Increased survival of persons with tuberculosis and human immunodeficiency virus infection, 1991--2000

Duration of anti-tuberculosis therapy and timing of antiretroviral therapy initiation: association with mortality in HIV-related tuberculosis

Background

Antiretroviral therapy (ART) decreases mortality risk in HIV-infected tuberculosis patients, but the effect of the duration of anti-tuberculosis therapy and timing of anti-tuberculosis therapy initiation in relation to ART initiation on mortality, is unclear.

Methods

We conducted a retrospective observational multi-center cohort study among HIV-infected persons concomitantly treated with Rifamycin-based anti-tuberculosis therapy and ART in Latin America. The study population included persons for whom 6 months of anti-tuberculosis therapy is recommended.

Results

Of 253 patients who met inclusion criteria, median CD4+ lymphocyte count at ART initiation was 64 cells/mm³, 171 (68%) received >180 days of anti-tuberculosis therapy, 168 (66%) initiated anti-tuberculosis therapy before ART, and 43 (17%) died. In a multivariate Cox proportional hazards model that adjusted for CD4+ lymphocytes and HIV-1 RNA, tuberculosis diagnosed after ART initiation was associated with an increased risk of death compared to tuberculosis diagnosis before ART initiation (HR 2.40; 95% CI 1.15, 5.02; P = 0.02). In a separate model among patients surviving >6 months after tuberculosis diagnosis, after adjusting for CD4+ lymphocytes, HIV-1 RNA, and timing of ART initiation relative to tuberculosis diagnosis, receipt of >6 months of anti-tuberculosis therapy was associated with a decreased risk of death (HR 0.23; 95% CI 0.08, 0.66; P=0.007).

Conclusions

The increased risk of death among persons diagnosed with tuberculosis after ART initiation highlights the importance of screening for tuberculosis before ART initiation. The decreased risk of death among persons receiving > 6 months of anti-tuberculosis therapy suggests that current anti-tuberculosis treatment duration guidelines should be re-evaluated.

Factors that influence current tuberculosis epidemiology

According to WHO estimates, in 2010 there were 8.8 million new cases of tuberculosis (TB) and 1.5 million deaths. TB has been classically associated with poverty, overcrowding and malnutrition. Low income countries and deprived areas, within big cities in developed countries, present the highest TB incidences and TB mortality rates. These are the settings where immigration, important social inequalities, HIV infection and drug or alcohol abuse may coexist, all factors strongly associated with TB. In spite of the political, economical, research and community efforts, TB remains a major global health problem worldwide. Moreover, in this new century, new challenges such as multidrug-resistance extension, migration to big cities and the new treatments with anti-tumour necrosis alpha factor for inflammatory diseases have emerged and threaten the decreasing trend in the global number of TB cases in the last years. We must also be aware about the impact that smoking and diabetes pandemics may be having on the incidence of TB. The existence of a good TB Prevention and Control Program is essential to fight against TB. The coordination among clinicians, microbiologists, epidemiologists and others, and the link between surveillance, control and research should always be a priority for a TB Program. Each city and country should define their needs according to the epidemiological situation. Local TB control programs will have to adapt to any new challenge that arises in order to respond to the needs of their population.

HIV & immune reconstitution inflammatory syndrome (IRIS)

Antiretroviral therapy (ART) initiation in HIV-infected patients leads to recovery of CD4+T cell numbers and restoration of protective immune responses against a wide variety of pathogens, resulting in reduction in the frequency of opportunistic infections and prolonged survival. However, in a subset of patients, dysregulated immune response after initiation of ART leads to the phenomenon of immune reconstitution inflammatory syndrome (IRIS). The hallmark of the syndrome is paradoxical worsening of an existing infection or disease process or appearance of a new infection/disease process soon after initiation of therapy. The overall incidence of IRIS is unknown, but is dependent on the population studied and the burden of underlying opportunistic infections. The immunopathogenesis of the syndrome is unclear and appears to be result of unbalanced reconstitution of effector and regulatory T-cells, leading to exuberant inflammatory response in patients receiving ART. Biomarkers, including interferon-γ (INF-γ), tumour necrosis factor-α (TNF-α), C-reactive protein (CRP) and inter leukin (IL)-2, 6 and 7, are subject of intense investigation at present. The commonest forms of IRIS are associated with mycobacterial infections, fungi and herpes viruses. Majority of patients with IRIS have a self-limiting disease course. ART is usually continued and treatment for the associated condition optimized. The overall mortality associated with IRIS is low; however, patients with central nervous system involvement with raised intracranial pressures in cryptococcal and tubercular meningitis, and respiratory failure due to acute respiratory distress syndrome (ARDS) have poor prognosis and require aggressive management including corticosteroids. Paradigm shifts in management of HIV with earlier initiation of ART is expected to decrease the burden of IRIS in developed countries; however, with enhanced rollout of ART in recent years and the enormous burden of opportunistic infections in developing countries like India, IRIS is likely to remain an area of major concern.

A randomized trial of punctuated antiretroviral therapy in Ugandan HIV-seropositive adults with pulmonary tuberculosis and CD4⁺ T-cell counts of ≥ 350 cells/μL

BACKGROUND

Optimal treatment of human immunodeficiency virus (HIV)-associated tuberculosis in patients with high CD4⁺ T-cell counts is unknown. Suppression of viral replication during therapy for tuberculosis may block effects of immune activation on T cells and slow HIV disease progression.

METHODS

We conducted a randomized trial in 214 HIV-infected patients with active tuberculosis and CD4⁺ T-cell counts of ≥ 350 cells/μL to determine whether 6 months of antiretroviral therapy given during tuberculosis treatment would improve clinical outcomes. Subjects were randomized to receive 6 months of abacavir-lamivudine-zidovudine concurrent with tuberculosis therapy or delayed antiretroviral therapy. Endpoints were CD4⁺ T-cell counts of < 250 cells/μL, AIDS, or death.

RESULTS

Intervention and comparison arms had similar median CD4⁺ counts (517 and 534 cells/μL, respectively) and HIV RNA levels (4.6 and 4.7 log₁₀ copies/μL, respectively). Viral suppression was achieved in 86% of patients allocated to intervention. Seventeen subjects (15.6%) in the intervention arm developed study outcome compared to 25 subjects (22.8%) in the comparison arm (P = .17). Grade 3 or 4 adverse events were less frequent in the intervention arm. By 2 months, 90% of subjects in both arms were culture-negative for tuberculosis.

CONCLUSIONS

Short-term antiretroviral therapy during tuberculosis treatment in patients with CD4⁺T-cell counts of >350 cells/μL was safe and associated with clinical benefits.

Patients diagnosed with tuberculosis at death or who died during therapy: association with the human immunodeficiency virus

OBJECTIVES

To describe trends and risk factors for tuberculosis (TB) mortality.

DESIGN

We calculated trends, identified patient characteristics associated with TB diagnosis at death or death during TB treatment, and described diagnostic procedures using the United States National TB Surveillance System for 1997-2005.

RESULTS

Human immunodeficiency virus (HIV) infected TB patients had an adjusted odds ratio (aOR) of 4-11 for TB diagnosis at death (foreign-born non-Whites, aOR = 11) and of 3-19 for death during TB treatment vs. non-HIV-infected patients. Odds increased by age. Hispanic males had an aOR of 2 for TB diagnosis at death compared with female non-Hispanics. Multidrug-resistant TB (MDR-TB) patients had a three times greater aOR of death during treatment than non-MDR patients. American Indians, Black females, residents in long-term care facilities, US-born patients, and non-HIV-infected homeless persons aged 25-44 years each had an aOR of 2 for mortality during treatment; 86% of pulmonary patients diagnosed at death had a chest radiograph, but 34% had no sputum smear or culture reported.

CONCLUSION

During 1997-2005, controlling for age, HIV remained the characteristic with the greatest aOR for TB diagnosis at death or death during TB therapy. Race/ethnicity, country of birth and homelessness further increased the adjusted odds of death. Results show possible missed opportunities for TB diagnosis prior to death.

Timing of antiretroviral therapy for HIV in the setting of TB treatment

The convergent human immunodeficiency virus (HIV) and tuberculosis (TB) pandemics continue to collectively exact significant morbidity and mortality worldwide. Highly active antiretroviral therapy (HAART) has been a critical component in combating the scourge of these two conditions as both a preemptive and therapeutic modality. However, concomitant administration of antiretroviral and antituberculous therapies poses significant challenges, including cumulative drug toxicities, drug-drug interactions, high pill burden, and the immune reconstitution inflammatory syndrome (IRIS), thus complicating the management of coinfected individuals. This paper will review data from recent studies regarding the optimal timing of HAART initiation relative to TB treatment, with the ultimate goal of improving coinfection-related morbidity and mortality while mitigating toxicity resulting from concurrent treatment of both infections.

HIV-specific health care utilization and mortality among tuberculosis/HIV coinfected persons

Persons coinfected with tuberculosis (TB) and HIV are at high risk of death, in part due to suboptimal utilization of HIV-specific health care. We sought to better understand HIV-associated health care utilization and mortality in a retrospective cohort of TB/HIV coinfected cases reported in North Carolina 1993-2003. In this cohort, HIV was newly diagnosed during TB presentation for 34.2% of coinfected patients. Patients had advanced HIV (median CD4 104 cells/mm(3)) at TB diagnosis. Of 260 patients previously known to be HIV positive, 32.3% had seen a physician for HIV care in the previous 6 months and only 18.5% were taking antiretrovirals when TB was diagnosed; 34.8% of patients started antiretrovirals during TB treatment. Twenty-seven (5%) patients died prior to starting TB treatment; of those who survived, 13.6% (70/515) died prior to completing TB treatment, and 42.7% (220/515) died during a median 1408 days of follow-up. CD4 count (relative risk [RR] 0.53 per 100 cell increase, 95% confidence interval [CI] 0.34, 1.02) and highly active antiretroviral therapy (HAART) use during TB therapy (RR 0.37, 95% CI 0.13, 1.02) were independently associated with decreased mortality, while age greater than 45 (RR 2.18, 95% CI 1.11, 4.29) was independently associated with increased mortality during TB treatment. We conclude that TB/HIV coinfected patients had low utilization rates of HIV-specific care prior to TB diagnosis. Many did not receive potentially lifesaving HIV treatment while on TB therapy, and mortality was high as a result. Interventions to enhance utilization of HIV-related health care and integration of TB and HIV services should be studied to improve outcomes.

Timing of Antiretroviral Therapy Initiation in Tuberculosis Patients With AIDS

In HIV-infected tuberculosis patients with <200 CD4 lymphocytes/mm, highly active antiretroviral therapy (HAART) improves survival but can be complicated by immune reconstitution inflammatory syndrome (IRIS) and drug toxicity. We conducted a decision analysis in hypothetical cohorts of 1000 patients in which HAART was initiated during the first 2 months of tuberculosis therapy (early) or during months 2 through 6 of tuberculosis therapy (deferred) or was withheld until after tuberculosis therapy (no HAART). Outcomes assessed were 1-year mortality and the combined outcome of 1-year mortality, new AIDS-defining illness, severe IRIS, and severe drug toxicity. There were 33, 48, and 147 deaths and 497, 501, and 501 combined outcome events in the early HAART, deferred HAART, and no-HAART groups, respectively; most events were drug toxicity in the early and deferred groups and HIV-related mortality or AIDS-defining illness in the no-HAART group. In a 2-way sensitivity analysis of mortality, early HAART was favored, even with the highest reported rates of IRIS (70%) and severe drug toxicity (56%). Deferred HAART was favored over early HAART only if the IRIS-related mortality rate in the early group exceeded 4.6%. These results support early initiation of HAART in patients with AIDS, except when IRIS-related mortality rates are high.

Risk factors for mortality among patients with extrapulmonary tuberculosis at an academic inner-city hospital in the US

Despite an overall decrease in numbers of tuberculosis (TB) cases in the US, the proportion of extrapulmonary TB cases has increased. The study objective was to determine the most important predictors of all-cause mortality among patients with extrapulmonary TB. A retrospective chart review of adult extrapulmonary TB cases registered between 01/1995 and 12/2001 at Grady Memorial Hospital (a 1,000 bed, public inner-city hospital in Atlanta) was performed. Risk factors for death within 12 months after diagnosis of extrapulmonary TB were identified in multivariate analysis using log-binomial regression model. A total of 212 cases of extrapulmonary TB were identified; 100 (47%) were HIV-infected. The majority of patients were male (68%) and African-American (84%); mean age was 40 years. The most common sites of extrapulmonary TB were: lymph node (26%), pleural (21%), disseminated (20%), and central nervous system (CNS) or meningeal (16%). All-cause mortality rate in patients with extrapulmonary TB was 15% (21% among HIV-seropositive and 9% among HIV-uninfected patients, p = 0.02). In multivariate analysis, independent predictors of mortality included disseminated disease (PR = 4.66, 95% CI 1.93-11.24) and CNS/meningeal extrapulmonary TB (PR = 4.29, 95% CI 1.78-10.33), controlling for HIV infection. Extrapulmonary TB continues to be a persistent problem in the inner city and is associated with high mortality rates, especially among HIV-infected. Disseminated disease and the presence of CNS/meningeal TB are associated with poor prognosis.

HIV-1-induced pulmonary oxidative and nitrosative stress: exacerbated response to endotoxin administration in HIV-1 transgenic mouse model

Human immunodeficiency virus (HIV)-1 causes lung disease by increasing the host's susceptibility to pathogens. HIV-1 also causes an increase in systemic oxidative/nitrosative stress, perhaps enhancing the deleterious effects of secondary infections. Here we examined the ability of HIV-1 proteins to increase lung oxidative/nitrosative stress after lipopolysaccharide (LPS) (endotoxin) administration in an HIV-1 transgenic mouse model. Lung oxidative/nitrosative stress biomarkers studied 3 and 6 h after LPS administration were as follows: lung edema, tissue superoxide, NO metabolites, nitrotyrosine, hydrogen peroxide, and bronchoalveolar lavage fluid (BALF) glutathione (GSH). Blood serum cytokine levels were quantified to verify immune function of our nonimmunocompromised animal model. Results indicate that 3 h after LPS administration, HIV-1 transgenic mouse lung tissue has significantly greater edema and superoxide. Furthermore, NO metabolites are significantly elevated in HIV-1 transgenic mouse BALF, lung tissue, and blood plasma compared with those of wild-type mice. HIV-1 transgenic mice also produce significantly greater lung nitrotyrosine and hydrogen peroxide than wild-type mice. In addition, HIV-1 transgenic mice produce significantly less BALF GSH than wild-type mice 3 h after LPS treatment. Without treatment, serum cytokine levels are similar for HIV-1 transgenic and wild-type mice. After treatment, serum cytokine levels are significantly elevated in both HIV-1 transgenic and wild-type mice. Therefore, HIV-1 transgenic mice have significantly greater lung oxidative/nitrosative stress after endotoxin administration than wild-type mice, independent of immune function. These results indicate that HIV-1 proteins may increase pulmonary complications subsequent to a secondary infection by altering the lung redox potential.

Cost and enrollment implications of targeting different source population for an HIV treatment program

BACKGROUND

Rapid scale-up of antiretroviral therapy (ART) is a worldwide priority, and ambitious targets for numbers on ART have been set. Antenatal clinics (ANCs) and tuberculosis (TB) clinics have been targeted as entry points into HIV care.

METHODS

We developed a conditional probability model to evaluate the effects of ANC and TB clinic populations on ART program enrollment.

RESULTS

To start 1 individual on ART, 3 TB patients have to be screened at a crude program cost of 36 US dollars per patient initiated on therapy. By contrast, 48 ANC patients have to be screened at a cost of US 214 US dollars per patient on therapy. In an incremental analysis in which ANC HIV testing was borne by a program to prevent mother-to-child transmission, recruitment efficiency increased (8 screened per patient starting ART) and cost decreased (114 US dollars per patient on therapy). Absolute numbers starting ART, however, remained fixed. If all 60,000 ANC patients seen yearly in the Lusaka District were screened, 1247 would start ART. Approaching the district's 35,000 annual TB patients would generate 11,947 patients on ART.

CONCLUSION

In areas with high HIV prevalence, targeting chronically ill populations for HIV treatment may have significant short-term benefits in cost savings and recruitment efficiency.

Infectious lung complications in patients with HIV/AIDS

PURPOSE OF REVIEW

The aim of this article is to review recent observations in the area of infectious lung complications in individuals with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Since the immunodeficiency was first characterized, it has been associated with enhanced susceptibility to opportunistic infection, and life-threatening infections of the lung in particular. In the past few years there have been a large number of reports documenting the changes to this disease profile in the age of highly active antiretroviral therapy (HAART). Furthermore, there have been considerable advances in our understanding of the immunology and vaccinology of many of the pathogens implicated in pulmonary infections in this context, including Mycobacterium tuberculosis, Streptococcus pneumoniae and Pneumocystis pneumonia.

RECENT FINDINGS

In considering the time-course and spectrum of HIV-associated respiratory infections, the field must now be divided into studies undertaken in parts of the world where HAART is accessible and those where it is not. Despite the enormous impact of HAART, it has brought with it a new set of concerns, including the effects of immune restoration disease (IRD), and the complex interplay between HAART and tuberculosis therapy.

SUMMARY

The overriding conclusion from recent experience is that HAART, in those parts of the world where it is readily available, has changed the clinical picture of infections associated with HIV, and needs to be available to patients across the developing world as well. Furthermore there have been important developments in vaccination programs against pathogens involved in HIV-associated pneumonia.

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.

Recent advances in the diagnosis and management of tuberculosis

PURPOSE OF REVIEW

Tuberculosis (TB) remains one of the leading infectious killers of adults in the world today. This paper will review recent advances and understanding in the epidemiology, diagnosis, and management of TB.

RECENT FINDINGS

Tuberculosis remains a significant global threat, particularly in regions of the world heavily affected by HIV. Diagnosis of TB infection and disease rely on outdated and problematic methods, but newer immunologic and nucleic acid-based techniques are emerging. Treatment of latent TB infection still relies mainly on the use of isoniazid but several treatment-shortening strategies are being studied. Treatment of active disease has advanced little since the introduction of short-course chemotherapy with rifampin, but several new drugs are being developed and studied. Timely initiation of HIV treatment in co-infected patients is increasingly seen as important and strategies for initiating therapy for both diseases are being refined. The existence of immune reconstitution inflammatory reactions is also becoming more widely appreciated. Other populations at risk for TB such as those receiving TNF-alpha antagonists are being recognized and improved screening and control measures implemented.

SUMMARY

The global epidemiology of TB has been shaped in recent decades by HIV, urbanization and poverty. Diagnosis and treatment remain challenging, however, improved screening of at-risk populations and new diagnostic modalities and treatment strategies offer hope to the millions who suffer from tuberculosis.

Epidemiological trend in tuberculosis in the Italian region of Liguria: impact of immigration and AIDS

BACKGROUND

Tuberculosis (TB) uniformly decreased in all industrialized countries from 1950 to 1985. However, since 1985 an upsurge of the disease has been observed, probably due to the increases in AIDS and immigration. It is for this reason that in the last decade all industrialized countries have intensified their controls on TB and a new reduction has been recently observed.

METHODS

In this study we collected epidemiological data (mortalities and reported cases) for the region of Liguria over the last 15 years. We then calculated the incidence rate of TB per 100,000 residents according to age, HIV infection and nationality, making a distinction between European Union (EU) citizens and immigrants coming from countries outside the EU.

RESULTS

The rate of mortality, after the last peak at the end of the Second World War, has progressively decreased from 1946 to today, so much so that presently we record fewer than two cases per 100,000 people. We observed a consistent downward trend in the incidence rate up to 1987, but from 1988 onwards this trend stopped and, in subsequent years, we detected an increase in the incidence rate, which peaked in 1996. This led to increased interventions, which has resulted in a considerably decreased overall rate of cases of TB during the last few years. The number of TB cases specifically among foreigners increased considerably during the last 5 years, whereas there was a drastic reduction in the number of total TB cases, as well as an interesting reduction in AIDS cases. During the same period there was a progressive decrease in tuberculin skin positivity in all school classes.

CONCLUSIONS

The reduction in TB notifications is probably due to an increase in surveillance and control of social and health conditions. These results show that immigrant workers are considered to be a high-risk group, whereas the risk has progressively decreased in the HIV group.

Cytokine responses induced by Mycobacterium tuberculosis in patients with HIV-1 infection and tuberculosis

OBJECTIVE

Tuberculosis (TB) is an important opportunistic infection in HIV patients. Immune responses to Mycobacterium tuberculosis in HIV/TB patients were evaluated.

METHODS

Fifteen patients with HIV/TB, ten with HIV, four with TB, and five controls were enrolled. Peripheral blood mononuclear cells were isolated and stimulated with mycobacterial antigen (PPD). Interferon (IFN)-gamma and TNF-alpha in culture supernatants were measured by ELISA.

RESULTS

IFN-gamma and TNF-alpha production after PPD stimulation was markedly decreased in HIV patients, but not in HIV/TB patients. In HIV patients with a CD4 cell count of less than 200/mm3, IFN-gamma and TNF-alpha production after PPD stimulation was higher in HIV/TB patients than in HIV patients. Cytokine responses to M. tuberculosis reconstituted after highly active antiretroviral therapy (HAART) and were prominent in HIV/TB patients.

CONCLUSIONS

Cytokine responses to M. tuberculosis were retained in HIV-infected patients with tuberculosis, even in patients with a CD4 cell count of less than 200/mm3, and reconstituted after HAART.

Tuberculosis in New York city: recent lessons and a look ahead

In the late 1980s and early 1990s, after decades of decline, the incidence of tuberculosis began to rise in New York city, reaching a peak of 3811 cases by 1992. The epidemic took root in a setting of inadequate treatment regimens, homelessness, a diminished public-health system, and the onset of the HIV/AIDS epidemic. In addition, a subepidemic of drug-resistant tuberculosis occurred throughout New York city, most notably in a series of well documented nosocomial outbreaks. By 1994, using broadened initial treatment regimens, directly observed therapy, and improved US Centers for Disease Control and Prevention guidelines for hospital control and disease prevention, New York city began to effectively halt the progression of the epidemic. By 2002, tuberculosis rates in New York city reached an historic low of 1084. However, given the presence of a large reservoir of latently infected individuals in the city and an ongoing tuberculosis pandemic, New York city continues to face significant challenges from this persistent pathogen.

Tuberculosis in HIV-infected patients: a comprehensive review

The incidence of tuberculosis (TB) is currently increasing in HIV-infected patients living in Africa and Asia, where TB endemicity is high, reflecting the susceptibility of this group of patients to mycobacteria belonging to the TB group. In this population, extension of multiple resistance to anti-tuberculous drugs is also a matter of anxiety. HIV-induced immunosuppression modifies the clinical presentation of TB, resulting in atypical signs and symptoms, and more frequent extrapulmonary dissemination. The treatment of TB is also more difficult to manage in HIV-infected patients, particularly with regard to pharmacological interactions secondary to inhibition or induction of cytochrome P450 enzymes by protease inhibitors with rifampicin or rifabutin, respectively. Finally, immune restoration induced by highly active anti-retroviral therapy (HAART) in developed countries may be responsible for a paradoxical worsening of TB manifestations.

Immunization with a DNA vaccine cocktail protects mice lacking CD4 cells against an aerogenic infection with Mycobacterium tuberculosis

Tuberculosis (TB) is the most common opportunistic disease and a potentially fatal complication among immunocompromised individuals infected with human immunodeficiency virus (HIV). Effective vaccination against TB in persons with HIV has been considered unlikely because of the central role that CD4 cells play in controlling tuberculous infections. Here we show that the vaccination of CD8(-/-) mice with a TB DNA vaccine cocktail did not significantly enhance protective responses to a Mycobacterium tuberculosis infection. In contrast, immunization with a DNA vaccine cocktail or with the current TB vaccine, Mycobacterium bovis BCG, induced considerable antituberculosis protective immunity in immune-deficient mice lacking CD4 cells. In vaccinated CD4(-/-) animals, substantially reduced bacterial burdens in organs and much improved lung pathology were seen 1 month after an aerogenic M. tuberculosis challenge. Importantly, the postchallenge mean times to death of vaccinated CD4(-/-) mice were significantly extended (mean with DNA cocktail, 172 +/- 7 days; mean with BCG, 156 +/- 22 days) compared to that of naïve CD4(-/-) mice (33 +/- 6 days). Furthermore, the treatment of DNA-vaccinated CD4(-/-) mice with an anti-CD8 or anti-gamma interferon (IFN-gamma) antibody significantly reduced the effect of immunization, and neither IFN-gamma(-/-) nor tumor necrosis factor receptor-deficient mice were protected by DNA immunization; therefore, the primary vaccine-induced protective mechanism in these immune-deficient mice likely involves the secretion of cytokines from activated CD8 cells. The substantial CD8-mediated protective immunity that was generated in the absence of CD4 cells suggests that it may be possible to develop effective TB vaccines for use in HIV-infected populations.

Epidemiology of HIV-associated cryptococcosis in France (1985-2001): comparison of the pre- and post-HAART eras

OBJECTIVE

To analyse the epidemiological evolution of cryptococcosis in France after the introduction of highly active antiretroviral therapy (HAART).

DESIGN

Retrospective study of cryptococcosis cases recorded at the National Reference Center for Mycoses in France since 1985.

METHODS

Using the national surveillance data, we reviewed 1644 cases of HIV-associated cryptococcosis diagnosed in France (population, 59 million) between 1985 and 2001 and compared them to 335 cases recorded in HIV-negative patients.

RESULTS

The total number of cryptococcosis cases evolved in parallel to that recorded for HIV-infected patients. Changes occurring after HAART introduction were analysed. A negative binomial regression model established a 46% decrease of the incidence of cryptococcosis during the post-HAART era (1997-2001, n = 292) compared to the pre-HAART era (1985-1996, n = 1352). According to multivariate analysis, African origin, older age, heterosexual HIV contamination, no previous AIDS-defining illness, and no previous HIV infection diagnosis were variables independently associated with an increased risk of cryptococcosis during the post-HAART era. During the same period, the characteristics of the HIV-negative population did not change.

CONCLUSIONS

Our analysis of the national surveillance identified demographic factors associated with an increased risk of cryptococcosis in the post-HAART era suggesting that failure to consult and considering oneself not at risk were determinant in the current epidemiology of HIV-related cryptococcosis in France.

Improved outcomes of HIV-1-infected adults with tuberculosis in the era of highly active antiretroviral therapy

OBJECTIVES

To compare the survival and treatment responses to antiretroviral therapy between HIV-1-infected patients with active TB (TB patients) and without (non-TB patients) in the era of highly active antiretroviral therapy (HAART).

DESIGN

8-year prospective observational study at a university hospital.

METHODS

A total of 125 (17.5%) TB patients (median CD4 cell count at TB diagnosis, 37 x 10(6) cells/l) and 591 non-TB patients (CD4 cell count at enrolment, 79 x 10(6) cells/l) were prospectively observed between June 1994 and October 2002. Virologic and immunologic responses were assessed in 230 antiretroviral-naive non-TB patients and 46 TB patients who concurrently initiated antituberculous therapy and HAART. The clinical outcome was evaluated by comparing incidence of new AIDS-associated opportunistic illnesses (OIs) and survival of all TB and non-TB patients. RESULTS Among antiretroviral-naive patients, CD4 cell count increase (71 versus 64 x 10(6) cells/l, P = 0.70) and proportions of patients achieving undetectable plasma viral load [20 of 46 versus 107 of 230, relative risk (RR), 0.93; 95% confidence interval (95% CI), 0.65-1.34; P = 0.71] at week 4 of HAART were similar between the 46 TB and 230 non-TB patients, as was the virologic failure during HAART (RR, 1.49; 95% CI, 0.92-2.41; P = 0.14). The risk for HIV progression to new OIs was also similar between the two groups (adjusted RR, 1.16; 95% CI, 0.764-1.77). The adjusted hazard ratio for death of TB patients compared with non-TB patients was 1.18 (95% CI, 0.65-2.32) before HAART era and 0.89 (95% CI, 0.57-1.69) in HAART era.

CONCLUSIONS

Our data indicated that virologic, immunologic, and clinical responses to HAART and prognosis of HIV-1-infected TB patients who were concurrently treated with antituberculous therapy and HAART were similar to those of non-TB patients.