Herpes simplex virus type 1 (HSV-1)--induced retinitis following herpes simplex encephalitis: indications for brain-to-eye transmission of HSV-1

Acute Retinal Necrosis Associated with Pseudorabies Virus Infection: A Case Report and Literature Review

PURPOSE

To analyze a case of acute retinal necrosis (ARN) associated with pseudorabies virus (PRV) infection and discusses the clinical characteristics of PRV-induced ARN (PRV-ARN).

METHODS

Case report and literature review of ocular features in PRV-ARN.

RESULTS

A 52-year-old female diagnosed with encephalitis presented with bilateral vision loss, mild anterior uveitis, vitreous opacity, occlusive retinal vasculitis, and retinal detachment in her left eye. The result of metagenomic next-generation sequencing (mNGS) indicated that both cerebrospinal fluids and vitreous fluid tested positive for PRV.

CONCLUSION

PRV, a zoonosis, can infect both humans and mammals. Patients affected with PRV may experience severe encephalitis and oculopathy, and the infection has been associated with high mortality and disability. ARN is the most common ocular disease, which develops rapidly following encephalitis and is characterized by five figures: bilateral onset, rapid progression, severe visual impairment, poor response to systemic antiviral drugs, and an unfavorable prognosis.

Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants

Purpose

Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases.

Methods

We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score > 15 and frequency in GnomAD < 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance.

Results

We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients.

Discussion

We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications.

Uveo-meningeal syndrome secondary to Herpes Simplex Virus related acute retinal necrosis

Purpose

To present a rare case of uveo-meningeal syndrome secondary to herpes simplex virus (HSV-1) in a patient with acute retinal necrosis.

Observations

A 49-year-old female with a past medical history of herpes simplex encephalitis 18 years prior presented with a 3-day history of right sided headache and decreased vision of the right eye. Her visual acuity was 20/30 in the right eye and 20/20 in the left eye. Clinical examination revealed right relative afferent pupillary defect, panuveitis, and retinal necrosis. Examination of the left eye was unremarkable. Cerebral spinal fluid (CSF) analysis by polymerase chain reaction (PCR) was negative for herpes simplex virus 1 (HSV-1) but did reveal pleocytosis consistent with meningitis. The patient was admitted and empirically treated with intravenous acyclovir (10 mg/kg every 8 hours) and systemic steroids. Topical steroids and cycloplegia were also started. Magnetic resonance imaging revealed no leptomeningeal, pachymeningeal, or parenchymal enhancement. Systemic autoimmune and infectious workup were unremarkable. Based on clinical exam findings and negative PCR results, an anterior chamber tap was performed with aqueous fluid PCR testing which revealed 71,000 copies of HSV-1. A repeat lumbar puncture was performed on day three of admission and revealed a decrease in pleocytosis after initiation of acyclovir therapy and remained negative for HSV on PCR testing. She was discharged home on intravenous acyclovir, topical steroids, and topical cycloplegics. Her retinal necrotic lesions continued to regress and her headaches continued to improve.

Conclusions and importance

Uveo-meningeal syndromes are a rare clinical entity that involve the uvea, retina, and meninges. This case highlights the importance of aqueous fluid PCR testing despite negative CSF PCR, as it may hasten treatment with antiviral therapies to preserve vision and limit neurologic sequelae.

From Severe Herpes Zoster to Rare Suid Herpesvirus Encephalitis: A New Twist of the Varicellovirus Genus Infection in Patients with Kidney Diseases

Both the herpes zoster virus and suid herpesvirus type 1 (SuHV-1) belong to the Varicellovirus genus of the α-herpesviridae subfamily. They may cause opportunistic infections especially in patients with kidney diseases, varying from latent illness to overt lethality. Under these circumstances, impaired renal function is both the culprit for and victim of the infection. However, fulminant eruption of severe skin herpes zoster in lupus nephritis (LN) patients under prolonged immunosuppressive therapy is rare and even more rarely seen is the SuHV-1 encephalitis in human. Facing the evolution of these rare infections, we hence chose to review the clinical pathogenicity of these two viruses which were cognate in origin but distinct in virulence. As such, we began with the first of the two above viral diseases and proceeded with peculiar renal involvement, unique clinical symptoms and pertinent lethal risk. Of importance, LN was used to exemplify the reciprocally detrimental interactions between impaired renal function and suppressed immune response. Then in a manner similar to the gradient overlay, SuHV-1 encephalitis was discussed focusing on its neurotropic features, specific MRI findings and exclusive test of high throughput sequencing. Our report highlighted novel presentations of the Varicellovirus genus infection by providing a productive multidisciplinary communication with pointed disclosure of the renal involvement. It may therefore be of great medical relevance and educational value for clinicians, especially the unseasoned ones, to foresee and manage similar cases in susceptible patients.

Acute retinal necrosis in a patient with remote severe herpes simplex encephalitis

A 60-year-old man with a history of severe herpes simplex virus type 1 (HSV-1) encephalitis 2 years prior presented with acute onset of visual loss in the left eye. Dilated funduscopic examination showed retinitis and occlusive vasculitis with retinal necrosis. PCR of the vitreous fluid was positive for HSV-1, and he was diagnosed with acute retinal necrosis (ARN) due to HSV-1. The patient was treated with intravenous acyclovir and intravitreous foscarnet for 2 weeks, followed by high dose oral valacyclovir for 2 weeks. He was subsequently placed on planned life-long suppressive valacyclovir. His case demonstrates that acute visual loss concomitant with or subsequent to HSV-1 encephalitis warrants suspicion of ARN. Prompt therapy with effective antiviral medication is necessary to reduce the risk of sight-threatening complications. Chronic suppression with oral antiviral therapy after ARN is recommended to prevent involvement of the contralateral eye, though there is no consensus on the duration and dosage of antivirals.

Response to anti-VEGF therapy in macular oedema secondary to acute retinal necrosis

A 55 year-old female patient with unilateral Acute Retinal Necrosis (ARN) developed macular oedema (MO) after the resolution of her necrosis. The macular oedema (MO) was managed and controlled for four years with intravitreal anti-VEGF injections. Anti-VEGF therapy could be useful for the treatment of MO secondary to ARN, the same as for treating MO resulting from panuveitis, where its efficacy has been already demonstrated.

Recent Updates on Treatment of Ocular Microbial Infections by Stem Cell Therapy: A Review

Ocular microbial infection has emerged as a major public health crisis during the past two decades. A variety of causative agents can cause ocular microbial infections; which are characterized by persistent and destructive inflammation of the ocular tissue; progressive visual disturbance; and may result in loss of visual function in patients if early and effective treatments are not received. The conventional therapeutic approaches to treat vision impairment and blindness resulting from microbial infections involve antimicrobial therapy to eliminate the offending pathogens or in severe cases; by surgical methods and retinal prosthesis replacing of the infected area. In cases where there is concurrent inflammation, once infection is controlled, anti-inflammatory agents are indicated to reduce ocular damage from inflammation which ensues. Despite advances in medical research; progress in the control of ocular microbial infections remains slow. The varying level of ocular tissue recovery in individuals and the incomplete visual functional restoration indicate the chief limitations of current strategies. The development of a more extensive therapy is needed to help in healing to regain vision in patients. Stem cells are multipotent stromal cells that can give rise to a vast variety of cell types following proper differentiation protocol. Stem cell therapy shows promise in reducing inflammation and repairing tissue damage on the eye caused by microbial infections by its ability to modulate immune response and promote tissue regeneration. This article reviews a selected list of common infectious agents affecting the eye; which include fungi; viruses; parasites and bacteria with the aim of discussing the current antimicrobial treatments and the associated therapeutic challenges. We also provide recent updates of the advances in stem cells studies on sepsis therapy as a suggestion of optimum treatment regime for ocular microbial infections.

Chronic herpes simplex virus type 2 encephalitis associated with posterior uveitis

We report on a patient with chronic herpes simplex virus-2 encephalitis who was characteristic for concomitantly having chronic or recurrent posterior uveitis. A 66-year-old immunocompetent man suffering from a 6-month refractory posterior uveitis developed a 1-month history of impaired short-term memory and orientation. Brain MRI demonstrated hyperintense lesions in the right parietal lobe in diffusion and fluid attenuated inversion recovery (FLAIR) sequences. Cerebrospinal fluid (CSF) examination showed mild pleocytosis and increased protein concentration. Quantitative PCR for HSV-2 DNA was positive in CSF. Treated with acyclovir, his cognitive functions gradually improved and the posterior uveitis was cured. Clinicians must be aware that HSV-2 should be considered in the aetiological investigation of chronic encephalitis in an immunocompetent patient. HSV-2 is well known for its ability to cause unilateral chronic or recurrent posterior uveitis. Therefore, posterior uveitis should be considered as an associated feature of HSV-2 encephalitis.

[Acute retinal necrosis from the virologist's perspective]

Acute retinal necrosis occurs in approximately one per million persons per year and is caused in approximately 70% of the cases by the varicella zoster virus or in about 30% of the cases by herpes simplex virus. The early diagnosis is primarily based on virus-specific polymerase chain reaction in fluid from the anterior chamber or vitreous humor and can be supported by the determination of specific antibody titers from fluid and serum. Virus detection provides the basis for early causative therapy which limits disease progression and risk of complications. Retinal infections by varicella zoster virus or herpes simplex virus are treated with aciclovir, ganciclovir, or famciclovir. Ganciclovir and valganciclovir are used for the therapy of retinal cytomegalovirus infections. In the case of resistance development, foscarnet or cidofovir are available as second line antiviral drugs. The early use of specific antiviral agents is a crucial prerequisite for optimized therapy of acute retinal necrosis.

Unilateral Acute Retinal Necrosis 2 Months After Herpes Simplex Encephalitis

A case with unilateral acute retinal necrosis (ARN) following herpes simplex virus (HSV) encephalitis was reported. A 40-year-old man presented with unilateral visual loss. He had a history of HSV encephalitis 2 months previously, and had been successfully treated with intravenously acyclovir. The ophthalmologic examination in his left eye suggested ARN syndrome. The best-corrected visual acuity was 20/222. Magnetic resonance imaging (MRI) showed high density signals from the optic chiasm to optic disc. The patient underwent encircling scleral buckling, lensectomy, and vitrectomy with endolaser photocoagulation and silicone oil tamponade. Postoperatively, the high density signals on MRI decreased, the retina maintained attached, and the visual acuity at the final visit improved to 20/20. Unilateral ARN can develop after HSV encephalitis. Acyclovir should be administered over the long term to control the virus.

Intravitreal Foscarnet Therapy for Acyclovir-Resistant Acute Retinal Necrosis After Herpes Simplex Encephalitis

The development of acute retinal necrosis (ARN) is not uncommon among individuals with a history of herpes simplex encephalitis, as the virus may be capable of transport via axonal cells to the neuroretina. Though it is known that ARN severely threatens vision, timely initiation of effective therapy can help save a patient's vision and retina. In this case report, clinical resistance to acyclovir was found. Subsequent treatment with intravitreal foscarnet resulted in immediate clinical improvement. This case suggests that patients with acute retinal necrosis can be considered for treatment with intravitreal foscarnet in the setting of systemic acyclovir resistance.

Impaired Plasmacytoid Dendritic Cell Innate Immune Responses in Patients with Herpes Virus-Associated Acute Retinal Necrosis

Plasmacytoid dendritic cells (PDC), the main producers of type I IFNs in the blood, are important for the recognition and control of viral and bacterial infections. Because several viruses induce IFN-alpha production, severe courses of herpes virus infections in nonimmunocompromised patients may be related to numerical or functional PDC deficits. To evaluate this hypothesis, PBMC and PDC were repeatedly isolated from nine patients with acute retinal necrosis (ARN), caused by herpes simplex or varicella zoster virus. The patients experienced meningitis/encephalitis and frequent infections in childhood (n = 2), recurrent herpes virus infections at unusual localizations (n = 2), ocular surgery (n = 1), infections (n = 4), and stress around ARN (n = 6). The median percentage of isolated PDC was significantly lower in patients compared with 18 age-matched healthy controls (p < 0.001), confirmed by FACS analysis using peripheral blood, and was extremely low during acute disease. PDC counts dropped in five controls suffering from respiratory infections or diarrhea. IFN-alpha production in PDC and PBMC exposed to different stimuli was significantly lower in patients than in controls (p < 0.05). Anergy to these stimuli was observed on four occasions, in particular during acute disease. PDC of patients showed up-regulated IFN regulatory factor-7 mRNA levels and evidence of in vivo activation (CD80) and maturation (CD83) (p < 0.05). CD8+ cell responses were significantly lower in patients vs controls (p = 0.04). These data support a risk factor model in which numerical and functional deficits in PDC-mediated innate immune responses contribute to an impaired control of latent herpes virus infections and subsequent development of ARN.

Nécrose rétinienne aiguë bilatérale associée à une méningo-encéphalite à Herpes simplex virus 2

INTRODUCTION

Acute retinal necrosis syndrome (ARN syndrome) is a rare viral disease with a poor prognosis in most cases. It is characterized by substantial ocular inflammation with progressive retinal necrosis, occlusive vasculitis and sometimes extraocular features.

CASE REPORT

We report the case of a 62-year-old woman who was referred for a suspicion of a stroke. Ophthalmological examination revealed a profound bilateral visual loss due to extensive retinal necrosis. The patient was immediately treated with antiherpetic drugs. ARN syndrome with meningoencephalitis caused by herpes simplex virus type 2 was confirmed by PCR studies performed on aqueous humor and cerebrospinal fluid. Herpes simplex virus 2 (IgG+ , IgM-) was probably reactivated after intrathecal injection of steroids because of pain associated with narrowing of the lumbar vertebral canal. The patient was treated with intravenous Acyclovir for 3 weeks. After 4 months, both retinas were detached.

DISCUSSION AND CONCLUSION

ARN syndrome caused by herpes simplex virus 2 most often occurs after reactivation of the latent virus in patients with a neurological medical history or congenital infection. Antiviral treatment must begin early to decrease risks of bilateralization and complications.

Prise en charge diagnostique et thérapeutique des rétinites nécrosantes herpétiques

PURPOSE

To study the viral cause and present the management of necrotizing herpetic retinopathies.

METHODS

Charts of patients presenting with acute retinal necrosis (ARN) or progressive outer retinal necrosis (PORN) diagnosed between March 1997 and June 2001 were retrospectively reviewed. Intraocular specimens were obtained in 33 cases to determine the viral cause using polymerase chain reaction-based assays and/or detection of intraocular antibody production.

RESULTS

The mean age was 43.4 Years. Herpesvirus genome was identified in 29 patients (80.5%). In the ARN group (32 patients, 38 eyes), herpes simplex virus (HSV) DNA was found in 11 patients (34.4%), varicella-zoster virus (VZV) in nine patients (28.1%), and cytomegalovirus (CMV) in four patients (12.5%). One patient (3.1%) presented an Epstein-Barr virus (EBV) infection. ARN was bilateral at initial examination in six patients and secondary bilateralization was observed in four patients. In the PORN group (four patients, eight eyes), the retinitis was bilateral and VZV DNA was detected in all cases. Two patients were treated with intravenous acyclovir, six with foscarnet alone, ten with intravenous foscarnet + acyclovir, 18 with intravenous foscarnet and intravitreous ganciclovir injections. Complications of necrotizing herpetic retinitis were cataract (26%), optic nerve atrophy (23.9%), and retinal detachment (17.4%). Final visual acuity was less or equal to 20/200 in 47.8% of cases.

CONCLUSIONS

It is important to determine the specific viral etiology since progression and prognosis may be different in herpetic necrotizing retinitis caused by HSV, VZV, or CMV. Visual prognosis is improved by intensive antiviral therapy, but remains poor if complications occur.