Improved outcome of cytomegalovirus retinitis in AIDS patients after introduction of protease inhibitors

Foreign Body Granuloma: A New Manifestation of Immune Restoration Syndrome

Background:

People with human immunodeficiency virus may experience an immune restoration syndrome during the lymphocyte recovery period following effective highly active antiretroviral therapy. In this syndrome, antigens that previously were ignored by the immune system now induce an exaggerated response with obvious clinical effects. Most cases have been associated with infectious agents such as cytomegalovirus or mycobacterium avium intracellulare. However, the sudden onset of sarcoidal granulomatous reactions have also been described in this setting.

Objective:

We report a 66-year-old HIV-positive man who presented with exacerbation of multiple foreign body granulomas decades after the original injuries. The presentation coincided with a significant rise in CD4 count after beginning highly active antiretroviral therapy.

Conclusion:

We propose that this case demonstrates another manifestation of the immune restoration syndrome and postulate that an uncontrolled Th1 response is the causative mechanism.

HIV-associated retinopathy in the HAART era

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Immune restoration disease after antiretroviral therapy

Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.

The effect of cytomegalovirus retinitis on the quality of life of patients with AIDS in the era of highly active antiretroviral therapy

PURPOSE

To evaluate the effect of cytomegalovirus (CMV) retinitis on quality of life (QOL) in patients with the acquired immune deficiency syndrome (AIDS).

DESIGN

Enrollment data from a multicenter, prospective cohort study.

PARTICIPANTS

Patients >/=13 years of age with AIDS in three groups: no CMV retinitis, 709 patients; long-standing CMV retinitis (diagnosed a median of 34.5 months previously), 212 patients; and newly diagnosed CMV retinitis (diagnosed </=45 days previously), 50 patients.

METHODS

Patients were enrolled at 19 centers throughout the United States. CMV retinitis status was determined by ophthalmoscopy. Vision-related QOL was assessed with a questionnaire designed for patients with CMV retinitis. General health-related QOL was evaluated with a modified version of the Medical Outcomes Survey-HIV instrument. Health utility was measured with the EuroQol instrument.

MAIN OUTCOME MEASURES

Patient-reported vision-related QOL, general health-related QOL, and health utility.

RESULTS

All domains of vision-related QOL were substantially lower in both the long-standing and newly diagnosed CMV retinitis groups than in the group with no CMV retinitis. The long-standing CMV retinitis group was similar to the no CMV retinitis group in most general health-related QOL domains and in health utility measures. The newly diagnosed CMV retinitis group scored substantially worse than the other groups in many of the general health-related QOL domains and in visual analog scale-measured health utility. Adjustment of selected scale scores for demographic characteristics and for CD4(+) T-cell count, human immunodeficiency virus viral load, and use of highly active antiretroviral therapy (HAART) attenuated most of the differences in general health-related QOL, except that physical function scores remained significantly lower in the newly diagnosed CMV retinitis group. Adjustment did not alter the pattern of vision-related QOL results.

CONCLUSIONS

These results suggest that in the HAART era, CMV retinitis is associated with reduced vision-related QOL in patients both with newly diagnosed and with long-standing disease, even though patients with long-standing CMV retinitis seem to have general health-related QOL and health utility similar to that of patients with AIDS who do not have CMV retinitis. Newly diagnosed CMV retinitis also is associated with lower general health-related QOL in most domains and with lower health utility.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CMVR diagnoses and progression of CD4 cell counts and HIV viral load measurements in HIV patients on HAART

AIM

To assess the impact of highly active antiretroviral therapy (HAART) on the prevalence and progression of CMV retinitis (CMVR) among AIDS patients with baseline CD4 cell counts <100 cells x 10(6)/l.

METHODS

A longitudinal cohort study of 1292 patients. CD4 cell counts and HIV viral load measurements were obtained before commencing therapy, at 3 months, 1 year, 2 years, and at last follow up. The CMVR prevalence rate was measured for the subgroup with baseline CD4 cell counts <100 cells x 10(6)/l. CMVR adverse event (AE) rates per 100 person days at risk were calculated for the subgroup with CMVR and baseline CD4 cell counts <100 cells x 10(6)/l.

RESULTS

1292 patients were started on HAART. 8% of patients had CD4 counts <50 cells x 10(6)/l and 40% had detectable HIV viral load at last follow up. The prevalence of CMVR for the subgroup with baseline CD4 <100 cells x 10(6)/l was 10%. For those with baseline CD4 <100 cells x 10(6)/l, the mean CMVR AE rate was greatest during the first 6 months of follow up after HAART commencement (p <0.003). The mean AE rate per 100 person days at risk was 0.36 (95% CI 0.167 to 0.551) before starting HAART, and 0.14 (95% CI 0.085 to 0.199) after starting HAART (p = 0.03).

CONCLUSIONS

HAART significantly prolongs the disease-free intervals in patients with pre-existing disease but recurrences persist within the first 6 months of starting therapy. AE were absent beyond 18 months of follow up in all patients including those with persistently low CD4 counts and detectable HIV viral load indicating clinical immunorestoration. New methods for monitoring the response to therapy are needed to identify those at risk.

Qualitative and quantitative PCR measures of cytomegalovirus in patients with advanced HIV infection who require transfusions

The Viral Activation Transfusion Study (VATS) was a randomized trial that compared leukocyte-reduced transfusions with unfiltered red blood cell transfusions in HIV and cytomegalovirus (CMV) antibody-positive patients with anemia who were undergoing their first blood transfusion. The relations of the baseline qualitative and quantitative polymerase chain reaction (PCR) measures of plasma CMV viremia, HIV RNA, CD4(+) cell counts, and quality of life in these study subjects were examined. The 511 study subjects had a median CD4(+) cell count equal to 15 cells/mm3, and 110 (21.5%) had CMV viremia by qualitative assay. In multivariate models, frequency of positive qualitative CMV increased with decreasing CD4(+) cell counts (p =.04 trend), higher HIV RNA (p <.001), and a history of CMV disease (p <.001). Quantitative CMV PCR were performed on the 110 qualitative assay-positive study subjects. Median CMV viral load was 1780 copies/ml. In multivariate regression models, lower CD4(+) cell count (p =.03), and a history of CMV disease (p <.001) correlated with the level of CMV load. HIV RNA load and CMV load were not correlated. A lower Karnofsky score was associated with both the presence and quantity of CMV DNA.

Discontinuation of maintenance therapy for cytomegalovirus retinitis in HIV-infected patients receiving highly active antiretroviral therapy

OBJECTIVE

To study the safety of discontinuing cytomegalovirus (CMV) maintenance therapy among patients with cured CMV retinitis receiving highly active antiretroviral therapy (HAART).

METHODS

Patients with a history of CMV retinitis who were receiving anti-CMV maintenance therapy and who had a CD4 cell count > 75 x 10(6) cells/l and a plasma HIV RNA level < 30000 copies/ml while on HAART were included in a multicentre prospective study. Maintenance therapy for CMV retinitis was discontinued at enrolment and all the patients were monitored for 48 weeks by ophthalmological examinations and by determination of CMV markers, CD4 cell counts and plasma HIV RNA levels. T helper-1 anti-CMV responses were assessed in a subgroup of patients. The primary study endpoint was recurrence of CMV disease.

RESULTS

At entry, the 48 assessable patients had been taking HAART for a median of 18 months. The median CD4 cell count was 239 x 10(6) cells/l and the median HIV RNA load was 213 copies/ml. Over the 48 weeks, 2 of the 48 patients had a recurrence of CMV disease. The cumulative probability of CMV retinitis relapse was 2.2% at week 48 (95% confidence interval, 0.4-11.3) and that of all forms of CMV disease 4.2%. CMV blood markers remained negative throughout follow-up. The proportion of patients with CMV-specific CD4 T cell reactivity was 46% at baseline and 64% at week 48.

CONCLUSIONS

CMV retinitis maintenance therapy may be safely discontinued in patients with CD4 cell counts above 75 x 10(6) cells/l who have been taking HAART for at least 18 months.

The incidence of cytomegalovirus (CMV) antigenemia and CMV disease is reduced by highly active antiretroviral therapy

Cytomegalovirus (CMV) infection was one of the most common opportunistic infections in AIDS patients, leading to blindness or life-threatening disease in about 40% of patients in the later stages of AIDS before highly active antiretroviral therapy (HAART). In a retrospective multicenter study we investigated the incidence of CMV retinitis and organ involvement in Northern Italy before (1995 and 1996) and after the introduction of HAART (1997 and 1998) as well as the data regarding CMV antigenemia. We found a sharp drop in the incidence of CMV disease in AIDS patients as well as a decline in the incidence of relapses of CMV-disease after the widespread introduction of HAART. Moreover, there was a decrease in the incidence of antigenemia-positive cases in AIDS patients in the era of HAART and the median CMV viral load was significantly higher in patients who didn't receive HAART than in patients who received HAART (p = 0.001, t test).

Immune restoration disease after the treatment of immunodeficient HIV-infected patients with highly active antiretroviral therapy

BACKGROUND

To determine if infectious disease events in HIV-infected patients treated with highly active antiretroviral therapy (HAART) are a consequence of the restoration of pathogen-specific immune responses, a single-centre retrospective study of all HIV-infected patients commencing HAART prior to 1 July 1997 was undertaken to determine the incidence, characteristics and time of onset of disease episodes in HAART responders (decrease in plasma HIV RNA of > 1 log10 copies/mL).

METHODS

Baseline and post-therapy changes in CD4 T-cell counts and HIV RNA were compared in patients with and without disease and delayed-type hypersensitivity responses to mycobacterial antigens were measured in selected patients.

RESULTS

Thirty-three of 132 HAART responders (25%) exhibited one or more disease episodes after HAART, related to a pre-existent or subclinical infection by an opportunistic pathogen. Disease episodes were most often related to infections by mycobacteria or herpesviruses but hepatitis C virus (HCV), molluscum contagiosum virus and human papilloma virus were also implicated. They were most common in patients with a baseline CD4 T-cell count of < 50/uL and occurred most often during the first 2 months of therapy and when CD4 T-cell counts were increasing. Mycobacteria- and HCV-related diseases were associated with restoration of pathogen-specific immune responses.

CONCLUSIONS

We conclude that improved immune function in immunodeficient patients treated with HAART may restore pathogen-specific immune responses and cause inflammation in tissues infected by those pathogens.

Comparison of three assays for cytomegalovirus detection in AIDS patients at risk for retinitis

The purpose of this study was to determine the sensitivity and specificity of three different methods of cytomegalovirus (CMV) detection for AIDS patients at risk for CMV retinitis. Patients with CD4(+) counts of <100/microl and negative baseline screening eye examinations were tested for CMV infection by (i) pp65 antigenemia expression in leukocytes, (ii) the Digene Hybrid Capture CMV DNA System, and (iii) the Roche Amplicor Qualitative PCR Test. The incidence of CMV retinitis in our study of 296 patients at the Medical Center of Louisiana-New Orleans HIV Outpatient Clinic was 7. 2 per 100 person-years (a total of 20 episodes in 18 patients from April 1997 to February 1999). Receiver operating characteristic curves were calculated for each assay to determine optimal cutoff points which maximized the sensitivity and specificity of each assay. The sensitivities of the assays compared to the eye examinations were 80% for the pp65 antigenemia assay (cutoff, >0 cell per 1.5 x 10(5) leukocytes), 85% for the Digene assay (cutoff, 1,400 genome copies/ml of whole blood), and 60% for the Amplicor assay. The specificities of the assays were 84, 84, and 87%, respectively. The Digene assay with a cutoff of >/=1,400 genome copies/ml gave optimal sensitivity and specificity and was found to have predictive values equal to those of the more technically cumbersome antigenemia assay.

Indinavir: a review of its use in the management of HIV infection

Indinavir is a protease inhibitor used in the treatment of patients with HIV infection. Combination antiretroviral therapy with indinavir plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) is associated with greater reductions in viral load, greater increases in CD4+ cell counts, and reduced morbidity and mortality when compared with 2 NRTIs alone. In the landmark clinical trial ACTG 320, the rate of progression to AIDS or death (primary end-point) among zidovudine-experienced patients treated with indinavir, zidovudine and lamivudine was approximately half that of patients who received only zidovudine plus lamivudine (6 vs 11%; p < 0.001). The durability of an indinavir-containing regimen was demonstrated in Merck protocol 035, an ongoing trial in which a significant proportion of patients had sustained viral suppression for up to 3 years. Merck protocol 039, also an ongoing trial, showed a greater effect on surrogate markers of HIV disease progression with indinavir-based triple therapy than with zidovudine plus lamivudine or indinavir monotherapy in patients with advanced disease (median baseline CD4+ count 15 cells/microL). Numerous additional clinical trials have established the beneficial antiviral and immunological effects of indinavir in both antiretroviral-naive and -experienced patients with HIV infection. Indinavir is associated with various drug class-related adverse events, including gastrointestinal disturbances (e.g. nausea, diarrhoea), headache and asthenia/fatigue. A lipodystrophy syndrome has been commonly reported with indinavir and other protease inhibitors combined with NRTIs, but it has also been reported in many protease inhibitor-naive patients, and a definitive causal link has not been established between the syndrome and protease inhibitors. Nephrolithiasis may develop in about 9% of patients receiving indinavir but does not appear to be associated with other protease inhibitors; <0.5% of patients receiving indinavir discontinue the drug because of nephrolithiasis, which may be the extreme end of a continuum of crystal-related renal syndromes. Additional renal problems (e.g. nephropathy) have been reported in small numbers of patients receiving indinavir. In summary, indinavir is a protease inhibitor with well documented efficacy when used as part of combined therapy in patients with HIV infection. Both US and UK treatment guidelines continue to recommend protease inhibitor-based regimens including indinavir as a first-line option. Indinavir is being studied as a twice daily and once daily regimen with a low dosage of ritonavir as a way to alleviate tolerability, drug interaction and patient compliance/adherence issues. Indinavir-containing triple therapy has demonstrated positive effects not only on surrogate markers of disease progression, but also on clinical end-points of mortality and morbidity in patients with HIV disease. Protease inhibitors are a significant advance in the care of patients with HIV infection, and, in an era of evidence-based medicine, indinavir represents an important component of antiretroviral treatment strategies.

Human cytomegalovirus: challenges, opportunities and new drug development

In the age of highly active antiretroviral therapy, the incidence of human cytomegalovirus (HCMV) retinitis in AIDS patients has decreased substantially. However, this change does not indicate that HCMV disease in AIDS patients and other immunocompromised patients has abated and is no longer a concern. On the contrary, HCMV disease in graft recipients, newborns, and even in AIDS patients still accounts for considerable morbidity, and drug resistance to the anti-HCMV compounds is a major problem. Furthermore, HCMV may have a role in metabolic diseases, such as atherosclerosis. Fortunately there are novel and potentially very effective new compounds undergoing pre-clinical and clinical evaluation. These developments point the way toward new therapies and also to a clearer understanding of the biology of HCMV replication, infection and disease.

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.