AIDS-related opportunistic illnesses occurring after initiation of potent antiretroviral therapy: the Swiss HIV Cohort Study

Effect of long-term highly active antiretroviral therapy in restoring HIV-induced abnormal B-lymphocyte function

Although highly active antiretroviral therapy (HAART) has been reported to restore defects in cell-mediated immunity to a significant degree, little is known of its effects in restoring HIV-induced abnormal antibody-mediated immunity. We conducted a cross-sectional study of 1) 29 HIV-infected patients on chronic HAART whose HIV viral load was undetectable and whose absolute CD4+ T-lymphocyte count had been consistently sustained by > or =150 cells/microL over their pre-HAART nadir value for >1 year; and 2) 29 untreated HIV-infected patients with current CD4 counts matching the treated patients' prior nadir CD4 counts. Serum was tested for total IgG and by protein electrophoresis with immunofixation for paraproteins. Although serum IgG levels were significantly lower in patients who had received long-term virologically effective HAART than in CD4 count-matched untreated patients (1488 +/- 475 mg/dL vs. 1999 +/- 775 mg/dL, p =.004), serum IgG was still abnormally elevated in 45% of the untreated group despite a mean 28 months of HAART-induced HIV suppression and CD4 count restoration. Paraprotein spikes were confirmed by immunofixation in 7% of patients in each group. This study provides the longest reported observation to date of the effect of HAART on HIV-induced abnormal antibody-mediated immunity. Larger and longer-term studies of HAART effect on B-cell reconstitution are needed.

Vacuolar myelopathy and vacuolar cerebellar leukoencephalopathy: a late complication of AIDS after highly active antiretroviral therapy-induced immune reconstitution

Controversy exists as to whether vacuolar myelopathy (VM) responds to highly active antiretroviral therapy (HAART) in a salutary fashion similar to other primary human immunodeficiency virus (HIV)-related neurologic complications such as acquired immune deficiency syndrome (AIDS) dementia complex and progressive multifocal leukoencephalopathy. Herein, we describe the case of a patient with AIDS, non-Hodgkin's lymphoma, and cytomegalovirus colitis, who began HAART and cytotoxic chemotherapy. After 6 months of therapy, restaging studies showed no residual lymphoma or active opportunistic infection. For 2 years he was maintained on HAART, during which time his HIV viral load remained nondetectable and his CD4+ count improved from 20 to 300 cells per microliter. Shortly after developing the acute onset of cerebellar ataxia, he aspirated, developed adult respiratory distress syndrome, and died. At autopsy the spinal cord demonstrated a characteristic vacuolated appearance that extended into the cerebellum. No relation between HIV and the development of VM was discerned by in situ hybridization studies. Experience with this one patient suggests that HAART may not alter the natural history of VM. Whether this case represents yet another variant of the recently described inflammatory immune response syndrome whereby progression of previously quiescent disorders evolve to symptomatic disease after initiation of HAART is uncertain.

Pathological findings in the central nervous system of AIDS patients on assumed antiretroviral therapeutic regimens: retrospective study of 1597 autopsies

OBJECTIVE

To evaluate the prevalence of HIV-related central nervous system (CNS) lesions (HIV-encephalitis and/or HIV-leukoencephalopathy: HIV-E/L) with and without concomitant opportunistic diseases in a large autopsy series, and to correlate it with the changes in antiretroviral treatment that have occurred since the beginning of the epidemic.

METHODS

We reviewed 1597 consecutive autopsies of HIV-positive patients performed between 1984 and 2000, and divided into four time periods on the basis of the therapeutic regimens available: 1984-1987, no therapy; 1988-1994, monotherapy (zidovudine); 1995-1996, dual combination therapy with nucleoside reverse transcriptase inhibitors (NRTI); and 1997-2000, triple combination therapy including two NRTI and at least one protease inhibitor or non-NRTI. The data concerning the treatment actually received were collected only for the patients who died during the last period. The chi -test was used to assess the significance of the differences in prevalence.

RESULTS

The CNS of 1210 patients (76%) was affected by opportunistic diseases, HIV-related lesions or both. The prevalence of HIV-related lesions in the four periods was respectively 54%, 32%, 18% and 15%; this reduction was statistically significant (P < 0.000001). During the last period, however, differences in HIV-E/L between treated and untreated patients were not statistically significant, although there were fewer than expected cases among the treated patients (six instead of eight) and more than expected among the untreated patients (10 instead of eight).

CONCLUSIONS

These neuropathological data from a large autopsy series confirm clinical observations concerning the efficacy of antiretroviral treatment in reducing the frequency of HIV-related CNS lesions in AIDS patients.

[Adherence to antiretroviral therapy measured by pill count and drug serum concentrations. Variables associated with a bad adherence]

BACKGROUND

We aimed at measuring the adherence to HAART by means of pill count and drug plasma levels. In addition, we aimed at determining variables associated with suboptimal adherence.

PATIENTS AND METHOD

Prospective observational study of 202 consecutive patients with HIV infection who were receiving antiretroviral treatment, followed up during 9 months. At baseline and at the end of the study a structured questionnaire was administered and a review of medical charts was performed. The adherence was assessed by monthly pill count while drug plasma levels were measured every three months. We considered that a patient adherence was not fulfilled when the mean pill count was < 90% or when any plasma drug level was lower than that expected.

RESULTS

Of 143 available patients, 41.2% were non-adherent. According to the univariate analysis, non-adherent patients were more likely to be younger, female, under a methadone maintenance scheme, under psychiatric treatment, to have depression (according to the Beck Depression Inventory), to have adverse antiretroviral effects and to have a previous history of voluntary withdrawal of the treatment. Men who had sex with other men were significantly more adherent. In the multivariate analysis, female sex [OR 2.6 (1.04-6.65)], to be under a methadone program [OR 9.43 (1.01-88)], to have adverse drug effects [OR 2.63 (1.09-6.33)] and to have a previous history of voluntary withdrawal [OR 2.63 (1.09-6.36)] were independent risk factors for non-adherence.

CONCLUSIONS

Adherence to antiretroviral therapy was 58.8%, similar to that seen in other chronic diseases. To be under a methadone maintenance program and having an active drug addiction was related with non-adherence. Women with worst adherence levels had frequently psychiatric comorbidity and more adverse drug effects.

Changes in the cause of death among HIV positive subjects across Europe: results from the EuroSIDA study

OBJECTIVES

The causes of death among HIV-positive patients may have changed since the introduction of highly active antiretroviral therapy (HAART). We investigated these changes, patients who died without an AIDS diagnosis and factors relating to pre-AIDS deaths.

METHODS

Analyses of 1826 deaths among EuroSIDA patients, an observational study of 8556 patients. Incidence rates of pre-AIDS deaths were compared to overall rates. Factors relating to pre-AIDS deaths were identified using Cox regression.

RESULTS

Death rates declined from 15.6 to 2.7 per 100 person-years of follow-up (PYFU) between 1994 and 2001. Pre-AIDS incidence declined from 2.4 to 1.1 per 100 PYFU. The ratio of overall to pre-AIDS deaths peaked in 1996 at 8.4 and dropped to < 3 after 1998. The adjusted odds of dying following one AIDS defining event (ADE) increased yearly (odds ratio, 1.53; P < 0.001), conversely the odds of dying following three or more ADE decreased yearly (odds ratio, 0.79; P < 0.001). The proportion of deaths that followed an HIV-related disease decreased by 23% annually; in contrast there was a 32% yearly increase in the proportion of deaths due to known causes other than HIV-related or suicides. Injecting drug users (IDU) were significantly more likely to die before an ADE than homosexuals (relative hazard, 2.97; P < 0.0001) and patients from northern/eastern Europe (relative hazard, 2.01; P < 0.0001) were more likely to die pre-AIDS than southern patients.

CONCLUSIONS

The proportion of pre-AIDS deaths increased from 1994 to 2001; however, the incidence of pre-AIDS deaths and deaths overall declined. IDU and subjects from northern/eastern Europe had an increased risk of pre-AIDS death. HIV-positive patients live longer therefore it is essential to continue to monitor all causes of mortality to identify changes.

The relationship of preventable opportunistic infections, HIV-1 RNA, and CD4 Cell counts to chronic mortality

BACKGROUND

Both HIV-1 RNA and absolute CD4 cell counts have been identified as important predictors of HIV-1 disease progression and mortality. The independent impact of opportunistic infections on the risk of chronic mortality, defined as death beyond 30 days of an opportunistic infection, has not been studied when controlling for HIV-1 RNA. Our objective was to determine the relationship between a history of any of five preventable opportunistic infections (Pneumocystis carinii pneumonia, Mycobacterium avium complex, toxoplasmosis, cytomegalovirus, and candida esophagitis) and chronic mortality.

METHODS

Using the Multicenter AIDS Cohort Study (MACS) public use data set of 2193 HIV-infected men in four U.S. cities, we employed a Cox regression model to estimate the impact of a history of preventable opportunistic infection on chronic mortality while controlling for maximum HIV-1 RNA, CD4 cell count, use of antiretroviral drugs, and age.

FINDINGS

The chronic mortality rate among individuals with a history of preventable opportunistic infection was 66.7 per 100 person-years compared with 2.3 per 100 person-years for those without a history of preventable opportunistic infection (RR = 28.4, 95% CI: 24.7-32.8). In the adjusted analysis, the relative hazard of death for those with a history of preventable opportunistic infections was 7.0 (5.8-8.3), whereas antiretroviral therapy was associated with a decreased risk of death (0.37 [0.30-0.44]). We found no association between maximum HIV-1 RNA and chronic mortality. There was statistically significant effect modification between preventable opportunistic infections and CD4 cell count (p <.0001).

INTERPRETATION

Preventable opportunistic infections cause not only short-term mortality in HIV-1 disease but appear to have a major impact on chronic mortality.

Clinical efficacy of early initiation of HAART in patients with asymptomatic HIV infection and CD4 cell count > 350 x 10(6) /l

OBJECTIVE

To evaluate the efficacy of early initiation of highly active antiretroviral therapy (HAART), we compared the clinical course of two nested, matched cohorts within the Swiss HIV Cohort Study.

METHODS

We selected all asymptomatic patients who started HAART between 1 January 1996 and 31 December 1999 with a CD4 cell count > 350 x 10(6)/l. We then matched them with asymptomatic participants who were seen at around the same time and who remained untreated during the following 12 months. This control group was further matched for age, sex, CD4 cell count, viral load, and HIV risk category, generating 283 pairs of treated versus untreated patients.

RESULTS

During observation of median 3.19 versus 2.66 years, CDC stage B/C occurred in 6.4% versus 21.2%, AIDS in 1.8% versus 5.3%, death in 2.1% versus 6.4%, and AIDS or death of 'natural' causes in 2.8% versus 6.7% of the treated versus untreated patients. In multivariable Cox regression analysis, treatment reduced the risk of clinical progression by a factor of four- to five fold. During follow-up, the treated group had significantly higher CD4 counts and lower HIV-1 RNA levels. Intolerance/adverse events led to change or stop of at least one drug in 35% of treated patients. The entire regimen was interrupted at least once by 41% of patients, and 24% had no treatment anymore at the end of follow-up.

CONCLUSIONS

The initiation of HAART in asymptomatic patients with CD4 cell count > 350 x 10(6)/l significantly delayed clinical progression. However, the risk of severe clinical events with deferred therapy was low and must be counter balanced against the burden and toxicity of HAART.

Effect of highly active antiretroviral therapy on incidence of tuberculosis in South Africa: a cohort study

BACKGROUND

Studies of the effect of highly active antiretroviral therapy (HAART) on the risk of HIV-1-associated tuberculosis have had variable results. We set out to determine the effect of HAART on the risk of tuberculosis in South Africa.

METHODS

We compared the risk of tuberculosis in 264 patients who received HAART in phase III clinical trials and a prospective cohort of 770 non-HAART patients who were attending Somerset Hospital adult HIV clinic, University of Cape Town, between 1992 and 2001. Poisson regression models were fitted to determine risk of tuberculosis; patients were stratified by CD4 count, WHO clinical stage, and socioeconomic status.

FINDINGS

HAART was associated with a lower incidence of tuberculosis (2.4 vs 9.7 cases per 100 patient-years, adjusted rate ratio 0.19 [95% CI 0.9-0 38]; p<0.0001). This finding was apparent across all strata of socioeconomic status, baseline WHO stage, and CD4 count, except in patients with CD4 counts of more than 350 cells/microL. The number of tuberculosis cases averted by HAART was greatest in patients with WHO stage 3 or 4 (18.8 averted cases per 100 patient-years, adjusted rate ratio 0. 22 [0.09-0.41]; p=0.03) and in those with CD4 counts of less than 200 cells/microL (14.2 averted cases per 100 patient-years, adjusted rate ratio 0.18 [0.07-0.47]; p,0.0001).

INTERPRETATION

HAART reduced the incidence of HIV-1-associated tuberculosis by more than 80% (95% CI 62-91) in an area endemic with tuberculosis and HIV-1. The protective effect of HAART was greatest in symptomatic patients and those with advanced immune suppression.

AIDS related opportunistic infections, going but not gone

It is now more than two decades since the AIDS epidemic began with a cluster of Pneumocystis carinii pneumonia (PCP) in a community of homosexual men. Since then, many other infections have been characterized as opportunistic infections secondary to HIV infection. These include, but are not limited to, infections with Toxoplasma gondii, Cytomegalovirus (CMV), Mycobacterium avium complex (MAC), and Cryptococcus neoformans. Over the last two decades, there have been dramatic improvements in diagnosis, prevention and treatment of all these infections. As a result, in North America and Western Europe the rates of opportunistic infections secondary to AIDS have decreased substantially. We will review these common opportunistic infections below.

[Recommendations of the Spanish AIDS Study Group (GESIDA) and the National Aids Plan (PNS) for antiretroviral treatment in adult patients with human immunodeficiency virus infection in 2002]

OBJECTIVE

To provide an update of recommendation on antiretroviral treatment (ART) in HIV-infected adults.Methods. These recommendations have been agreed by consensus by a committee of the spanish AIDS Study Group (GESIDA) and the National AIDS Plan. To do so, advances in the physiopathology of AIDS and the results on efficacy and safety in clinical trials, cohort and pharmacokinetics studies published in biomedical journals or presented at congresses in the last few years have been reviewed. Three levels of evidence have been defined according to the data source: randomized studies (level A), case-control or cohort studies (level B) and expert opinion (level C). Whether to recommend, consider, or not to recommend ART has been established for each situation.

RESULTS

Currently, ART with combinations of at least three drugs constitutes the treatment of choice in chronic HIV infection. In patients with symptomatic HIV infection, initiation of ART is recommended. In asymptomatic patients initiation of ART should be based on the CD41/mL lymphocyte count and on the plasma viral load (PVL): a) in patients with CD41 lymphocytes < 200 cells/mL, initiation of ART is recommended; b) in patients with CD41 lymphocytes between 200 and 300 cells/mL, initiation of ART should, in most cases, be recommended; however, it could be delayed when the CD41 lymphocyte count remains close to 350 cells/mL and the PVL is low, and c) in patients with CD41 lymphocytes > 350 cells/mL, initiation of ART can be delayed. The aim of ART is to achieve an undetectable PVL. Adherence to ART plays a role in the durability of the antiviral response. Because of the development of cross-resistance, the therapeutic options in treatment failure are limited. In these cases, genotypic analysis is useful. Toxicity limits ART. The criteria for ART in acute infection, pregnancy and postexposure prophylaxis and in the management of coinfection with HIV and hepatitis C and B virus are controversial.

CONCLUSIONS

The current approach to initiating ART is more conservative than in previous recommendations. In asymptomatic patients, the CD41 lymphocyte count is the most important reference factor for initiating ART. Because of the considerable number of drugs available, more sensitive monitoring methods (PVL) and the possibility of determining resistance, therapeutic strategies have become much more individualized.

Involvement of Bcl-2 and IL-2R in HIV-positive patients whose CD4 cell counts fail to increase rapidly with highly active antiretroviral therapy

OBJECTIVE

Combination antiretroviral therapy in a subset of HIV-infected patients, here called CD4-low responders (CD4-LR), fails to produce a rapid rise in CD4 cell counts despite effective control of plasma viral load (< 50 copies/ml). The mechanism responsible for this failure was investigated.

DESIGN AND METHODS

CD4-LR patients (n = 13) included in the study had been receiving stable antiretroviral therapy for > 9 months, resulting in undetectable viral load, but nontheless showed a CD4 cell count of < 200 x 106 cells/l. Samples from these patients were analysed for intracellular expression of the anti-apoptotic molecule Bcl-2 and the in vitro apoptosis of their CD4 lymphocytes. Since interleukin-2 (IL-2) induces Bcl-2 and participates in the control of lymphocyte apoptosis, we also investigated the IL-2/IL-2 receptor (IL-2R) system in these CD4-LR patients. All these investigations were performed before and after the CD4-LR patients received IL-2 therapy.

RESULTS

CD4 T lymphocytes from these patients underexpressed the anti-apoptotic molecule Bcl-2 and were more susceptible to spontaneous apoptosis. Peripheral CD4 T lymphocytes from the CD4-LR patients showed a regulatory dysfunction in the IL-2R system that resulted in a lack of reactivity to IL-2. Overall, the results obtained with CD4-LR patients differed radically from those in patients undergoing successful antiretroviral therapy. Finally, an increase in Bcl-2 expression and IL-2 reactivity was observed in the CD4 T lymphocytes of CD4-LR patients receiving IL-2 immunotherapy. This correlated with a reduction in their apoptosis.

CONCLUSION

Our study characterizes the defective maintenance of peripheral CD4 T lymphocytes in CD4-LR patients, probably resulting from Bcl-2 underexpression and dysregulation of the IL-2R system.

Hospital and outpatient health services utilization among HIV-infected patients in care in 1999

BACKGROUND

The evolving epidemiology and therapeutic management of HIV disease has important implications for health care resource utilization in HIV-infected patients, and health care resource use data are also needed to support policy and financial decision making.

METHODS

Demographic, clinical, and resource utilization data were collected from 9 U.S. HIV primary and specialty care sites in calendar year 1999. Rates of resource use were calculated for hospital admission, length of hospital stay, and outpatient clinic/office visits.

RESULTS

The sample included 5255 patients from HIV primary care sites in 3 eastern, 3 midwestern, and 3 western areas of the United States. Hospital admissions accounted for an annual mean of 297 days per 100 persons/y in 1999. Hospital days ranged from a low of 165 per 100 persons/mo for a CD4 > 500 cells/mm(3) to 840 per 100 persons/mo for a CD4 < 50 cells/mm(3) (p <.01). Mean annual outpatient clinic/office visits were 10.7 per person in 1999. A declining CD4 level and an increasing HIV-1 RNA level were both associated with higher hospital and outpatient utilization. HAART use was associated with fewer hospital days, and a higher outpatient visit rate. Injecting drug use risk was associated with an increase in hospital days. African American race was associated with a higher number of hospital days, but a lower outpatient visit rate. Female gender was associated with higher outpatient utilization. Mean monthly inpatient and outpatient expenditures in 1999 were $423 and $168, respectively.

CONCLUSION

As HIV care continues to evolve, data from our network of HIV providers will be useful in quantifying changes in HIV health services utilization to guide policy makers, as well as HIV care payers and providers.

Impact of antiretroviral therapy on decreasing hospitalization rates of HIV-infected patients in 2001

Effective antiretroviral therapy initially resulted in large decreases in hospitalization rates of HIV-infected patients. The goal of this study was to determine whether these gains were being maintained in 2001. A cross-sectional study of hospital admission characteristics during four time periods was performed. All patients receiving care at the HIV clinics of New York Presbyterian Hospital-Cornell Medical Center (NYPH) in New York City were included. In 1995, 883 outpatients were receiving care for HIV infection at NYPH; this increased to 1990 outpatients by 2001. Demographic and laboratory information was obtained for these outpatients, and diagnoses were recorded for all patients requiring hospitalization on at NYPH during the time periods January 1 through June 30, in 1995, 1997, 1999, and 2001. The incidence of hospital admission declined in all four time periods: 1995 (95 per 100 patient-years [pt-yr]), 1997 (48 per 100 pt-yr), 1999 (38 per 100 pt-yr, p < 0.05), and 2001 (25 per 100 pt-yr). The incidence of bacterial pneumonia and opportunistic infections (OIs) decreased in all four time periods. The median hospitalization were CD4(+) cell count for outpatients increased from 231 (1995) to 364 (2001). Important predictors of hospitalization were CD4(+) < 200, and IVDU as an HIV risk factor. Since 1995 and the introduction of highly active antiretroviral therapy, continuing increases in CD4(+) cell counts of outpatients has been reflected in persistent declines in hospitalization rates. Large decreases in OIs and pneumonia have been minimally offset by stable rates of hospital admissions for diagnoses such as hepatitis, cirrhosis, and cellulitis.

Evaluation of the effectiveness of highly active antiretroviral therapy in persons with human immunodeficiency virus using biomarker-based equivalence of disease progression

The association of different CD4(+) cell counts with the same disease risk in treated and untreated populations reflects the effectiveness of highly active antiretroviral therapy (HAART) in persons with human immunodeficiency virus (HIV). Clinical progression of disease following initiation of HAART was determined for 679 HIV-infected men in the Multicenter AIDS Cohort Study by means of Kaplan-Meier survival analyses. Cox proportional hazards models were used to assess the effects of markers of HIV disease, antiretroviral history, and demographic factors. Men who had been followed since January 1993 (pre-HAART) were used to identify CD4(+) levels associated with the acquired immunodeficiency syndrome (AIDS)-free time equivalent to that of men starting HAART with CD4(+) cell counts of <200 cells/microl. Within 3.5 years following HAART initiation, 11.3% of the subjects developed AIDS and 8.5% died. Determinants of AIDS were a CD4(+) cell count of <200 cells/microl at initiation (relative hazard = 2.25, 95% confidence interval: 1.13, 4.49) and age >45 years at initiation (relative hazard = 1.92, 95% confidence interval: 0.98, 3.77). An increase in CD4(+) cell count of >50 cells/microl immediately after HAART initiation also improved prognosis (relative hazard = 0.34, 95% confidence interval: 0.16, 0.71). AIDS risk in men starting HAART with CD4(+) counts of <200 cells/microl (median = 132) was similar to that of non-HAART users with CD4(+) counts of 375-475 cells/microl (median = 432). The equivalence of disease progression to that of nonusers with approximately 300 more cells per microl demonstrates that HAART users have a broader reconstitution of the immune system beyond that of observed increases in CD4(+) cell count.

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

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

Decreased frequency of cytomegalovirus (CMV)-specific CD4+ T lymphocytes in simian immunodeficiency virus-infected rhesus macaques: inverse relationship with CMV viremia

The frequency of cytomegalovirus (CMV)-specific CD4+ T lymphocytes was determined in CMV-seropositive rhesus macaques with or without simian immunodeficiency virus (SIV) infection by using the sensitive assays of intracellular cytokine staining and gamma interferon ELISPOT. Both techniques yielded 3- to 1,000-fold-higher frequencies of CMV-specific CD4+ T lymphocytes than traditional proliferative limiting dilution assays. The median frequency of CMV-specific CD4+ T lymphocytes in 23 CMV-seropositive SIV-negative macaques was 0.63% (range, 0.16 to 5.8%). The majority of CMV-specific CD4+ T lymphocytes were CD95(pos) and CD27(lo) but expressed variable levels of CD45RA. A significant reduction (P < 0.05) in the frequency of CMV-specific CD4+ T lymphocytes was observed in pathogenic SIV-infected macaques but not in macaques infected with live attenuated strains of SIV. CMV-specific CD4+ T lymphocytes were not detected in six of nine pathogenic SIV-infected rhesus macaques. CMV DNA was detected in the plasma of four of six of these macaques but in no animal with detectable CMV-specific CD4+ T lymphocytes. In pathogenic SIV-infected macaques, loss of CMV-specific CD4+ T lymphocytes was not predicted by the severity of CD4+ T lymphocytopenia. Neither was it predicted by the pre-SIV infection frequencies of CD45RA(neg) or CCR5(pos) CMV-specific CD4+ T lymphocytes. However, the magnitude of activation, as evidenced by the intensity of CD40L expression on CMV-specific CD4+ T lymphocytes pre-SIV infection, was three- to sevenfold greater in the two macaques that subsequently lost these cells after SIV infection than in the two macaques that retained CMV-specific CD4+ T lymphocytes post-SIV infection. Future longitudinal studies with these techniques will facilitate the study of CMV pathogenesis in AIDS.

HIV-related morbidity and mortality in patients starting protease inhibitors in very advanced HIV disease (CD4 count of < 50 cells/microL): an analysis of 338 clinical events from a randomized clinical trial

BACKGROUND

AIDS defining events occur infrequently in the presence of CD4 counts above 200 cells/microL. It is, however, uncertain for most of the AIDS defining conditions whether this threshold can be considered equally safe in patients with a previously very low CD4 nadir.

METHODS

We evaluated in detail all the AIDS defining events observed during a 48-week clinical trial in 1251 nucleoside reverse transcriptase inhibitor-experienced patients who started protease inhibitors (PIs) at CD4 counts below 50 cells/microL. The type of event, immunological status at the moment of event and time between start of PI treatment and event occurrence were analysed cumulatively and by event type; event rates were calculated.

RESULTS

Concomitant data on CD4 counts were available for 338 AIDS defining events (81% of total events). Median time between start of treatment with PI and event was 94.5 days and median absolute CD4 value at the occurrence of event was 20 per microL. Only 14 events (in 12 patients) were observed above the threshold of 200 CD4 cells/microL. An analysis of the 67 deaths with concomitantly available CD4 counts (57%) showed a median CD4 count of 10 cells/microL, with only four deaths occurring in the presence of a CD4 count above 100 cells/microL.

CONCLUSIONS

Very few clinical AIDS defining conditions were observed in patients who start PIs at very low CD4 counts and with treatment restore absolute values in CD4 counts above 200 cells/microL. This threshold can therefore be considered a clinically effective goal of treatment with respect to occurrence of all AIDS defining conditions in patients starting PIs in very advanced HIV disease.

Impact of occasional short interruptions of HAART on the progression of HIV infection: results from a cohort study

OBJECTIVES AND DESIGN

To investigate the clinical consequences of occasional and short (<or= 3 months) treatment interruptions in patients having initiated highly active antiretroviral therapy (HAART). Data from the prospective Swiss HIV Cohort Study were used.

METHODS

Four different endpoints [death, Centers for Disease Control and Prevention (CDC) stages B and C, and CD4 cell count increase >or= 50 x 106/l] were studied in relation to the number of interruptions that occurred. In order to focus on short interruptions exclusively, observations of patients with a treatment interruption of > 3 months were censored. The CD4 cell count and viraemia were treated as time-dependent variables because of the importance of these factors when an interruption occurs.

RESULTS

Between 1 January 1996 and 31 October 2000, 4720 Swiss HIV Cohort Study participants initiated HAART, which was interrupted at least once by 1299 participants. The main reasons for the interruptions were social factors. Interruptions did not increase significantly the risk of HIV-associated morbidity and mortality, except for a marginally increased risk for a CDC stage C event after the first interruption. The first interruption decreased significantly the likelihood of increasing the CD4 cell count. Subsequent interruptions had no further significant effect. High CD4 cell count and low viraemia, assessed as baseline and as longitudinal variables, were associated with a decreased risk of clinical progression.

CONCLUSIONS

Occasional treatment interruptions of < 3 months neither worsen nor improve disease outcome on an average term (3-4 years). Our results suggest that interruptions might be non-risky, particularly when viraemia is low and CD4 cell count is high. These results require confirmation.

New developments in laboratory monitoring of HIV-1 infection

The laboratory tests currently available to the clinician for day-to-day management of HIV infection are generally limited to the measurement of the viral load and of the CD4 cell count. More recently, analysis of drug resistance and of plasma drug levels have been added to the monitoring armamentarium. There are, however, numerous other techniques currently available to researchers that may in the future be incorporated into clinical routine. These include the analysis of human and viral genetic determinants of disease evolution, detailed analyses of immune recovery and reserve, pharmacogenetic determinants of treatment response, and toxicity. These approaches may in the future provide highly individualized disease management.

Reduced risk of tuberculosis among Brazilian patients with advanced human immunodeficiency virus infection treated with highly active antiretroviral therapy

This observational study assessed the effect of combination antiretroviral therapy on the risk of tuberculosis among 255 patients with human immunodeficiency virus (HIV) infection and advanced immunodeficiency who were living in an area of Brazil with a high incidence of tuberculosis. The use of highly active antiretroviral therapy in regions with a high prevalence of coinfection with HIV and Mycobacterium tuberculosis may contribute a lower incidence of tuberculosis.

Simultaneous occurrence of 2 HIV-related immunereconstitution diseases after initiation of highly active antiretroviral therapy

The case of a 44-y-old woman with HIV infection and cytomegalovirus retinitis in whom antiretroviral therapy (HAART) revealed pulmonary cryptococcosis is presented. Pulmonary cryptococcosis occurred simultaneously with immune recovery uveitis after starting HAART, showing that complex clinical pictures may arise from immunreconstitution diseases.

HIV disease and advanced age: an increasing therapeutic challenge

The mean age of patients at both first HIV detection and AIDS diagnosis is progressively rising over time. However, reliable epidemiological estimates, clinical data or controlled therapeutic and outcome figures are lacking for elderly patients, especially with regard to laboratory and clinical response to antiretroviral therapy, treatment tolerability, drug-drug interactions, short- and long-term toxicity, and interactions with underlying illnesses and concurrent pharmacological treatment. In fact, the large majority of randomised, controlled trials evaluating and comparing new antiretroviral drugs or anti-HIV therapeutic strategies, as well as antimicrobial treatment or chemoprophylaxis of HIV-related complications, either excluded patients with advanced age and/or concurrent disorders or did not offer substudies or detailed data analysis focusing on older patients compared with younger ones. The life expectancy of HIV-infected persons receiving highly active antiretroviral therapy (HAART) is now extended (approaching that of the general population), so that the definition of AIDS has lost its epidemiological and clinical significance thanks to the immune reconstitution resulting from potent antiretroviral therapy. However, an ever-increasing number of individuals aged > or =50 years with HIV infection is expected in the coming years, as a result of both increased survival of patients with treated disease and delayed recognition of individuals with occult HIV disease. The limited data available about combined antiretroviral therapy in the elderly seem to show an overlapping virological success rate but a slower and blunted immune recovery compared with younger patients. Thymic output, however, seems somewhat preserved even in adulthood and may contribute to the reconstitution of most of the quantitative and functional T cell abnormalities caused by HIV disease. More attention must be paid to underlying end-organ disorders, as well as expected pharmacological interactions and combined drug toxicity that may interfere with HAART efficacy and patients' compliance with recommended regimens and could lead to increased adverse effects. The available guidelines for antiretroviral treatment and therapy and prophylaxis of AIDS-related illnesses should be regularly updated and should include problems related to HIV disease in an aging population. Specific trials or substudies focusing on older people are warranted to obtain controlled data on all issues of antiretroviral therapy in the elderly, including time and mode of initiation, and modification and salvage HAART regimens. Antiretroviral drug dosage adjustment to take into account underlying pathological conditions or other pharmacological treatments is another emerging issue.

Paradoxical reaction to the treatment of tuberculosis uncovering previously silent meningeal disease

The development of paradoxical clinical worsening following initiation of tuberculosis treatment may complicate the clinical course of both HIV-infected and uninfected patients. We report a severe manifestation of the so called paradoxical reaction to the treatment of tuberculosis that unmasked previously silent meningeal disease in a 34-year-old HIV-infected male patient.

Human immunodeficiency virus-related lymphoma: relation between clinical features and histologic subtypes

PURPOSE

Non-Hodgkin's lymphoma occurs frequently in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). We determined the association between the clinical and histologic features of HIV-related lymphoma.

SUBJECTS AND METHODS

We reviewed the medical records of 291 patients with noncerebral HIV-related lymphoma who had been treated in multicenter trials coordinated by the Groupe d'Etude des Lymphomes de l'Adulte between 1988 and 1997. This study was performed mainly before the availability of combination antiretroviral therapy.

RESULTS

The main histologic subtypes were centroblastic lymphoma in 131 patients (45%), immunoblastic lymphoma in 39 patients (13%), and Burkitt's lymphoma (including the classical form and the variant with plasmacytic differentiation) in 115 patients (40%). Burkitt's lymphoma was the most aggressive form, whereas immunoblastic lymphoma occurred in severely immunodeficient patients. Two-year survival after enrollment was 15% in immunoblastic lymphoma, 32% in Burkitt's lymphoma, and 31% in centroblastic lymphoma (P = 0.006), but multivariate analysis did not confirm the independent prognostic value of histologic subtype. Instead, five independent pretreatment factors increased the risk of mortality: age 40 years or older [relative risk (RR) = 1.5; 95% confidence interval (CI), 1.1 to 2.1; P = 0.005], elevated serum lactate dehydrogenase level (RR = 1.5; 95% CI, 1.1 to 2.1; P = 0.02), having a diagnosis of AIDS before lymphoma (RR = 1.8; 95% CI, 1.2 to 2.6; P = 0.006), CD4(+) cell count less than 100 x 10(6)/L (RR = 1.8; 95% CI, 1.3 to 2.6; P = 0.0004), and impaired performance status (RR = 2.4; 95% CI, 1.7 to 3.4; P <0.0001).

CONCLUSION

Several pretreatment characteristics of HIV-related lymphoma were linked to the histologic form, but HIV disease parameters other than those of lymphoma were the main determinants of outcome, so the histologic features of the lymphoma were not associated with prognosis.

Durability of HIV-1 viral suppression over 3.3 years with multi-drug antiretroviral therapy in previously drug-naive individuals

BACKGROUND

Relatively little is known about the long-term durability of viral suppression in individuals initially achieving a viral load of less than 50 copies/ml within 24 weeks of starting antiretroviral therapy, nor the extent to which therapy interruption accounts for the loss of suppression.

METHODS

We intensely followed all 336 antiretroviral-naive patients attending the Goethe Universitat Clinic who began multi-drug combination regimens and in whom a viral load of less than 50 copies/ml was achieved within 24 weeks, in order to assess the risk of viral load rebound. Inspection of case notes allowed the distinction of viral rebound according to whether there was an associated complete interruption of therapy.

RESULTS

A total of 61 patients experienced viral rebound during 543.1 person-years of follow-up, giving a 25.3% risk of rebound by 3.3 years from first achieving viral suppression. However, for 47 of the patients with viral rebound there was an associated documented complete interruption of antiretroviral therapy, mostly as a result of co-morbidities, leaving 14 who appear to represent a failure of the virological efficacy of therapy (viral breakthrough; 5.2% risk by 3.3 years). The risk of viral breakthrough declined with the increased duration of suppression (P = 0.01).

CONCLUSION

The intrinsic virological effectiveness of multi-drug antiretroviral therapy in previously drug-naive individuals appears to be such that viral suppression, once achieved, can be maintained for several years in patients not interrupting therapy. The major challenge is to develop regimens that can be taken consistently and safely for such long periods of time.

Immune reconstitution in HIV-1-infected individuals treated with potent antiretroviral therapy

Potent combination antiretroviral therapy that was introduced in the mid-1990s for treatment of HIV-1 infection has resulted in unprecedented decreases in HIV-1 replication and increases in CD4+ T cell counts in many individuals. Coincident with the introduction of potent combination antiretroviral therapy, substantial declines in AIDS-related morbidity and mortality have been observed. Although these declines strongly suggest that significant immune reconstitution is occurring, increasing evidence suggests that immune reconstitution is neither uniform nor complete in all treated individuals. Clinical data suggest that some HIV-1-associated malignancies have not declined despite the new therapies, and that not all treated individuals reconstitute CD4+ T cell numbers to normal values. Laboratory studies reveal that immune responses to ubiquitous antigens are reconstituted, but that responses to rarely encountered antigens, such as tetanus, are not reconstituted without repeat vaccination. Many questions remain concerning the extent and clinical significance of the immune reconstitution that occurs in the setting of antiretroviral drug therapy. A better understanding of the nature of the immune reconstitution that results from potent antiretroviral therapy is critical to the optimal clinical management of HIV-1-infected individuals, and may provide important insights into the immunopathogenesis of HIV-1 infection as well.

Cidofovir treatment of progressive multifocal leukoencephalopathy in a patient receiving highly active antiretroviral therapy

Progressive multifocal leukoencephalopathy (PML), a frequently fatal demyelinating disease caused by JC virus, occurs as an opportunistic infection in patients with acquired immunodeficiency syndrome. Curative therapy has been elusive, but recent reports suggest its improvement after institution of highly active antiretroviral therapy (HAART). We describe a case of PML that developed 6 months after the patient, a 55-year-old man, began to receive HAART. The PML progressed despite good virologic and immunologic response to HAART. Substantial symptomatic and radiographic improvement occurred after the addition of cidofovir to the treatment regimen. We reviewed the scientific literature on this rare occurrence of PML after institution of HAART and describe the patient characteristics, potential pathogenesis, and therapeutic options, including the successful use of cidofovir as an adjunctive agent.

Trends in immunologic and clinical status of newly diagnosed HIV-positive patients initiating care in the HAART era

OBJECTIVE

To evaluate whether the availability of highly active antiretroviral therapy (HAART) has motivated people at risk for HIV infection to be tested earlier.

METHODS

Data are from the Adult and Adolescent Spectrum of HIV Disease (ASD) Study, a chart review study of HIV-infected people receiving care. The sample comprised newly diagnosed HIV-positive persons initiating care at five ASD clinics in New York City (NYC) 1994 to 1999. CD4 + lymphocyte count and clinical status (asymptomatic, major AIDS-related symptoms, AIDS-defining opportunistic illnesses) at first visit were ascertained. Trends in these two outcomes were analyzed comparing each time period after the second half of 1996 with the aggregate period from 1994 to the first half of 1996.

RESULTS

Between 1994 and 1999, we identified 545 patients newly diagnosed as positive for HIV with a first visit to an ASD clinic. Patients were predominantly black or Hispanic (93%). The mean CD4 + count at baseline was 246 cells/microl and the median was 152 cells/microl. After adjusting for covariates, the mean CD4 + count of newly diagnosed HIV-positive patients was significantly lower ( p =.04) only during the second half of 1997. The proportion of patients who were asymptomatic at baseline ranged from 29% in the second half of 1998 to 61% in the first half of 1994 (chi 2 = 48.8; p =.0008). After adjustment for covariates, the probability of a patient having a major symptom or an opportunistic illness at baseline was significantly higher only during the second half of 1998 ( p =.001).

DISCUSSION

During most time periods, both before and after the introduction of HAART, most newly diagnosed patients at these five HIV clinics in NYC were immune suppressed and symptomatic.

Cardiology and AIDS--HAART and the consequences

Since the introduction of highly active antiretroviral therapy (HAART), AIDS has become a treatable disease. A steep decline in morbidity and mortality has been observed in most western countries. The HIV epidemic is now moving into middle-aged populations which are already at increased risk for cardiovascular disease. Since the cardiovascular system is frequently affected in HIV infection, reflections on traditional cardiovascular risk factors is a pressing issue. Moreover, during the last few years, complex lipodystrophic body changes in association with metabolic abnormalities such as dyslipidemia and insulin resistance have become a common feature in HIV+ patients on HAART. Although the precise mechanisms are not fully understood, early reports on myocardial infarctions and vascular changes have raised concern about the possibility of an epidemic of cardiovascular events among HAART patients within the next decade. Not only more data on lipid-lowering drugs in the context of HAART, on switching strategies, and treatment interruptions, but also from intervention studies on traditional risk factors such as smoking, are urgently needed. In this review the key issues concerning cardiovascular aspects of HIV infection in the era of HAART and possible preventive strategies are discussed.

Does plasma HIV RNA predict outcome in a cohort of treated HIV-infected individuals followed over 3 years?

BACKGROUND

Despite reductions in AIDS illness and mortality, it is increasingly apparent that a significant proportion of individuals treated with combination antiretroviral (cARV) therapy have continuing or recrudescent HIV RNA in plasma. The predictive value of plasma HIV RNA in treated individual remains uncertain and rates of and risk factors for adverse outcomes such as hospitalisation, opportunistic infections and deaths are needed.

OBJECTIVES

The objectives of this study were to establish a retrospective cohort of individuals treated with cARVs, to assess factors associated with detectable HIV RNA and to determine rates of and risk factors for hospitalisation, opportunistic infection and mortality over 3 years of follow-up.

STUDY DESIGN

All individuals treated at The Alfred Hospital, Melbourne, Victoria between January and June 1997 who had had plasma HIV RNA measured were included in the retrospective cohort. Clinical, virological and hospitalisation data were recorded and validated by cross-reference with electronically stored laboratory, hospital activity and state notification databases. Outcome was assessed at October 2000.

RESULTS

Amongst the 555 individuals tested, 438 (60.7%) had detectable (>500 copies/ml) HIV RNA (bDNA assay, version 2) at baseline. The overall mortality rate was 5.5 per 100 person years; the AIDS rate 1.99 per 100 person years and hospitalisation rate 16.4 per 100 person years. Risk factors for death in this population identified by univariate analysis were HIV RNA concentration at baseline and at follow-up October 2000, nadir and most recent CD4 lymphocyte number, not receiving cARV as initial treatment, total number of ARV agents and number of changes in ARV per year, developing AIDS and being hospitalised during follow-up. In a multivariate model, the most recent CD4 lymphocyte number, the number of different ARVs per year and having more than one hospitalisation remained predictive of death.

CONCLUSIONS

HIV RNA remained detectable in the majority (60.7%) of this treatment-experienced population over 3 years, yet mortality rate remained relatively low at 5.5 per 100 person years. Factors associated with death were immunological (CD4 lymphocyte number) and treatment related (numbers of changes of ARV and hospitalisation) rather than virological (HIV RNA) in this cohort. We believe hospitalisation rates may be a useful marker of HIV disease in cARV treated populations and may identify groups at risk of poorer outcome and in need of intervention.

Virologic and immunologic parameters that predict clinical response of AIDS-associated Kaposi's sarcoma to highly active antiretroviral therapy

The purpose of the work was to assess the predictive value of biologic factors on the efficacy of highly active antiretroviral therapy alone or combined with chemotherapy on AIDS-associated Kaposi's sarcoma. Twenty-six AIDS-Kaposi's sarcoma patients who started therapy with protease inhibitors were investigated. No baseline chemotherapy was associated with less severe initial clinical status. Median follow-up was 652 d. The main outcome measures were as follows: best Kaposi's sarcoma clinical response; Kaposi's-sarcoma-associated herpesviral load in peripheral blood mononuclear cells using real-time quantitative polymerase chain reaction (non-detectable if less than 100 copies per microg); human immunodeficiency viral charge in plasma (non-detectable if less than 200 copies per ml); and CD4 lymphocyte count. Time to undetectable Kaposi's-sarcoma-associated herpesviral load, time to undetectable human immunodeficiency viral charge, and time to CD4 >or= 150 per microl were also recorded over time, from 2 mo measurements. Patients were staged according to the AIDS Clinical Trials Group-based tumor, immune, systemic staging system criteria. At baseline, Kaposi's sarcoma was progressive for 25 (96%) of the 26 enrolled patients. Complete or partial response to highly active antiretroviral therapy alone or combined with chemotherapy was achieved in 22 patients (85%). Median time to clinical response was estimated at 251 d. Clinical response was faster in patients without chemotherapy at baseline (p = 0.003) as well as in patients not previously treated with reverse transcriptase inhibitors (p = 0.0012). Using univariable analyses, predictive factors of clinical response were undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.013), undetectable human immunodeficiency viremia (p = 0.03), and relative variation of CD4 lymphocytes (p = 0.004). Using multivariable analysis, undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.009) and relative variation of CD4 (p = 0.005) were independently selected as having a predictive value for clinical response. Occurrence of nondetection of either Kaposi's-sarcoma-associated herpesvirus or human immunodeficiency virus was not associated with baseline CD4 value. Kaposi's-sarcoma-associated herpesvirus quantitative viral charge is an independent predictive factor of the efficacy of highly active antiretroviral therapy on AIDS-Kaposi's sarcoma. Our results support immune reconstitution as a mechanism of response of Kaposi's sarcoma to highly active antiretroviral therapy.

Human immunodeficiency virus pathogenesis: insights from studies of lymphoid cells and tissues

Although plasma virus load is invaluable for monitoring human immunodeficiency virus (HIV) infection, key pathogenesis events and most viral replication take place in lymphoid tissues. Decreases in virus load associated with therapy occur in plasma and tissues, but persistent latent infection and ongoing viral replication are evident. Many unanswered questions remain regarding mechanisms of HIV-associated lymphocyte depletion, but partial CD4(+) cell reconstitution after therapy likely reflects retrafficking from inflamed tissues, increased thymic or peripheral production, and decreased destruction. Rapid establishment of latent infection and the follicular dendritic cell-associated viral pool within lymphoid tissues suggest that only early intervention could substantially alter the natural history of HIV. If therapy is started prior to seroconversion, some individuals retain potent HIV-specific cellular immune responsiveness that is suggestive of delayed progression. Although complete virus eradication appears out of reach at present, more attention is being directed toward the prospect of boosting HIV-specific immune responses to effect another type of "clinical cure": immune-mediated virus suppression in the absence of therapy.

Interferon-alpha generation and immune reconstitution during antiretroviral therapy for human immunodeficiency virus infection

OBJECTIVES

To quantify the effect of HIV infection and HIV-suppressive therapy on interferon-alpha (IFN-alpha) production by human blood mononuclear cells; to compare, in parallel, effects on CD4+ T-cell numbers; and to ascertain the relationship of these interferon and CD4 parameters to resistance to opportunistic infections.

DESIGN

Serial studies of 294 unselected patients with HIV infection during therapy, with outcomes analysis.

METHODS

Determination of IFN generation by blood mononuclear cells via bioassay, and T-lymphocyte subset analysis via flow cytometry; serial studies of individual patients; linear regression and chi2 contingency table analysis.

RESULTS

HIV burden is inversely related to interferon-alpha generation, much as it is to CD4+ T-cell counts. Both of these recover during HIV-suppressive therapy. Reconstitution of IFN-alpha generation to levels commensurate with protection against opportunistic infection occurs prior to similar restoration of CD4 counts. In the outcomes analyses, such immune reconstitution was associated with protection from recurrent or new opportunistic infection. Conversely, viral suppression without such immunologic recovery was not protective against opportunistic infection.

CONCLUSIONS

Rapidly responding IFN-alpha generating cells appear to participate in resistance to opportunistic intracellular infection. Recovery of IFN-alpha generation may be an early marker of immune reconstitution in AIDS.

Predicting the unpredictable: transmission of drug-resistant HIV

We use a mathematical model to understand (from 1996 to 2001) and to predict (from 2001 to 2005) the evolution of the epidemic of drug-resistant HIV in San Francisco. We predict the evolutionary trajectories for 1,000 different drug-resistant strains with each strain having a different fitness relative to a drug-sensitive strain. We calculate that the current prevalence of resistance is high, and predict it will continue to rise. In contrast, we calculate that transmission of resistance is currently low, and predict it will remain low. We show that the epidemic of resistance is being generated mainly by the conversion of drug-sensitive cases to drug-resistant cases, and not by the transmission of resistant strains. We also show that transmission of resistant strains has not increased the overall number of new HIV infections. Our results indicate that transmission of resistant strains is, and will remain, a relatively minor public health problem.

A prospective study of discontinuing primary and secondary Pneumocystis carinii pneumonia prophylaxis after CD4 cell count increase to > 200 x 106 /l

OBJECTIVE

To assess the incidence of Pneumocystis carinii pneumonia (PCP) after discontinuation of either primary or secondary prophylaxis.

DESIGN

This was a prospective, non-randomized, non-blinded study.

SETTING

Twenty-five University-based AIDS Clinical Trials Group units.

PARTICIPANTS

Participants either had a CD4 cell count < or = 100 x 106/l at any time in the past and no history of confirmed PCP (group I; n = 144), or had a confirmed episode of PCP > or = 6 months prior to study entry (group II; n = 129). All subjects had sustained CD4 cell counts > 200 x 106/l in response to antiretroviral therapy.

INTERVENTIONS

Subjects discontinued PCP prophylaxis within 3 months or at the time of study entry. Evaluations for symptoms of PCP and CD4 cell counts were performed every 8 weeks. Prophylaxis was resumed if two consecutive CD4 cell counts were < 200 x 106/l.

MAIN OUTCOME MEASURE(S)

The main outcome was development of PCP.

RESULTS

No cases of PCP occurred in 144 subjects (median follow-up, 82 weeks) in group I or in the 129 subjects (median follow-up, 63 weeks) in group II (95% upper confidence limits on the rates of 1.3 per 100 person-years and 1.96 per 100 person-years for groups I and II, respectively). Eight subjects (five in group I and three in group II) resumed PCP prophylaxis after two consecutive CD4 cell counts < 200 x 106/l.

CONCLUSIONS

The risk of developing initial or recurrent PCP after discontinuing prophylaxis is low in HIV-infected individuals who have sustained CD4 cell count increases in response to antiretroviral therapy. Neither lifelong primary nor secondary PCP prophylaxis is necessary.

Epidemiology and prognosis of AIDS-associated progressive multifocal leukoencephalopathy in the HAART era

Whereas most AIDS-related neurologic disorders have reduced incidence since HAART therapy was introduced, we find that the incidence of progressive multifocal leukoencephalopathy (PML) did not significantly differ between the pre-HAART and the HAART period (OR 0.78; 95% CI 0.41-1.50). These findings were confirmed by the preliminary results of the Italian Register Investigative Neuro AIDS (IRINA) Study, a prospective multicenter study started in January 2000, which showed that PML was the second most frequently diagnosed neurologic disorder after TE. A similar proportion of cases were found in HAART-naïve and HAART-experienced patients in our experience. PML was more common in the presence of HIV RNA > 500 copies/ml. Most of the cases occurring in HAART-exposed patients developed within the first 6 months of therapy. As others have reported, we find a prolonged survival in PML subjects prescribed HAART (245 days in the group treated with HAART versus 66 days in the group not treated with HAART; P at log rank = 0.001). However despite the survival benefit, AIDS-associated PML still has a serious prognosis. In fact, PML had the lowest 1-year survival probability of any cerebral disorder in our study (P = 0.0005). Our findings also confirm that CSF JCV DNA burden at baseline is a useful prognostic indicator with a threshold of 4.7 log(10) JCV copies/ml (P at log rank = 0.01) in our experience. CSF JCV DNA load at 4 weeks of follow-up and clearance of JCV-DNA from CSF are associated with a better neurologic outcome and a longer survival.

Clinical, biologic, and behavioral predictors of early immunologic and virologic response in HIV-infected patients initiating protease inhibitors

Predictors of virologic (plasma HIV RNA viral load [VL] < 500 copies/ml) and immunologic (rise in CD4+ cell count > 50 cells/mm3) response after 4 months of therapy (M4) were studied in 750 HIV-1-infected patients prospectively enrolled at the initiation of a protease inhibitor (PI)-containing regimen. A virologic response was observed in 80% of patients, and an immunologic response was observed in 64%. Sixty-two percent of patients self-reported full adherence to therapy at 1 month of therapy (M1) and M4. In multivariate analysis, a virologic response was more frequent in fully adherent patients (odds ratio [OR] = 2.0; p =.001). An immunologic response was associated with age < 36 years (OR =1.4; p =.03), baseline VL (OR = 1.5 per 1 log10 copies/ml higher; p <.01), decrease in VL at M1 (OR = 1.5 per 1 log10 copies/ml decrease; p <.01), baseline total lymphocyte count (OR = 1.7 per 50% lower; p <.001), and baseline CD4+ cell percentage > or = 20% (OR =1.9; p <.001) but not with adherence to therapy. Full adherence seems to be a major predictor of a virologic response to PI-containing triple therapy. An immunologic response may be possible despite incomplete adherence, at least early in therapy.

Incidence of primary opportunistic infections in two human immunodeficiency virus-infected French clinical cohorts

BACKGROUND

Clinical guidelines for the prevention of opportunistic infections in human immunodeficiency virus (HIV)-infected individuals have been developed on the basis of natural history data collected in the USA. The objective of this study was to estimate the incidence of primary opportunistic infections in HIV-infected individuals in geographically distinct cohorts in France.

METHODS

We conducted our study on 2664 HIV-infected patients from the Tourcoing AIDS Reference Centre and the hospital-based information system of the Groupe d'Epidémiologie Clinique du SIDA en Aquitaine enrolled from January 1987 to September 1995 and followed through December 1995. We estimated: (1) CD4-adjusted incidence rates of seven primary opportunistic infections in the absence of prophylaxis for that specific infection or any antiretroviral drugs other than zidovudine; and (2) CD4 lymphocyte count decline.

RESULTS

The highest incidence rates for all opportunistic infections studied occurred in patients with CD4 counts < 200/microl. With CD4 counts < 50/microl, the most common opportunistic infections were toxoplasmic encephalitis (12.6 per 100 person-years) and Pneumocystis carinii pneumonia (11.4 per 100 person-years). Mycobacterium tuberculosis was the least common opportunistic infection (< 5.0/100 person-years). Even with CD4 counts > 300/microl, cases of Pneumocystis carinii pneumonia and toxoplasmic encephalitis were reported. The mean CD4 lymphocyte decline per month was 4.6 cells/microl. There was a significant association between HIV risk behaviour and the incidence of cytomegalovirus infection, between calendar year and the incidence of Pneumocystis carinii pneumonia, toxoplasmic encephalitis and Candida esophagitis, and between geographical area and the incidence of Pneumocystis carinii pneumonia and cytomegalovirus infection.

CONCLUSIONS

Geographical differences exist in the incidence of HIV-related opportunistic infections. These results can be used to define local priorities for prophylaxis of opportunistic infections.

Longitudinal sero-reactivity to human herpesvirus 8 (KSHV) in the Swiss HIV Cohort 4.7 years before KS

The relationship between viral infection with Kaposi sarcoma-associated herpesvirus (KSHV) and the onset of Kaposi sarcoma (KS) in AIDS patients is incompletely understood. This study investigates the use of three serological assays to predict the development of KS in HIV-positive patients. Serially collected serum samples from 36 patients with KS and matched controls in the Swiss HIV Cohort Study (SHCS) were analyzed in a case control study. Three serologic assays to detect antibodies against KSHV (nuclear and membrane antigen immunofluorescence assay, N-IFA, M-IFA and ORF 65.2 ELISA) were used to determine the predictive value of KSHV-seropositivity. Serial samples from the cases were also analyzed to determine longitudinal patterns of seroreactivity and identify cases of seroconversion. Assay sensitivity for detection of KSHV antibodies was highest for M-IFA (83%), followed by N-IFA (74%) and 65.2 ELISA (52%). At the time of initial serum sampling (median 4.7 years before KS), only the N-IFA distinguished case and control sera (61% vs. 32%) and no assay was clearly predictive of subsequent onset of clinical KS. Moreover, an unexpectedly high rate of reversions to seronegativity were observed by N-IFA (27/33) as well as by 65.2 ELISA (11/26) in the longitudinal analysis. Analysis of the ORF65.2 ELISA index indicated that these reversions before the clinical onset of KS were associated with antibody levels that frequently hovered around the level of detectability. A marked increase in ORF 65.2 antibody titer occurred in a third of the patients at the time of KS diagnosis. Only two seroconversions were documented. KSHV infection within the SHCS is likely to have preceded HIV infection. KSHV infection alone is not highly predictive of KS development in this cohort of HIV-infected homosexual men as compared with matched controls. Three KSHV serologic assays, though sensitive at the time of clinical KS are inconsistently positive before the development of AIDS-related KS.