Changes in the Pattern of Respiratory Diseases Necessitating Hospitalization of HIV-infectedPatients Since the Advent of Highly Active Antiretroviral Therapy

Pulmonary Toxoplasmosis Diagnosed on Transbronchial Lung Biopsy in a Mechanically Ventilated Patient

Toxoplasma gondii is a protozoan parasite that infects up to a third of the world's population. Infection is mainly acquired by ingestion of food or water that is contaminated with oocysts shed by cats or consuming undercooked meat containing tissue cysts. Primary infection is subclinical in immunocompetent hosts. Invasive toxoplasmosis often manifests as cerebral toxoplasmosis in immunosuppressed patients. In persons living with human immunodeficiency virus (HIV), toxoplasmosis occurs when CD4 counts are very low and is considered an acquired immunodeficiency syndrome (AIDS) defining illness. Pulmonary toxoplasmosis is rarely seen in the highly active antiretroviral therapy era. The diagnosis can be challenging due to the nonspecific nature of clinical and radiographic findings. In this report, we present a case of pulmonary toxoplasmosis in a new onset AIDS patient, which was initially clinically misdiagnosed as Pneumocystis jiroveci pneumonia (PJP). Due to a poor response to treatment for PJP, the patient underwent a transbronchial lung biopsy, which led to the diagnosis of pulmonary toxoplasmosis.

Lower Respiratory Tract Infections

This review will focus on the infectious etiologies and more common noninfectious causes of lower respiratory tract syndromes among major immunosuppressed populations. The changing epidemiology of infections in the era of highly active antiretroviral therapy (HAART) in the case of HIV-positive patients and the impacts of both newer immune-suppressant therapies and anti-infective prophylaxis for other immunocompromised hosts will be discussed, with emphasis on diagnostic approaches and practice algorithms.

Bronchopulmonary Kaposi's sarcoma

Kaposi's sarcoma (KS) is a highly vascular tumour, which was first described by the Hungarian dermatologist Moritz Kaposi Kohn before the discovery of the human immunodeficiency virus (HIV). Historically, KS has been linked to immunosuppression or to elderly male patients, especially in relation to diffuse cutaneous KS. We describe a case of Bronchopulmonary Kaposi's sarcoma in a patient with AIDS who was successfully treated with HAART and Liposomal Doxorubicin chemotherapy.

The impact of HAART on the respiratory complications of HIV infection: longitudinal trends in the MACS and WIHS cohorts

OBJECTIVE

To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART).

DESIGN

Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women's Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively.

METHODS

Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era.

RESULTS

Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2-2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3-1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8-2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02-8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3-1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5-2.4; p<0.001).

CONCLUSION

HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality.

Giant cell carcinoma causing rapidly progressive respiratory failure as the presenting feature of AIDS

The incidence of lung cancer has been increasing among HIV-positive patients. The majority of these cases were in patients previously diagnosed as HIV-positive and treated with highly active antiretroviral therapy (HAART). Here, we report a 56-year-old male patient with lung cancer, who was diagnosed as HIV-positive after the onset of neck pain and lumbago and thus, was not treated with anti-AIDS therapy. The patient developed rapidly progressive and fatal respiratory failure. Autopsy demonstrated giant cell carcinoma of the lung responsible for carcinomatous lymphangitis. This case highlighted the possibility that pulmonary carcinogenesis in HIV-positive patients is not necessarily associated with HAART therapy.

Cholesterol as a Mediator of Alcohol-Induced Risks for Respiratory Disease Hospitalizations among People Living With HIV

We analyzed the role of cholesterol as a potential mediator of alcohol-increased risk of respiratory infections that required hospitalization in People Living with HIV (PLWH). Using a longitudinal clinic-based design, 346 PLWH were consecutively admitted and followed at Jackson Memorial Medical Center(enrolled in the study). Following national guidelines, PLWH were stratified according to cholesterol levels: <150 mg/dl (Hypocholesterolemia= HypoCHL), 151-200, and >200 mg/dl Hypercholesterolemia =HyperCHL), and compared on the basis of clinical outcomes, lymphocyte phenotypes and behavioral risks. Analyses indicated that compared to HyperCHL participants, HypoCHL subjects were more likely to be hospitalized, particularly for lower respiratory tract infections (LRTI). Excessive admissions were associated with more deviant lymphocyte profiles, particularly limited NK cells. In logistic regression analyses, smoking (OR=1.5), HypoCHL (OR=7.7), and alcohol (OR=1.2) were predictors of LRTI. These findings warrant further investigation of the potential use of HypoCHL as a risk marker, and the cost-effectiveness of switching prevention gears towards HypoCHL, alcohol and tobacco in PLWH.

Trends in hospitalizations for AIDS-associated Pneumocystis jirovecii Pneumonia in the United States (1986 to 2005)

BACKGROUND

Although hospitalizations for AIDS-associated Pneumocystis jirovecii pneumonia (PCP) in the United States have decreased since the introduction of chemoprophylaxis and potent combination antiretroviral therapy (ART), PCP remains an important cause of illness and death among AIDS patients.

METHODS

We analyzed trends in AIDS-associated PCP hospital discharges using the National Hospital Discharge Surveys between 1986 and 2005.

RESULTS

An estimated 539 million patients were discharged from hospitals between 1986 and 2005, of whom an estimated 312,411 had AIDS-associated PCP. The proportion of patients discharged from the hospital with AIDS-associated PCP decreased from 31% before the introduction of chemoprophylaxis (1986 to 1989) to 17% with chemoprophylaxis (1990 to 1995) and subsequently to 9% after the introduction of ART in 1996 (p < 0.001). Mortality from AIDS-associated PCP decreased from 21 to 16% and subsequently to 7% between these three time periods (p < 0.001). Among those who received mechanical ventilation, mortality decreased from 79% in the prechemoprophylaxis era to 31% in the ART era (p < 0.001) alongside an increase (from 5 to 11%) in the use of mechanical ventilation. We also observed a shift in the population at-risk for PCP over time: a greater proportion of black people, women, and people from Southern states were affected (all p < 0.001).

CONCLUSIONS

While there have been significant reductions in hospitalizations and hospital mortality for AIDS-associated PCP over the last 20 years, these reductions have not been homogenous across demographic subpopulations and geographic regions and point to new at-risk populations. Furthermore, mortality in severe cases of PCP that require mechanical ventilation has improved substantially.

Giant cell lung carcinoma in a man with acquired immunodeficiency syndrome

A 66-year-old man, who was discovered to have human immunodeficiency virus (HIV) infection 22 months previously and was treated with highly active antiretroviral (HAART) therapy, developed giant cell carcinoma of the lung. In English literature, this is the first case of such cell type of lung cancer during HAART therapy. Since giant cell carcinoma of the lung occurs mainly in elderly men who smoke heavily, there may not be a possibility that the HIV or HAART was causative in our patient.

Impact of highly active antiretroviral therapy (HAART) on the incidence of opportunistic infections, hospitalizations and mortality among children and adolescents living with HIV/AIDS in Belo Horizonte, Minas Gerais State, Brazil

The impact of highly active antiretroviral therapy (HAART) can be evaluated using indicators, such as rates of opportunistic infections, hospitalizations by cause of infection, and associated death. This study aimed to estimate the impact of HAART on the incidence of these indicators, in children and adolescents with HIV/AIDS. It was a hybrid cohort study; 371 patients were followed from 1989 to 2003. In December 2003, 76% of the patients were still being followed, while 12.1% had died, 9.5% had dropped out, and 2.4% had been transferred. The overall rate of opportunistic infections was 18.32 infections/100 persons-year and 2.63 in the pre- and post-HAART periods, respectively. In the multivariate analysis, the risk of developing an opportunistic infection was 5.4 times greater and 3.3 times greater for hospitalization risk before HAART. Respiratory causes represented 65% of the hospitalizations and they were reduced by 44.6% with therapeutic intervention. The average hospital stay of 15 days was reduced to 9. There was a post-HAART decline in deaths of 38%. This study demonstrates the effectiveness of HAART in significantly reducing opportunistic infections, hospitalizations, and deaths in this Brazilian cohort.

Influenzavirus infection is a primary cause of febrile respiratory illness in HIV-infected adults, despite vaccination

BACKGROUND

There are, to our knowledge, no prospective studies of respiratory tract infections in human immunodeficiency virus (HIV)-infected adults in the highly active antiretroviral therapy (HAART) era. We performed a surveillance study of outpatients who presented with fever and respiratory symptoms to examine the role of viral pathogens in these patients.

METHODS

Consecutive patients with a temperature of >38.0 degrees C and respiratory symptoms were recruited from a tertiary care HIV clinic during the period 2003-2006. Nasal pharyngeal samples were tested for influenzavirus A and B, respiratory syncytial virus, and human metapneumovirus using real-time multiplex polymerase chain reaction assays. Paired acute- and convalescent-phase serum samples were tested for respiratory viruses by complement fixation.

RESULTS

Fifty patients (90% of whom were receiving HAART) were included in the study (median CD4(+) T cell count, 325 cells/microL; median HIV RNA level, <50 copies/mL). A causative pathogen was identified in 25 patients (50%). Even though 76% of subjects had received influenza vaccine, viral infections were diagnosed in 21 patients (42%), as follows: influenza A, 10 patients; influenza B, 10; and parainfluenza virus type 3 infection, 1. Patients with and those without viral infection had similar demographic characteristics and HIV statuses. No patients with influenza and 23% of patients with other conditions had radiography-confirmed pneumonia (P=.07). Antibiotic prescriptions were common: 70% of patients received antibiotics. No patients with influenza required hospitalization, compared with 21% of other patients (P=.03).

CONCLUSIONS

Although illness was mild, influenza accounted for a large proportion of unscheduled visits to a health care provider for respiratory illness and was associated with unnecessary antibiotic prescriptions that may contribute to antimicrobial resistance. Vaccination alone was insufficient to prevent infection. Thus, specific identification and management of influenza should be performed in HIV-infected outpatients who present with fever and respiratory symptoms.

Lung cancer in HIV infected patients: facts, questions and challenges

AIDS related mortality has fallen sharply in industrialised countries since 1996 following the introduction of highly active antiretroviral therapy. This has been accompanied by an increase in the proportion of deaths attributable to non-AIDS defining solid tumours, especially lung cancer. The risk of developing lung cancer seems to be higher in HIV infected subjects than in the general population of the same age, partly because the former tend more frequently to be smokers and, especially, intravenous drug users. The carcinogenic role of the antiretroviral nucleoside drugs and their interaction with smoking needs to be examined. Interestingly, there is no clear relationship between the degree of immunosuppression and the risk of lung cancer, so the reason for the increased risk is unknown. The mean age of HIV infected patients at the time of lung cancer diagnosis is 45 years and most are symptomatic. Lung cancer is diagnosed when locally advanced or metastatic (stage III-IV) in 75-90% of cases, similar to patients with unknown HIV status. Adenocarcinoma is the most frequent histological type. The prognosis is worse in HIV infected patients than in the general lung cancer population. Efficacy and toxicity data for chemotherapy and radiation therapy are few and imprecise. Surgery remains the treatment of choice for localised disease in patients with adequate pulmonary function and general good health, regardless of immune status. Prospective clinical trials are needed to define the optimal detection and treatment strategies for lung cancer in HIV infected patients.

Management of patients with HIV in the intensive care unit

Because there are more than one million Americans with HIV, intensive care units continue to see frequent patients with HIV infection. In the era of highly active antiretroviral therapy, clinicians must be aware of drug toxicities and drug interactions. They must also recognize traditional opportunistic infections, as well as newer syndromes such as immune reconstitution syndrome, multicentric Castleman's disease, and primary pleural cell lymphoma.

Lung cancer, a new challenge in the HIV-infected population

HIV infection predisposes patients to AIDS-defining malignancies, some of which, such as Kaposi's sarcoma and non-Hodgkin lymphoma, can affect the lungs. In 1996, AIDS-related mortality started to fall sharply in industrialized countries following the introduction of highly active antiretroviral treatments (HAART). This was accompanied by an increase in the proportion of deaths attributable to non AIDS-defining solid tumors, and especially lung cancer (LC). The increased risk of LC relative to the general population of the same age seems to be due partly to a higher prevalence of smoking among HIV-infected subjects. The average age of HIV-infected patients at LC diagnosis is about 45 years. Most patients are symptomatic at diagnosis and have only mild or moderate immunosuppression. LC is diagnosed when it is locally advanced or metastatic (stages III-IV) in 75-90% of cases, as in patients with unknown HIV serostatus. Adenocarcinoma is the most frequent histologic type. The prognosis of LC is poorer in HIV-infected patients than in the general population. Data on the efficacy and toxicity of chemotherapy in this setting are rare and rather imprecise. Surgery remains the reference treatment for localized disease in patients with adequate functional status and general health, regardless of their immune status. Prospective clinical trials are needed to define the optimal LC treatment strategies in HIV-infected patients.

Once-Daily Regimen of Saquinavir, Ritonavir, Didanosine, and Lamivudine in HIV-Infected Patients With Standard Tuberculosis Therapy (TBQD Study)

OBJECTIVES

To assess the efficacy and safety of a once-daily regimen with didanosine, lamivudine, saquinavir, and low-dose ritonavir in antiretroviral (ARV)-naive patients with tuberculosis treated with rifampin and the influence of rifampin on plasma trough concentration (Ctrough) of saquinavir.

METHODS

Single-arm, prospective, multicenter, open-label pilot study, including 32 adult ARV-naive subjects with HIV infection and tuberculosis under standard treatment that included rifampin (600 mg q.d.) and isoniazid (300 mg q.d.). After 2 months of tuberculosis treatment, patients were started on once-daily ARV therapy, consisting of didanosine, lamivudine, ritonavir (200 mg), and saquinavir soft gel capsules (1600 mg). HIV RNA level, CD4 cell count, clinical and laboratory toxicity, and saquinavir Ctrough during and after antituberculosis therapy were analyzed.

RESULTS

After 48 weeks of follow-up, 20 of 32 patients (62.5%; 95% CI: 45.8% to 79.2%) in the intent-to-treat population and 20 of 28 (71.4%; 95% CI: 54.4% to 88.4%) in the on-treatment population had an HIV RNA level <50 copies/mL. Treatment tolerance was acceptable in all patients except for 2 with biologic hepatic toxicity leading to discontinuation. Seven patients had virologic failure. In 10 patients (36%), saquinavir Ctrough was <0.05 microg/mL during tuberculosis therapy and 5 of them had virologic failure. The median saquinavir Ctrough was 44% lower (interquartile range: 19% to 71%) with coadministration of rifampin than without.

CONCLUSION

The combination of didanosine, lamivudine, saquinavir, and ritonavir may be a useful treatment regimen for patients with tuberculosis in whom a once-daily protease inhibitor-containing regimen is considered indicated. Nevertheless, on the basis of pharmacokinetic profile the dose of 1600/200 mg of saquinavir/ritonavir cannot be recommended. Further studies with higher doses of saquinavir (2000 mg) boosted with ritonavir are warranted.