Morphological and ultrastructural changes induced in corneal epithelial cells by HIV-1 and HHV-6 in vitro

Human Herpesvirus-6 corneal Endotheliitis after intravitreal injection of Ranibizumab

BACKGROUND

To report the first case of human herpesvirus-6 (HHV-6) corneal endotheliitis that developed after intravitreal ranibizumab injections.

CASE PRESENTATION

A 63-year-old man with a medical history of diabetes and systemic steroid treatment for bullous pemphigoid had been receiving intravitreal injections of ranibizumab in the left eye for 2 years according to a Pro Re Nata treatment regimen for macular edema associated with branch retinal vein occlusion. Twenty days after the last injection, the patient presented with pain and decreased visual acuity in his left eye. His best corrected visual acuity in the left eye was 2/200, and intraocular pressure was 45 mmHg with edema of the central stromal cornea, mild conjunctival injection, intermediate keratic precipitates, and mild anterior chamber reaction. HHV-6 DNA was detected in the aqueous humor using multiplex strip polymerase chain reaction, and it was identified as variant A, HHV-6A. A diagnosis of HHV-6A-associated corneal endotheliitis was made. Oral valganciclovir and topical ganciclovir therapy was initiated with good resolution of all symptoms and signs.

CONCLUSIONS

HHV-6A can be a possible complication of intravitreal ranibizumab therapy. To the best of our knowledge, this is the first reported case of HHV-6A corneal endotheliitis following intravitreal ranibizumab injection.

Human immunodeficiency virus and its effects on the visual system

During the first 15 years of the AIDS epidemic patients experienced a high incidence of blindness due to cytomegalovirus (CMV) retinitis and other severe ocular opportunistic infections. Highly active anti-retroviral therapy, introduced in 1996, dramatically decreased the incidence of CMV retinitis. Though CMV retinitis still causes 40% of vision loss in AIDS patients, other conditions such as immune reconstitution uveitis, cataracts, and a significant othercategory -which most investigators believe is directly due to HIV - comprise the majority of cases. HIV causes vascular abnormalities of the conjunctiva and retina in the majority of AIDS patients, as well as retinitis, anterior and posterior uveitis and vasculitis. HIV frequently causes an optic neuropathy and is responsible for the majority of eye movement disorders among HIV patients. Physicians need to be aware that these problems may be the initial manifestation of HIV infections or a sign of highly active anti-retroviral therapy (HAART) failure. Therefore, patients with identifiable risk factors for AIDS who present with ophthalmologic conditions of unknown etiology should be considered for HIV testing. Finally, anti-retroviral therapy has been reported to cause asymptomatic deposits as well as degenerative conditions of both the anterior and posterior segments of the eye.

Human herpesvirus-6B active infection associated with relapsing bilateral anterior optic neuritis

BACKGROUND AND OBJECTIVES

Human herpesvirus-6 (HHV-6) is the causative agent of exanthem subitum. Both HHV-6 variants, A and B, have been associated with central nervous system (CNS) diseases, suggesting a wide neuropathogenic potential. We describe a case of recurrent bilateral anterior optic neuritis with HHV-6 active infection associated with clinical relapses.

CASE REPORT

A 23-year old woman presented with progressive visual impairment, bilateral papillitis and painful ocular movements. Nested polymerase chain reaction (PCR) for DNA viruses, HHV-6 variant specific real time quantitative PCR, serological analysis and retrotranscription PCR (RT-PCR) for HHV-6 mRNA transcripts were performed. Nested PCR in PBMC and CSF samples was negative for all viruses but positive for HHV-6 DNA, subtyped as HHV-6B. The disease had a relapsing/remitting course. During relapses PBMC samples remained positive for HHV-6 DNA, and HHV-6 active infection was confirmed by the presence of anti-HHV-6 IgM and of HHV-6 U27 mRNA transcript. High viremia levels and relapses were overlapping. After the last relapse, the patient was successfully treated with gancyclovir.

CONCLUSIONS

The case reported here suggests a possible association of HHV-6 in bilateral optic neuritis. HHV-6 could be monitored when bilateral optic neuritis is identified, in order to establish an appropriate antiviral therapy.

Bilateral optic neuropathy and unilateral tonic pupil associated with acute human herpesvirus 6 infection: a case report

BACKGROUND

Human herpesvirus 6 (HHV-6), a widespread virus and causative agent of exanthema subitum in children, has been associated with a number of neurologic disorders including cranial nerve palsies, seizures, encephalitis, meningitis, and multiple sclerosis.

PATIENT

A 31-year-old man presented with bilateral optic neuropathy, disc edema, and unilateral tonic pupil, which were found to be associated with acute HHV-6 infection. The patient had been suffering from juvenile diabetes for 5 years. One week after onset of intravenous antiviral therapy with foscarnet, disc edema subsided, and tonic pupil reaction was no longer detectable.

CONCLUSIONS

HHV-6 infection may play a role as a causative agent in patients with optic neuropathy and tonic pupil.

In vitro Inhibition of HHV-6 replication by sophocarpines

The virostatic activity of sophocarpines and gancyclovir (GCV) was tested using HHV-6 Z29 strain and Molt-3 cells. The cytotoxic (IC(50)) and the antiviral (ED(50)) values were first experimentally determined and selective indices (SI) were then calculated. The SI values for sophocarpines 1 and 2 and GCV were in the order 184, 183, and 23, respectively. Though preliminary, these findings indicate that sophocarpines have the potential to inhibit HHV-6 replication.

A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction

This study investigated the biological basis of visual processing disabilities in adults with Chronic Fatigue Syndrome. The study involved 61 adults with symptoms of Chronic Fatigue Syndrome who were screened for visual processing problems (Irlen Syndrome) and divided into two groups according to the severity of symptoms of Irlen Syndrome. Significant variations were identified in blood lipids and urine amino and organic acids of the two groups, which may be indicative of activation of the immune system due to some infective agent. It was suggested that metabolic profiling may help the development of more valid diagnostic categories and allow more investigation of immune system dysfunction as a possible causal factor in a range of learning and behaviour disorders.

Efficient and sustained transgene expression in human corneal cells mediated by a lentiviral vector

The development of vectors and techniques able to transfer potentially therapeutic genetic information to corneal tissues efficiently may have broad clinical applications. Although a variety of vectors have been tested for their ability to transduce corneal tissue, these systems have been ineffective at transducing all cell types or have been associated with a relatively short duration of transgene expression. Towards the implementation of efficient, long-term transgene expression in all corneal cell types, we have studied the ability of a recombinant lentiviral vector, containing the enhanced green fluorescent protein (eGFP), to mediate gene transfer into human corneal tissue in vitro and in situ. Human primary keratocytes, cultured in vitro, were efficiently transduced by a lentiviral vector as determined by fluorescent-activated cell sorting (FACS) and by fluorescent microscopy. Transduction efficiency was found to be dependent upon multiplicity of infection (MOI); 92% of keratocytes were transduced at an MOI of 1000. The proportion of eGFP-positive cells remained unchanged throughout continuous culture for 60 days, indicating stable expression and a lack of selective pressure for or against transduced cells. Human corneal tissue, obtained at the time of penetrating keratoplasty, demonstrated efficient in situ transduction with this vector. Endothelial cells, epithelial cells and stromal keratocytes at the exposed cut edge of the corneal tissue in situ demonstrated eGFP expression. Underlying stromal cells not in direct contact with vector-containing media, were not transduced, implying that virus-cell contact is required for transduction. Transduced corneal tissues expressed eGFP in situ for the life of the corneal button in extended organ culture (60 days). These results imply that lentiviral vectors may prove to be useful tools, able to transduce corneal tissue efficiently, and that transgene expression is temporally stable. Gene Therapy (2000) 7, 196-200.

PCR studies on the potential sites for latency of BHV-4 in calves

The aim of the study was to examine various tissues of experimentally infected calves for the BHV-4 genome so as to detect in which cells the virus persists during the latent phase of the infection. The presence of the bovine herpesvirus type 4 genome was detected by a nested PCR in a variety of tissues collected from two susceptible calves experimentally infected 62 days earlier. Mild clinical signs of bronchitis, an elevated body temperature for 2-3 days, and a slightly increased number of blood leukocytes were observed in both inoculated calves. BHV-4 was demonstrated in seven samples from the 12 different parts of the nervous system tested from each calf (29.1%), from the cornea, from lymph nodes near to the inoculation site, from the gallbladder and from the bone marrow. Thus a member of the predominantly lymphotropic Gammaherpesvirinae subfamily was detected in neural tissue and other organs that have never been associated with persistence.