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

Incidence and trends in Kaposi's sarcoma in the era of effective antiretroviral therapy

OBJECTIVE

To evaluate the impact of antiretroviral and antiherpesvirus therapies on the incidence of KS and assess trends in incidence of Kaposi's sarcoma (KS) in a large multicenter HIV/AIDS surveillance system between 1990 and 1998.

METHODS

Incidence was calculated per 100 person-years (py); the effects of therapies on risk for KS were calculated by using multivariate Poisson regression controlling for gender, race/ethnicity, age, HIV exposure mode, CD4+ cell count, and calendar year. Antiretroviral therapy was defined as monotherapy, dual therapy, or triple therapy (95% of triple therapy regimens contained a protease inhibitor). Acyclovir, ganciclovir, and foscarnet were the antiherpesvirus therapies evaluated.

RESULTS

There were 37,303 HIV-infected people in the study contributing 70,238 py. Those prescribed triple antiretroviral therapy had a 50% reduction in the incidence of KS (95% confidence interval, 20%-70%) compared with those who were not prescribed antiretroviral therapy and there was a reduction in risk for KS among persons prescribed foscarnet (p =.05). Overall, KS incidence declined an estimated 8.8% per year (observed incidence 4. 1 per 100 py in 1990 to 0.7 per 100 py in 1998; p <.001).

CONCLUSION

Incidence of KS is declining in this large U.S. population and may continue to decline as new, more effective antiretroviral agents are developed and used widely.

Discontinuation of prophylaxis against Mycobacterium avium complex disease in HIV-infected patients who have a response to antiretroviral therapy. Terry Beirn Community Programs for Clinical Research on AIDS

BACKGROUND

Several agents are effective in preventing Mycobacterium avium complex disease in patients with advanced human immunodeficiency virus (HIV) infection. However, there is uncertainty about whether prophylaxis should be continued in patients whose CD4+ cell counts have increased substantially with antiviral therapy.

METHODS

We conducted a multicenter, double-blind, randomized trial of treatment with azithromycin (1200 mg weekly) as compared with placebo in HIV-infected patients whose CD4+ cell counts had increased from less than 50 to more than 100 per cubic millimeter in response to antiretroviral therapy. The primary end point was M. avium complex disease or bacterial pneumonia.

RESULTS

A total of 520 patients entered the study; the median CD4+ cell count at entry was 230 per cubic millimeter. In 48 percent of the patients, the HIV RNA value was below the level of quantification. The median prior nadir CD4+ cell count was 23 per cubic millimeter, and 65 percent of the patients had had an acquired immunodeficiency syndrome-defining illness. During follow-up over a median period of 12 months, there were no episodes of confirmed M. avium complex disease in either group (95 percent confidence interval for the rate of disease in each group, 0 to 1.5 episodes per 100 person-years). Three patients in the azithromycin group (1.2 percent) and five in the placebo group (1.9 percent) had bacterial pneumonia (relative risk in the azithromycin group, 0.60; 95 percent confidence interval, 0.14 to 2.50; P=0.48). Neither the rate of progression of HIV disease nor the mortality rate differed significantly between the two groups. Adverse effects led to discontinuation of the study drug in 19 patients assigned to receive azithromycin (7.4 percent) and in 3 assigned to receive placebo (1.1 percent; relative risk, 6.6; P=0.002).

CONCLUSIONS

Azithromycin prophylaxis can safely be withheld in HIV-infected patients whose CD4+ cell counts have increased to more than 100 cells per cubic millimeter in response to antiretroviral therapy.

Prevention of recurrent cytomegalovirus disease in renal and liver transplant recipients: effect of oral ganciclovir

BACKGROUND

Although the primary treatment of symptomatic cytomegalovirus (CMV) disease in organ transplant recipients is successful in >90% of individuals, relapsing disease, particularly in those with primary infection, remains an important problem. Previously, we had observed that the rate of symptomatic recurrence was >60% in those with primary disease (seronegative for CMV prior to transplant), and approximately 20% in those who were seropositive prior to transplant. The present study was undertaken to determine whether a maintenance regimen of oral ganciclovir for 2-3 months added to the routine 14-21 days of intravenous ganciclovir would further prevent symptomatic CMV recurrence.

METHODS

From May 1995 until June 1998, all kidney and liver transplant recipients with confirmed tissue-invasive CMV disease or CMV syndrome were treated with 14-21 days of intravenous ganciclovir (5 mg/kg b.i.d. with dose adjusted for renal dysfunction) followed by 2-3 months of oral ganciclovir (2 g daily). The incidence of recurrence of CMV disease and/or viremia during and after oral therapy was then determined over a mean follow-up of 530.6 days.

RESULTS

Thirty-seven patients, 19 kidney and 18 liver transplant recipients, were studied; 5 had biopsy-proven tissue-invasive disease (13.5) and 32 suffered a CMV syndrome (86.5). Twenty-one of these patients (58.6) were seronegative for CMV prior to transplant and received an allograft from a seropositive donor (D+/R-). Overall, 10 patients (27.0) developed CMV recurrence. Eight of 21 patients who were D+/R- for CMV (38.1) developed recurrence as opposed to 2 of 16 patients with other serologic status (12.5) (P=0.14). Patients with recurrent CMV disease and/or viremia had a peak antigenemia assay titer during their initial CMV event of 319.2 positive cells/2 slides compared with 109.8 positive cells/2 slides for patients without recurrent CMV infection (P=0.14); the trend of having a higher peak antigenemia assay titer among patients who recurred occurred both in patients who were at risk of primary CMV infection (D+/R- for CMV) and in those who were not. Two patients developed recurrent infection with strains of CMV that were resistant to ganciclovir.

CONCLUSIONS

This new therapeutic regimen of oral ganciclovir following intravenous ganciclovir slightly reduced the overall rate of recurrent CMV disease and/or viremia, but it still did not adequately prevent CMV recurrence in patients who are at risk of primary infection prior to transplant. Of particular concern, 2 patients with primary infection treated with this regimen developed ganciclovir-resistant recurrent disease.

Monitoring plasma levels of ganciclovir in AIDS patients receiving oral ganciclovir as maintenance therapy for CMV retinitis

OBJECTIVES

To investigate whether low ganciclovir serum levels in patients on maintenance oral ganciclovir therapy are associated with recurrence of CMV retinitis.

METHODS

A prospective study of the plasma concentration of ganciclovir after initiation of maintenance oral ganciclovir therapy in 14 AIDS patients who had recovered from acute cytomegalovirus (CMV) retinitis.

RESULTS

Five of the 14 patients exhibited a mean time to recurrence of 37 days. The mean trough plasma concentration of ganciclovir in these patients after 1 month of oral ganciclovir therapy, was 0.40 +/- 0.30 mg/L. Nine patients had a mean time of progression of 263 days. The mean trough plasma concentration of ganciclovir in the latter patients was 0.80 +/- 0.60 mg/L.

CONCLUSIONS

Patients exhibiting trough plasma levels of ganciclovir below 0.6 mg/L may be at higher risk of progression than patients who exhibited levels above 0.6 mg/L.

Role of the cytomegalovirus (CMV)-antigenemia assay as a predictive and follow-up detection tool for CMV disease in AIDS patients

Forty-two patients were evaluated to determine the value of the CMV antigenemia (CMV-Ag) test as a follow-up marker as well as a prediction marker of CMV disease. Twenty patients were positive for at least one positive CMV-Ag assay and 9 of them developed CMV retinitis. With the threshold value (10 positive cells), sensitivity was 56% and specificity was 94%. The CMV-Ag assay, with the threshold value, produced high specificity, positive predictive value and negative predictive value but relatively poor sensitivity. Eight patients experienced CMV disease relapse a total of 16 times. At relapse, 8 of the 16 times showed negative for CMV-Ag assay; 7 underwent systemic maintenance while 1 underwent local maintenance. It is inferred that the CMV-Ag test is a poor follow-up marker to detect the relapse of CMV disease, particularly in patients undergoing systemic maintenance.

Therapeutic developments in cytomegalovirus retinitis

The incidence of cytomegalovirus (CMV) retinitis in AIDS has declined significantly due to the use of highly active antiretroviral therapy (HAART). However, patients with HIV, especially those failing HAART, may still suffer with CMV retinitis, which can lead to significant loss of vision and blindness. Ganciclovir has traditionally been considered the recommended treatment for CMV retinitis; however, due to side effects and the possibility of developing viral resistance, other agents may be preferred in certain situations. Foscarnet, which has similar efficacy to ganciclovir but a different side effect profile, is more difficult to administer and is less well-tolerated. Intravenous cidofovir, which may be more effective than either iv. ganciclovir or foscarnet, can also be used as a first line agent; however, it is associated with toxicity (renal and ocular) and thus needs careful use. Local therapy for CMV retinitis has been a significant advance. The intraocular ganciclovir implant has the highest efficacy of the approved agents and is well-tolerated. Fomivirsen, an oligonucleotide injected intravitreally, is a newly approved agent which offers alternative treatment. Intravitreal ganciclovir or foscarnet, although not approved, have been used successfully in some patients especially those with recurrent or refractory disease. The development of new anti-CMV agents has been stalled by the decreased incidence of the disease. Valganciclovir, a prodrug of ganciclovir, offers excellent oral bioavailability and is the closest to approval of all the new anti-CMV drugs. High ganciclovir blood levels are achieved without the complications associated with the requirement for long-term iv. access. The monoclonal antibody (mAb) MSL-109, did not offer a significant advantage when added to traditional anti-CMV therapy. Development plans of other agents such as cyclic HPMPC and lobucavir have been put on hold by their respective manufacturers. Adefovir is a nucleotide analogue that possesses anti-CMV activity, but is currently only being pursued for the treatment of hepatitis B virus. Other compounds possessing significant anti-CMV activity, including BAY 38-4766 and GW1263W94 are still in the early stages of development.

Recent advances in the therapy and prevention of CMV infections

The introduction of highly active antiretroviral therapy (HAART) for HIV has had a major impact on the treatment of CMV disease in HIV-infected individuals. There is mounting evidence that in patients with CMV retinitis who have a sustained response to HAART, CMV maintenance treatment can be discontinued without relapse of retinitis. In HAART-naïve individuals with newly diagnosed CMV retinitis, the optimal timing for the initiation of HAART relative to the start of anti-CMV treatment is currently unknown. New local therapies for CMV retinitis (e.g. ganciclovir implant, the new antisense compound fomivirsen) provide treatment options in situations where high local drug delivery is warranted. A treatment algorithm for CMV disease in the HAART era is proposed. In the transplant setting, ganciclovir and foscarnet remain the major compounds used for treatment of CMV disease. In marrow and stem cell transplant recipients, CMV pneumonia still carries a high mortality. Ganciclovir in combination with CMV-specific immunoglobulin or regular intravenous IG remains the treatment of choice for CMV pneumonia; extended antiviral maintenance for several months is recommended in patients with continued immunosuppression. Preemptive treatment based on virologic markers (e.g. pp65 antigenemia, CMV DNA) has been very successful in reducing the incidence of early CMV disease in the transplant setting. The duration of preemptive treatment should be guided by the underlying immunosuppression and virologic markers. Late CMV disease is a challenge in marrow and stem cell transplant recipients, and occurs increasingly in highly immunosuppressed solid organ transplant recipients as well. Recent advances in prophylaxis strategies include oral ganciclovir for liver transplant recipients and valacyclovir for kidney transplant recipients.

Value of different assays for detection of human cytomegalovirus (HCMV) in predicting the development of HCMV disease in human immunodeficiency virus-infected patients

In the present prospective study, five blood tests for detection of human cytomegalovirus (HCMV), nucleic acid sequence-based amplification (NASBA) for detection of early (immediate-early antigen) and late (pp67) mRNA, PCR for detection of HCMV DNA (DNA PCR), culture, and pp65 antigenemia assay, and culture and DNA PCR of urine and throat swab specimens were compared for their abilities to predict the development of disease caused by HCMV (HCMV disease). Of 101 human immunodeficiency virus (HIV)-infected patients with Collapse

Key Words Collapse

MESH Headings

• AIDS-Related Opportunistic Infections/diagnosis
• AIDS-Related Opportunistic Infections/virology
• Adult
• Antigens, Viral/analysis
• Blood/virology
• Cytomegalovirus/genetics
• Cytomegalovirus/isolation & purification
• Cytomegalovirus/physiology
• Cytomegalovirus Infections/diagnosis
• Cytomegalovirus Infections/virology
• DNA, Viral/analysis
• Female
• Humans
• Immediate-Early Proteins/analysis
• Male
• Pharynx/virology
• Phosphoproteins/blood
• Polymerase Chain Reaction
• Predictive Value of Tests
• Prospective Studies
• Risk
• Urine/virology
• Viral Matrix Proteins/blood
• Viral Proteins/metabolism

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Grants Collapse

Affiliation(s)

B S Blank National AIDS Therapy Evaluation Center, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, The Netherlands.
P L Meenhorst
J W Mulder
G J Weverling
H Putter
W Pauw
W C van Dijk
P Smits
S Lie-A-Ling
P Reiss
J M Lange

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Quantitative pp65-antigenemia assay for the prediction of human cytomegalovirus disease in HIV-infected patients

OBJECTIVE

To evaluate the ability of a quantified pp65-antigenemia assay to predict the development of human cytomegalovirus (HCMV) disease in patients with an advanced HIV infection.

DESIGN

A prospective longitudinal study between March 1993 and December 1996. Blood samples for the pp65-antigenemia assay were drawn at 2-3 month intervals.

SETTING

AIDS department of an institutional tertiary care centre.

PATIENTS

A total of 101 HIV-infected patients with CD4 lymphocyte counts of 100/mm3 or less were enrolled. Ninety-seven patients were eligible for analysis. All patients gave informed consent.

MAIN OUTCOME MEASURES

The development of HCMV disease.

RESULTS

Of the 97 patients, 24 developed HCMV disease after a median follow-up of 10.6 months. Three months before the development of HCMV disease, an increase in the median number of pp65-antigen-positive leukocytes was observed. The highest combination of sensitivity (45%) and specificity (94%) for the development of HCMV disease within the next 3 months was found when an assay cut-off level of 48/10(5) pp65-antigen-positive leukocytes was applied, with a positive predictive value (PPV) for the development of HCMV disease of 75%. The Kaplan-Meier estimate of HCMV disease-free survival after patients reached 48/10(5) or more antigen-positive leukocytes on longitudinal follow-up was a median 3.7 months [95% confidence interval (CI), 2.5-8.5]. The hazard ratio (HR) of this threshold level for the development of HCMV disease was 9.6 (95% CI, 4.2-21.8).

CONCLUSION

Longitudinal follow-up using the pp65-antigenemia assay of HIV-infected patients with a low CD4 lymphocyte count improves the identification of patients who will develop HCMV disease in the foreseeable future, and should be considered for the selection of patients who may benefit from pre-emptive HCMV treatment.

Ocular manifestations of HIV infection

Ophthalmic abnormalities are common in HIV-infected patients. Serious ophthalmic diseases often result from opportunistic infections and can cause blindness in the absence of prompt diagnosis and therapy. We review recent advances in the diagnosis and management of HIV-associated ocular disease, including cytomegalovirus retinitis, the leading cause of vision loss in HIV-infected patients. The widespread use of highly active antiretroviral therapy (HAART) over the past 3 years has reduced the morbidity and mortality associated with HIV infection. HAART has dramatically altered the incidence and natural history of many opportunistic infections, and we discuss the impact of HAART on ophthalmic disease.

Cytomegalovirus viraemia has poor predictive value for the development of cytomegalovirus disease in patients with advanced HIV-infection

OBJECTIVE

Cytomegalovirus (CMV) continues to be one of the most important opportunistic infections associated with human immunodeficiency virus (HIV) infection. This study investigated the value of CMV-viraemia in predicting the development of clinical CMV disease in patients with advanced HIV infection.

METHODS

This was a prospective observational study performed over a 2-year period between 1994-96 in the Department of Infection and Tropical Medicine at Leicester Royal Infirmary. Adult HIV-positive patients attending a hospital clinic were included if they were CMV-seropositive with CD4 counts < or =50 cells/mm3. Subjects were seen at approximately 6-weekly intervals in the clinic and were reviewed by an experienced ophthalmologist. Serum for CMV PCR was taken and stored at regular intervals and qualitative and quantitative PCR was performed at the end of the study period. The value of PCR in predicting the development of CMV disease was then assessed.

RESULTS

Twenty-six patients were followed up during the study period and 77 evaluable specimens were analysed for CMV PCR. Twenty-three (30%) samples were positive and 54 negative. Seven (27%) patients developed CMV disease (five retinitis alone, and two with retinitis and oesophagitis) during the study period. Viraemia was often intermittent and there was no significant difference in the proportions of patients with positive or negative tests who subsequently developed CMV disease. The sensitivity, specificity, positive and negative predictive values of the qualitative PCR were 71%, 47%, 33% and 82% respectively and 57%, 74%, 44% and 82% respectively for the quantitative PCR (>10(3) copies/ml).

CONCLUSIONS

The results from this study, which was performed before the introduction of protease inhibitors, found that cytomegalovirus PCR was of limited clinical value in predicting the patients at greatest risk of developing CMV-disease and provided little useful prognostic information.

Management of CMV retinitis in the era of highly active antiretroviral therapy

Although the epidemiological features of CMV retinitis is changing in patients receiving highly active antiretroviral therapy (HAART), continued attention must be paid to detect and treat earlier CMV infections in AIDS patients to prevent severe ophthalmic complications. Initial therapy must be based on characteristics of the CMV retinitis and patient conditions. Long term therapy of HAART must be pursued, even in patients with increased CD4 and undetectable HIV viral load, until results from large controlled studies are available. reserved.

Incidence and risk factors for developing cytomegalovirus retinitis in HIV-infected patients receiving protease inhibitor therapy. Spanish CMV-AIDS Study Group

OBJECTIVE

To assess the incidence and risk factors for cytomegalovirus (CMV) retinitis in HIV-infected patients who initiated protease inhibitor-containing antiretroviral therapy.

DESIGN AND SETTING

Prospective, multicentre study.

PATIENTS

A cohort of 172 HIV-infected patients with a CD4 cell count below 100x10(6) cells/l at the time of protease inhibitor introduction.

MAIN OUTCOME MEASURES

Confirmed CMV retinitis and mortality, according to CD4 cell count, HIV load, and CMV viraemia.

RESULTS

The cumulative incidence of CMV retinitis was 5% at 1 year and 6% at 2 years. Only a positive CMV polymerase chain reaction (PCR) test at therapy initiation was significantly associated with the development of disease (relative hazard, 4.41; 95% confidence interval, 2.12-8.93; P<0.00001). The 12-month Kaplan-Meier CMV retinitis event rate was 38% in patients who were CMV PCR-positive compared with 2% in those who were CMV PCR-negative (P<0.001). Mean CMV load was significantly higher in those individuals who went on to develop CMV retinitis (3700 versus 384 copies/ml, P = 0.002). Only 2% of patients remained CMV PCR-positive after 3 months of protease inhibitor therapy, and CMV viraemia was not associated with a worse therapy response or shorter survival. Transient CMV positivity without a higher risk of disease was observed in 7% of patients at the first month on therapy.

CONCLUSIONS

Protease inhibitor-containing antiretroviral therapy significantly reduces the incidence of CMV viraemia and disease. Although a positive CMV PCR test identifies those patients on therapy at highest risk of CMV retinitis, it is not associated with an increased risk of death or a worse response to protease inhibitor therapy.

Cytomegalovirus (CMV) DNA load is an independent predictor of CMV disease and survival in advanced AIDS

The impact of cytomegalovirus (CMV) on human immunodeficiency virus type 1 (HIV-1) disease progression has been controversial. In this study, we sought to determine if CMV viral load is independent of HIV-1 viral load in predicting CMV disease and survival. Our findings indicate that in patients with advanced AIDS, CMV DNA load is an independent marker of CMV disease and survival and is more predictive than HIV-1 RNA load. Moreover, patients who respond to preemptive therapy with oral ganciclovir, with resulting undetectable levels of CMV DNA, in their plasma, have a significantly lower risk of developing CMV disease and higher rates of survival, despite stable or increasing HIV-1 RNA loads. These data provide support for CMV as an independent risk factor for mortality in persons with advanced AIDS and further suggest that effective preemptive therapy for CMV can improve patient survival rates.

Cytomegalovirus retinitis in immunosuppressed children

PURPOSE

To describe the ocular and systemic features of children with cytomegalovirus retinitis and their disease outcomes.

METHODS

Review of all cases of cytomegalovirus retinitis diagnosed or treated at a tertiary care pediatric hospital during a 10-year period.

RESULTS

Nine immunocompromised children younger than 16 years were diagnosed as having cytomegalovirus retinitis. The underlying causes of immunocompromise were severe combined immunodeficiency syndrome (n = 2), severe combined immunodeficiency syndrome after bone marrow transplantation (n = 1), acquired immunodeficiency syndrome (AIDS) (n = 2), AIDS and previous bone marrow transplantation for leukemia (n = 1), immunosuppressive therapy after renal transplantation (n = 1), chemotherapy for leukemia (n = 1), and congenital cytomegalovirus infection (n = 1). Five children (56%) had symptomatic extraocular cytomegalovirus infection. Only two children reported visual symptoms with cytomegalovirus retinitis at initial examination. Cytomegalovirus retinitis was bilateral in eight children (89%) and involved the posterior pole in at least one eye of all nine children. Four children (44%) died within 10 months of being diagnosed with cytomegalovirus retinitis. The remaining five children were alive, with follow-up ranging from 14 to 70 months. Successful bone marrow transplantation in one child and discontinuation of immunosuppressive medications in two children improved systemic immune function and permitted discontinuation of anticytomegaloviral therapy.

CONCLUSION

Pediatric cytomegalovirus retinitis is often asymptomatic and bilateral and involves the posterior pole at initial examination. Recovery of systemic immune function may occur in some children. Evaluation of children at risk and prompt treatment of cytomegalo. virus retinitis are important to prevent long-term visual morbidity.

Antiinfectives update: focus on treatment and prevention of viral and associated infections

OBJECTIVE

To review the clinically significant antiinfectives approved by the Food and Drug Administration (FDA) since 1996, with an emphasis on agents used for treatment, prevention, or suppression of infection in immunocompromised individuals.

DATA SOURCES

A MEDLINE search covering November 1994 to March 1998 was conducted to identify all antiinfectives (new medications and old medications with new indications) and the pertinent literature for review. The search was updated in August 1998 and supplemented with an FDA listing of approved drugs to enhance completeness.

STUDY SELECTION

Clinically relevant studies were selected to highlight specific points about each medication. Preclinical publications were used when sufficient information was not available from clinical trials and this information was needed for clinical practice.

CONCLUSIONS

Several new and promising antiretroviral agents (stavudine, lamivudine, saquinavir soft-gel capsules, nelfinavir, efavirenz) have been approved, which may allow more options to control HIV viremia. New options for treatment, prevention, and suppression of infections in immunocompromised individuals include azithromycin, cidofovir, famciclovir, valacyclovir, and itraconazole suspension. Liposomal-based amphotericin products may be associated with less toxicity than conventional amphotericin B; however, superior efficacy has not been proven.

Oral ganciclovir for patients with cytomegalovirus retinitis treated with a ganciclovir implant. Roche Ganciclovir Study Group

BACKGROUND

The intraocular ganciclovir implant is effective for local treatment of cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome (AIDS), but it does not treat or prevent other systemic manifestations of cytomegalovirus infection.

METHODS

Three hundred seventy-seven patients with AIDS and unilateral cytomegalovirus retinitis were randomly assigned to one of three treatments: a ganciclovir implant plus oral ganciclovir (4.5 g daily), a ganciclovir implant plus oral placebo, or intravenous ganciclovir alone. The primary outcome measure was the development of new cytomegalovirus disease, either contralateral retinitis or biopsy-proved extraocular disease.

RESULTS

The incidence of new cytomegalovirus disease at six months was 44.3 percent in the group assigned to the ganciclovir implant plus placebo, as compared with 24.3 percent in the group assigned to the ganciclovir implant plus oral ganciclovir (P=0.002) and 19.6 percent in the group assigned to intravenous ganciclovir alone (P<0.001). As compared with placebo, oral ganciclovir reduced the overall risk of new cytomegalovirus disease by 37.6 percent over the one-year period of the study (P=0.02). However, in the subgroup of 103 patients who took protease inhibitors, the rates of new cytomegalovirus disease were low and of similar magnitude, regardless of treatment assignment. Progression of retinitis in the eye that initially received an implant was delayed by the addition of oral ganciclovir, as compared with placebo (P=0.03). Treatment with oral or intravenous ganciclovir reduced the risk of Kaposi's sarcoma by 75 percent (P=0.008) and 93 percent (P<0.001), respectively, as compared with placebo.

CONCLUSIONS

In patients with AIDS and cytomegalovirus retinitis, oral ganciclovir in conjunction with a ganciclovir implant reduces the incidence of new cytomegalovirus disease and delays progression of the retinitis. Treatment with oral or intravenous ganciclovir also reduces the risk of Kaposi's sarcoma.

Recent advances in antiviral therapy

In the early 1980s many institutions in Britain were seriously considering whether there was a need for specialist departments of virology. The arrival of HIV changed that perception and since then virology and antiviral chemotherapy have become two very active areas of bio-medical research. Cloning and sequencing have provided tools to identify viral enzymes and have brought the day of the "designer drug" nearer to reality. At the other end of the spectrum of drug discovery, huge numbers of compounds for screening can now be generated by combinatorial chemistry. The impetus to find drugs effective against HIV has also stimulated research into novel treatments for other virus infections including herpesvirus, respiratory infections, and hepatitis B and C viruses. The need to understand the function of the immune system during HIV infection has brought virologists and immunologists together into new partnerships. The huge increase in activity in antiviral research is reflected in the frequency with which these drugs are now being licensed: in 1985 there were two licensed antiviral drugs for systemic use. Since then approximately 20 compounds have been licensed and more are being submitted to the regulatory authorities on a regular basis.

Gastrointestinal infections in the immunocompromised host

Gastrointestinal infections are a frequent and important complication of immunodeficiency diseases and immunosuppressive therapy. Such infections may be severe, prolonged, or even fatal, whereas the same infections are typically mild and transient in immunocompetent persons. In this regard, the strong association between HIV-induced immunosuppression and the increased prevalence of severe enteric infections is strong evidence of the link between immune function and defense against enteric pathogens. Because gastrointestinal infections in immunocompromised persons are frequently severe and life-threatening, a vigorous approach to the diagnostic evaluation and therapeutic management is advocated by many clinical investigators. In this review, we summarize the important new developments, particularly during the past year, regarding gastrointestinal infections in immunocompromised persons.

A randomized prospective controlled trial of oral acyclovir versus oral ganciclovir for cytomegalovirus prophylaxis in high-risk kidney transplant recipients

BACKGROUND

Posttransplantation cytomegalovirus (CMV) infection remains a significant cause of morbidity in kidney transplant recipients. We performed a randomized prospective controlled trial of oral acyclovir versus oral ganciclovir for CMV prophylaxis in a group of renal allograft recipients considered at high risk for CMV disease due to the use of OKT3 induction therapy.

METHODS

A total of 101 recipients of cadaveric (83) and zero haplotype-matched live donor (18) kidney transplants were entered into the trial. A total of 22 D-R- patients received no prophylaxis. Twenty-seven D+R-, 29 D+R+, and 23 D-R+ patients were randomized to receive 3 months of either oral acyclovir (800 mg q.i.d.) or oral ganciclovir (1000 mg t.i.d.). Doses were adjusted according to the level of renal function. The D+R- patients were also given CMV immune globulin biweekly for 16 weeks. Surveillance blood cultures were obtained at transplantation, at months 1, 2, 3, and 6, and when clinically indicated. The primary study end points were time to CMV infection and disease the first 6 months after transplantation.

RESULTS

The mean follow up was 14.4 months. Both agents were well tolerated, and no drug interruptions for toxicity occurred. CMV was isolated in 14 of 39 (35.9%) acyclovir-treated and 1 of 40 (2.5%) ganciclovir-treated recipients by 6 months (P=0.0001). Symptomatic CMV disease occurred in 9 of 14 (64%) of the acyclovir patients, two with tissue-invasive disease. Infection rates for acyclovir vs. ganciclovir, respectively, stratified by CMV serology were: D+R-, 54 vs. 0%, P=0.0008; D+R+, 43 vs. 6.6%, P=0.01; D-R+, 8.3 vs. 0%, P=NS. No patient developed CMV infection while taking oral ganciclovir, however three delayed infections occurred 2-7 months after finishing therapy. Each patient had been previously treated for acute rejection.

CONCLUSIONS

Oral acyclovir provides effective CMV prophylaxis only for recipients of seronegative donor kidneys. Oral ganciclovir is a superior agent providing effective CMV prophylaxis for recipients of seropositive donor kidneys. Recipients who are treated for acute rejection are at risk for delayed CMV infection during the first posttransplantation year.

Human immunodeficiency virus infection, Part II

The acceptance of highly active antiretroviral therapy (HAART) among patients and health care providers has had a dramatic impact on the epidemiology and clinical characteristics of many opportunistic infections associated with human immunodeficiency virus (HIV). Previously intractable opportunistic infections and syndromes are now far less common. In addition, effective antibiotic prophylactic therapies have had a profound impact on the risk of patients developing particular infections and on the incidence of these infections overall. Most notable among these are Pneumocystis carinii, disseminated Mycobacterium avium complex, tuberculosis, and toxoplasmosis. Nevertheless, infections continue to cause significant morbidity and mortality among patients who are infected with HIV. The role of HAART in many clinical situations is unquestioned. Compelling data from clinical trials support the use of these therapies during pregnancy to prevent perinatal transmission of HIV. HAART is also recommended for health care workers who have had a "significant" exposure to the blood of an HIV-infected patient. Both of these situations are discussed in detail in this article. In addition, although more controversial, increasing evidence supports the use of HAART during the acute HIV seroconversion syndrome. An "immune reconstitution syndrome" has been newly described for patients in the early phases of treatment with HAART who develop tuberculosis, M avium complex, and cytomegalovirus disease. Accumulating data support the use of hydroxyurea, an agent with a long history in the field of myeloproliferative disorders, for the treatment of HIV. Newer agents, particularly abacavir and adefovir dipivoxil, are available through expanded access protocols, and their roles are being defined and clarified.

Oral ganciclovir dosing in transplant recipients and dialysis patients based on renal function

BACKGROUND

An oral formulation of ganciclovir (GCV) was recently approved for the prevention of cytomegalovirus disease in solid organ transplant recipients. This study was designed to determine the bioavailability of GCV and to test a dosing algorithm in transplant and dialysis patients with different levels of renal function.

METHODS

Pharmacokinetic studies were carried out in 23 patients who were either a recipient of an organ transplant or on hemodialysis. Drug dosing was established by the following algorithm based on calculated creatinine clearance (CrCl): CrCl = [(140-age) x body weight]/(72 x Cr) x 0.85 for women that is, CrCl >50 ml/min, 1000 mg every 8 hr; CrCl of 25-50 ml/min, 1000 mg every 24 hr; CrCl of 10-24 ml/ min, 500 mg every day; CrCl < 10 ml/min (or on dialysis), 500 mg every other day after dialysis. GCV was taken within 30 min after a meal. The patients received oral GCV for between 12 days and 14 weeks. Serum specimens (or plasma from patients on hemodialysis) obtained at steady state were analyzed for GCV concentrations by high-performance liquid chromatography. In nine of the transplant recipients, absolute bioavailability was determined by comparing GCV levels after single oral and intravenous doses of GCV.

RESULTS

The following GCV concentrations (mean +/-SD) were determined: with CrCl of > or =70 ml/min, the minimum steady-state concentration (Cmin) and maximum concentration (Cmax) were 0.78+/-0.46 microg/ml and 1.42+/-0.37 microg/ml, respectively, with a 24-hr area under the concentration time curve (AUC0-24) of 24.7+/-7.8 microg x hr/ml; with CrCl of 50-69 ml/min, the Cmin and Cmax were 1.93+/-0.48 and 2.57+/-0.39 microg/ml, respectively, with an AUC0-24 of 52.1+/-10.1 microg x hr/ml; with CrCl of 25-50 ml/min, the Cmin and Cmax were 0.41+/-0.27 and 1.17+/-0.32 microg/ml, respectively, with an AUC0-24 of 14.6+/-7.4 microg x hr/ml. For one patient with a CrCl of 23.8 ml/min, the Cmin and Cmax were 0.32 and 0.7 microg/ml, respectively, with an AUC0-24 of 10.7 microg x hr/ml. With CrCl of <10 ml/min, the mean Cmin and Cmax were 0.75+/-0.42 and 1.59+/-0.55 microg/ml, respectively, with a mean AUC0-24 of 64.6+/-18.8 microg x hr/ml. Absolute bioavailability, for the nine patients so analyzed, was 7.2+/-2.4%. For those patients with end-stage renal failure, GCV concentrations fell during dialysis from a mean of 1.47+/-0.48 microg/ml before dialysis to 0.69+/-0.38 microg/ml after dialysis.

CONCLUSIONS

The bioavailability of oral GCV in transplant patients was similar to that observed in human immunodeficiency virus-infected patients. However, levels between 0.5 and 1 microg/ml (within the IC50 of most cytomegalovirus isolates) could be achieved with tolerable oral doses. The proposed dosing algorithm resulted in adequate levels for patients with CrCl greater than 50 ml/min and for patients on dialysis. For patients with CrCl between 10 and 50 ml/min, the levels achieved were low and these patients would likely benefit from increased doses.

Virus infections of the eye

In reviewing the clinical features, diagnostic evaluations and therapies of the most common ocular viral infections we attempt to whet your appetite for attacking the numerous challenges in diagnosis and treatment of viral eye disease. The herpes viruses, HSV, VZV and CMV are the cause of significant ocular morbidity. HSV most commonly affects the cornea producing keratitis that can be recurrent and may lead to corneal clouding and neovascularisation. Manifestations can be purely infectious or immunological and treatment options must be tailored to the underlying pathophysiology. Herpes zoster ophthalmicus, caused by VZV infection of the first branch of the trigeminal nerve, produces a characteristic rash and can progress to keratitis and uveitis. HSV and VZV can cause retinitis in both immunocompetent and immunocompromised individuals. There has been a significant increase in the incidence of CMV retinitis since the beginning of the AIDS epidemic. We review the numerous new treatments, diagnostic tests and treatment strategies which have been developed in response to this potentially blinding retinal infection. Adenovirus produces an epidemic conjunctivitis and epidemic keratoconjunctivitis which are severe and extremely contagious conjunctival infections. HIV, molluscum contagiosum, EBV and rubeola also cause ocular diseases which are described.Copyright 1998 John Wiley & Sons, Ltd.

Summary of the II International Symposium on Cytomegalovirus

Human cytomegalovirus (HCMV) is a highly species-specific DNA virus belonging to the Betaherpesvirinae subfamily of the herpesviridae family. Like other herpesviruses, primary infection with HCMV is followed by persistence of the virus in a latent form. The sites of latency are still largely undefined, but they probably include bone marrow progenitor cells and peripheral blood monocytes. From these sites, the virus can reactivate, resulting in renewed shedding of the virus, or, in immunocompromized persons, development of disease. Humans are the only reservoir of HCMV and transmission occurs by person-to-person contact. Infection with HCMV is common. In most developed countries, HCMV seroprevalence steadily increases after infancy and 10-20% of children are infected before puberty. In adults, the prevalence of antibodies ranges from 40 to 100%. Although HCMV has a world-wide distribution, infection with HCMV is more common in the developing countries and in areas of low socioeconomic conditions, which is predominantly related to the closeness of contacts within these populations. Except for a mononucleosis-like illness in some persons, infection with HCMV rarely causes disease in immunocompetent individuals. However, HCMV can cause severe morbidity and mortality in congenitally infected newborns and immunocompromized patients, most notably transplant-recipients and HIV-infected persons. This article provides a review of the information presented at the Second International Symposium on Cytomegalovirus organized and convened by The Macrae Group (New York City, NY) in Acapulco, Mexico on 24-28 April 1998. During this symposium, the state-of-the-art knowledge on diagnosis, treatment and prophylaxis of HCMV infections were discussed, and, based on this information, attempts to highlight the future directions in basic and clinical research areas that need to be stimulated to facilitate advancement in prevention and treatment of CMV disease.

Incidence and sexual risk factors of cytomegalovirus seroconversion in HIV-infected subjects. The SEROCO Study Group

BACKGROUND

Data on incidence of cytomegalovirus (CMV) seroconversion in HIV-infected (HIV(+)) subjects was sparse.

GOAL

To determine the incidence of CMV seroconversion in sexually active HIV(+) subjects and sexual factors associated with CMV seroconversion.

STUDY DESIGN

One hundred eighty four persons not infected by CMV at enrollment in a cohort of HIV(+) persons were studied. A case-control study within the cohort was conducted to determine the effect of sexual behavior in the 6 months prior to CMV seroconversion. Thirty seven cases of CMV seroconversion were compared with 136 controls.

RESULTS

The overall incidence of CMV seroconversion was 9.18 per 100 person-years (95% confidence interval (CI), 6.67-12.28) and was particularly high among homosexual men. After adjustment for age, socio-professional category, sexual orientation, and casual sex, the risk of CMV seroconversion was higher in subjects who never used condoms than in those who used them systematically (adjusted odds ratio (OR) 3.37;95% CI, 1.05-11.00).

CONCLUSIONS

In addition to the need to protect their sexual partners from HIV infection, HIV(+) subjects free of CMV infection should use condoms to avoid CMV infection and its complications.

Detection of cytomegalovirus in plasma and cerebrospinal fluid specimens from human immunodeficiency virus-infected patients by the AMPLICOR CMV test

We have developed the AMPLICOR CMV Test, which is rapid and sensitive for the detection of cytomegalovirus (CMV) in plasma and cerebrospinal fluid (CSF) specimens. The test incorporated an internal control in the reaction mixture to monitor the amplification efficiency and the presence of inhibitors. The AMPLICOR CMV Test was very specific in detecting 12 clinical CMV isolates and four laboratory CMV strains tested. Cross-reactivity with 26 non-CMV pathogens was not observed. The AMPLICOR CMV Test requires only 50 microl of specimen (plasma or CSF) for processing. The performance of the AMPLICOR CMV Test was compared to those of the CMV antigenemia assay and the conventional tube culture method. Among 112 plasma specimens from 43 human immunodeficiency virus-infected patients, CMV was detected in 20 (18%) of the specimens by the AMPLICOR CMV Test, 21 (19%) of the specimens by the CMV antigenemia assay, and 10 (9%) of the specimens by culture. In CSF specimens from AIDS patients, CMV was detected in 10 of 58 (17%) specimens tested by the AMPLICOR CMV Test, 5 of 28 (18%) specimens tested by the antigen assay, and none of the 25 specimens tested by culture. While the performance of the AMPLICOR CMV Test in this study was comparable to that of the CMV antigen assay, processing of specimens by the AMPLICOR CMV Test was much simpler than that by the antigen assay; in addition, the antigen assay requires greater than 10(5) leukocytes from blood or 1 ml of CSF to perform the assay. Our study suggested that the AMPLICOR CMV Test could provide a rapid and sensitive assay for the detection of CMV in plasma and CSF specimens.

Risk of developing CMV retinitis following non-ocular CMV end organ disease in AIDS patients

AIM

To describe the risk of developing cytomegalovirus (CMV) retinitis after a first episode of extraocular CMV disease in AIDS patients.

METHODS

A review of the clinical records of 20 AIDS patients, without CMV retinitis, with histologically confirmed extraocular CMV disease, was performed. The main outcome measures were occurrence of CMV retinitis, time to development of CMV retinitis, relation to maintenance therapy, and survival.

RESULTS

A CMV retinitis was diagnosed in 17 of 20 (85%) patients with an immunohistologically confirmed diagnosis of extraocular CMV disease after a mean follow up of 6.4 months. Four patients received maintenance therapy. Three of them developed retinitis after a mean of 9.6 months (range 2-16 months). Sixteen did not receive maintenance and retinitis was diagnosed in 14 of them after a mean of 5.7 months (range 2-11 months). Mean survival was 9.9 months after the diagnosis of extraocular disease, and 4.5 months after the diagnosis of retinitis. In the four patients receiving maintenance therapy, mean survival was 11.5 months, and in the 16 other patients mean survival was 9.5 months. Patients did not receive protease inhibitors.

CONCLUSION

In the preprotease inhibitor era extraocular CMV disease strongly predisposes to the subsequent development of CMV retinitis. Although maintenance therapy did not prevent the occurrence of retinitis, the time period between both events seems to lengthen considerably. In patients receiving maintenance survival is also longer.

Quantitation of cytomegalovirus: methodologic aspects and clinical applications

Cytomegalovirus (CMV) is an important pathogen in transplant recipients and human immunodeficiency virus (HIV)-infected individuals. Major progress has been made in developing quantitative detection methods for CMV in recent years. Due to their high sensitivity, these assays can detect CMV early, and quantitation may be useful in predicting the patient's risk for disease and in monitoring the effect of antiviral therapy. This review discusses methodological aspects of currently used quantitative assays for CMV (i.e., viral culture techniques, antigen detection assays, DNA detection assays including PCR, branched-DNA assay, and the DNA hybrid capture assay) and addresses the correlation of systemic and site-specific CMV load and CMV disease in different populations of immunosuppressed patients as well as the response to antiviral treatment. To date, direct antigen detection and molecular techniques have largely replaced traditional culture-based techniques for CMV quantitation. In general, a high systemic CMV load is correlated with CMV disease. This correlation is strong in the HIV-infected population and in solid-organ transplant recipients but less clear in allogeneic marrow transplant recipients. Measuring the viral load at specific anatomic sites may be an alternative way to assess disease activity in situations where the systemic viral load correlates poorly with disease activity. A reduction of the systemic CMV load also correlates with a response to antiviral treatment, but more research is needed to evaluate the role of viral load as a surrogate marker for drug resistance. Due to the widespread use of quantitative CMV detection techniques to direct and monitor antiviral treatment, there is a great need for an assessment of the reproducibility of test results and better standardization of the assays.

Cytomegalovirus colitis in acquired immunodeficiency syndrome: a clinical and endoscopic study

BACKGROUND

Cytomegalovirus colitis is an important complication of the acquired immunodeficiency syndrome (AIDS), although the clinical and colonoscopic manifestations of this disease have not been systematically characterized.

METHODS

Patients with AIDS and cytomegalovirus colitis were prospectively identified at two medical centers. The diagnosis of cytomegalovirus disease was based on established endoscopic and histologic criteria. At the time of sigmoidoscopic and/or colonoscopic examination, clinical features were recorded; the location, size, and appearance of all endoscopic abnormalities were documented; and multiple biopsies of any lesions were performed.

RESULTS

Fifty-six patients were studied. The majority of the patients were homosexual men with severe immunodeficiency (median CD4 lymphocyte count 15/mm3, range 1 to 294/mm3). Chronic diarrhea and abdominal pain were the most frequent clinical manifestations, seen in 45 (80%) and 28 (50%) patients, respectively. Five patients (9%) presented with lower gastrointestinal hemorrhage, three of whom had no antecedent history of diarrhea. The colonoscopic abnormalities could be categorized into three main groups: colitis associated with ulcer (39%), ulceration alone (38%), or colitis alone (20%). Subepithelial hemorrhage was a prominent endoscopic manifestation of disease. Of the 31 patients undergoing colonoscopy to the cecum, in four (13%) endoscopic evidence of disease was limited to the colon proximal to the splenic flexure.

CONCLUSIONS

Cytomegalovirus colitis in AIDS appears to have variable but stereotypical clinical and colonoscopic manifestations. Distal colitis associated with ulceration is the most common colonoscopic pattern.

Cytomegalovirus (CMV) strain differences between the eye and blood in AIDS patients with CMV retinitis

OBJECTIVE

To investigate possible differences in cytomegalovirus (CMV) strain distribution between the eye and blood in AIDS patients with CMV retinitis.

METHODS

CMV DNA sequences from aqueous humour and peripheral blood leukocytes (PBL), obtained from 13 AIDS patients with CMV retinitis, were compared. DNA was isolated and the CMV IE-1 sequence (part of the immediate early-1 gene) and the a-sequence (located in the a-region) were amplified by polymerase chain reaction (PCR). The PCR products of the a-sequence were analysed by Southern blotting for amplified fragment-length polymorphisms. The level of divergence between the a-sequences of aqueous humour- and PBL-derived CMV was studied in two patients by cloning these sequences followed by sequence analysis.

RESULTS

CMV DNA could be detected in all aqueous humour samples and in 10 out of 13 paired blood samples. In the 10 patients, with CMV DNA detectable in both aqueous humour and PBL, seven cases showed differences between the amplified products of both compartments. Sequence analysis in two patients revealed that the aqueous humour and PBL of the same patient can harbour both identical, similar and highly divergent CMV a-sequences.

CONCLUSION

These results indicate that despite the haematogenous spread of CMV, the eye, being a relatively shielded organ, may contain CMV strains different from those found in the blood.

A Monte Carlo simulation of advanced HIV disease: application to prevention of CMV infection

BACKGROUND

Disagreement exists among decision makers regarding the allocation of limited HIV patient care resources and, specifically, the comparative value of preventing opportunistic infections in late-stage disease.

METHODS

A Monte Carlo simulation framework was used to evaluate a state-transition model of the natural history of HIV illness in patients with CD4 counts below 300/mm3 and to project the costs and consequences of alternative strategies for preventing AIDS-related complications. The authors describe the model and demonstrate how it may be employed to assess the cost-effectiveness of oral ganciclovir for prevention of cytomegalovirus (CMV) infection.

RESULTS

Ganciclovir prophylaxis confers an estimated additional 0.7 quality-adjusted month of life at a net cost of $10,700, implying an incremental cost-effectiveness ratio of roughly $173,000 per quality-adjusted life year gained. Sensitivity analysis reveals that this baseline result is stable over a wide range of input data estimates, including quality of life and drug efficacy, but it is sensitive to CMV incidence and drug price assumptions.

CONCLUSIONS

The Monte Carlo simulation framework offers decision makers a powerful and flexible tool for evaluating choices in the realm of chronic disease patient care. The authors have used it to assess HIV-related treatment options and continue to refine it to reflect advances in defining the pathogenesis and treatment of AIDS. Compared with alternative interventions, CMV prophylaxis does not appear to be a cost-effective use of scarce HIV clinical care funds. However, targeted prevention in patients identified to be at higher risk for CMV-related disease may warrant consideration.

Current status of anti-HBV chemotherapy

In the past decade, significant progress has been achieved in the battle against hepatitis B virus. In addition to the immunomodulating agents such as interferon-alpha and thymosin, many novel antiviral agents have been discovered, among which nucleoside analogues are the mainstay. New-generation compounds such as 3TC and famciclovir have shown promise in the treatment of patients chronically infected by this virus, and are on the line for approval. However, viral rebound after cessation of therapy still remains a major problem. Additionally, the reports on the drug resistance to these antiviral agents suggest that combination therapy will be the eventual strategy (Bartholomew et al., 1997; Tipples et al., 1996). Therefore, developments of safe and effective antiviral agents which do not cross-resist with currently available antiviral drugs are still much needed.

Single tube competitive PCR for quantitation of CMV DNA in the blood of HIV+ and solid organ transplant patients

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in transplant and HIV-infected patients. However, CMV can also cause asymptomatic infection. An elevated blood viral load as assessed by various methods appears to be a predictor for symptomatic infections, and can be used to identify patients at the highest risk of developing CMV disease. We developed a single tube competitive quantitative PCR assay for CMV DNA, using as a competitor a plasmid carrying the target sequence for amplification with an internal deletion. The analysis of data from repeated extractions and amplifications of samples showed that the coefficient of variation of the assay was typically less than 20%. Clinical samples from 14 HIV-infected and 13 solid organ transplant patients were analyzed. Widely varying CMV DNA levels were found in leukocytes, with a positive correlation with the measure of infectivity in the leukocytes by quantitative culture on fibroblasts. The highest CMV DNA content in leukocytes was found in two patients with presumptive CMV disease. In HIV patients, the amount of DNA in leukocytes was much larger than in solid organ transplant recipients, when standardized for infectivity. Although based on a very limited number of patients, this observation probably points to a difference in the biology of CMV infection in these two categories of susceptible individuals. CMV DNA was also found in the plasma of some of the patients with a high CMV DNA leukocyte load. The present test should be useful for identifying patients at high risk of developing CMV disease, for monitoring therapeutic efficacy of antiviral regimens and to improve the understanding the pathogenesis of CMV infection.