Antiviral therapy for cytomegalovirus retinitis in AIDS with dihydroxy propoxymethyl guanine

A rare case of cytomegalovirus papillitis in patient with immunodeficiency

A 26-year-old male diagnosed with AIDS came with sudden blurred vision and central sco-toma in left eye since 2 weeks before admission. His visual acuity was counting finger at 5 meters with normal IOP and anterior segment. The posterior segment revealed edematous optic nerve covered by exudates and hemorrhages. Due to low CD4+ count and serological test result, we considered a HIV-related opportunistic ocular infection, specifically HSV infection. As visual acuity worsened during treatment with acyclovir, we performed PCR ex-amination from aqueous tap which revealed positive CMV DNA. Unfortunately, the visual acuity had worsened to no light perception before he received any specific anti-CMV agent. CMV papillitis is an unusual presentation of CMV retinitis. PCR examination from aqueous or vitreous tap should be performed while waiting for serological test result, especially in doubtful cases. Therefore, appropriate diagnosis and management can be established early to prevent irreversible visual loss.

Cytomegalovirus infection with MRI signal abnormalities affecting the optic nerves, optic chiasm, and optic tracts

A 49-year-old woman who had been immunosuppressed after a renal transplant developed bilateral severe visual loss. Visual acuities were finger counting and hand movements in the two eyes. Both optic nerves were pale. There were no other ophthalmic abnormalities. Brain MRI disclosed marked signal abnormalities involving the optic nerves, optic chiasm, and optic tracts. Cerebrospinal fluid polymerase chain reaction (PCR) was positive for cytomegalovirus. Treatment did not restore vision. Such extensive clinical and imaging involvement of the anterior visual pathway, which has been previously reported with other herpes viruses, illustrates the propensity for this family of viruses to track along axons.

Cytomegalovirus papillitis in patients with acquired immune deficiency syndrome. Visual prognosis of patients treated with ganciclovir and/or foscarnet

BACKGROUND

Of those patients with acquired immune deficiency syndrome in whom cytomegaloviral retinitis develops, cytomegaloviral papillitis reportedly develops in up to 4% as well. Although occasionally patients have a good visual outcome, the majority have a poor visual prognosis, with a visual acuity of 20/200 or worse, even with treatment.

METHODS

To evaluate the effects of prolonged induction with foscarnet or ganciclovir on the visual prognosis of cytomegalovirus (CMV) papillitis, the records of 22 patients seen between 1990 and 1995 at the Los Angeles County-University of Southern California Eye Clinic were reviewed. Papillitis was defined as greater than 270 degrees of disc edema/blurring of the disc margins as seen on direct examination and on color fundus photographs.

RESULTS

Eighteen patients with a mean initial visual acuity of 20/69 (range, 20/ 15-20/400) were treated with induction doses of intravenous ganciclovir (range, 5-7.5 mg/kg twice daily) or foscarnet (range, 60-90 mg/kg twice or 3 times daily) for a mean of 3.3 weeks. The mean follow-up period was 4.8 months (range, 1-13 months). These patients maintained a mean final visual acuity of 20/68 (range, 20/ 25-20/400) with greater than 90% resolution of the papillitis. The remaining four patients had poor outcomes (visual acuity < 20/400) because of progressive CMV papillitis or retinitis. The median survival time was 4.5 months from the diagnosis of papillitis, but 7 months from the onset of CMV ocular infection.

CONCLUSION

Patients with CMV papillitis have good visual prognosis when managed with high and prolonged doses of intravenous foscarnet and/or ganciclovir.

High dose intravitreal foscarnet in the treatment of cytomegalovirus retinitis in AIDS

The efficacy and tolerance of high dose intravitreal foscarnet for cytomegalovirus retinitis in patients with AIDS was studied. Foscarnet in a dose of 2400 micrograms was injected directly into the vitreous of 11 patients (15 eyes). Five patients had active retinitis (eight eyes, 53.3%), and received a 3 week induction therapy of six injections as the first step. Six patients had initial inactive retinitis (seven eyes, 46.7%), and received only maintenance therapy which consisted of a weekly injection. The main indications for intravitreal therapy were: myelosuppression, kidney toxicity, catheter related sepsis, or refusal of intravenous therapy. The patients were followed for a mean period of 16 weeks (range 8-28 weeks) and received a total of 304 injections. Vitreous foscarnet levels were measured by high performance liquid chromatography. After a 3 week course of induction therapy, complete resolution of the active retinitis was seen in 62.5% (5/8 cases), while 37.5% (3/8 cases) had partial resolution. No cases failed to respond or progress. The rate of relapse on maintenance therapy was 33% (five of 15 eyes) by 20 weeks, and two of these eyes did not respond to reinduction and progressed in involvement of the macula or optic nerve. Neither important local complications nor intraocular drug toxicity were observed. Vitreous foscarnet levels in two different patients were 896 mumol/l and 74.9 mumol/l at 22 3/4 hours and 42 1/2 hours after the injection. Intravitreal foscarnet appears to be a safe, effective, and useful alternative in patients with intolerance to intravenous and viral therapy.

Retinal disease associated with AIDS

In recent years an enormous amount of new information in the area of retinitis and retinal disease in immunosuppressed patients has been acquired. There have been exciting new developments in our understanding of the pathogenesis of retinal disease in AIDS patients as well as important advances in the diagnosis and therapy of infectious retinitis. This article will summarise the recent advances in this area and outline the direction of future research as it applies to the clinical management of patients with retinal manifestations of AIDS. Diagnostic and therapeutic difficulties will be addressed including the appropriate selection of antiviral drugs and other therapeutic modalities in patients with sight-threatening retinitis.

Ocular complications of the acquired immunodeficiency syndrome. Focus on the treatment of cytomegalovirus retinitis with ganciclovir and foscarnet

The most common ocular complication in patients with the acquired immunodeficiency syndrome (AIDS) is cytomegalovirus retinitis. Incidence figures vary from 20 to 76%. Patients with cytomegalovirus may suffer from mild visual impairment of one or both eyes, but as the disease progresses the retinitis will almost certainly lead to blindness. Although cytomegalovirus retinitis is not a life-threatening infection, it can largely diminish the patient's quality of life. Clinical trials for the treatment of cytomegalovirus retinitis with a number of antiviral drugs have resulted in two drugs of choice, ganciclovir and foscarnet. Both drugs have an initial efficacy with induction therapy of 80-90%, but maintenance therapy is always needed to prevent a relapse. To exclude systemic side-effects of ganciclovir, intravitreal administration has been investigated with good results. Combination therapy of foscarnet and ganciclovir may be worthwhile in resistant cytomegalovirus retinitis.

Systemic viral infections and their retinal and choroidal manifestations

Viruses are one of the most common causes of infections involving the posterior segment of the eye. Such infections can occur either on a congenital or an acquired basis, and may affect primarily the retina or the choroid. Congenital cytomegalovirus (CMV) and rubella infections may result in retinitis. CMV retinitis is also the most common cause of acquired viral retinitis, primarily because of the acquired immunodeficiency syndrome (AIDS). Other types of viral retinitis, such as those caused by herpes simplex or herpes zoster, can occur in immunocompromised or immunocompetent individuals. Retinitis or choroiditis caused by viruses such as measles, influenza, Epstein-Barr virus, and Rift Valley fever virus, typically occurs subsequent to an acute viral systemic illness. The systemic and ocular manifestations, as well as the histopathology, laboratory tests, differential diagnoses, and treatment regimens for each of the individual viruses are discussed in detail.

Intravitreal foscarnet for cytomegalovirus retinitis in a patient with acquired immunodeficiency syndrome

We treated a patient who had acquired immunodeficiency syndrome and cytomegalovirus retinitis of the left eye. After anesthetic had been topically administered, the patient received intravitreal injections of 1,200 micrograms of foscarnet. Plasma and vitreous foscarnet levels were measured by high-performance liquid chromatography. Systemic absorption of the drug was not evident. Elimination half-life from the vitreous after one injection was 54.0 hours. Vitreous levels remained above the mean 50% inhibition value for cytomegalovirus for approximately 56 hours and above the mean inhibition value for human immunodeficiency virus for approximately 241 hours. The patient's visual acuity improved from 20/30 to 20/25 in the left eye. Ophthalmoscopy showed the retinal lesion to have become inactive, and no reactivation occurred during the follow-up period of more than four months. The drug was well tolerated and no retinal toxicity was evident. We suggest an induction treatment regimen of two injections weekly for three weeks, followed by a maintenance treatment regimen of one injection weekly.

Systemic antiviral drugs used in ophthalmology

Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.

Repair of retinal detachment caused by cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome

Twenty-two eyes of 19 patients with the acquired immunodeficiency syndrome who had pars plana vitrectomy and silicone-oil injection after retinal detachment caused by cytomegalovirus retinitis were studied. All patients but one were monitored until time of death. The postoperative survival time and the factors that predicted anatomic success (retinal attachment) and functional success (visual acuity) were analyzed. No intraoperative complications were encountered. The mean survival time after surgery was four months. Of all of the preoperative and intraoperative factors studied, only the duration of cytomegalovirus retinitis was predictive of survival (P less than .03). The anatomic success rate was 89.5% (17 of 19 patients). None of the factors showed a trend or statistical significance in relation to anatomic success. Fifteen of 19 patients (79%) had lost at least two lines of Snellen visual acuity at time of death. Vision declined in a bimodal pattern (within the first postoperative month and after four months postoperatively). The optic nerve was pink and well perfused preoperatively in 16 of 19 patients (81.8%), but optic-nerve atrophy was observed postoperatively in 18 of 19 patients (95.5%). There was a trend for functional success to be influenced by increased intraocular pressure and optic-nerve atrophy, although our sample size was too small for statistical significance.

Efficacy and tolerance of intravitreal ganciclovir in cytomegalovirus retinitis in acquired immune deficiency syndrome

Forty-four patients with acquired immune deficiency syndrome with cytomegalovirus (CMV) retinitis (64 eyes) intolerant of or refusing systemic antiviral therapy received 710 intravitreal injections of ganciclovir at the dosage of 400 micrograms per injection. The patients were followed for a mean period of 9 weeks. Induction therapy consisted of two injections a week until healing. Maintenance therapy consisted of one injection a week until relapse. All but 1 of 53 induction courses led to cicatrization, after a mean of 6.6 injections. In 54 maintenance courses, the 8-week relapse rate was 53%. During intravitreal therapy, involvement of the fellow eye occurred in 11% of the patients and CMV infection developed in a nonocular site in 16% of the patients. Five retinal detachments and two intravitreal hemorrhages occurred. No endophthalmitis or cataract was noted. Intravitreal ganciclovir appears to be a safe and effective alternative in patients intolerant of intravenous anti-CMV drugs.

Cytomegalovirus infection in AIDS. Patterns of disease, response to therapy and trends in survival

Among 347 AIDS patients seen at St Mary's Hospital, London between 1983 and 1989, cytomegalovirus (CMV) disease was observed in 75 (22%). Of these, 58 (77%) had CMV retinitis, 26 (35%) CMV colitis, and 12 (16%) had CMV infection diagnosed at other sites. Relapse occurred in 71%. A favourable response to the use of ganciclovir as induction therapy for CMV retinitis was observed in 92%. Relapse of CMV retinitis occurred in 54% at a median time of 97 days. Neutropenia was the most frequent and serious side-effect of ganciclovir, 76% patients having neutrophil counts less than 1.0 x 10(9)/l and 48% less than 0.5 x 10(9)/l at some stage of therapy. Thrombocytopenia was also common, and platelet counts of less than 50 x 10(9)/l occurred in 43% patients on ganciclovir. The concurrent use of zidovudine made the development of severe neutropenia and thrombocytopenia more likely. Median survival following the diagnosis of CMV disease increased from 5-8 months between 1984 and 1987, to over 12 months in 1988. Patients with CMV colitis had a worse prognosis than patients with CMV retinitis, with median survival of 4.5 and 7 months respectively. In conclusion, CMV is an important opportunist infection in AIDS and both the disease and its treatment cause considerable morbidity. Hence, it is important to develop more effective and less toxic forms of therapy for CMV infection.

Activity of acyclic halogenated tubercidin analogs against human cytomegalovirus and in uninfected cells

Novel acyclic halogenated tubercidins (4-amino-5-halo-7-[(2-hydroxyethoxy)-methyl]pyrrolo[2,3-d]pyrimidines) were examined for their ability to inhibit human cytomegalovirus (HCMV) in yield reduction assays. 5-Bromo acyclic tubercidin (compound 102) was a more potent inhibitor of virus replication than the chloro- and iodo-substituted analogs (compounds 100 and 104). At a 100 microM concentration, the bromo and chloro compounds were more potent than acyclovir but not ganciclovir. Virus titers were reduced more than 99% by compounds 102 and 104 whereas compound 100 and the equally potent acyclovir reduced titers by only 90%. Quantitation of viral DNA by DNA hybridization demonstrated strong inhibition of HCMV DNA synthesis by these compounds. The most potent inhibitor, compound 102, had a 50% inhibitory (I50) concentration (1.6 microM) comparable to that of ganciclovir (1.8 microM). Cytotoxicity in uninfected human cells was evaluated and revealed the following: cell growth rates slowed markedly in the presence of 10 microM compound 102 whereas the same concentration of compounds 100 and 104 led to only a slight prolongation of population doubling time; these compounds inhibited cellular DNA synthesis but not RNA or protein synthesis, as measured by incorporation of radiolabeled precursors into acid-precipitable macromolecules; flow cytometry indicated that compound 102 was a mid-S phase blocker, and adenosine antagonized the inhibition of [3H]dThd incorporation by compound 102. Together, these results demonstrate that compound 102 is a potent and selective inhibitor of viral and cellular DNA synthesis and that acyclic halogenated pyrrolo-pyrimidine nucleosides may have therapeutic potential.

Patterns of cytomegalovirus retinitis in immunocompromised patients treated with 9-(2-hydroxy-1-(hydroxymethyl)ethoxymethyl) guanine (ganciclovir)

Five immunocompromised patients, four with AIDS and one who had undergone bone marrow transplantation, showing ocular signs of cytomegalovirus retinitis, were treated with 9-(2-hydroxy-1-(hydroxymethyl)ethoxymethyl) guanine (Ganciclovir), given intravenously at the dose of 5 mg/kg twice daily for a period ranging from 10 to 20 days. At the end of the treatment, in 4 of 5 patients, the ophthalmoscopic picture had improved, with reduced exudation and an arrest in the progression of retinal necrosis, the pattern clearly indicating a trend towards organization and scarring. Complete resolution of the retinitis without subsequent relapse was observed only in the bone marrow transplant patient, who recovered immunologically, whereas improvement of the eye involvement was only transient in the three AIDS patients.

Longitudinal study of cytomegalovirus retinitis in acquired immune deficiency syndrome

The authors prospectively evaluated 67 consecutive patients with the acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis during a 33-month period to assess the clinical patterns of retinal infection, efficacy of treatment, long-term survival, and relationship of retinitis to immune function. Immediately sight-threatening retinitis presented in six patients (9%) with peripapillary disease; primary foveal infection was not observed. Eighty-seven percent of patients were treated with ganciclovir. Thirty-nine patients (58%) presented with unilateral disease and contralateral infection developed in 15% of those while on ganciclovir. Smoldering (incompletely responsive) retinitis was seen in 33% of the 21 patients whose retinitis progressed while receiving ganciclovir. Progression of treated retinitis was associated with a lower lymphocyte count (P = 0.04). Median survival after diagnosis of CMV retinitis was 8 months. This represents the largest reported prospective study of CMV retinitis and indicates that (1) CMV infrequently poses an immediate threat to vision on presentation, (2) response to therapy may be related to immune function, and (3) smoldering retinitis should be recognized as an important clinical entity associated with treatment failure.

Severe visual loss related to isolated peripapillary retinal and optic nerve head cytomegalovirus infection

We examined ten patients from a consecutive series of 73 patients with either isolated cytomegalovirus papillitis or limited cytomegalovirus retinitis contiguous with the optic disk. Patients with peripheral retinitis and other areas of retinitis were excluded. All patients were treated with ganciclovir. Two distinct types of cytomegalovirus infection of the peripapillary area were identified. Type I was characterized by spread of limited retinitis to the optic disk margin, good central visual acuity, and permanent arcuate and altitudinal visual field defects that enlarged and became more complete as the retinitis progressed toward the disk. Type II appeared to be a true cytomegalovirus infection of the optic nerve characterized by primary, isolated papillitis with peripapillary retinitis, an early afferent pupillary defect, and good initial visual acuity, which rapidly deteriorated despite prompt antiviral therapy. Peripapillary cytomegalovirus retinitis appears to be an important and underreported cause of visual morbidity in patients with AIDS.

Long-term outpatient treatment of CMV retinitis with ganciclovir in AIDS patients

Cytomegaloviral retinitis was diagnosed in nine eyes of seven patients with acquired immune deficiency syndrome (AIDS) on the basis of the characteristic ocular findings and a positive culture for cytomegalovirus (CMV) obtained systemically. Treatment with ganciclovir was begun on a protocol which provided two weeks of inpatient therapy at daily doses of 2.5 to 10 mg/kg followed by outpatient therapy at a reduced dosage three to six days per week. Outpatient maintenance dosage ranged from 15 mg/kg per week to 30 mg/kg per week. In seven eyes of six patients the treatment decreased retinal inflammation and stabilised the margins of the lesions. Six patients have tolerated long term maintenance therapy for 10-30 weeks. Six of seven patients (85%) in this study developed side effects from ganciclovir which required periods of a reduction in dosage or interruption of therapy. The side effects from ganciclovir included neutropenia, thrombocytopenia, drug fever, and neuropathy. Physicians using ganciclovir in AIDS patients must watch for the signs of drug toxicity and adjust treatment accordingly. Ganciclovir appears to be a promising therapy for CMV retinitis, but further work is necessary to determine the best regimen for optimal efficacy with minimal side effects.

Cytomegalovirus retinitis

Cytomegalovirus retinitis is a frequent and serious complication of various conditions, including diseases characterized by impaired immunity, such as the acquired immunodeficiency syndrome. Due to recent advances in the treatment of cytomegalovirus retinitis, accurate diagnosis and management have become increasingly important. In this review, the authors present the epidemiology, clinical features, diagnostic testing, treatment with complications, and prognosis of cytomegalovirus retinitis. A differential diagnosis is presented and the characteristic ocular lesions are illustrated.

Cytomegalovirus infection in immunocompromised guinea pigs: a model for testing antiviral agents in vivo

An experimental model for testing antiviral agents against severe cytomegalovirus (CMV) infection in immunocompromised hosts was developed. The model consisted of cyclophosphamide (Cy) treatment of CMV-infected guinea pigs to simulate CMV infection in immunodeficient individuals. Of the 3 Cy regimens tested, a single 300 mg/kg dose administered one day after virus inoculation resulted in the most severe CMV infection considering mortality rates, mean day of death and loss of body weight. Evaluation of responses to both T and B cell mitogens suggested that the severe and lethal CMV infection resulted from the combined immunosuppressive effect of Cy and CMV. The nucleoside analog [9-(1-3-dihydroxy-2-propoxymethyl)guanine (DHPG) was used to assess the usefulness of the CMV-infected immunocompromised host model. DHPG (100 mg/kg/day for 8 days) prevented death but did not reduce virus infectivity titers in blood of Cy-treated, CMV-infected guinea pigs. This model of CMV infection in immunocompromised guinea pig is a relevant and convenient experimental tool for the assessment of candidate anti-CMV agents under well-defined experimental conditions, such as appropriate CMV inoculum and Cy regimen.

Foscarnet in the treatment of cytomegalovirus retinitis in acquired immune deficiency syndrome

Cytomegalovirus (CMV) retinitis is the major cause of visual loss in acquired immune deficiency syndrome (AIDS). Thirty-one patients with active CMV retinitis were treated with the new antiviral drug, Foscarnet (trisodium phosphonoformate). After a 3-week course of induction therapy, the retinitis improved in 29 of 31 patients (93.5%). Complete resolution of the retinitis was seen in 19 cases (61.3%). Ten patients had partial resolution (32.2%) and two (6.5%) failed to respond. After induction therapy, six patients were put on a low-dose maintenance regimen. All patients without maintenance therapy relapsed within 3 weeks after discontinuation of Foscarnet. The rate of relapse on maintenance therapy was 50% (3/6) within the first 5 weeks. The three other patients of Foscarnet maintenance did not relapse after a follow-up period of 12 weeks. In contrast to ganciclovir, Foscarnet did not induce neutropenia but it produced kidney toxicity that led to reversible renal insufficiency in three cases. Thus, Foscarnet appears to be a useful alternative to ganciclovir, particularly when combined with bone marrow toxic drugs, such as zidovudine (azidothymidine).

The spectrum of optic nerve disease in human immunodeficiency virus infection

We studied four patients with HIV-associated optic neuropathies. One had syphilitic optic perineuritis, which responded promptly and completely to penicillin therapy. The second had cytomegalovirus papillitis and visual acuity subsequently deteriorated to no light perception. The third showed varicella zoster optic neuritis, which improved after intravenous acyclovir treatment. The fourth patient developed cryptococcal retrobulbar neuritis and died shortly thereafter. Optic neuropathy was among the initial symptoms of HIV infection in two of the four cases.

Treatment of cytomegalovirus retinitis with intravitreal ganciclovir. Long-term results

Long-term management of cytomegalovirus (CMV) retinitis by intravitreal injection of ganciclovir was evaluated in ten patients with acquired immune deficiency syndrome (AIDS). Patients were unable to tolerate systemic ganciclovir because of severe neutropenia (8 cases), catheter-induced sepsis (1 case), or the need to continue therapy for human immunodeficiency virus (HIV) with zidovudine (ZDV) (1 case). All patients had a favorable response to initial treatment. Cytomegalovirus retinitis progressed in four fellow eyes in which treatment was deferred. Vision improved or remained stable in all but one eye. Patients were followed for a mean of 4 months and received an average of 16.6 intravitreal injections in each eye. Relapse occurred late in the course while on maintenance treatment in five eyes (33%). There was no evidence of toxicity from repeated intravitreal injections. Treatment was very well tolerated. The only severe complication in a total of 249 injections was a single case of Staphylococcus epidermidis endophthalmitis which responded to intravitreal antibiotic treatment. Intravitreal ganciclovir is an effective alternative to systemic ganciclovir in those patients with severe neutropenia and in those patients who desire to remain on systemic ZDV.

Evaluation of ganciclovir for cytomegalovirus disease

Cytomegalovirus (CMV) infections are a common cause of morbidity and mortality in immunosuppressed patients. Ganciclovir is an acyclic deoxyguanosine analog structurally similar to acyclovir but with superior activity against CMV. The median ganciclovir concentration required to inhibit viral replication by 50 percent is 2.15 mumol versus 72 mumol for acyclovir. Pharmacokinetic properties of ganciclovir include biexponential decay with a terminal half-life of 2.5 hours, tissue uptake, cerebrospinal fluid penetration, and renal dependence for elimination. CMV treatment approaches have commonly used dosages of 3-15 mg/kg/d. In uncontrolled trials, the response rate of CMV retinitis is approximately 80 percent. The overall response rate for CMV pneumonitis has been approximately 50 percent. However, AIDS (acquired immunodeficiency syndrome) and other immunosuppressed patients appear to respond more favorably (approximately 70 percent) than do marrow transplant recipients. Relapse is common once ganciclovir is stopped and maintenance therapy may be required for sustained benefit. Neutropenia appears to be the drug-limiting adverse reaction. Although the development of ganciclovir-resistant CMV, risk factors for neutropenia, and alternative administration strategies all need further study, ganciclovir appears to have a role in the treatment of cytomegalovirus disease.

Treatment of cytomegalovirus retinitis with ganciclovir (9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl] guanine (BW B759U)

Six patients (11 eyes) with virologically confirmed cytomegalovirus (CMV) retinitis involving the posterior pole of the eye were treated with a new drug, ganciclovir. Treatment with intravenous ganciclovir consistently halted progression of retinitis and produced improvement in measures of visual function. However, within three weeks after cessation of therapy renewed CMV activity and worsening of visual function were observed in most cases. Maintenance therapy with ganciclovir extended the period of remission from CMV retinitis.

Ganciclovir prophylaxis for cochlear pathophysiology during experimental guinea pig cytomegalovirus labyrinthitis

The effectiveness of the antiviral agent ganciclovir (9-[1,3-dihydroxy-2-propoxymethyl]guanine) against guinea pig cytomegalovirus was tested in vitro in guinea pig embryonic fibroblasts and in vivo in an experimental guinea pig cytomegalovirus labyrinthitis model. In vitro, ganciclovir completely prevented guinea pig cytomegalovirus infection of guinea pig embryonic fibroblasts at concentrations above 32.6 micrograms/ml. In vivo, antibody-negative animals had an average 17-dB elevation in their auditory nerve compound action potential thresholds (P less than 0.01, t test) and showed signs bilaterally of guinea pig cytomegalovirus labyrinthitis 8 days after intrathecal inoculation of virus. Ganciclovir administration starting 1 day before inoculation prevented the development of both cochlear histopathologic change and hearing loss. Guinea pig cytomegalovirus meningitis was observed in both the drug-treated and untreated groups. High-pressure liquid chromatography confirmed the presence of ganciclovir in the serum, perilymph, and cerebrospinal fluid of the drug recipients. Prophylactic ganciclovir thus can protect the cochlea from the histopathologic changes and hearing loss normally associated with experimental guinea pig cytomegalovirus labyrinthitis.

Atypical retinitis in patients with the acquired immunodeficiency syndrome

We examined three patients with AIDS who had large, sharply demarcated areas of thinned retina consistent with inactive cytomegalovirus retinitis and who were not treated with ganciclovir. These lesions appeared identical to clinically inactive areas of cytomegalovirus retinitis after effective antiviral treatment. All patients were receiving azidothymidine or ribavirin, or both, which have activity against the human immunodeficiency virus and which may improve immune function. All patients also received oral acyclovir at doses ineffective against cytomegalovirus retinitis.

Intravitreal ganciclovir in the treatment of AIDS-associated cytomegalovirus retinitis

Ganciclovir (BW B759U, DHPG, dihydroxy propoxymethyl guanine) was injected directly into the vitreous in 14 eyes of 11 patients with severe acquired immune deficiency syndrome (AIDS)-associated cytomegalovirus (CMV) retinitis. All 11 patients either demonstrated serious myelosuppression which precluded the continuation of intravenous ganciclovir therapy (5 patients) or were experiencing progressive CMV retinitis despite therapy with maximum-tolerable dosages of intravenous ganciclovir (6 patients). Suppression of the retinitis was observed in 11 (78%) of the 14 treated eyes. Three eyes (22%) showed no improvement after the initial intravitreal injection. One rhegmatogenous retinal detachment (RD) occurred during an injection. There were no other complications, and no intraocular drug toxicity was observed. Reactivation of CMV retinitis necessitated repeated injections in 9 (64%) of the 14 eyes. The authors' experience with these 30 intravitreal injections indicates that the procedure is safe and effective both as an alternative to intravenous ganciclovir therapy in myelosuppressed patients and as a supplement to intravenous therapy in uncontrolled CMV retinitis.

Efficacy of S26308 against guinea pig cytomegalovirus infection

Prophylactic use of antiviral agents against cytomegalovirus (CMV) is particularly indicated for the immunocompromised host because morbidity and mortality due to CMV occur most frequently following immunosuppression. We have evaluated the new Riker compound S26308 for its therapeutic and prophylactic antiviral activity against CMV in guinea pigs. The efficacy of the compound was assessed in vitro in guinea pig embryo cells and in vivo in both immunocompetent and immunocompromised guinea pigs. Guinea pig CMV plaque formation was reduced only in cells treated with S26308 prior to virus infection. The antiviral activity remained even when the compound was removed after virus absorption and was due to neither virus destruction nor inhibition of cell growth. The frequency of viremia was reduced in guinea pigs for which S26308 therapy was initiated 24 h prior to virus inoculation compared with sham-treated animals. This reduction in the frequency of viremia did not prevent virus spread to target tissues but did result in a reduction of the severity of CMV-induced disease in immunocompromised guinea pigs. Low levels of interferon were detected in supernatants of S26308-treated cells, and interferon was detected in the serum of guinea pigs given S26308. These results indicate that S26308 can induce interferon and reduce CMV infectivity in vivo and in vitro when used prophylactically. This antiviral activity, although modest, was accompanied by beneficial effects on CMV-induced morbidity and mortality. Prophylactic use of S26308 in combination with other therapeutic agents may be a useful strategy against CMV infections.

Active cytomegalovirus particles in the eyes of an AIDS patient being treated with 9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl] guanine (Ganciclovir)

The eyes of an AIDS patient with cytomegalovirus (CMV) retinitis and pneumonitis who died while receiving maintenance therapy with the antiviral agent 9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl] guanine (Ganciclovir) were obtained for pathological examination. While under treatment the patient had significant improvement but not complete regression of retinitis. Electron microscopic and immunofluorescent techniques revealed cytomegalovirus particles in the retina, sclera, iris, and ciliary body. These findings are consistent with a virostatic type of inhibition of CMV by this agent. They also suggest that CMV involvement in the eye and other organs may be more widespread than is clinically apparent in AIDS patients.

Can AZT treatment in AIDS patients aggravate pre-existing CMV retinitis?

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Viral infections in the acquired immunodeficiency syndrome

The following communication is a tripartite synopsis of the role of viral infection in the acquired immunodeficiency syndrome (AIDS). The first section describes the impact of viral opportunistic infection in AIDS; for each virus, clinical presentation and diagnosis, laboratory diagnostic approaches (with emphasis on electron microscopy), and therapeutic interventions attempted to date are discussed. The second segment explores current theories on the pathogenesis of AIDS, and describes diagnostic and therapeutic approaches to the syndrome itself. The final section catalogues ultrastructural anomalies in the cells of AIDS patients, many of which have been mistakenly identified as etiologic agents.

Efficacy and safety of two different dose levels of ganciclovir for the treatment of cytomegalovirus chorioretinitis in AIDS patients

The effect of different dosages of ganciclovir on proved cytomegalovirus chorioretinitis was tested in a randomized trial on 11 homosexual men with AIDS. The effect of 5 mg/kg/day was as good as 10 mg/kg/day. The lower dosage had less toxicity.

Treatment of CMV retinitis in an AIDS patient

We present a case of cytomegalovirus (CMV) retinitis in an AIDS patient who survived for 10 months after the start of his ocular problems. The retinitis responded to dihydroxy propoxy methyl guanine (DHPG) but relapsed four to six weeks after each course of treatment with progressive retinal destruction. One relapse was therefore treated with trisodium phosphoformate hexahydrate (Foscarnet). There are few reports of the use of this drug in the treatment of CMV retinitis with AIDS, but it appeared to be less effective in our patient than DHPG, possibly because of poor penetration of the blood-ocular barrier. A final course of outpatient maintenance therapy with DHPG failed to prevent a preterminal relapse of the retinitis. Fundus photographs demonstrated the resolution and relapse of the retinitis associated with each course of treatment. Maintenance therapy with DHPG would appear to be necessary to prevent relapse, but the logistics of this are difficult, and the effective dosage of DHPG is as yet uncertain.

Treatment of cytomegalovirus retinopathy with ganciclovir

Ganciclovir is an experimental antiviral drug with activity against human cytomegalovirus (CMV). Forty patients with acquired immune deficiency syndrome (AIDS) and CMV retinopathy were treated with ganciclovir on a compassionate protocol basis. Initial treatment doses ranged from 5.0 to 14.0 mg/kg/day for 9 to 26 days. Signs of drug response were a halt to enlargement of lesions, decreased opacification of retinal tissue, and resolution of hemorrhage and vasculitis. Complete response was seen in 88% of patients and incomplete response was seen in 9%. Vision improved or remained stable in 88% of patients. Initial treatment did not eradicate live virus from the eye. To prevent reactivation of disease, 26 patients received low-dose maintenance therapy ranging from 1.5 to 7.5 mg/kg/day, once or twice daily, 3 to 7 days per week. Reactivation of disease developed for unknown reasons in 50% of patients on continuous, uninterrupted maintenance therapy for longer than 3 weeks. Reversible neutropenia, requiring cessation of treatment, developed in 30% of patients on initial treatment and in 38% of patients on maintenance therapy. Rhegmatogenous retinal detachment was a late complication in seven patients. By reducing or delaying visual loss, ganciclovir appears to be useful in the management of CMV retinopathy in patients with AIDS.

Treatment of cytomegalovirus retinitis with ganciclovir

Eighteen immunocompromised patients with cytomegalovirus (CMV) retinitis were treated with ganciclovir, an investigational antiviral drug. CMV retinitis in association with acquired immune deficiency syndrome (AIDS) developed in 17 patients; CMV retinitis developed in one patient after cardiac transplantation. Fourteen patients responded to ganciclovir treatment with improvement in CMV retinitis. In 11 patients, the response was classified as complete; in three patients, the response was partial. Continued improvement in the retinitis was often seen while the patient was on maintenance treatment. Maintenance ganciclovir therapy was required; relapse occurred in five of seven patients in whom ganciclovir treatment was interrupted. The major limiting toxic side effect of ganciclovir was neutropenia, which necessitated temporary discontinuation of ganciclovir in five patients but was reversible in all cases. Ganciclovir appears to be an effective therapy for CMV retinitis, but chronic maintenance therapy is required.

Combined short- and long-term therapy for the treatment of cytomegalovirus retinitis using ganciclovir (BW B759U)

A total of 66 eyes in 41 patients were treated for cytomegalovirus (CMV) retinitis with a new acyclic nucleoside, ganciclovir (BW B759U). At the completion of the short-term therapy period of 21 days, 87.7% of eyes had stabilized or improved. Seventy-two percent of eyes stabilized or improved during long-term home maintenance therapy. Leukopenia and increased liver function abnormalities were the most common adverse drug reactions seen in this series. Ganciclovir dramatically improved the quality of life in these patients, but clinical evidence suggests that it is a virostatic medication requiring indefinite long-term maintenance therapy.

Neurological complications in AIDS

Neurological complications in the acquired immunodeficiency syndrome (AIDS) are an important aspect of this new infectious disease and occur frequently. The existence of neurotropic variants of the human immunodeficiency virus (HIV), the causative agent of AIDS, is probable. Direct infection of the nervous system with HIV leads to a variety of HIV-induced neurological syndromes, the AIDS dementia complex being its most important representative. In addition, a large number of opportunistic infections and malignancies of the nervous system may complicate the disease. Major aspects of the clinical pictures, rational diagnostic approaches and treatment options of the most important sequels of HIV infection of the nervous system are discussed.

Prevalence, pathophysiology, and treatment of rhegmatogenous retinal detachment in treated cytomegalovirus retinitis

Seventeen patients with the acquired immune deficiency syndrome and cytomegalovirus retinitis were treated with the antiviral drug ganciclovir (9-[1,3-dihydroxy-2-propoxy-methyl]-guanine, DHPG). Eight eyes of five patients developed rhegmatogenous retinal detachment after initiation of treatment. Multiple breaks in areas of peripheral, healed, atrophic retina accounted for the detachments. All seven eyes that underwent surgery had extensive retinal detachments that were reattached with vitrectomy and silicone oil. Retinotomy and retinal tacks were necessary in two cases that were complicated by severe proliferative vitreoretinopathy. In the fellow eye of one patient, laser treatment was used prophylactically to wall off a peripheral patch of healed retinitis. Endoretinal biopsies and culture were taken in five eyes; evidence of persistent cytomegalovirus was seen in two cases despite concurrent and clinically effective antiviral therapy.

Cytomegalovirus retinitis and response to therapy with ganciclovir

A 15-month prospective study of 109 patients with the acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC) was conducted. Cytomegalovirus (CMV) retinitis developed in 18 of these patients; they were treated with ganciclovir. Five other patients with CMV retinitis who were not part of the prospective study were also treated with ganciclovir. CMV retinitis frequently involved the peripheral retina. All 23 patients treated with ganciclovir showed clinical regression of retinitis, although breakthrough recurrence of CMV retinitis occurred in seven patients (30.4%) while on maintenance therapy with ganciclovir. During treatment, neutropenia (less than 1000 leukocytes/mm3) developed in three patients (13%). Ganciclovir is an effective means of therapy for CMV retinitis, but it must be given chronically to prevent reactivation. Breakthrough recurrences while on maintenance therapy are not uncommon, but can be successfully treated with more aggressive treatment with ganciclovir. In addition, the prognosis for survival of AIDS patients being treated with ganciclovir is improved when compared with that of untreated patients.

Use of intravitreal ganciclovir (dihydroxy propoxymethyl guanine) for cytomegalovirus retinitis in a patient with AIDS

A patient with acquired immune deficiency syndrome with bilateral cytomegalovirus retinitis was treated with intravitreal 200-micrograms/0.1-ml doses of ganciclovir (9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl]guanine). The ganciclovir serum and intravitreal concentrations were measured with an enzyme-linked immunosorbent assay and pharmacokinetic factors were determined. There was no evidence of systemic absorption of ganciclovir from the eye. The elimination half-life of ganciclovir from the vitreous was estimated to be 13.3 hours. The intravitreal concentration remained above the ID50 of cytomegalovirus for approximately 62 hours after a single injection. Clinically, the patient retained useful vision in his right eye for three months. A total of 28 intravitreal injections were given on an outpatient basis under topical anesthesia and were well tolerated. There was no evidence of retinal toxicity from the drug.

2'-nor-cGMP, a new cyclic derivative of 2'NDG, inhibits HSV-1 replication in vitro and in the mouse keratitis model

The present study examined the antiherpetic effect of 2'-nor-cGMP, a new cyclic phosphate derivative of 2'NDG, in vitro and in the mouse keratitis model. The 50% inhibitory dose (ID50) was determined with HSV-1 RE strain in Vero cell monolayers for 2'-nor-cGMP (6.9 mcg./ml), 2'NDG (.06 mcg/ml), and trifluridine (F3T) (.72 mcg/ml). Balb C mice underwent bilateral ocular inoculation with HSV-1 RE strain, and then were treated with different therapeutic regimens. The antiviral efficacy of each drug was evaluated by ocular virus titers, clinical grading of epithelial keratitis, and histological evaluation of stromal keratitis. 2'-nor-cGMP was the most effective drug (P = .0001) in reducing ocular viral titers. Both 2'-nor-cGMP and 2'NDG were significantly more effective (P = .0001) than F3T in reducing epithelial keratitis, and as effective as F3T in reducing stromal keratitis.