Five-year follow-up of a cohort of profoundly immunosuppressed patients discontinuing therapy for cytomegalovirus retinitis

Antimicrobial guide to posterior segment infections

PURPOSE

This review article is meant to serve as a reference guide and to assist the treating physician in making an appropriate selection and duration of an antimicrobial agent.

METHODS

Literature review.

RESULTS

Infections of the posterior segment require prompt medical or surgical therapy to reduce the risk of permanent vision loss. While numerous options exist to treat these infections, doses and alternative therapies, especially with contraindications for first-line therapy, are often elusive. Antimicrobial agents to treat posterior segment infections can be administered via various routes, including topical, intravitreal, intravenous, and oral.

CONCLUSIONS

Although there are many excellent review articles on the management of endophthalmitis, we take the opportunity in this review to comprehensively summarize the appropriate antimicrobial regimen of both common and rare infectious etiologies of the posterior segment, using evidence from clinical trials and large case series.

Long-Term Follow-up of a Cohort of HIV-Infected Patients Who Discontinued Maintenance Therapy for Cytomegalovirus Retinitis

PURPOSE

To determine the long-term safety of discontinuation of maintenance therapy for cytomegalovirus retinitis (CMVR) and to identify predictors for relapse.

METHOD

This was a prospective cohort study. Patients with treated CMVR who responded to HAART were followed by ophthalmologic assessment, markers for CMV replication (blood and urine cultures, CMV antigenemia, CMV DNA by PCR), and in vitro lymphoproliferative responses to CMV and other antigens after discontinuation of CMVR maintenance therapy.

RESULTS

23 patients were followed a median of 34 (range, 5-61) months. Median CD4 count was 321/mm3 at enrollment and 395/mm3 at last follow-up. HIV RNA was <50 copies/mL in 78% of patients at enrollment and 65% at last follow-up. One CMVR reactivation occurred at 12 months at a CD4 count of 395/mm3 (21%) and HIV RNA <50 copies/mL. Urine cultures were a poor predictive marker for reactivation. Other CMV replication markers had good negative predictive value. 96% of patients had a good lymphoproliferative response to CMV antigen in vitro.

CONCLUSION

Maintenance therapy for CMVR can safely be discontinued in patients who have responded to HAART. Combining our results with the published literature, the risk of reactivation is estimated at 0.016 per person year of follow-up. Markers to predict relapse and the need for re-initiation of maintenance therapy are not yet identified.

Valganciclovir in the treatment of cytomegalovirus retinitis in HIV-infected patients

Oral valganciclovir is a new and highly efficacious alternative to the chronic administration of ganciclovir in the treatment of cytomegalovirus (CMV) retinitis in HIV-infected patients. In addition to its excellent bioavailability and favorable pharmacokinetic profile, valganciclovir has also proved cost effective and is the most widely used drug in the armamentarium for the treatment of CMV retinitis. Valganciclovir is a prodrug of ganciclovir, the erstwhile commonly used therapy. In March 2001, the US Food and Drug Administration approved valganciclovir for the induction and maintenance treatment of CMV disease, including CMV retinitis. Valganciclvoir has compared favorably with both oral and intravenous treatments for induction and maintenance therapy with ganciclovir. The reduced pill burden and the ease of oral administration has helped avoid the risks associated with intravenous therapy. The most serious adverse event is neutropenia, which makes the patient susceptible to infections. In the current review, we have compiled all the available evidence-based information on valganciclovir.

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.

Valganciclovir: a review of its use in the management of CMV infection and disease in immunocompromised patients

Valganciclovir (Valcyte) is an orally administered prodrug of the standard anti-cytomegalovirus (CMV) drug ganciclovir. Valganciclovir is as effective as intravenous ganciclovir for the treatment of AIDS-related CMV retinitis, and oral ganciclovir for the prophylaxis of CMV infection and disease in high-risk solid organ transplant recipients. The drug is generally well tolerated and has a similar tolerability profile to that of oral or intravenous ganciclovir, but is devoid of adverse events related to intravenous or indwelling catheter access associated with the use of intravenous ganciclovir, cidofovir and foscarnet. The simple and convenient once-daily valganciclovir regimen offers potential for improved patient compliance. It provides greater systemic ganciclovir exposure than oral ganciclovir, thus reducing the risk of viral resistance when used for prophylaxis in high-risk solid organ transplant recipients. Furthermore, the use of valganciclovir instead of intravenous ganciclovir may provide significant cost savings, based on data comparing oral versus intravenous regimens for the treatment of AIDS-related CMV retinitis. Overall, valganciclovir appears to have some advantages over ganciclovir. Therefore, when used as prophylaxis against CMV infection and disease in high-risk solid organ transplant recipients or as induction and maintenance therapy of CMV retinitis in patients with AIDS, oral valganciclovir is an attractive alternative to other available anti-CMV drugs.