Oral ganciclovir for the prevention of cytomegalovirus disease in persons with AIDS. Roche Cooperative Oral Ganciclovir Study Group

A randomized, placebo-controlled trial of the safety and efficacy of oral ganciclovir for prophylaxis of cytomegalovirus disease in HIV-infected individuals. Terry Beirn Community Programs for Clinical Research on AIDS

OBJECTIVE

Evaluate safety and efficacy of oral ganciclovir (GCV) for preventing cytomegalovirus (CMV) disease in HIV-infected persons at high risk for CMV disease.

DESIGN

Double-blind, placebo-controlled, randomized clinical trial in primary care clinics and private practice offices specializing in the care of people with HIV. Interventions were oral GCV (1000 mg three times/day) or placebo. Protocol amendment allowed switch to open-label oral GCV. Main outcome measures were confirmed CMV retinal or gastrointestinal mucosal disease, and death. The study enrolled 994 people co-infected with CMV and HIV, with at least one CD4 count recorded < 100 x 10(6) cells/l.

RESULTS

At study completion (15 months median follow-up), CMV event rates in the oral GCV and control groups were 13.1 and 14.6 per 100 person years, respectively, a hazard ratio (HR) of 0.92 [95% confidence interval (CI), 0.65-1.27; P = 0.6]. At protocol amendment event rates were 12.7 and 15.0, respectively (HR, 0.85; 95% CI, 0.56-1.30; P = 0.45). At study completion, event rates for death were 26.6 and 32.0 (HR, 0.84; P = 0.09), and at protocol amendment were 18.9 and 19.6 (HR, 0.95; P = 0.78), respectively. At protocol amendment for the CMV endpoint, the oral GCV treatment effect was associated with baseline use of didanosine (ddI). For patients taking ddI at randomization, HR was 7.48 (P = 0.02). For patients not taking ddI, HR was 0.62 (P = 0.04). These HR were statistically different (P = 0.0006).

CONCLUSIONS

In our study, 3 g/day oral GCV did not significantly reduce CMV disease incidence, but there was a suggestion of a death-rate reduction. Furthermore, results suggest that oral GVC decreased risk of CMV disease in patients not prescribed ddI, and increased risk in those prescribed ddI. For the CMV endpoint, our study differs markedly from the only similar study, although for the death endpoint, a combined analysis of studies indicated significant reduction in death rate.

Pharmacokinetics and absolute bioavailability of oral foscarnet in human immunodeficiency virus-seropositive patients

The pharmacokinetics, absolute bioavailability, accumulation, and tolerability over 8 days of an oral formulation of foscarnet (90 mg/kg of body weight once daily [QD] [n = 6], 90 mg/kg twice daily [BID] [n = 6], and 180 mg/kg QD [n = 31) were investigated in 15 asymptomatic, human immunodeficiency virus-seropositive male patients free of active cytomegalovirus infection and with normal upper gastrointestinal function. Peak plasma drug concentrations were (mean +/- standard deviation) 46.4 +/- 10.8 microM (90 mg/kg QD), 45.7 +/- 6.9 microM (90 mg/ kg BID), and 64.9 +/- 31.7 microM (180 mg/kg QD) on day 1 and rose to 86.2 +/- 35.8, 78.7 +/- 35.2, and 86.4 +/- 25.0 microM, respectively, on day 8. The mean peak concentration in plasma following the intravenous administration of foscarnet (90 mg/kg) was 887.3 +/- 102.7 microM (n = 13). The terminal half-life in plasma remained unchanged, averaging 5.5 +/- 2.2 h on day 1 (n = 15) and 6.6 +/- 1.9 h on day 8 (n = 13), whereas it was 5.7 +/- 0.7 h following intravenous dosing. Oral bioavailabilities were 9.1% +/- 2.2% (90 mg/kg QD), 9.5% +/- 1.7% (90 mg/kg BID), and 7.6% +/- 3.7% (180 mg/kg QD); the accumulation ratios on the 8th day of dosing were 2.1 +/- 1.1, 1.8 +/- 0.4, and 1.7 +/- 0.7, respectively. The overall 24-h urinary excretion of oral foscarnet averaged 7.8% +/- 2.6% (day 1) and 13.4% +/- 6.0% (day 8), whereas it was 95.0% +/- 4.9% after intravenous dosing. The glomerular filtration rate and creatinine clearance remained constant, and the mean 24-h renal clearances of foscarnet for the entire study group were 96 +/- 18 ml/min (day 1), 88 +/- 13 ml/min (day 8), and 103 +/- 16 ml/min after intravenous dosing. Adverse effects were largely confined to gastrointestinal disturbances, with all subjects experiencing diarrhea that was dose dependent in its severity. The results suggest that the formulation studied would require significant improvement with respect to tolerability and bioavailability to gain clinical acceptance.

Plasma cytomegalovirus (CMV) DNA load predicts CMV disease and survival in AIDS patients

In this study, baseline plasma from 619 persons with acquired immunodeficiency syndrome (AIDS) (median CD4+ lymphocyte count -21/microl) who participated in a trial to determine the efficacy of oral ganciclovir for cytomegalovirus (CMV) disease prevention were evaluated for CMV DNA load by qualitative and quantitative polymerase chain reaction (PCR), and correlated with the development of CMV disease and survival. For participants without detectable plasma CMV DNA, the 12-mo Kaplan-Meier CMV disease event rate was 14% and 1% for the placebo and ganciclovir groups, respectively (P < 0.001). For PCR positive participants, CMV disease developed in 43% of placebo and 26% ganciclovir recipients (P < 0.017). Among placebo recipients, CMV PCR positivity was associated with a 3.4-fold increased risk of developing CMV disease (P < 0.001) whereas CD4+ lymphocyte count was not a useful predictor (P = 0.47). A positive plasma CMV DNA PCR was also associated with a 2.5-fold increased risk of death. Each log10 increase in baseline CMV DNA load was associated with a 3.1-fold increase in CMV disease (P < 0.001) and a 2.2-fold increase in mortality (P < 0.001). These data indicate that the risk of developing CMV disease and death in persons with advanced AIDS is directly related to the quantity of CMV DNA in plasma, and is a better predictor than CD4+ lymphocyte count in this population.

Long-term predictive value of a single cytomegalovirus (CMV) DNA PCR assay for CMV disease in human immunodeficiency virus-infected patients

Universal prophylaxis with oral ganciclovir is not cost-effective for the prevention of cytomegalovirus (CMV) disease in human immunodeficiency virus infection. For a preemptive strategy to be considered, patients at highest risk for CMV disease need to be easily and accurately identified. In this study, the sensitivity, specificity, positive predictive value, and negative predictive value of a single CMV DNA PCR assay for the subsequent development of CMV disease were 0.75, 0.89, 0.75, and 0.89, respectively.

Randomised trial of efficacy and safety of oral ganciclovir in the prevention of cytomegalovirus disease in liver-transplant recipients. The Oral Ganciclovir International Transplantation Study Group [corrected]

BACKGROUND

Cytomegalovirus (CMV) disease is a frequent cause of serious morbidity after solid-organ transplantation. The prophylactic regimens used to prevent CMV infection and disease have shown limited benefit in seronegative recipients. We studied the safety and efficacy of oral ganciclovir in the prevention of CMV disease following orthotopic liver transplantation.

METHODS

Between December, 1993, and April, 1995, 304 liver-transplant recipients were randomised to receive oral ganciclovir 1000 mg or matching placebo three times a day. Seronegative recipients of seronegative livers were excluded. Study drug was administered as soon as the patient was able to take medication by mouth (no later than day 10) until the 98th day after transplantation. Patients were assessed at specified times throughout the first 6 months after surgery for evidence of CMV infection, CMV disease, rejection, opportunistic infections, and possible drug toxicity.

FINDINGS

The Kaplan-Meier estimate of the 6-month incidence of CMV disease was 29 (18.9%) of 154 in the placebo group, compared with seven (4.8%) of 150 in the ganciclovir group (p < 0.001). In the high-risk group of seronegative recipients (R-) of seropositive livers (D+), incidence of CMV disease was 11 (44.0%) of 25 in the placebo group, three (14.8%) of 21 in the ganciclovir group (p = 0.02). Significant benefit was also observed in those receiving antibodies to lymphocytes, where the incidence of CMV disease was 12 (32.9%) of 37 in the placebo group and two (4.6%) of 44 in the ganciclovir group (p = 0.002). Oral ganciclovir reduced the incidence of CMV infection (placebo 79 [51.5%] of 154; ganciclovir 37 [24.5%] of 150; p < 0.001) and also reduced symptomatic herpes-simplex infections (Kaplan-Meier estimates: placebo 36 [23.5%] of 154; ganciclovir five [3.5%] of 150; p < 0.001).

INTERPRETATION

Oral ganciclovir is a safe and effective method for the prevention of CMV disease after orthotopic liver transplantation.

Quantification of cytomegalovirus DNA in peripheral blood leukocytes by a branched-DNA signal amplification assay

Quantification of cytomegalovirus (CMV) DNA in blood may aid in the identification of patients at highest risk for developing CMV disease, the evaluation of new therapeutics, and the prompt recognition of drug-resistant CMV strains. A branched-DNA (bDNA) assay was developed for the reliable quantification of CMV DNA in peripheral blood leukocytes. The bDNA assay allowed for the highly specific and reproducible quantification of CMV DNA in clinical specimens. Furthermore, the bDNA assay was at least as sensitive as culture techniques and displayed a nearly 3 log10 dynamic range in quantification. Changes in CMV DNA levels measured by the bDNA assay in a human immunodeficiency virus-positive patient undergoing therapy were consistent with CMV culture, antigen, and genotype results and correlated with disease progression and resistance markers. The bDNA assay for the quantification of CMV DNA may provide a useful tool that can be used to aid physicians in monitoring disease progression, evaluating therapeutic regimens, and recognizing viral resistance and drug failure.

Adverse events and autopsy findings after intravitreous cidofovir (HPMPC) therapy in patients with acquired immune deficiency syndrome (AIDS)

OBJECTIVE

The purpose of the study is to evaluate the adverse events and autopsy findings in a series of consecutive 20-microg intravitreous cidofovir injections at a single institution.

DESIGN

The study design was a nonrandomized, consecutive case series.

PARTICIPANTS

Seventy-six patients with acquired immune deficiency syndrome with cytomegalovirus retinitis were studied prospectively. Sixty-three patients had 1 month's follow-up or longer, and this comprised the study group. In addition, histopathologic findings from 18 eyes of 9 patients were studied at autopsy.

INTERVENTION

A total of 296 injections of 20 microg cidofovir were given in 115 eyes. Sixty-three patients who had 246 injections in 93 eyes had 1 month's follow-up or longer for the evaluation of adverse events.

MAIN OUTCOME MEASURES

Postinjection chronic hypotony associated with permanent visual loss, transient hypotony, iritis, and its long-term sequela (posterior synechia and cataract, retinal detachment, extraocular cytomegalovirus involvement) were the outcomes of interest in this study. Additionally, light and electron microscopic studies of human eyes were performed.

RESULTS

The most severe adverse event was postinjection chronic hypotony. This phenomenon was associated with permanent visual loss. This was observed in 1% of the injections and 3% of the eyes of the patients (95% confidence interval, 0%-6%). Transient hypotony associated with mild-to-moderate visual loss developed in 14%, but vision recovered to baseline levels in these eyes subsequently. Analysis showed that transient hypotony in the injected eye could predict postinjection chronic hypotony in the fellow eye (two-tailed Fisher's exact test, P = 0.02). The incidence of iritis was 32%; posterior synechia and cataract were the long-term sequela of the iritis and developed in 19% and 11% of the eyes, respectively. The incidence of retinal detachment was lower (6%). Histopathologic evaluation of the eyes showed mild-to-moderate atrophy of the nonpigmented epithelium of the ciliary body and no other evidence of intraocular toxicity.

CONCLUSIONS

The most serious adverse event was postinjection chronic hypotony, which occurred in 3% of eyes. Episodes of transient hypotony appear to indicate that the fellow eye was predisposed to chronic hypotony. Therefore, it may be prudent to give intravitreous injections at least 2 weeks apart in the fellow eye to evaluate the clinical response of the injected eye.

Preventing and treating major opportunistic infections in AIDS. What's new and what's still true

New highly active antiretroviral therapies are boosting the blood absolute CD4+ counts of many patients with AIDS and are decreasing the prevalence of AIDS-related opportunistic infections. Nevertheless, the prevention, diagnosis, and treatment of opportunistic infections remain important features of management of HIV infection. In recent years, significant advances have been made in the prevention and treatment of opportunistic diseases such as Pneumocystis carinii pneumonia, Cytomegalovirus retinitis, disseminated Mycobacterium avium-intracellulare infection, and mucosal candidiasis. Tuberculosis, cryptococcal meningitis, herpes simplex virus infection, shingles, and infectious enteritis also continue to be troublesome. Kaposi's sarcoma may be the newest AIDS-related opportunistic infection to be identified. The immune system effects of highly active antiretroviral therapy are as yet poorly understood. Therefore, an aggressive approach to diagnosis and treatment of opportunistic infections remains mandatory, and patients receiving antiretroviral therapy should continue to adhere to recommendations for prophylaxis against such infections.

Trends in incidence of AIDS illnesses in Australia from 1983 to 1994: the Australian AIDS cohort

To assess time trends in incidence of AIDS illnesses in Australia, a retrospective cohort of people diagnosed with AIDS from January 1, 1983 to December 31, 1994 in three HIV medicine units in Sydney, Melbourne, and Perth was established. Data on initial and subsequent AIDS illnesses were available for 2580 AIDS cases, or 45% of Australian AIDS notifications over the study period. Males represented 97.2% of the cohort, and HIV exposure category was homosexual contact for 89.9%. Subcohorts were formed by interval of AIDS diagnosis: 1983 through 1987, 1988 through 1990, and 1991 through 1994, with estimation of cumulative risk for each AIDS illness by the Kaplan-Meier method. The cumulative risk declined for Pneumocystis carinii pneumonia (PCP) (p < 0.0001) and for Kaposi's sarcoma (KS) (p < 0.0001); PCP cumulative risk estimates 2 years following AIDS diagnosis were 70% for people diagnosed with AIDS in 1983 through 1987 and 48% in 1991 through 1994, and KS cumulative risk estimates 2 years following AIDS diagnosis were 44% in 1983 through 1987 and 32% in 1991 through 1994. In contrast, cumulative risk increased from 34% to 40% for cytomegalovirus (CMV) disease (p = 0.005), from 47% to 50% for Mycobacterium avium complex (MAC) (p < 0.0001), and from 26% to 33% for esophageal candidiasis (p < 0.0001). Corresponding to this changing spectrum of AIDS illness has been an increase in severity of immunodeficiency at AIDS, with median CD4 cell count declining from 54 cells/mm3 in 1983 through 1987 to 34/mm3 in 1991 through 1994 (p = 0.002).

The pp65 antigenaemia test as a predictor of cytomegalovirus-induced end-organ disease in patients with AIDS

OBJECTIVE

To evaluate the predictive value of pp65 antigenaemia quantitative test for cytomegalovirus (CMV) end-organ disease in patients with advanced HIV infection.

DESIGN AND PATIENTS

A prospective study in AIDS patients or HIV-infected subjects with CD4 count < 150 x 10(6)/l or CD4 percentage < 10% was carried out. Patients with a history of CMV disease or positive viraemia or antigenaemia tests and subjects under anti-herpes suppressive therapy were excluded. Clinical, ophthalmoscopic, biochemical and virological (antigenaemia test) evaluations were performed at baseline and every 1-3 months until the onset of CMV end-organ disease.

SETTING

Institutional tertiary care centre.

RESULTS

Forty-nine patients were evaluable for this study. End-organ disease was observed in 13 patients, 11 with at least one positive test, two with persistently negative assays. Thirteen patients without CMV disease had at least one positive test, whereas 23 always had negative tests. The 12-month Kaplan-Meier estimate of the incidence of CMV disease in our population was 30.9% and was 75% in antigenaemia-positive subjects. The negative predictive value (NPV) of the test was 92%, and the positive predictive value (PPV) was 45.8%. However, the NPV of quantitative (> 20 cells) antigenaemia assay was 92.1% and the PPV was 90.9%.

CONCLUSIONS

The antigenaemia test is a quick, simple and easy to perform assay for diagnosing CMV infection. The NPV is fairly good, as is the PPV when the quantitative method (> 20 positive cells) is used. This test could be used as an alternative to polymerase chain reaction in order to select patients at higher risk of CMV disease who can be treated with pre-emptive anti-CMV therapy.

Cost-utility analysis of prophylactic treatment with oral ganciclovir for cytomegalovirus retinitis

OBJECTIVE

Cytomegalovirus (CMV) retinitis is a relatively common opportunistic infection in late-stage HIV disease, causing significant morbidity and mortality. Prophylactic use of oral ganciclovir has recently been shown to decrease the incidence of CMV retinitis but is relatively expensive and may not be very well tolerated by many patients. We performed a decision analysis to assess the cost-effectiveness of prophylactic oral ganciclovir therapy.

METHODS

A decision analysis using a Markov approach compared absence of prophylaxis and prophylaxis with oral ganciclovir. Estimates of effectiveness of prophylaxis and costs of illness were obtained from published literature. Drug costs were based on national average wholesale prices. All health care costs were based on 1996 U.S. dollars. Sensitivity analyses were done over ranges of estimates of cost and effectiveness.

RESULTS

Using our baseline estimates of cost and effectiveness, use of oral ganciclovir prophylaxis in patients with CD4 counts <50 cells/mm3 would be associated with average lifetime health care costs of $104,746, compared with $90,985 for no prophylaxis. Using oral ganciclovir, the average quality-adjusted life-years (QALYs) would be 2.05, and the CMV retinitis-free life-years would be 1.64, compared with 1.87 and 1.27, respectively, for no prophylaxis. The incremental cost-utility of oral ganciclovir is $76,676 per year of life saved and $37,542 per year of additional CMV retinitis-free life. Oral ganciclovir would become more cost-effective relative to no prophylaxis if the probability of CMV retinitis while taking oral ganciclovir declined. Oral ganciclovir would be less cost-effective if the cost of treating CMV retinitis declines, if our estimates of quality of life are low, or if the overall incidence of CMV retinitis declines.

CONCLUSIONS

Oral ganciclovir is a less cost-effective approach than several other interventions used for HIV-disease prophylaxis. It would potentially become cost-effective if it is possible to target oral ganciclovir prophylaxis to patients who are most likely to benefit.

Applications of the Medical Outcomes Study health-related quality of life measures in HIV/AIDS

The leading health status instruments in human immunodeficiency virus (HIV) research are based on the pool of items developed as part of the Medical Outcomes Study (MOS). The measures include the SF-20, MOS-HIV, SF-36, SF-12, SF-56, SF-38 (Patient Reported Status and Experience Survey (PARSE)), SF-21 and HIV Cost and Service Utilization Study (HCSUS) questionnaires. The instrument length ranges from 12 to 56 items, covering two to 11 dimensions. Completion requires from 2 to 14 minutes. Subscales are scored on a 0-100 scale (a higher score indicates better health); physical and mental health or overall summary scores are available for most of the measures. Three of the instruments are available in multiple languages. The instruments have been administered to over 20,000 persons with HIV in descriptive studies and clinical trials and there is substantial evidence for their reliability, construct and predictive validity and responsiveness. In several studies the measures have shown important differences between treatments. Although existing measures do not assess all domains relevant to HIV disease, additional subscales are available from the MOS pool. Some of the subscales may be prone to floor and ceiling effects. However, summary scales that encompass all of the subscales reduce this issue. Selection among MOS measures should be dictated by specific questions, the balance of available time and resources, and practical concerns.

Review article: the therapy of gastrointestinal infections associated with the acquired immunodeficiency syndrome

Although there have been dramatic strides in the therapy of human immunodeficiency virus infection over the last few years, the number of infected people world-wide is tremendous and, at least in developing countries, continues to expand. Complications which involve the gastrointestinal tract are common in these patients, because the gut is a major site for involvement by opportunistic infections and neoplasms in patients with the acquired immunodeficiency syndrome. It is important to recognize the clinical spectrum of gastrointestinal diseases, as well as the appropriate and most cost-effective diagnostic strategies, as therapies for a number of these disorders are both widely available and high effective. This review summarizes the major gastrointestinal infections which are seen in patients with the acquired immunodeficiency syndrome, and their treatment.

Cost-effectiveness of cytomegalovirus (CMV) disease prevention in patients with AIDS: oral ganciclovir and CMV polymerase chain reaction testing

OBJECTIVE

To perform a cost-effectiveness analysis of strategies to prevent cytomegalovirus (CMV) disease.

METHOD

Markov model and published data.

PATIENTS

Hypothetical HIV-infected patients with CD4 cell counts < or = 50 x 10(6)/l and positive CMV serologies.

INTERVENTIONS

Oral ganciclovir daily versus plasma CMV DNA polymerase chain reaction (PCR) testing every 3 months with oral ganciclovir for patients with positive tests.

OUTCOME MEASURES

The number of CMV disease cases prevented by the interventions, life expectancy, disease-free life expectancy, and the cost to extend life by 1 year.

RESULTS

Oral ganciclovir preventive therapy reduces the lifetime number of CMV disease cases by 50 per 1000 cohort, extends life expectancy by 5 days and disease-free life expectancy by 18 days, and costs US$ 1,762,517 per year of life extended. Periodic PCR testing reduces the lifetime number of CMV disease cases by eight per 1000 cohort, extends life expectancy by 1 day and disease-free life expectancy by 3 days, and costs US$ 495,158 per year of life extended. The prevention strategies could be acceptably cost effective only under a combination of optimistic assumptions and reduced costs.

CONCLUSIONS

Oral ganciclovir preventive therapy and periodic plasma testing for CMV PCR with oral ganciclovir for those with positive tests result in small benefits at great cost. They are not cost-effective prevention strategies for persons with advanced HIV infection and positive CMV serologies.

Determination of antigen-specific memory/effector CD4+ T cell frequencies by flow cytometry: evidence for a novel, antigen-specific homeostatic mechanism in HIV-associated immunodeficiency

The highly regulated secretion of effector cytokines by CD4+ T cells plays a critical role in immune protection against pathogens such as cytomegalovirus. Here, we directly compare the frequency and functional characteristics of cytomegalovirus-specific CD4+ memory/effector T cells in normal and HIV+ subjects using a novel, highly efficient multiparameter flow cytometric assay that detects the rapid intracellular accumulation of cytokine(s) after short-term (6 h) in vitro antigen stimulation. Responses in this assay correlate precisely with independent measures of sensitization history (e.g., seroreactivity), and allow the simultaneous assessment of multiple cytokines in single effector T cells. Healthy HIV- individuals manifested an average of 0.71, 0.72, 0.38, and 0.06% CD4+ T cells responding to cytomegalovirus with gamma-IFN, TNF-alpha, IL-2, and IL-4 production, respectively, with the simultaneous production of gamma-IFN, TNF-alpha, and IL-2 being the most common effector phenotype. Significantly, overall cytomegalovirus-specific CD4+ effector frequencies were markedly higher among 40% of HIV+ subjects (2.7-8.0%), and demonstrated a predominately polarized gamma-IFN+/TNF-alpha+/IL-2-/IL-4- phenotype. In contrast, CD4+ effector frequencies for heterologous, nonubiquitous viruses such as the mumps virus were low or absent in the HIV+ group. These data suggest the existence of homeostatic mechanisms in HIV disease that selectively preserve memory T cell populations reactive with ubiquitous pathogens such as cytomegalovirus-likely at the expense of T cell memory to more sporadically encountered infectious agents.

Predictors of cytomegalovirus disease, natural history and autopsy findings in a cohort of patients with AIDS

OBJECTIVE

To identify the predictors of acquiring cytomegalovirus (CMV) disease, and to describe natural history, therapeutic management and autopsy findings in affected patients.

DESIGN

Observational study of a consecutive cohort of AIDS patient diagnosed and followed in the same institution.

METHODS

All of the patients with CMV were included. Statistical analyses were performed to establish the risk of acquiring the disease at or after AIDS presentation, survival, and the occurrence and time of relapses in relation to maintenance therapy. The presence of CMV infection at autopsy was also investigated.

RESULTS

CMV disease was diagnosed in 304 (24.8%) out of 1,227 patients, its incidence increasing according to the year of AIDS diagnosis. Women, homosexual men, patients given zidovudine and Pneumocystis carinii pneumonia (PCP) prophylaxis before AIDS, and severely immunodepressed patients were at higher risk for the disease. CMV disease was an independent factor of worse survival (hazard ratio, 1.7 versus PCP; 95% confidence intervals, 1.28-2.13). Patients untreated during the acute phase had a 4.3 higher risk of dying than those treated. Relapses occurred less frequently and later in patients given continuous maintenance treatment (23 out of 113; 17 months) than in untreated patients (13 out of 16; 3 months) or those given discontinuous therapy (22 out of 40; 7 months), whereas survival was independent from treatment. CMV infection was found in 97 out of 134 patients at autopsy, but was unassociated with relapse.

CONCLUSIONS

CMV is a severe disease whose frequency is higher in severely immunodepressed patients. Continuous treatment leads to a lower relapse rate even if it does not change survival or eradicate the infection.

Viral infections in human immunodeficiency virus disease

A number of the herpesviruses as well as representatives of other viral genera can produce serious opportunistic infections in persons infected with HIV. Although some, such as JC virus, HHV-6, and HHV-8, remain essentially untreatable at this time, others are readily treatable or can be retarded with chemoprophylaxis. Further therapeutic advances for some of these viral superinfections, particularly CMV, HSV, VZV, HHV-8, and human genital papillomavirus, will considerably improve the longevity and quality of life of persons with AIDS.

Development of cytomegalovirus (CMV) disease may be predicted in HIV-infected patients by CMV polymerase chain reaction and the antigenemia test

OBJECTIVE

Cytomegalovirus (CMV) is a frequent opportunistic viral pathogen in patients with AIDS leading to retinitis and other serious manifestations. CMV disease may be successfully treated. Prophylactic antiviral therapy has been shown to reduce the risk of CMV disease if initiated early. We evaluated PCR and the antigenemia tests as methods for early detection of CMV disease.

METHODS

Two-hundred HIV-seropositive subjects with CD4 T-cell counts below 100 x 10(6)/l were monitored with CMV polymerase chain reaction (PCR), the antigenemia test, blood cultures and CMV immunoglobulin (Ig) G and IgM titres every second month for 1 year.

RESULTS

Thirty-eight patients (19%) developed CMV disease. The PCR test detected CMV DNA a median of 46 days before onset of disease. This was earlier than the median of 34 for the antigenemia test and a median of 1 day for CMV blood cultures. Univariate analysis showed that the CMV PCR, the antigenemia test and blood cultures all had significant predictive values for subsequent development of CMV disease with odds ratios (OR) of 30, 22 and 20. CMV serology had no predictive value. Multivariate analysis showed that the PCR method was superior to the other tests; OR: CMV PCR 10.0, antigenemia test 4.4 and CMV cultures 4.3. No clinical parameters had any significant predictive value in the stepwise multivariate model.

CONCLUSIONS

The CMV PCR and the CMV antigenemia tests are both sensitive methods that may predict development of CMV disease up to several months prior to clinical disease. These methods make it possible to select patients at high risk for CMV disease and suitable for prophylactic therapy against CMV.

Drug treatment of HIV-related opportunistic infections

The AIDS epidemic has led to the emergence of several disease entities which in the pre-AIDS era were rare or seemingly innocuous. Experience of treating these diseases varies. In some instances, such as Pneumocystis carinii pneumonia, there is an abundance of published literature to direct our course of action. However, for many of these newly recognised diseases our treatment experience is limited. Furthermore, in many instances, well controlled trials evaluating treatment modalities in the AIDS population are lacking. We have identified 13 disease entities (P. carinii pneumonia, toxoplasmosis, cryptococcosis, histoplasmosis, Mycobacterium tuberculosis, Mycobacterium avium complex, cytomegalovirus, coccidioidomycosis, isosporiasis, candidosis, Kaposi's sarcoma, herpes simplex virus, and varicella zoster virus) and have reviewed the current literature with regard to their treatment.

Cytomegalovirus retinitis: diagnosis and status of systemic therapy

Cytomegalovirus (CMV) retinitis is a disease of advanced immunosuppression that occurs almost exclusively in patients with CD4+ counts of < or =50 cells/mm3. Therefore, this disease usually presents in patients who have already been diagnosed with acquired immunodeficiency syndrome (AIDS). The rate of progression of untreated CMV retinitis is variable. Typical initial complaints of patients with CMV retinitis may include blurred or decreased vision, loss of peripheral or central vision, and multiple "floaters." The diagnosis of CMV retinitis requires ruling out a number of other ocular disorders that may be confused with CMV retinitis. This review discusses the different appearances of CMV retinitis at presentation and the possible retinal responses to therapy for CMV retinitis. An overview of intravenous (i.v.) ganciclovir or i.v. foscarnet as systemic therapy for treatment of CMV retinitis and their use in combination is also presented. Results indicate that combination therapy with both ganciclovir and foscarnet is more effective in controlling progression of CMV retinitis in relapsed patients than is monotherapy with either drug. However, combination systemic therapy is time-consuming, and this regimen has the greatest negative impact on quality of life. Treatment should involve a cooperative effort between the patient's ophthalmologist and the primary AIDS-treating physician. Both must be aware of the location and activity of the retinitis and of other medical conditions and concomitant medications.

Current therapeutic challenges in the treatment of cytomegalovirus retinitis

Cytomegalovirus (CMV) retinitis has become one of the most common manifestations of active CMV infection in patients with acquired immunodeficiency syndrome (AIDS). If left untreated, it results in complete loss of vision. At present, three systemic antiviral agents-ganciclovir, foscarnet, and cidofovir-are available for treatment of CMV retinitis. Unfortunately, reactivation of retinitis will occur with all three agents, and almost all patients eventually experience disease progression while receiving treatment. Therefore, our primary therapeutic challenge is to develop a means of preventing reactivation of CMV retinitis. Another challenge is to develop drugs that can be easily administered. Thus far, oral formulations have not succeeded in effectively meeting this challenge. Direct delivery of an antiviral agent into the vitreous of an infected eye, although easily performed and more effective in delaying time to progression, is unable to prevent or delay the progression of extraocular CMV disease. The ideal antiviral agent would have high central nervous system and tissue penetration, would suppress viral replication and mutation, would be administered orally, and would be inexpensive.

pp65 antigenemia as a marker of future CMV disease and mortality in HIV-infected patients

We retrospectively evaluated the role of pp65 antigenemia (AGM) as a marker of cytomegalovirus (CMV) disease and mortality in 241 HIV-infected patients with fever. Of 225 patients in whom CD4 count was available, 189 (84%) had counts below 100/microL and 209 (92.8%) below 200/microL, 149 patients had negative AGM (AGM-) and 92 had positive AGM (AGM+), AGM+ patients were at a more advanced stage of HIV disease, as evaluated by CD4 count (p < 0.001) and prior AIDS diagnosis (p < 0.001). Overall, 29 patients (12%) presented concomitant CMV disease (18 retinitis): 24 (26%) in the AGM+ group and 5 (3.3%) in the AGM- group (p < 0.001). AGM had a negative predictive value of 96.6% but a positive predictive value of 26% which increased to 65% if a cut-off of > 10 CMV-positive cells/10(5) leukocytes was considered. The cumulative rate of future CMV disease at 3 months was 0% in AGM patients, 3% in patients with AGM 1-10/10(5) and 36% in patients with AGM > 10/10(5). In a multivariate analysis, no antiretroviral therapy, AGM+ and CMV disease were independently associated with mortality. The role of AGM as a marker of present CMV disease is limited. However, quantitative AGM may select patients at a high risk of future CMV disease. In addition, AGM may be a marker of shorter survival in severely immunosuppressed HIV-infected patients.

Cidofovir: a new therapy for cytomegalovirus retinitis

Cidofovir, (S)-1-[3-hydroxy-2-(phosphonylmethoxy)propyl]cytosine, formerly known as HPMPC, is the first antiviral nucleotide analogue available for the treatment of cytomegalovirus (CMV) retinitis. Because cidofovir does not require viral activation, it has two advantages over nucleoside analogues such as ganciclovir and acyclovir. Cidofovir is active in uninfected cells and may act preemptively, and it may retain activity against ganciclovir-resistant strains. Preclinical studies showed the major toxicity of cidofovir to be dose-, schedule-, and species-dependent nephrotoxicity. These studies also showed that concomitant administration of probenecid protects animal models against cidofovir-induced nephrotoxicity. Two phase I-II studies were undertaken in HIV-positive patients with asymptomatic CMV excretion to evaluate several dose-escalation regimens. Data from both phase I-II studies showed that in patients receiving cidofovir at > or =3 mg/kg, the virologic response rate (> or =2 log reduction in CMV titer) was 93% for urine and 74% for semen. In addition, four treatment modifications were indicated to reduce the incidence of cidofovir-related nephrotoxicity: (a) dose reduction or interruption for changes in renal function; (b) concomitant administration of probenecid; (c) administration of 1 L of normal saline 1 h before infusion of cidofovir; and (d) extension of the dosing interval.

Evaluation of the Digene Hybrid Capture System for detection and quantitation of human cytomegalovirus viremia in human immunodeficiency virus-infected patients

The Digene Hybrid Capture System (DHCS) is a solution hybridization antibody capture assay for the chemiluminescent detection and quantitation of cytomegalovirus (CMV) DNA in leukocytes. This assay was compared with the CMV antigenemia assay and shell vial and tube cultures for the detection of CMV in 234 blood specimens from 72 patients with human immunodeficiency virus. Intra- and interrun precision of the DHCS assay gave coefficients of variation of 17.8 and 16.3%, respectively. The correlation coefficient for the quantitative results obtained by the DHCS assay and the antigenemia assay was 0.911 (95% confidence interval, 0.885 to 0.930). Agreement between the DHCS assay and the other three assays ranged from 83 to 86%. The DHCS assay detected 71, 87, and 84% of specimens that were positive by antigenemia, shell vial cultures, and tube culture, respectively. A total of 92% of specimens that were positive by the DHCS assay were also positive by at least one of the other assays. Evaluation of the usefulness of quantitation of CMV DNA by using the DHCS assay and its correlation with clinical disease demonstrated that, with some exceptions, patients with clinical CMV disease tended to have high levels of DNA whereas asymptomatic patients tended to have low or undetectable levels. Overall, the DHCS assay provided a rapid, quantitative, and objective measure of CMV activity in leukocytes, but results did not always correlate with clinical disease.

Summary of the International Consensus Symposium on Advances in the Diagnosis, Treatment and Prophylaxis and Cytomegalovirus Infection

CMV infection and CMV disease can be difficult to differentiate and the diagnosis is usually based on a compatible clinical picture and the results of a diagnostic test for CMV. The only exception to this rule is in HIV-infected patients where fundoscopy is sufficient to diagnose CMV retinitis. Of the current diagnostic tests, qualitative and quantitative PCR, branched DNA and Hybrid Capture, are the most promising. The pp65 antigenemia assay has the disadvantage of being more labor-intensive than the DNA based tests. Preliminary data show that a positive qualitative PCR in a HIV-infected patient has a predictive value for the development of CMV retinitis. However, of the patients positive by qualitative PCR, those with high viral loads in quantitative PCR were at the greatest risk of CMV disease. This might make it possible to identify with great certainty the patients who will go on to develop CMV retinitis, thereby decreasing the number of patients eligible for preemptive or prophylactic therapy and increasing the cost-benefit of this therapeutic measure. Quantitative test might also be useful in monitoring response to therapy, but randomized trials comparing the test are needed. Prophylactic antiviral agents should not be used in seronegative transplant recipients receiving organs from seronegative donors. In high-risk transplant recipients, ganciclovir should be used. CMV vaccines are useful for the protection of babies from CMV seronegative mothers against congenital CMV disease. It also may be useful in seronegative transplant recipients receiving a seropositive donor organ, although the benefit of chemo prophylaxis may surpass that of vaccine. HIV-infected patients with CMV retinitis who relapse under either ganciclovir or foscarnet benefit from subsequent combination therapy, rather than switching to the other drug. However, the cost is high in terms of quality of life. Intravitreal therapy for CMV retinitis is very efficacious, suggesting that drug delivery is a problem in systemic therapy. However, intravitreal therapy does not protect against the development of CMV retinitis in the contralateral eye or from CMV disease elsewhere. Therefore, systemic therapy should be added. CMV disease of the CNS should be diagnosed early and treated agressively, possible with combination therapy. A diagnosis of CMV disease should be based on a compatible clinical picture and the demonstration of CMV in CSF by DNA or antigen assays which are more sensitive than culture.