Discontinuation of maintenance therapy in patients with quiescent cytomegalovirus retinitis and elevated CD4+ counts

The Safety of Discontinuation of Maintenance Therapy for Cytomegalovirus (CMV) Retinitis and Incidence of Immune Recovery Uveitis Following Potent Antiretroviral Therapy

BACKGROUND

Reconstitution of immune function during potent antiretroviral therapy can prompt discontinuation of maintenance cytomegalovirus (CMV) therapy but has also been associated with sight-threatening inflammatory conditions including immune recovery uveitis (IRU).

METHOD

Patients with inactive CMV retinitis and a CD4+ cell count above 100/mm3, receiving CMV therapy and stable combination antiretroviral therapy, were assigned to one of two groups based on willingness to discontinue CMV therapy.

RESULTS

Thirty-eight participants were enrolled: 28 discontinued anti-CMV therapy (Group 1) and 10 continued CMV treatment (Group 2). Median on-study follow-up was 16 months. One Group 1 participant who experienced an increase in plasma HIV viral load and a decline in CD4+ cell count developed confirmed progression of CMV retinitis. Progression or reactivation CMV retinitis was not observed among Group 2. IRU was present at study entry in 3 participants. Six participants in Group 1 and 3 participants in Group 2 developed IRU on-study. CMV viremia was not detected in any participants, and urinary shedding of CMV was intermittent.

CONCLUSION

Recurrence of CMV retinitis following discontinuation of anti-CMV therapy among patients with antiretroviral-induced increases in CD4+ cell count was rare. However, IRU was common in both those who maintained and discontinued anti-CMV therapy.

Evaluation of the United States public health service guidelines for discontinuation of anticytomegalovirus therapy after immune recovery in patients with cytomegalovirus retinitis

PURPOSE

To evaluate United States Public Health Service (USPHS) guidelines for discontinuing anticytomegalovirus (CMV) therapy in patients with AIDS who have immune recovery and quiescent retinitis after initiating highly active antiretroviral therapy.

DESIGN

Cohort study of patients with CMV retinitis (Longitudinal Study of Ocular Complications of AIDS).

METHODS

Participants had CMV retinitis and CD4+ T-cell counts of 50 cells/μL or fewer enrolled from 1998 through 2009 who demonstrated sustained immune recovery (2 consecutive CD4+ T-cell counts of 100 cells/μL or more at least 6 months apart) and inactive retinitis. Participants were classified into 2 groups according to anti-CMV treatment after immune recover: (1) continued anti-CMV therapy and (2) discontinued therapy. We evaluated survival, visual acuity, and CMV retinitis activity; we used propensity scores to adjust for confounding factors for these analyses.

RESULTS

Of 152 participants reviewed, 71 demonstrated immune recovery, 37 of whom discontinued therapy and 34 of whom continued therapy. At immune recovery, participants continuing therapy tended to be older (44 vs 40 years; P = .09), have bilateral retinitis (53% vs 32%; P = .10), and have lower CD4+ T-cell counts (148 vs 207 cells/μL; P < .001). There were no statistical differences in any of the clinical outcomes (death, retinitis progress, visual acuity, or incidence of bilateral retinitis). Both groups lost visual acuity during follow-up, on average 1.2 letters per year (P < .01).

CONCLUSIONS

Discontinuation of anti-CMV therapy after immune recovery did not increase the risk of poor outcomes. These results support the current guidelines for discontinuation of anti-CMV therapy after achievement of sustained immune recovery.

Recurrent CMV retinitis in a non-HIV patient with drug-resistant CMV

BACKGROUND

We report a case of recurrent cytomegalovirus (CMV) retinitis in an HIV-negative patient with CD4+ T lymphocytopenia.

METHODS

Case report.

RESULTS

A 41-year-old HIV-negative woman with a history of systemic lupus erythematosus, idiopathic thrombocytopenic purpura requiring splenectomy, and diabetes presented with primary CMV infection, high-grade viremia, CMV pneumonia followed by CMV retinitis (CMVR) and a CD4+ T lymphocyte (CD4) count of 12 cells/mm(3) after therapy with rituximab, prednisone, and methotrexate. Persistent CMV viremia led to genotypic analysis of the circulating virus, which revealed UL97 and UL54 mutations known to be associated with resistance to ganciclovir (GCV) and cidofovir. CMV clearance from the bloodstream followed systemic antiviral therapy and recovery of CD4 cell count. However, CMVR recurred multiple times despite GCV implants, systemic valganciclovir, intravitreal GCV injections, and persistent CD4 counts greater than 100 cells/mm(3). Recurrent episodes of CMVR responded to multiple high dose intravitreal GCV injections (5000-6000 micrograms) and recovery of CD4 cell counts to greater than 200 cells/mm(3).

CONCLUSION

This case demonstrates that recurrent CMVR occurs in HIV-negative patients at CD4 cell counts thought to be protective in HIV patients, and suggests that an ineffective local immune response to retinal infection combined with CMV drug resistance may have been important factors leading to recurrent disease in this patient. Treatment producing high local concentrations of GCV may be effective therapy for CMV retinitis due to GCV-resistant virus.

Medical devices for the treatment of eye diseases

Development of intraocular drug delivery systems (DDSs) is urgently required for the treatment of eye diseases, especially in the posterior segment of the eye (the vitreous cavity, retina, and choroid), most of which are refractory to conventional pharmacologic approaches; eye drops and systemically administered drugs cannot achieve therapeutic drug concentrations in the posterior segment of the eye. Repeated intravitreal injections of anti-angiogenic agents are effective in the treatment of age-related macular degeneration, but there remain risks of serious side effects such as endophthalmitis associated with repeated injections. Intraocular DDSs may address these problems. Intraocular sustained drug release from implantable or injectable devices has been investigated to treat vitreoretinal diseases. A reservoir-type nonbiodegradable implant was first launched in the market in 1996 for the treatment of cytomegalovirus retinitis secondary to the acquired immunodeficiency syndrome, followed by clinical trials for a variety of potent devices to treat other challenging eye diseases. An injectable rod-shaped insert releasing a steroid is presently being assessed in a phase III trial to treat macular edema secondary to diabetic retinopathy or retinal vein occlusion. Thus various types of intraocular DDSs will be commercially available to treat vision-threatening intraocular diseases in the near future.

Seven Years of HAART Impact on Ophthalmic Management of HIV-Infected Patients

PURPOSE

The widespread use of highly active antiretroviral therapy (HAART) has changed the clinical picture of HIV-associated eye disease. We evaluated the incidence of ocular manifestations of HIV infection since the introduction of HAART.

METHODS

Between January 1996 and December 2002, we examined 539 HIV-infected patients in our hospital. Follow-up of the patients was performed in case of ophthalmologic symptoms, regardless of current immunologic status, or for screening.

RESULTS

A total of 217 patients (40.3%) had HIV-associated eye disease. Of these patients, 42.0% had no eye symptoms. Fifty-eight (10.8%) of the 539 patients had cytomegalovirus (CMV) retinitis, most of whom had CMV retinitis before receiving HAART. Four patients developed immune-recovery uveitis. A total of 145 patients (26.9%) had HIV-related microangiopathy and 96 (17.8%) had dry-eye syndrome.

CONCLUSION

The introduction of HAART had a major impact on the medical history of patients with HIV-related eye disease with improved survival time and decreased morbidity.

Posterior segment manifestations of human immunodeficiency virus/acquired immune deficiency syndrome

Ocular manifestations can occur in up to 50% of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) patients and posterior segment involvement is the most common presentation. The posterior segment manifestations of AIDS can be divided into four categories: retinal vasculopathy, opportunistic infections, unusual malignancies and neuro-ophthalmologic abnormalities. Retinal microvasculopathy and cytomegalovirus (CMV) retinitis are the most common manifestations, even in the era of highly active anti-retroviral therapy (HAART). Highly active anti-retroviral therapy has been shown to cause regression of CMV retinitis, reduce the incidence of CMV-related retinal detachments, and prolong patient survival. Immune recovery uveitis is a new cause of vision loss in patients on HAART. Diagnosis and treatment are guided by the particular conditions and immune status of the patient.

Treatment of CMV retinitis with intravitral ganciclovir in the HAART era

OBJECTIVE

To describe the course and outcome of cytomegalovirus (CMV) retinitis among AIDS patients treated with intravitreal ganciclovir and systemic highly active antiretroviral therapy (HAART). The secondary objective was to compare the course of CMV retinitis between patients receiving HAART and those not receiving this treatment.

DESIGN

A retrospective cohort design consisting of 21 eyes from 16 patients with AIDS and CMV retinitis consecutively enrolled between January 1996 and August 1999. All patients received intravitreal ganciclovir therapy, and half of the patients began HAART as well. Duration of intravitreal therapy and ensuing disease quiescence, as well as CD4+ T cell counts at diagnosis and at cessation of ganciclovir, were calculated. Secondly, instantaneous hazards for outcomes such as CMV retinitis progression, ocular complications and mortality were compared.

SETTING

Tertiary care centre in Ottawa, Ontario.

RESULTS

Five of eight patients receiving HAART discontinued intravitreal ganciclovir after a mean treatment period of 428 days. During this period, their mean CD4+ count rose from 7.5 to 190microL. Subsequently, none of these patients experienced retinitis progression during follow-up periods lasting up to 820 days (mean of 617 days). Progression of CMV retinitis was 11.4 times more likely among those not receiving HAART (P=0.049).

CONCLUSIONS

On initiating HAART, patients with CMV retinitis may enjoy significant recovery in CD4+ counts and sustained retinitis quiescence without specific anti-CMV therapy. Intravitreal ganciclovir injections seem well suited to offer effective CMV control during temporary periods of decreased CD4+ counts while awaiting HAART-mediated immune system reconstitution.

Cytomegalovirus retinitis: the neglected disease of the AIDS pandemic

The authors describe CMV retinitis in resource-poor settings and suggest possibilities for management.

Withdrawal of maintenance therapy for cytomegalovirus retinitis in AIDS patients exhibiting immunological response to HAART

BACKGROUND: Before the introduction of highly active antiretroviral therapy (HAART), CMV retinitis was a common complication in patients with advanced HIV disease and the therapy was well established; it consisted of an induction phase to control the infection with ganciclovir, followed by a lifelong maintenance phase to avoid or delay relapses. METHODS: To determine the safety of CMV maintenance therapy withdrawal in patients with immune recovery after HAART, 35 patients with treated CMV retinitis, on maintenance therapy, with CD4+ cell count greater than 100 cells/mm³ for at least three months, but almost all patients presented these values for more than six months and viral load < 30000 copies/mL, were prospectively evaluated for the recurrence of CMV disease. Maintenance therapy was withdrawal at inclusion, and patients were monitored for at least 48 weeks by clinical and ophthalmologic evaluations, and by determination of CMV viremia markers (antigenemia-pp65), CD4+/CD8+ counts and plasma HIV RNA levels. Lymphoproliferative assays were performed on 26/35 patients. RESULTS: From 35 patients included, only one had confirmed reactivation of CMV retinitis, at day 120 of follow-up. No patient returned positive antigenemia tests. No correlation between lymphoproliferative assays and CD4+ counts was observed. CONCLUSION: CMV retinitis maintenance therapy discontinuation is safe for those patients with quantitative immune recovery after HAART.

Distinct Functions between Toll-Like Receptors 3 and 9 in Retinal Pigment Epithelial Cells

Retinal pigment epithelial cells (RPE cells) are key players in the first-line defense against invading organisms such as viruses and bacteria. The interaction between RPE cells and viral or bacterial components is very important for clearance of these organisms. Toll-like receptors are a family of recognition receptors involved in innate immunity. Each TLR acts as a primary sensor of conserved microbial components and drives the induction of specific biological responses. TLR 3 is involved in the recognition of viral components, such as double-stranded RNA (dsRNA) and poly(I:C), while TLR 9 recognizes viral or bacterial DNA without methylation at CpG motifs. In the present study, we investigated the expression and function of TLR 3 and 9 in RPE cells. PCR analysis revealed expression of genes for TLR 3 and 9 in RPE cells. Expression of TLR 3 and 9 protein was detected in RPE cells by flow cytometry. TLR 3 and 9 showed strong intracellular expression. To detect angiogenetic factors produced by RPE cells, culture supernatant was examined with the Human Angiogenesis Antibody Array, which can simultaneously detect 20 different angiogenetic factors including cytokines, chemokines, soluble cytokine receptors, and growth factors. RPE cells showed high production of interleukin-8 (IL-8) and monocyte chemotactic protein-I (MCP-I). Furthermore, stimulation of RPE cells with the dsRNA analogue poly(I:C) enhanced the secretion of IL-8 and MCP-I, as well as enhancing the expression of junctional adhesion molecule-I (Jam-I) and intracellular adhesion molecule-I (ICAM-I), and promoted the adhesion of monocyte to these cells. In contrast, stimulation with the CpG-DNA motif only enhanced the secretion of IL-8. However, CpG-DNA motif enhanced phagocytosis in RPE cells. These results may indicate that TLR 3 and 9 play a distinct role in the inflammatory response that clears viruses from the retina.

Economic evaluation of treatment administration strategies of ganciclovir for cytomegalovirus retinitis in HIV/AIDS patients in Thailand: a simulation study

BACKGROUND

There are many effective interventions, via various routes (intravenous [IV], oral [OR], intravitreal injection [IVT] and intraocular implantation [IMP]), for treating cytomegalovirus retinitis (CMVR) that have become available. There are large variations in treating CMVR in clinical practice in Thailand.

OBJECTIVE

To evaluate the incremental cost-effectiveness ratio (ICER) of providing (i) IVT, (ii) IV/OR and (iii) IMP ganciclovir to patients with HIV/AIDS and CMVR versus providing no treatment.

DESIGN

A simulation study for which the input parameters were derived from a systematic review of the literature, a hospital-based survey and patient interviews.

SETTING

The analysis assumed a Thai healthcare system perspective. However, the model was run using both societal and healthcare provider perspectives.

RESULTS

Our results suggest that IVT ganciclovir was cost effective and the best option for treating patients with CMVR irrespective of whether patients received antiretroviral treatment (ART). In patients receiving ART, moving from IVT to IV/OR ganciclovir was also likely to be a cost-effective option. Offering IMP ganciclovir was not likely to be cost effective. Providing treatments for patients with bilateral CMVR was more cost effective than providing treatments for those with unilateral CMVR, and offering treatments for patients receiving ART was better value for money than treating patients without ART.

CONCLUSIONS

Our models suggest that IV/OR ganciclovir should be recommended for the treatment of unilateral and bilateral CMVR for patients receiving ART in the Thai healthcare system. IVT ganciclovir may also have a role in the treatment of CMVR patients not receiving ART.

Immunological recovery and antiretroviral therapy in HIV-1 infection

Potent antiretroviral therapy has dramatically improved the prognosis of patients infected with HIV-1. Primary and secondary prophylaxis against Pneumocystis carinii, Mycobacterium avium, cytomegalovirus, and other pathogens can be discontinued safely once CD4 cell counts have increased beyond pathogen-specific thresholds. Approximately one-third of individuals receiving antiretroviral therapy will not reach CD4 cell counts above 500 cells per muL after 5 years despite continuous suppression of plasma HIV-1 RNA. Whether this failure represents a risk factor for the long-term incidence of opportunistic diseases--eg, tuberculosis or malignancies--remains uncertain. We describe the time course of CD4 cell concentrations in patients whose plasma HIV-1 RNA is durably suppressed by antiretroviral therapy, in patients with incomplete suppression of plasma HIV-1 RNA, and during treatment interruptions. In addition, immune reconstitution disease, an inflammatory syndrome associated with immunological recovery occurring days to weeks after the start of antiretroviral therapy, is briefly described.

Outcomes Associated with Ganciclovir Implants in Patients with AIDS-Related Cytomegalovirus Retinitis

PURPOSE

To investigate complications associated with ganciclovir implants used to treat AIDS-related cytomegalovirus (CMV) retinitis, and to identify factors that predict poor outcomes.

DESIGN

Retrospective chart review.

PARTICIPANTS

Consecutive patients with AIDS-related CMV retinitis from 3 clinical facilities who underwent implantation procedures during the period January 1, 1995 through December 31, 2001.

METHODS

Baseline for each patient was the date of the first implantation procedure performed during the study period by one of the facilities' surgeons (index implant). Medical and ophthalmological data were collected at baseline and at specific time points after baseline. The dates on which additional implantation procedures were performed and the dates on which complications or vision loss were identified were also recorded. Relationships between potential risk factors and outcomes were studied by Kaplan-Meier analyses and Cox proportional hazards regression models.

MAIN OUTCOME MEASURES

Primary outcome measures included postoperative complications specifically related to or possibly related to ganciclovir implants. A secondary outcome measure was vision loss after implantation procedures.

RESULTS

The charts of 174 patients (one study eye per patient; 279 implants) were reviewed. Median follow-up was 14.4 months (range, 0-7 years). Complications specifically related to implants occurred throughout follow-up at a rate of 0.064 events per patient-year. Complications possibly related to implants occurred at an overall rate of 0.377 per patient-year, but seemed to be more common during the first 2 years after baseline. During the first 2 years of follow-up, retinal detachments occurred at a rate of 0.156 events per patient-year. The cumulative risk of vision loss (> or =3 lines of Snellen visual acuity) at 7 years was 70%. Poor outcomes were associated with disease factors (size and activity of lesions), lack of highly active antiretroviral therapy (HAART), and lack of HAART-associated immune reconstitution, but not with surgical factors or implant-specific complications.

CONCLUSIONS

Complications specifically associated with ganciclovir implants can occur many years after implantation procedures, but the incidence of such complications is low. Continued vision loss is not attributable directly to complications of implants in most cases. This information will help in planning of treatment strategies for CMV retinitis in long-term survivors of human immunodeficiency virus disease.

HIV-associated retinopathy in the HAART era

BACKGROUND

The effectiveness of highly active antiretroviral therapy (HAART) in restoring immune function in patients with acquired immunodeficiency syndrome (AIDS) has led to changes in the incidence, natural history, management, and sequelae of human immunodeficiency virus (HIV)-associated retinopathies, especially cytomegalovirus (CMV) retinitis.

METHODS

The medical literature pertaining to HIV-associated retinopathies was reviewed with special attention to the differences in incidence, management strategies, and complications of these conditions in the eras both before and after the widespread use of HAART.

RESULTS

In the pre-HAART era, CMV retinitis was the most common HIV-associated retinopathy, occurring in 20%-40% of patients. Median time to progression was 47 to 104 days, mean survival after diagnosis was 6 to 10 months, and indefinite intravenous maintenance therapy was mandatory. Retinal detachment occurred in 24%-50% of patients annually. Herpetic retinopathy and toxoplasmosis retinochoroiditis occurred in 1%-3% of patients and Pneumocystis carinii choroiditis, syphilitic retinitis, tuberculous choroiditis, cryptococcal choroiditis, and intraocular lymphoma occurred infrequently. In the HAART era the incidence of CMV retinitis has declined 80% and survival after diagnosis has increased to over 1 year. Immune recovery in patients on HAART has allowed safe discontinuation of maintenance therapy in patients with regressed CMV retinitis and other HIV-associated retinopathies. Immune recovery uveitis (IRU) is a HAART dependent inflammatory response that may occur in up to 63% of patients with regressed CMV retinitis and elevated CD4 counts and is associated with vision loss from epiretinal membrane, cataract, and cystoid macular edema.

CONCLUSIONS

The incidence, visual morbidity, and mortality of CMV retinitis and other HIV-associated retinopathies have decreased in the era of HAART and lifelong maintenance therapy may safely be discontinued in patients with restored immune function. Patients with regressed CMV retinitis, however, may still lose vision from epiretinal membrane, cystoid macular edema, and cataract secondary to IRU.

Virtual screening of HIV-1 protease inhibitors against human cytomegalovirus protease using docking and molecular dynamics

The clearance of cytomegalovirus viraemia in HIV-1-infected patients may partly result from the inhibition of cytomegalovirus protease by HIV-1 protease inhibitors contained in highly active antiretroviral therapy. We used a computational method to calculate the binding affinity of six HIV-1 protease inhibitors to cytomegalovirus protease based on its X-ray crystallography structure. The calculations showed that amprenavir and indinavir occupy the substrate-binding site of the cytomegalovirus protease with high affinity, and may be implicated in alleviating cytomegalovirus infection.

Ocular manifestations of AIDS: new considerations for patients using highly active anti-retroviral therapy (HAART)

BACKGROUND

Highly active anti-retroviral therapy (HAART) effectively restores the immune system and lowers the viral load in patients with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). Since widespread use of HAART drugs began in 1996, many AIDS patients are living longer and enjoying a higher quality of life. The incidence of AIDS-related ophthalmic infections, such as cytomegalovirus (CMV) retinitis, have declined sharply. AIDS patients with CMV are less likely to experience necrotizing retinitis and retinal detachment, once the major causes of vision loss. HAART and immune recovery is now considered the preferred treatment for CMV retinitis. The role of immune recovery vitritis (IRV), a new manifestation of CMV retinitis, is now understood. In patients with pre-existing CMV retinitis who begin HAART the manifestations of an active immune system are seen, as the body is now able to fight the CMV infection. Incidence of Kaposi's sarcoma has declined by an estimated 87% and molluscum contagiosum is seen less frequently in those using HAART. With the clinical picture of ocular AIDS changing, the role of optometry in the management of AIDS patients is also changing.

Drug delivery systems for vitreoretinal diseases

The eye has an environment that is specific unto itself in terms of pharmacokinetics: the inner and outer blood-retinal barriers separate the retina and the vitreous from the systemic circulation and vitreous body, which physiologically has no cellular components, occupies the vitreous cavity, an inner space of the eye, and reduces practical convection of molecules. Considering this, development of a drug delivery system (DDS) is becoming increasingly important in the treatment of vitreoretinal diseases not only to facilitate drug efficacy but also to attenuate adverse effects. The DDS has three major goals: enhances drug permeation (e.g., iontophoresis and transscleral DDS), controls release of drugs (e.g., microspheres, liposomes, and intraocular implants), and targets drugs (e.g., prodrugs with high molecular weight and immunoconjugates). Comprehensive knowledge of these should lead to development of innovative treatment modalities.

Immune reconstitution in HIV-infected patients

The prognosis of patients infected with human immunodeficiency virus (HIV) type 1 has dramatically improved since the advent of potent antiretroviral therapies (ARTs), which have enabled sustained suppression of HIV replication and recovery of CD4 T cell counts. Knowledge of the function of CD4 T cells in immune reconstitution was derived from large clinical studies demonstrating that primary and secondary prophylaxis against infectious agents, such as Pneumocystis jirovecii (Pneumocystis carinii), Mycobacterium avium complex, cytomegalovirus, and other pathogens, can be discontinued safely once CD4 T cell counts have increased beyond pathogen-specific threshold levels (usually >200 CD4 T cells/mm3) for 3-6 months. The downside of immune reconstitution is an inflammatory syndrome occurring days to months after the start of ART, with outcomes ranging from minimal morbidity to fatal progression. This syndrome can be elicited by infectious and noninfectious antigens. Microbiologically, the possible pathogenic pathways involve recognition of antigens associated with ongoing infection or recognition of persisting antigens associated with past (nonreplicating) infection. Specific antimicrobial therapy, nonsteroidal anti-inflammatory drugs, and/or steroids for managing immune reconstitution syndrome should be considered.

Posterior segment manifestations of HIV/AIDS

The ocular posterior segment manifestations of AIDS may be divided into four categories: retinal vasculopathy, unusual malignancies, neuro-ophthalmologic abnormalities, and opportunistic infections. Microvasculopathy is the most common manifestation. Opportunistic infections, particularly cytomegalovirus retinitis and progressive outer retinal necrosis, are the most likely to result in visual loss due to infection or subsequent retinal detachment. Diagnosis and treatment are guided by the particular conditions and immune status of the patient.

Prevention of opportunistic infections in adult and adolescent patients with HIV infection. GESIDA/National AIDS Plan guidelines, 2004 [correction]

OBJECTIVE

To provide an update of guidelines from the Spanish AIDS Study Group (GESIDA) and the National AIDS Plan (PNS) committee on the prevention of opportunistic infections in adult and adolescent HIV-infected patients.

METHODS

These consensus recommendations have been produced by a group of experts from GESIDA and/or the PNS after reviewing the earlier document and the scientific advances in this field in the last years. The system used by the Infectious Diseases Society of America and the United States Public Health Service has been used to classify the strength and quality of the data.

RESULTS

This document provides a detailed review of the measures for the prevention of infections caused by viruses, bacteria, fungi and parasites in the context of HIV infection. Recommendations are given for preventing exposure and for primary and secondary prophylaxis for each group of pathogens. In addition, criteria are established for the withdrawal of prophylaxis in patients who respond well to highly active antiretroviral therapy (HAART).

CONCLUSIONS

HAART is the best strategy for the prevention of opportunistic infections in HIV-positive patients. Nevertheless, prophylaxis is still necessary in countries with limited economic resources, in highly immunodepressed patients until HAART achieves beneficial effects, in patients who refuse to take or who cannot take HAART, in those in whom HAART is not effective, and in the small group of infected patients with inadequate recovery of CD4+ T lymphocyte counts despite good inhibition of HIV replication.

Effect of anti-cytomegalovirus therapy on the incidence of immune recovery uveitis in AIDS patients with healed cytomegalovirus retinitis

PURPOSE

To determine the association between anticytomegalovirus (CMV) maintenance therapy after immune recovery and immune recovery uveitis in acquired immunodeficiency syndrome (AIDS) patients on highly active antiretroviral therapy (HAART).

DESIGN

Observational cohort study.

METHODS

Data were obtained on AIDS patients with CMV retinitis followed up at the AIDS Ocular Research Unit of University of California San Diego from November 1995 to October 1999. Immune recovery was defined as CD4 count greater than 50 cells/microl for more than 3 months. Patients with immune recovery uveitis presented with vitritis, cystoid macular edema, or epiretinal membrane. Statistical analyses were conducted to determine the risk of continued use of anti-CMV therapy after immune recovery and the relationship of developing immune recovery uveitis with the type of anti-CMV therapy.

RESULTS

Forty-three patients (64 eyes) had healed CMV retinitis and had achieved immune recovery. Thirty-one patients (48 eyes) received anti-CMV therapy after immune recovery, and 20 patients (29 eyes) developed immune recovery uveitis. Per-eye analyses revealed a 3.8-fold increase in the odds of developing immune recovery uveitis with anti-CMV therapy compared with no treatment (P =.02). If treated with cidofovir the odds were 3.3 greater than if treated with an alternative regimen (P =.04), 4.1 greater if treated intravenously (P =.01), and 5.2 greater than if not treated (P =.004). If not treated with cidofovir, a nonsignificant increase in the risk (2.4) of immune recovery uveitis was found (P =.15). Neither the potency nor the use of implants for noncidofovir treatment was related to the risk of recovery uveitis (P >.62).

CONCLUSIONS

The use of cidofovir is a primary risk factor in the subsequent development of immune recovery uveitis. Ongoing treatment of healed CMV retinitis after immune recovery does not appear to protect against the development of immune recovery uveitis.

Cytomegalovirus Disease in the Highly Active Antiretroviral Therapy Era

Cytomegalovirus (CMV) is a major cause of morbidity and mortality in AIDS patients. Epidemiologic studies indicate that until 10 years ago, nearly one half of HIV-infected patients eventually developed CMV end-organ disease, including chorioretinitis, esophagitis, colitis, pneumonia, and central nervous system disease. Since the introduction of highly active antiretroviral therapy (HAART) this incidence has declined dramatically. Nonetheless, patients still present with CMV disease and resistance or intolerance to HAART does develop, which may give rise to a resurgence of CMV syndromes in AIDS patients. Until recently, only intravenous ganciclovir and foscarnet were available for management of CMV infection. With the advent of additional agents, clinicians now face the challenge of optimizing therapy for individual patients. This paper reviews the most common clinical syndromes caused by CMV, the treatment options, as well as an approach to diagnosing and treating antiviral resistance.

Persisting murine cytomegalovirus can reactivate and has unique transcriptional activity in ocular tissue

Cytomegalovirus (CMV) retinitis is an important ocular complication in human immunodeficiency virus-infected individuals and the leading cause of blindness in those not undergoing highly active antiretroviral therapy. Murine CMV (MCMV) infection of mice has been shown to be a useful small-animal model for the study of CMV pathogenesis in the eye. The purpose of this study was to evaluate CMV persistence in ocular tissue and to determine the potential for reactivation. Following subretinal inoculation of immunocompetent BALB/c mice, tissues were tested for infectious virus by plaque assay and for the presence of viral DNA and RNA by PCR. The latent phase of the infection in mouse tissues was analyzed by plaque assay, PCR, and explantation cocultivation in both immunocompetent and cyclophosphamide-treated mice. The acute phase of the infection was resolved by 2 to 3 weeks postinfection, while viral DNA persisted beyond 12 months. Immediate-early 1 transcripts were detected in 100% of the ocular samples tested, and glycoprotein H transcripts were detected in 86% of the samples, but no difference in viral DNA or RNA levels between immunocompetent and immunosuppressed animals was measured. Irrespective of immune status, no in vivo reactivation was detected; however, reactivated virus was observed in 76 to 82% of the eyes following explantation onto a permissive cell layer. The transcriptional activity and relatively high frequency of explantation-induced reactivation in both immunocompetent and immunosuppressed mice suggest that control of MCMV latency in ocular tissue might involve other regulatory events that are not entirely dependent on intact specific immunity.

[Herpes and retinal lesions: what's new?]

The viral retinitis are linked to infection by herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV). When the diagnosis is clinically suspected the antiviral treatment has to be introduced immediately after performing the ocular sampling to try to identify the infectious agent. Despite the various antiherpetic drugs available by intravenous routes and intravitreal injection, the prognostic of the herpetic retinitis remained severe because of the occurrence of retinal detachment, optic neuritis, macular necrosis. Various clinical forms are described: (1) the classical "acute necrotizing retinitis" (2) a form with a slow progression of the necrotizing retinitis (3) occlusive retinal arteritis (4) the highly severe "progressive retinal necrosis". The incidence of the CMV retinitis diminished with the highly antiretroviral therapy; however uveitis may occur with no active CMV retinitis. The various antiherpetic drugs are described with special indications.

Paradoxical activity of CMV retinitis in patients receiving highly active antiretroviral therapy

PURPOSE

To report two types of atypical behaviors of cytomegalovirus (CMV) retinitis in the highly active antiretroviral therapy (HAART) era, including active CMV retinitis in the presence of persistently high CD4 cell counts during HAART and CMV retinitis that has not reactivated despite persistently low CD4 cell counts.

METHODS

Prospective, longitudinal, observational study of a cohort of 116 patients with acquired immunodeficiency syndrome who had a history of CMV retinitis during the HAART era.

RESULTS

Sixty (52%) of the 116 patients with acquired immunodeficiency syndrome and CMV retinitis were HAART responders. Subsequently, HAART failed for 9 of the 60 patients with low CD4 cell counts. Of these 9 patients, 5 developed reactivation of CMV retinitis, and 4 remained free of CMV retinitis despite CD4 cell counts of <50/microL and lack of anti-CMV therapy. Paradoxically, there was a patient with a documented median CD4 cell count of 204/microL for 19 months who had newly diagnosed active CMV retinitis.

CONCLUSION

In the HAART era, CMV retinitis may remain quiescent despite extremely low CD4 cell counts, and rarely, CMV retinitis may become active in the setting of persistently high CD4 cell counts in a subset of HAART responders.

Cytomegalovirus retinitis after initiation of highly active antiretroviral therapy in HIV infected patients: natural history and clinical predictors

PURPOSE

To characterize the natural course and clinical predictors of cytomegalovirus (CMV) retinitis in human immunodeficiency virus (HIV)-infected patients after initiation of highly active antiretroviral therapy (HAART).

METHODS

Retrospective analysis of 53 HIV-positive patients (73 eyes with CMV retinitis) treated with and without HAART. All participants continued to take anti-CMV therapy. Survival analysis was used to characterize the natural course of CMV retinitis. Proportional hazards analysis was performed to assess the correlation of the nine potential clinical predictors (baseline CD4 count, post-HAART CD4 count, post-HAART rise in CD4 count, baseline weight, post-HAART rise in weight, post-HAART percentage rise in weight, log of baseline HIV viral load, log of minimum post-HAART HIV viral load, and post-HAART log unit reduction in HIV viral load) with the duration of CMV retinitis remission.

RESULTS

Patients receiving HAART had a median CMV retinitis remission duration of 574 days (95% confidence interval, 336-NA) whereas those not receiving HAART had a median remission duration of 80.5 days (95% confidence interval, 28-NA; P < 0.001). Within the HAART-treated population, the minimal viral load reached after HAART was the only clinical predictor to demonstrate significance (P = 0.0075). Several other clinical predictors demonstrated borderline significance; however, this was most likely due to the high correlation of these variables with the minimum post-HAART viral load. A potential secondary clinical predictor identified was the post-HAART rise in CD4 count (P = 0.085).

CONCLUSION

With the introduction of HAART, HIV-infected patients have much longer remission durations from recurrent CMV retinitis. The minimum HIV viral load level reached after the initiation of HAART treatment appears to be more important than other clinical variables in the prediction of favorable CMV retinitis remission status. Furthermore, a rise in CD4 T-lymphocyte count by itself appears to be a less significant clinical predictor but may be useful in combination with the HIV viral load data. Selective discontinuation of anti-CMV therapy may be considered in patients with a favorable set of clinical predictors.

Predictive value of HIV-1 viral load on risk for opportunistic infection

OBJECTIVE

The relationship between HIV-1 viral load and the risk for opportunistic infection (OI) was examined in Adult AIDS Clinical Trial Group (AACTG) 722, a virology substudy of AACTG 323: a phase 4 randomized study designed to examine the use of chronic suppressive versus episodic fluconazole therapy.

METHODS

The primary analysis used a case-control sampling scheme with two controls per "case" (subjects that developed an OI) matched by gender, age, and time on study. Forty-five cases and matched controls were identified and used in the analysis.

RESULTS

Study 722 accrued 518 subjects between 5/97 and 11/99. Forty-five subjects developed serious OIs or refractory candidiasis. Median baseline CD4 count was 24 cell/mm3 for cases and 46 for controls (p =.003). Median viral load (VL) was 5.02 log10 copies/mL for cases and 4.08 for controls (p =.002). Multivariate analysis found four independent variables associated with time to OI: baseline VL and CD4 (RR = 2.2 per log increment and 6.0 per 50-cell increment, respectively), a one log increase in VL at any time (RR = 15), and history of an OI (RR = 5.2).

CONCLUSIONS

VL and changes in VL were independently associated with risk of development of OIs in a prospective study and should be considered by clinicians when assessing patients for risk of OI.

Management of Opportunistic Infection Prophylaxis in the Highly Active Antiretroviral Therapy Era

Prophylaxis and maintenance therapy against opportunistic infections are a mainstay of management of HIV-infected patients and have led to a significant improvement in quality of life and survival. Antiretroviral combination therapy (ART) has markedly changed the natural course of HIV infection. Incidence of opportunistic infections (OIs) has declined and survival after an OI has improved. Achieving a CD4 count of 200 cells/L after 6 months of ART is a valuable marker for low risk of OI afterwards. Therefore, recommendations on prophylaxis and maintenance therapy need to be redefined. Criteria for discontinuation, such as a CD4 count rise above threshold values and time above threshold values as response to ART, should be evaluated for the most frequent OIs. Reliable data in favor of discontinuation of primary prophylaxis against Pneumocystis carinii pneumonia, toxoplasmic encephalitis, and Mycobacterium avium infection have been published. Discontinuation of maintenance therapy against P. carinii pneumonia is possible, and may be safe against cytomegalovirus retinitis, M. avium, and cryptococcosis and toxoplasmosis in selected patients. Pharmacologic interactions between drugs used for OI prophylaxis and antiretroviral drugs need to be taken into account.

Discontinuation of secondary prophylaxis in patients with cytomegalovirus retinitis who have responded to highly active antiretroviral therapy

We performed a prospective study of discontinuation of secondary prophylaxis against cytomegalovirus (CMV) in 36 patients with acquired immunodeficiency syndrome and quiescent CMV retinitis after successful treatment with highly active antiretroviral therapy (HAART). No reactivation or progression of retinitis was observed in 35 patients with persistent response to HAART, findings that support the discontinuation of secondary prophylaxis against CMV retinitis in such patients.

Clinical indicators of immune restoration following highly active antiretroviral therapy

The course of human immunodeficiency virus (HIV) disease is characterized by a progressive decline in immune function. The advent of highly active antiretroviral therapy (HAART) has allowed patients to experience a significant degree of immune restoration when compared with the era before the availability of HAART. Multiple studies, which have employed sophisticated in vitro measures of immune function, have demonstrated improvement in CD4(+) lymphocyte (T4) responses to various opportunistic pathogens. In addition, for patients treated during acute HIV infection, HIV-specific T4 responses have been restored. By contrast, there are a limited number of in vivo measures of T4 function available to assess immune recovery following initiation of HAART. The primary measurement is an increase in CD4 lymphocyte count, the significance of which may be underappreciated. Delayed-type hypersensitivity testing to recall antigens and serological response to prophylactic vaccines may also have a role. This review discusses available markers of immune function and offers suggestions regarding their use in HAART recipients.

Highly active antiretroviral therapy-associated regression of cytomegalovirus retinitis: long-Term results in a small case series

PURPOSE

To report the stability of acquired immunodeficiency syndrome (AIDS)-associated cytomegalovirus (CMV) retinitis lesions that have undergone regression in the absence of specific anti-CMV medications owing to highly active antiretroviral therapy (HAART)-generated immune recovery.

METHODS

The initial examination revealed HAART-associated regression of CMV retinitis lesions in eight subjects at two institutions. Patients were monitored for recurrences of CMV activity. CD4+ T-lymphocyte counts and human immunodeficiency virus (HIV) loads were measured.

RESULTS

All patients had positive initial responses to HAART with an average HIV load decrease of 2.26 log units (range 0.3-5.57). Mean CD4+ T-lymphocyte count at baseline was 45.6 (range 4-107) and increased by an average of 132.5 (range 7-266) within the first 2 to 4 months of HAART. Patients were observed for an average of 15.5 months (range 11-20 months). Six subjects had a vigorous and sustained response to therapy, achieving an average HIV load of 9,400 copies/mL (3.32 log10 decrease) and CD4+ T-lymphocyte count of 158.2 cells/microL. These patients had no CMV retinitis progression. By contrast, two others who attained an average log10 decrease of only 0.48 had modest and short-lived increases in the CD4+ T-lymphocyte count. These patients experienced reactivation of CMV retinitis after 5 and 7 months, respectively.

CONCLUSIONS

Regressed CMV retinitis may remain healed for long periods. However, failure of HAART to induce substantial decreases in HIV load may predict poor or unsustainable rises in the CD4+ T-lymphocyte count and presage recurrence of CMV retinitis. Vigilance in ophthalmic examinations is especially mandatory in these subjects.

Declining levels of rescued lymphoproliferative response to human cytomegalovirus (HCMV) in AIDS patients with or without HCMV disease following long-term HAART

OBJECTIVE

To investigate the lymphoproliferative response (LPR) to human cytomegalovirus (HCMV) in two groups of AIDS patients undergoing long-term highly active antiretroviral therapy (HAART): group 1 ( n = 22) with nadir CD4(+) cell count <50/microl and no HCMV disease; group 2 ( n = 16) with <50/microl CD4(+) T-cell count and HCMV disease. All patients had previously undergone antiretroviral monotherapy or dual therapy before initiating HAART.

STUDY DESIGN AND METHODS

The two groups of patients were tested prospectively for CD4(+) T cell count, HIV RNA load, HCMV viremia, and LPR to HCMV at baseline, and then after 3 and 4 years of HAART. A control group of 13 recently diagnosed treatment-naive AIDS patients with CD4(+) T-cell counts <100/microl was also investigated.

RESULTS

No LPR to HCMV was found in any of the treatment-naive patients nor in any patient of the two groups examined at baseline, when HCMV viremia was 13.6% in the patient group without disease and 87.5% in the group with disease ( p <.0001). After 3 years of HAART, the frequency of patients who recovered an LPR to HCMV was not significantly different (81.8% in the group without HCMV disease, and 68.7% in the group with HCMV disease), whereas, compared with baseline, the HIV load decreased and the CD4(+) T-cell count increased significantly and to a comparable extent in the two groups of patients. In addition, the frequency of patients with HCMV viremia, although reduced, became comparable in both groups. After 4 years of HAART, the frequency of responders to HCMV without and with HCMV disease dropped to comparable levels (50.0 vs. 56.3%, respectively) in association with high median CD4(+) T-cell counts and low median HIV RNA plasma levels. In parallel, the frequency of patients with HCMV viremia did not change significantly. In addition, after between 3 and 4 years of HAART, although the frequency of stable responders and nonresponders remained unchanged (50%) in both groups, most of the remaining patients showed declining levels of responsiveness to HCMV. Although some patients from both groups were found to have CD4(+) T-cell counts >150/microl in the absence of LPR to HCMV, thus suggesting dissociation of specific and nonspecific immune reconstitution, a significant correlation was found between CD4(+) T-cell count and LPR to HCMV (r = 0.44; p <.001). From a clinical standpoint, anti-HCMV therapy could be safely discontinued in 8 patients with HCMV retinitis showing CD4(+) T-cell counts >150/microl, recovery of HCMV LPR, and no HCMV viremia.

CONCLUSIONS

Declining levels of the previously recovered LPR to HCMV are often observed after long-term HAART. However, because the role of LPR in the evolution of HCMV infection and disease during HAART remains to be defined, the clinical impact of the declining LPR to HCMV must still be clarified in long-term prospective studies.

Comparative analysis of human cytomegalovirus-specific CD4(+) T-cell frequency and lymphoproliferative response in human immunodeficiency virus-positive patients

Evaluation of human cytomegalovirus (HCMV)-specific T-helper immunity could contribute in optimizing anti-HCMV therapy in human immunodeficiency virus (HIV)-infected patients. Testin the lymphoproliferative response (LPR) is the standard technique used to evaluate T-helper response, but its use in the routine diagnostic laboratory setting can be problematic. The most promising new alternative technique is the determination of HCMV-specific CD4(+) T-cell frequency by flow cytometry detection of intracellular cytokine production after short-term antigen-specific activation of peripheral blood mononuclear cells. HCMV-specific LPR and CD4(+) T-cell frequency were compared in a group of 78 blood samples from 65 HIV-infected patients. The results showed concordance in 80.7% of samples. In addition, comparative analysis of sequential blood samples from 13 HIV-infected patients showed that while in about half of patients the T-helper HCMV-specific immune response remained stable during highly active antiretroviral therapy (HAART), in the other half declining levels of the HCMV-specific CD4(+)-mediated immune response were determined by either one or both assays. In conclusion, our data suggest that the determination of HCMV-specific CD4(+) T-cell frequency can be considered a valuable alternative to the LPR test for the detection of HCMV-specific T-helper response in HIV-infected patients. It could facilitate wider screening of anti-HCMV T-helper activity in HIV-infected patients, with potential benefits for clinicians in deciding strategies of discontinuation or maintenance of anti-HCMV therapy.

Biodegradable scleral plugs for vitreoretinal drug delivery

Intraocular controlled drug release is one way to facilitate drug efficacy and decrease side effects that occur with systemic administration. Vitreoretinal drug delivery with the biodegradable scleral plug has been investigated. The scleral plug, which is made of biodegradable polymers and drugs, can be implanted at the pars plana using a simple procedure, and it gradually releases effective doses of drugs with polymer biodegradation for several months. The release profiles of the drugs were dependent on the kind of polymers used, their molecular weights, and the amount of drug in the plug. The plugs are effective for treating vitreoretinal diseases such as proliferative vitreoretinopathy. The implantation site was replaced with connective tissue. Electroretinography and histologic studies revealed little retinal toxicity. This implantable scleral plug was supposed to be advantageous for diseases such as cytomegalovirus retinitis that respond to repeated intravitreal injections and for vitreoretinal disorders that require vitrectomy.

Cytomegalovirus infection: the point in 2001

The incidence of cytomegalovirus (CMV) disease, one of the most prevalent opportunistic infections in HIV-infected persons in the early 1990s, has decreased by more than 80% since the introduction of highly active antiretroviral therapy (HAART). The rare cases of CMV disease still observed in Western countries occur mainly in profoundly immunosuppressed patients who have failed to respond to HAART. A new finding is the occasional occurrence of inflammatory retinitis in some patients on HAART with a history of healed retinitis. New tools for CMV detection have become available recently, including use of polymerase chain reaction (PCR) to detect CMV DNA from plasma. It has been possible to redefine, in the HAART period, patients at risk for CMV disease as those who have a low CD4 cell count as well as a blood marker of CMV blood dissemination (plasma CMV DNAaemia or high pp65 antigenaemia). Besides the classical therapeutic approach using ganciclovir (GCV), foscarnet and cidofovir, development of valganciclovir (VGCV), an orally administered prodrug of GCV, appears promising. There is evidence to suggest that it is as effective as intravenous GCV for the treatment of CMV retinitis, and it is currently being studied as a pre-emptive therapy in patients at high risk for CMV disease. Finally, patients with inactive CMV retinitis receiving HAART and with stable immune reconstitution may be able to discontinue maintenance therapy provided a regular ophthalmological and virological surveillance is maintained.