Herpes simplex virus type 2: a cause of acute retinal necrosis syndrome

Long-term follow-up of acute retinal necrosis with retinal detachment secondary to herpes simplex virus type 2 with a successful visual outcome

A man in his early 20s presented with acute loss of vision in his only eye, the left eye (OS), and was on oral steroids. He had lost vision in his right eye during his childhood and the cause was unknown. There was no history of trauma. Best-corrected visual acuity (BCVA) in OS was 20/100 and in the right eye was hand movements. OS showed non-granulomatous keratic precipitates on the cornea, anterior chamber flare 1+ and cell 1+, early cataract, vitreous haze and cells 2+ with nasal retinal detachment and superior full thickness retinitis. He underwent pars plana vitrectomy with intravitreal ganciclovir and barrage laser away from the necrotic retina. PCR for herpes simplex virus 2 was positive from the aqueous and vitreous sample. He was started on oral valacyclovir 1 g three times a day and continued on tapering dose of oral steroids. BCVA in OS at 6-month follow-up was 20/25.

Acute retinal necrosis: Clinical manifestation and long-term visual outcomes in a series of polymerase chain reaction-positive patients

PURPOSE

To report the clinical spectrum, viral etiologies, therapeutic interventions, timing of rhegmatogenous retinal detachments (RRD), and visual outcomes in acute retinal necrosis (ARN) syndrome in a series of polymerase chain reaction (PCR)-positive eyes.

METHODS

From January 2010 to January 2017, consecutive patients with the clinical diagnosis of ARN and a positive aqueous viral PCR were included in this observational, retrospective study.

RESULTS

Nineteen eyes found to have a clinical diagnosis of ARN, of which 18 (94.7%) had a positive viral PCR. ARN was unilateral, except in one patient. None of the fellow eyes manifested ARN during follow-up. Varicella-zoster virus (VZV) was detected in 78.0% of ARN eyes. 61.1% of eyes experienced RRD. The median time for the occurrence of RRD was 12 weeks (range: 6-25 weeks) after disease onset. No correlation was found between the etiologic viral agent (VZV vs non-VZV; p = 1.000), extent of retinitis (1-2 quadrant vs 3-4 quadrants; p = 0.326), administration of intravitreal ganciclovir (injected vs not injected; p = 0.332), application of prophylactic laser retinopexy (applied vs not applied; p = 0.326), and subsequent occurrence of RRD.At a 2-year follow-up, visual impairment (VA ⩽ 20/200) and severe visual loss (VA ⩽ light perception) were significantly higher in those complicated by RRD compared to non-RRD eyes (81.8% vs 28.6%; p = 0.047, and 45.4% vs 0.0%; p = 0.004, respectively).

CONCLUSION

Aqueous PCR results are highly consistent with the clinical diagnosis of ARN. Regardless of the method of management, the rate of RRD is high and is associated with a poor visual outcome.

Intraocular Detection of Herpes viruses by xTAG Liquid Chip Technology in Patients with Acute Retinal Necrosis

PURPOSE

To evaluate the performance of the xTAG liquid chip technology (xTAG-LCT) for etiological diagnosis of acute retinal necrosis (ARN).

METHODS

Fifteen vitreous and 3 aqueous samples from 18 ARN patients were analyzed by xTAG-LCT and multiplex PCR (mPCR)/quantitative PCR (qPCR).

RESULTS

xTAG-LCT revealed positive results in 17 of the 18 samples: 10 for Varicella Zoster Virus (VZV) alone; 5 for VZV and Epstein-Barr virus (EBV); 1 for herpes simplex viruses type 1 (HSV-1) and EBV; 1 for VZV, HSV-1 and EBV. While mPCR revealed the same results as xTAG-LCT for VZV and HSV-1 in all samples, only 2 of the 7 samples positive for EBV on xTAG-LCT were confirmed by qPCR. None of the 28 control vitreous samples from 8 non-ARN patients and 10 pair of cadaveric eyes was positive for any of the tested viruses.

CONCLUSIONS

xTAG-LCT could be a useful alternative for etiological diagnosis of ARN.

Acute retinal necrosis (ARN) in the context of neonatal HSV-2 exposure and subconjunctival dexamethasone: case report and literature review

HSV-2 is an important cause of the acute retinal necrosis (ARN) syndrome in younger patients. We describe an atypical case of HSV-2 ARN in the context of neonatal exposure and subconjunctival steroid injection. Clinicians should be aware of the association of neonatal or congenital exposure to HSV-2 as a risk factor for this disease because early treatment may improve outcome and/or avoid involvement of both eyes.

Role of nectin-1, HVEM, and PILR-alpha in HSV-2 entry into human retinal pigment epithelial cells

PURPOSE

Herpes simplex virus-type 2 (HSV-2) can cause acute retinal necrosis (ARN), which can lead to exudative and rhegmatogenous retinal detachment, yet little is known about the cellular and molecular mechanisms of HSV-2 entry into retinal pigment epithelial (RPE) cells. The goal of this study was to establish the identity of the critical receptors used by the virus for infection.

METHODS

A reporter HSV-2 virus, which expresses beta-galactosidase, was used to quantify entry into RPE cells, and viral replication was ascertained using a plaque assay. Flow cytometry and immunocytochemistry were used to determine cellular expression of entry receptors. Localization of these receptors to the apical or basal surface of RPE cells was determined with immunocytochemistry. The necessity of these receptors, individually and in combination, for viral entry was established using receptor-specific antibodies and siRNAs.

RESULTS

RPE cells are highly susceptible to HSV-2 entry and replication. Several assays demonstrated the expression of the entry receptors nectin-1, HVEM, and PILR-alpha and their localization primarily to the apical surfaces of RPE cells. Receptor-specific antibodies and siRNA knockdown of receptors significantly reduced viral entry and implicated nectin-1 as an important receptor, with HVEM and PILR-alpha potentially also contributing to entry.

CONCLUSIONS

HSV-2 is capable of developing a productive infection in RPE cells by using nectin-1 as an important entry receptor. To lesser degrees, HVEM and PILR-alpha may also contribute to HSV-2 entry into RPE cells.

Acute retinal necrosis features, management, and outcomes

OBJECTIVE

To determine the viral diagnosis and factors affecting the visual outcome of eyes with acute retinal necrosis.

DESIGN

Nonrandomized, retrospective, interventional, noncomparative series.

PARTICIPANTS

A cohort of 22 human immunodeficiency virus-negative patients with acute retinal necrosis (ARN). There were 17 unilateral and 5 bilateral cases.

INTERVENTION

Diagnostic vitreous biopsy for polymerase chain reaction (PCR) viral DNA analysis, prophylactic barrier laser posterior to necrotic retina to try to prevent rhegmatogenous retinal detachment (RD), intravenous acyclovir in combination with oral, and vitrectomy for RD repair.

MAIN OUTCOME MEASURES

Results of PCR viral DNA analysis, relationship between prophylactic barrier argon laser photocoagulation and occurrence of RD, and visual acuities at presentation and follow-up.

RESULTS

Varicella-zoster virus (VZV) was detected in 66.7% (12/18) of eyes (66.7% of patients [10/15]) with vitreous biopsy and herpes simplex virus (HSV) in 22.2% (4/18) of eyes (20% of patients [3/15]). Epstein-Barr virus (EBV) was detected in 16.7% (3/18) of eyes (20% of patients [3/15]), and all the EBV-positive eyes were also positive for VZV. Polymerase chain reaction results were identical in both eyes of bilateral cases (5 patients) and were negative in 11.1% (2/18) of eyes (13.3% of patients [2/15]) biopsied. Systemic corticosteroid treatment given before ARN diagnosis did not appear to increase the risk of developing RD (P = 0.69). Rhegmatogenous RD occurred in 35.3% (6/17) of eyes given prophylactic argon laser treatment and in 80% (8/10) of eyes that could not be lasered prohylactically. Of RDs, 96.3% (13/14) occurred after the third week and up to 5 months from onset of symptoms. The VA after surgical repair of RD improved relative to the presentation acuity in 33.3% (4/12) of eyes.

CONCLUSION

Varicella-zoster virus is the leading cause of ARN. We recommend the management of ARN to include prompt diagnosis; prophylactic argon laser retinopexy, preferably within the first 2 weeks to reduce risk of RD; systemic acyclovir; and corticosteroids to control the severe inflammation associated with ARN. Despite the guarded visual prognosis, RD repair may result in improved visual outcomes.

Herpes simplex virus type 2 acute retinal necrosis 9 years after neonatal herpes

Many cases of acute retinal necrosis caused by HSV-2 have been reported in children, teenagers, and young adults as a result of reactivation of congenital or neonatal infections, which may have been subclinical. Pediatricians should be aware of this entity and alert to recurrences that may be delayed by years.

Nonrandom clusters of palindromes in herpesvirus genomes

Palindromes are symmetrical words of DNA in the sense that they read exactly the same as their reverse complementary sequences. Representing the occurrences of palindromes in a DNA molecule as points on the unit interval, the scan statistics can be used to identify regions of unusually high concentration of palindromes. These regions have been associated with the replication origins on a few herpesviruses in previous studies. However, the use of scan statistics requires the assumption that the points representing the palindromes are independently and uniformly distributed on the unit interval. In this paper, we provide a mathematical basis for this assumption by showing that in randomly generated DNA sequences, the occurrences of palindromes can be approximated by a Poisson process. An easily computable upper bound on the Wasserstein distance between the palindrome process and the Poisson process is obtained. This bound is then used as a guide to choose an optimal palindrome length in the analysis of a collection of 16 herpesvirus genomes. Regions harboring significant palindrome clusters are identified and compared to known locations of replication origins. This analysis brings out a few interesting extensions of the scan statistics that can help formulate an algorithm for more accurate prediction of replication origins.

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.

Clinical characteristics of acute HSV-2 retinal necrosis

PURPOSE

To report the clinical features and evaluate the visual outcome of eleven cases of herpes simplex virus-2 (HSV-2) related acute retinal necrosis syndrome (ARN).

DESIGN

Retrospective interventional case series.

METHODS

Twelve eyes of eleven patients from two European centers, diagnosed with HSV-2 related acute retinal necrosis syndrome were retrospectively reviewed. Herpes simplex virus-2 DNA was detected by polymerase chain reaction in intraocular fluids (aqueous and/or vitreous). Findings at initial examination, clinical evolution with antiviral therapy, complications and final visual acuity were evaluated.

RESULTS

Herpes simplex virus-2 DNA was detected in all cases. No sample was positive for more than one virus. The mean age of disease in the first eye was 36 years (ranged from 10 to 57 years). Five patients were women and six were men. All patients were immunocompetent. Previous medical history included neonatal herpes (n = 1), previous ARN (n = 3), trauma (n = 1) and systemic corticosteroid administration before occurrence of ARN (n = 3). Preexisting pigmented chorioretinal scars were found in three cases. Patients were treated with high dose intravenous acyclovir or foscarnet +/- intravitreal ganciclovir +/- interferon. The mean follow-up was 14.5 months (from 5 to 22 months). At the end of the follow-up period, five eyes (41.7%) showed improvement of visual acuity of two or more lines. Final visual acuity was 20/60 or better in four eyes (33.3%), 20/400 or better in four eyes (33.3%) and less than 20/400 in four eyes.

CONCLUSION

History of neonatal herpes, triggering events such as neurosurgery, periocular trauma, high-dose corticosteroids, and chorioretinal scars suggest that HSV-2 retinitis reflects reactivation of HSV-2 infection.