and, among other findings, ERU has also been recognized as a biofilm infection, providing new insights into the pathogenesis of ERU and explaining some thus far unexplainable phenomena of ERU. ERU may not only have transmissible aspects to some types of uveitis in humans but may also serve as a model for a spontaneously occurring biofilm infection. Vitreous material obtained during therapeutically indicated vitrectomy can be used for further studies on in vivo biofilm formation, biofilm composition and possible therapeutic approaches.

The impact of polymerase chain reaction (PCR) on diagnosis and management of infectious uveitis at a tertiary care facility

BACKGROUND

Polymerase Chain Reaction (PCR) is a well-accepted adjunct in the management of infectious uveitis. In turn, few reports in the literature have evaluated how PCR then impacts patient care. This study aims to evaluate the impact of PCR sampling on diagnosis and treatment of infectious uveitidies at a large tertiary care facility.

MAIN BODY

This is a retrospective, observational study of patients with aqueous and vitreous PCR samples obtained from 2014 to 2019. The study was undertaken at a single institution. At least one follow up visit following results of PCR testing was required for inclusion. If a patient had multiple PCR samples taken, only the first sample was included. The patients were divided into three categories based on pre-sampling diagnosis. A chi-square test was used to analyze the data. 108 cases were available for analysis. PCR did not change diagnosis or management in any of the cases where pre-sampling diagnosis carried a high clinical suspicion for negative PCR. Overall, the results of PCR testing had a more significant impact on diagnosis in those cases where pre-sampling diagnosis was unknown versus those where it was confirmatory in nature, thus presumed to be related to an infectious entity tested by PCR (74% vs. 29%, p = 0.00006). The rate of treatment change based on PCR was similar between those cases where there was a high clinical suspicion for positive PCR and those where pre-sampling diagnosis was unknown (32% vs. 33%, p = 0.95). Further analyzing specimens separately depending on source of sample, this pattern persisted for aqueous samples, with PCR showing a more significant impact on diagnosis in those cases where the diagnosis was unknown versus those where sampling was confirmatory (86% vs. 31%, p = 0.00004). The rate of change in treatment between the two groups was similar (35% vs. 31%, p = 0.79). Vitreous samples followed a similar pattern with a higher rate of diagnosis change for those cases where pre-sampling diagnosis was unknown and a similar rate in treatment change between the two groups, however this did not reach statistical signifigance (44% vs. 25%, p = 0.28; 27% vs. 33%, p = 0.74).

CONCLUSION

There is no well-defined algorithm as to when to employ PCR testing in uveitis. As expected, in our experience, it has the largest impact on diagnosis when the diagnosis is unknown, however even when confirmatory in nature, it continues to impact patient management.

Rapid Detection of High-Level Tigecycline Resistance in Tet(X)-Producing Escherichia coli and Acinetobacter spp. Based on MALDI-TOF MS

The emergence and spread of the novel mobile Tet(X) tetracycline destructases confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. and pose serious threats to human and animal health. Therefore, a rapid and robust Tet(X) detection assay was urgently needed to monitor the dissemination of tigecycline resistance. We developed a rapid and simple assay to detect Tet(X) producers in Gram-negative bacteria based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). This MALDI^Tet(X) test was based on the inactivation of tigecycline by a Tet(X)-producing strain after a 3-h incubation of bacterial cultures with tigecycline. Culture supernatants were analyzed using MALDI-TOF MS to identify peaks corresponding to tigecycline (586 ± 0.2 m/z) and a tigecycline metabolite (602 ± 0.2 m/z). The results were calculated using the MS ratio [metabolite/(metabolite + tigecycline)]. The sensitivity of the MALDI^Tet(X) test with all 216 test strains was 99.19%, and specificity was 100%. The test can be completed within 3 h. Overall, the MALDI^Tet(X) test is an accurate, rapid, cost-effective method for the detection of Tet(X)-producing E. coli and Acinetobacter spp. by determining the unique peak of an oxygen-modified derivative of tigecycline.

AIDS-related Cryptococcus neoformans choroiditis

We describe a case of Cryptococcal choroiditis in a person with advanced HIV/AIDS. A 29-year-old male with AIDS presented with fever, photophobia, and ataxia secondary to cryptococcal and toxoplasma meningoencephalitis. Dilated fundoscopic examination revealed bilateral and multifocal posterior infiltrates consistent with cryptococcal choroiditis. Treatment with parenteral and intravitreal liposomal amphotericin B, oral flucytosine, and oral trimethoprim-sulfamethoxazole led to resolution of his symptoms and improvement in his vision. Our case documents a rare, intraocular opportunistic infection and highlights the importance of ophthalmologic examination in immunocompromised hosts with visual symptoms and invasive fungal infection. We discuss diagnostic and treatment considerations in cryptococcal choroiditis.

HTLV-1 in Ophthalmology

Human T-cell leukemia virus type 1 (HTLV-1) was the first retrovirus described as a causative agent for human disease. In the field of ophthalmology, a close relationship between HTLV-1 infection and uveitis was identified through a series of clinical and laboratory studies in the late 1980s-1990s. Since then, HTLV-1-related ocular manifestations such as keratoconjunctivitis sicca, interstitial keratitis, optic neuritis and adult T-cell leukemia/lymphoma (ATL)-related ocular manifestations have continuously been reported. During the three decades since the association between HTLV-1 and ocular pathologies was discovered, ophthalmic practice and research have advanced with the incorporation of new technologies into the field of ophthalmology. Accordingly, new findings from recent research have provided many insights into HTLV-1-associated ocular diseases. Advanced molecular technologies such as multiplex polymerase chain reaction (PCR)/broad-range PCR using ocular samples have enabled rapid and accurate diagnosis. Advanced ophthalmic technologies such as widefield fundus camera and optical coherence tomography (OCT) have clarified various features of HTLV-1-associated ocular manifestations, and identified characteristics such as the "knob-like ATL cell multiple ocular infiltration" (KAMOI) sign. Advanced drug delivery methods such as intravitreal injection and sub-Tenon injection have led to progress in preventing disease progression. This article describes global topics and the latest research findings for HTLV-1-associated ocular diseases, with reference to a large-scale nationwide survey of ophthalmologists. Current approaches and unmet needs for HTLV-1 infection in ophthalmology are also discussed.

Characteristics of Corneal Endotheliitis among Different Viruses by in Vivo Confocal Microscopy

Objectives: To explore the cellular morphological characteristics and changes in corneal endotheliitis among different viruses by in vivo confocal microscopy (IVCM).Methods: Corneal confocal images of 44 eyes of 44 patients with HSV, VZV, CMV and EBV corneal endotheliitis were studied retrospectively. Corneal confocal images of 44 normal eyes were used as controls.Results: The pathogens included cytomegalovirus (n = 20), herpes simplex virus (n = 8), varicella zoster virus (n = 10), and Epstein Barr virus (n = 6). There were no differences in the evaluated structures among the different viruses except for the lengths of the subbasal nerves and Langerhans cell densities. Deviations in endothelial cell layers were not significant among different viruses except for owl's eye morphology.Conclusion: ICVM can assist in diagnosing endotheliitis. The results demonstrate that changes in the cornea were not different among the various viruses except for owl's eye morphology, the lengths of the subbasal nerves and Langerhans cell densities.