Pulmonary infectious complications of human immunodeficiency virus infection. Part II

Gene Expression in Lung Epithelial Cells Following Interaction with Pneumocystis carinii and its Specific Life Forms Yields Insights into Host Gene Responses to Infection

Pneumocystis spp. interacts with epithelial cells in the alveolar spaces of the lung. It is thought that the binding of Pneumocystis to host cell epithelium is needed for life cycle completion and proliferation. The effect of this interaction on lung epithelial cells have previously shown that the trophic form of this organism greatly inhibits p34 ^cdc2 activity, a serine/threonine kinase required for transition from G₂ to M phase in the cell cycle. To gain further insight into the host response during Pneumocystis pneumonia (PCP), we used microarray technology to profile epithelial cell (A549) gene expression patterns following Pneumocystis carinii interaction. Furthermore, we isolated separate populations of cyst and trophic forms of P. carinii, which were then applied to the lung epithelial cells. Differential expression of genes involved in various cellular functions dependent on the specific P. carinii life form in contact with the A549 cell were identified. The reliability of our data was further confirmed by Northern blot analysis on a number of selected up or down regulated transcripts. The transcriptional response to P. carinii was dominated by cytokines, apoptotic, and anti-apoptotic related genes. These results reveal several previously unknown effects of P. carinii on the lung epithelial cell and provide insight into the complex interactions of host and pathogen. This article is protected by copyright. All rights reserved.

Disseminated histoplasmosis presenting as diabetic keto-acidosis in an immunocompetent patient

Histoplasma capsulatum causes a spectrum of manifestations from asymptomatic to fatal disseminated disease. Disseminated histoplasmosis is mostly seen in endemic areas among immunocompromised patients such as those with AIDS. Here, we present a patient living in a non-endemic area with previously undiagnosed diabetes mellitus, who presented with septic shock and diabetic ketoacidosis (DKA), and was ultimately diagnosed with disseminated histoplasmosis. The patient rapidly recovered on administration of intravenous liposomal amphotericin followed by oral itraconazole. Uncontrolled diabetes may be a risk factor for disseminated or severe histoplasmosis in otherwise immunocompetent patients.

Lung microbiome in human immunodeficiency virus infection

The lung microbiome plays a significant role in normal lung function and disease. Because microbial colonization is likely influenced by immunodeficiency, one would speculate that infection with human immunodeficiency virus (HIV) alters the lung microbiome. Furthermore, how this alteration might impact pulmonary complications now seen in HIV-infected patients on antiretroviral therapy (ART), which has shifted from opportunistic infections to diseases associated with chronic inflammation, is not known. There have been limited publications on the lung microbiome in HIV infection, many of them emanating from the Lung HIV Microbiome Project. Current evidence suggests that the lung microbiome in healthy HIV-infected individuals with preserved CD4 counts is similar to uninfected individuals. However, in individuals with more advanced disease, there is an altered alveolar microbiome characterized by a loss of richness and evenness (alpha diversity) within individuals. Furthermore, as a group the taxa making up the HIV-infected and uninfected lung microbiome are different (differences in beta diversity), and the HIV-infected population is more spread out (greater dispersion) than the uninfected population. These differences decline with ART, but even after effective therapy the alveolar microbiome in HIV-infected individuals contains increased amounts of signature bacteria, some of which have previously been associated with chronic lung inflammation. Furthermore, more recent investigations into the lung virome in HIV infection suggest that perturbations in lung viral communities also exist in HIV infection, and that these too are associated with evidence of lung inflammation. Thus, it is likely both microbiome and virome alterations in HIV infection contribute to lung inflammation in these individuals, which has important implications on the changing spectrum of pulmonary complications in patients living with HIV.

Risk Factors Associated With Quantitative Evidence of Lung Emphysema and Fibrosis in an HIV-Infected Cohort

INTRODUCTION

The disease spectrum for HIV-infected individuals has shifted toward comorbid non-AIDS conditions including chronic lung disease, but quantitative image analysis of lung disease has not been performed.

OBJECTIVES

To quantify the prevalence of structural changes of the lung indicating emphysema or fibrosis on radiographic examination.

METHODS

A cross-sectional analysis of 510 HIV-infected participants in the multicenter Lung-HIV study was performed. Data collected included demographics, biological markers of HIV, pulmonary function testing, and chest computed tomographic examinations. Emphysema and fibrosis-like changes were quantified on computed tomographic images based on threshold approaches.

RESULTS

In our cohort, 69% was on antiretroviral therapy, 13% had a current CD4 cell count less than 200 cells per microliter, 39% had an HIV viral load greater than 500 copies per milliliter, and 25% had at least a trace level of emphysema (defined as >2.5% of voxels <-950HU). Trace emphysema was significantly correlated with age, smoking, and pulmonary function. Neither current CD4 cell count nor HIV viral load was significantly correlated with emphysema. Fibrosis-like changes were detected in 29% of the participants and were significantly correlated with HIV viral load (Pearson correlation coefficient = 0.210; P < 0.05); current CD4 cell count was not associated with fibrosis. In multivariable analyses including age, race, and smoking status, HIV viral load remained significantly correlated with fibrosis-like changes (coefficient = 0.107; P = 0.03).

CONCLUSIONS

A higher HIV viral load was significantly associated with fibrosis-like changes, possibly indicating early interstitial lung disease, but emphysematous changes were not related to current CD4 cell count or HIV viral load.

Massive gastrointestinal bleeding in AIDS patients secondary to histoplasma and cytomegalovirus infection

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Gastrointestinal CMV infection in the small bowel location is extremely rare.

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Disseminated histoplasmosis typically affects lower GI Tract and rarely small bowel in addition to other organs.

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The association between Histoplasmosis and Cytomegalovirus as massive gastrointestinal bleeding cause has not been described.

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If disseminated histoplasmosis affects small bowel, causes intermittent abdominal pain, chronic diarrhoea and malabsorption.

Introduction

The Cytomegalovirus (CMV) is a virus that affects the host and remains latent. When cellular immunity is suppressed, the virus is reactivated and can cause an asymptomatic or devastating infection in immunosuppressed patients.

On the other hand, Histoplasmosis is typically a respiratory condition. However, in immunosuppressed patients, it may be found in unusual locations, as in the case of an intestinal condition. In some cases, this can be fatal.

Small intestine CMV location is extremely rare.

Case presentation

40-year-old man with AIDS presenting secondary massive lower gastrointestinal bleeding (MLGB) symptoms and ulcer granulomatous injuries located in the proximal ileum produced by the association of CMV and histoplasmosis.

Conclusion

Lower gastrointestinal bleeding diagnosis and treatment pose a challenge, considering the intestine extension and difficulties for its exploration. On the other hand, the association between Histoplasmosis and CMV as a massive gastrointestinal bleeding cause has not been described. There is no bibliography on the matter.

Vascular sequelae of mediastinal fibrosis

Fibrosing mediastinitis is a condition in which mediastinal fat is replaced by fibrous tissue. Complications may arise due to progressive fibrotic infiltration and compression of major vascular, respiratory, and nervous structures within the mediastinum. We describe 3 similar cases of fibrosing mediastinitis with pulmonary vessel involvement. Imaging and intraoperative observation revealed involvement of the pulmonary vasculature in all 3 patients. Perfusion studies showed decreased or absent perfusion to one or both of the lungs. All patients tested negative for histoplasmosis, 2 required lung resection, with the 3rd forgoing surgery.

Proteomic landscape of bronchoalveolar lavage fluid in human immunodeficiency virus infection

The lung is an important reservoir of human immunodeficiency virus (HIV). Individuals infected with HIV are more prone to pulmonary infections and chronic lung disorders. We hypothesized that comprehensively profiling the proteomic landscape of bronchoalveolar lavage fluid (BALF) in patients with HIV would provide insights into how this virus alters the lung milieu and contributes to pathogenesis of HIV-related lung diseases. BALF was obtained from five HIV-negative (HIV(-)) and six asymptomatic HIV-positive (HIV(+)) subjects not on antiretroviral therapy. Each sample underwent shotgun proteomic analysis based on HPLC-tandem mass spectrometry. Differentially expressed proteins between the groups were identified using statistical methods based on spectral counting. Mechanisms of disease were explored using functional annotation to identify overlapping and distinct pathways enriched between the BALF proteome of HIV(+) and HIV(-) subjects. We identified a total of 318 unique proteins in BALF of HIV(-) and HIV(+) subjects. Of these, 87 were differentially up- or downregulated between the two groups. Many of these differentially expressed proteins are known to interact with key HIV proteins. Functional analysis of differentially regulated proteins implicated downregulation of immune responses in lungs of HIV(+) patients. Combining shotgun proteomic analysis with computational methods demonstrated that the BALF proteome is significantly altered during HIV infection. We found that immunity-related pathways are underrepresented in HIV(+) patients. These findings implicate mechanisms whereby HIV invokes local immunosuppression in the lung and increases the susceptibility of HIV(+) patients to develop a wide range of infectious and noninfectious pulmonary diseases.

HIV infection is associated with reduced pulmonary diffusing capacity

INTRODUCTION

Prior studies comparing abnormalities in pulmonary function between HIV-infected and HIV-uninfected persons in the current era are limited.

OBJECTIVES

To determine the pattern and severity of impairment in pulmonary function in HIV-infected compared with HIV-uninfected individuals.

METHODS

Cross-sectional analysis of 300 HIV-infected men and 289 HIV-uninfected men enrolled from 2009 to 2011 in 2 clinical centers of the Lung HIV Study. Participants completed pre- and postbronchodilator spirometry, diffusing capacity of the lung for carbon monoxide (DLCO) measurement, and standardized questionnaires.

RESULTS

Most participants had normal airflow; 18% of HIV-infected and 16% of HIV-uninfected men had airflow obstruction. The mean percent predicted DLCO was 69% in HIV-infected vs. 76% in HIV-uninfected men (P < 0.001). A moderately to severely reduced DLCO of ≤60% was observed in 30% of HIV-infected compared with 18% of HIV-uninfected men (P < 0.001), despite the fact that 89% of those with HIV were on antiretroviral therapy. A reduced DLCO was significantly associated with HIV and CD4 cell count in linear regression adjusting for smoking and other confounders. The DLCO was lowest in HIV-infected men with CD4 cell counts <200 cells per microliter compared with those with CD4 cell counts ≥200 cells per microliter and to HIV-uninfected men. Respiratory symptoms of cough, phlegm and dyspnea were more prevalent in HIV-infected patients particularly those with abnormal pulmonary function compared with HIV-uninfected patients.

CONCLUSIONS

HIV infection is an independent risk factor for reduced DLCO, particularly in individuals with a CD4 cell count below 200 cells per microliter. Abnormalities in pulmonary function among HIV-infected patients manifest clinically with increased respiratory symptoms. Mechanisms accounting for the reduced DLCO require further evaluation.

HIV gp120 induces mucus formation in human bronchial epithelial cells through CXCR4/α7-nicotinic acetylcholine receptors

Lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, and lung infections are major causes of morbidity and mortality among HIV-infected patients even in the era of antiretroviral therapy (ART). Many of these diseases are strongly associated with smoking and smoking is more common among HIV-infected than uninfected people; however, HIV is an independent risk factor for chronic bronchitis, COPD, and asthma. The mechanism by which HIV promotes these diseases is unclear. Excessive airway mucus formation is a characteristic of these diseases and contributes to airway obstruction and lung infections. HIV gp120 plays a critical role in several HIV-related pathologies and we investigated whether HIV gp120 promoted airway mucus formation in normal human bronchial epithelial (NHBE) cells. We found that NHBE cells expressed the HIV-coreceptor CXCR4 but not CCR5 and produced mucus in response to CXCR4-tropic gp120. The gp120-induced mucus formation was blocked by the inhibitors of CXCR4, α7-nicotinic acetylcholine receptor (α7-nAChR), and γ-aminobutyric acid (GABA)AR but not the antagonists of CCR5 and epithelial growth factor receptor (EGFR). These results identify two distinct pathways (α7-nAChR-GABAAR and EGFR) for airway mucus formation and demonstrate for the first time that HIV-gp120 induces and regulates mucus formation in the airway epithelial cells through the CXCR4-α7-nAChR-GABAAR pathway. Interestingly, lung sections from HIV ± ART and simian immunodeficiency virus (SIV) ± ART have significantly more mucus and gp120-immunoreactivity than control lung sections from humans and macaques, respectively. Thus, even after ART, lungs from HIV-infected patients contain significant amounts of gp120 and mucus that may contribute to the higher incidence of obstructive pulmonary diseases in this population.

How histopathology can contribute to an understanding of defense mechanisms against cryptococci

Invasive fungal infections, particularly those considered opportunistic, have become a common and significant complication of procedures performed in advanced contemporary medicine. Among such infections, cryptococcosis, which is usually caused by infection with Cryptococcus neoformans and Cryptococcus gattii, is particularly problematic because this fungal infection occurs in immunocompromised and apparently immunocompetent individuals. It has been largely accepted that Cryptococcus species are recognized by cellular receptors and that Th1-type immune responses play an important role in defense mechanisms against the yeast. However, the interaction between the yeast and host tissue varies depending on the characteristics of the yeast and the immune status of the host. To gain a better understanding of the pathophysiology of cryptococcosis, we wish to emphasize the usefulness of histopathological examinations, because it allowed more detailed information of an extremely complex interaction between the causative yeasts and tissue response. In the present review, we describe the pathophysiology of cryptococcosis as largely revealed in our previous histopathological investigations of the experimental infection.

Effect of bacterial pneumonia on lung simian immunodeficiency virus (SIV) replication in alcohol consuming SIV-infected rhesus macaques

BACKGROUND

Opportunistic infections in human immunodeficiency virus (HIV)-infected persons have been shown to increase the rate of HIV replication. In populations where prophylaxis against Pneumocystis pneumonia is utilized, bacterial pneumonia is now the leading cause of lower respiratory tract infection in HIV+ patients. Our prior studies have shown that chronic alcohol consumption in demarcated simian immunodeficiency virus (SIV)-infected rhesus macaques increases plasma viral load set point and accelerates progression to end-stage acquired immune deficiency syndrome. While chronic alcohol abuse is well known to increase the incidence and severity of bacterial pneumonia, the impact of alcohol consumption on local and systemic SIV/HIV burden during lung infection is unknown. Therefore, we utilized the macaque SIV infection model to examine the effect of chronic ethanol (EtOH) feeding on SIV burden during the course of pulmonary infection with Streptococcus pneumoniae, the most commonly identified etiology of bacterial pneumonia in HIV+ and HIV- persons in developed countries.

METHODS

Alcohol was administered starting 3 months before SIVmac251 inoculation to the end of the study via an indwelling intragastric catheter to achieve a plasma alcohol concentration of 50 to 60 mM. Control animals received isocaloric sucrose. Four months after SIV infection, the right lung was inoculated with 2 × 10(6) CFU S. pneumoniae.

RESULTS

Leukocyte recruitment into the lung, pulmonary bacterial clearance, and clinical course were similar between EtOH and control groups. While plasma SIV viral load was similar between groups postpneumonia, chronic EtOH-fed macaques showed a prolonged increase in SIV RNA in bronchoalveolar lavage fluid. Alveolar macrophages isolated from EtOH-fed macaques 1 day post-pneumonia showed greater nuclear factor kappa beta (NF-κB) activation.

CONCLUSIONS

This study indicates that chronic EtOH feeding results in enhanced local, but not systemic, SIV replication following pneumococcal pneumonia. Increased NF-κB activity in the setting of chronic EtOH ingestion may play a mechanistic role in this observation.

The spectrum of clinical and pathological manifestations of AIDS in a consecutive series of 236 autopsied cases in mumbai, India

The HIV epidemic in the Asian subcontinent has a significant impact on India. The AIDS associated pathology has not been well evaluated in a representative study hence very little is known about the spectrum of HIV/AIDS associated diseases in Indian subcontinent. To determine the important postmortem findings in HIV infected individuals in Mumbai, autopsy study was carried out. The patient population included patients with AIDS who died at the tertiary care hospital over a 20 year period from 1988 to 2007. A total of 236 (182; 77% males and 54; 23%) females) patients with AIDS were autopsied. The main risk factor for HIV transmission was heterosexual contact (226 patients; 96%) and 223/236 (94%) patients died of HIV-related diseases. Tuberculosis was the prime cause of death in 149 (63%) patients, followed by bacterial pneumonia 33 (14%), cryptococcosis 18 (8%), toxoplasmosis of brain 15 (6%), pneumocystis jiroveci (PCJ) 1 (0.5%) and Non-Hodgkin's lymphoma 7 (3%) cases. The major underlying pathologies are either preventable or treatable conditions. There is an urgent need for attention towards the diagnosis, issue of therapy, and care of HIV disease in developing countries. Reducing mortality in patients with AIDS from infections must be highest public health policy in India.

Respiratory Complications in Iranian Hospitalized Patients with HIV/AIDS

Background

The respiratory tract has been the most commonly affected site of illness in HIV-infected patients. The current study was done to identify the frequency of respiratory complications in a consecutive case series of HIV-positive patients in Iran.

Materials and Methods

This study was a retrospective analysis at the national academic reference medical center of Imam-Khomeini Hospital, in Tehran, Iran. The study included 199 new admissions for 177 HIV-infected patients between 2000 and 2005. Demographic characteristics, risk factors for HIV infection, respiratory complications, and CD4+ lymphocyte counts were evaluated in these patients.

Results

All patients were males. The mean age was 35 years (age range: 15 to 63 years). Among 34 cases with available CD4+ lymphocyte count results, 70.6% had results <200 cells/mm³. Nearly half the patients (47.7%) had respiratory symptoms. The most common pulmonary complications were cough (86.3%), sputum (71.6%), dyspnea (54.7%), and hemoptysis (10.5%). The most common diagnosis was pulmonary tuberculosis (27.1%), followed by other bacterial pneumonias (16.6%) and pneumocystis carinii pneumonia (4.5%). Intravenous drug users who had history of incarceration had the highest risk factors for Mycobacterium tuberculosis infection (59%), and other bacterial pneumonias (52%).

Conclusion

Our study demonstrates that respiratory complications are highly frequent in HIV patients in Iran and that pulmonary tuberculosis is still a common complication in HIV infected patients, despite the availability of effective treatment. Results suggest the need for more effective preventive and prophylactic measures, wider use of antiretroviral treatment and effective chemotherapy for Iranian patients with HIV/AIDS.

Measurement of antiretroviral drugs in the lungs of HIV-infected patients

AIMS: Prior studies have shown that HAART is associated with decreased HIV viral load in the lungs. The correlation between antiretroviral exposure in bronchoalveolar lavage (BAL) fluid and virologic response was evaluated in patients starting HAART and enrolled in The AIDS Clinical Trial Group Protocol 723. MATERIALS #ENTITYSTARTX00026; METHODS: A total of 24 subjects underwent blood and BAL sampling prior to starting HAART, and after 4 and 24 weeks of HAART. Drug concentrations and HIV RNA were measured in paired plasma and BAL samples. RESULTS: Antiretroviral drugs, including efavirenz, were detectable in BAL fluid of HIV-infected subjects beginning HAART. Efavirenz was also associated with a higher likelihood of clearing HIV RNA from the lungs. CONCLUSION: These results suggest the excellent pulmonary virologic response to antiretroviral therapy may, in part, be due to penetration of antiretroviral drugs into the alveolar compartment.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

HIV-Related Lung Disorders

Highly active antiretroviral therapy (HAART) has dramatically altered the spectrum of morbidity and mortality in HIV-infected patients. This has been attributed to improvements in the lung microenvironment leading to enhanced pulmonary immunity, either by preventing the progressive loss of immune function or by actually promoting immune restoration. However, these changes have been accompanied by the recognition of new pulmonary complications in HIV-infected subjects, especially those associated with immune reconstitution. In this review we will describe how HIV infection alters the normal pulmonary environment, highlight the effect of HAART on these perturbations, and discuss potential complications of HAART in the lung, focusing on the pulmonary immune reconstitution inflammatory syndrome.

O escarro induzido no diagnóstico das doenças pulmonares em pacientes positivos ao vírus da imunodeficiência humana

INTRODUÇÃO: O escarro induzido é utilizado para monitorar a inflamação de vias aéreas, porém seu papel como ferramenta diagnóstica de doenças pulmonares em pacientes imunocomprometidos ainda necessita de melhor definição. OBJETIVOS: Determinar o rendimento do escarro induzido no diagnóstico das doenças pulmonares em pacientes positivos ao virus da imunodeficiência humana (HIV). MÉTODO: No período de janeiro de 2001 a setembro de 2002, foram avaliados todos os pacientes com idade superior a 14 anos, infectados com o HIV, admitidos em Hospital de Referência. Foram incluídos aqueles indivíduos que apresentavam manifestações clínicas do aparelho respiratório há pelo menos 7 dias, associadas, ou não, a alterações radiológicas, bem como indivíduos assintomáticos do ponto de vista respiratório, com alterações no radiograma de tórax. Os pacientes foram submetidos à avaliação clínica, radiológica e laboratorial e realizaram a indução de escarro, seguida pela broncofibroscopia, lavado broncoalveolar e biópsia pulmonar transbrônquica. As amostras foram processadas para bacterioscopia pelo método de Gram e Ziehl-Neelsen, cultura quantitativa para bactérias, exame micológico direto, cultura para micobactérias e fungos, pesquisa de citomegalovírus e Pneumocystis jiroveci, bem como celularidade total e diferencial. RESULTADOS: 54 pacientes foram incluídos no estudo. A pesquisa de agente etiológico resultou negativa em 7 pacientes, sendo que nos casos restantes foram isolados 60 agentes. Dentre os agentes isolados, 46,7% foram P. jiroveci; 33,5% bactérias piogênicas e 16,7% Mycobacterium tuberculosis. O escarro induzido apresentou sensibilidade de 57,5%, especificidade de 42,9%, valor preditivo positivo de 87,1%, valor preditivo negativo de 13% e acurácia de 55,6%. CONCLUSÕES: Nesta população, a análise do escarro induzido é um procedimento simples, seguro e com bom rendimento diagnóstico.

Respiratory symptoms among HIV-seropositive individuals

STUDY OBJECTIVES

Recent evidence suggests that chronic or latent viral infection may be an important predisposing factor in the development of COPD among smokers. As such, understanding if HIV-seropositive smokers are at heightened risk for respiratory symptoms may have relevance with regard to COPD pathogenesis. The current study was done to systematically identify the prevalence of respiratory symptoms among an HIV-seropositive population and to identify associated clinical features.

DESIGN AND SETTING

Cross-sectional analysis at an academic medical center.

PARTICIPANTS

Three hundred twenty-seven HIV-seropositive individuals without a history of AIDS-related pulmonary complications. Fifty-two HIV-negative individuals with a similar age and smoking history served as a comparison group.

MEASUREMENTS

Administration of the American Thoracic Society Division of Lung Diseases respiratory questionnaire, and pulmonary function studies.

RESULTS

Respiratory symptoms including dyspnea (41.6% vs 7.7%), cough (40% vs 25%), and phlegm production (41.9% vs 23.1%) were extremely common in the HIV-group and significantly more common than in the HIV-negative group. Current or prior cigarette smoking was the most important predictor of respiratory symptoms among the HIV-seropositive group. The use of the antiretroviral agent lamivudine was associated with a significant reduction in dyspnea.

CONCLUSION

HIV-seropositive individuals are at increased risk for the development of respiratory symptoms even prior to the onset of AIDS-related pulmonary complications. This may reflect a heightened susceptibility to the effects of cigarette smoking.

Low incidence of community-acquired pneumonia among human immunodeficiency virus-infected patients after interruption of Pneumocystis carinii pneumonia prophylaxis

We compared the incidence of bacterial pneumonia among 336 patients who discontinued trimethoprim-sulfamethoxazole (TMP-SMX) as prophylaxis against Pneumocystis carinii pneumonia (PCP) with that among 75 patients who fulfilled the criteria for discontinuation but continued receiving prophylaxis. The difference in the overall incidence rates for the 2 groups (1.2 events per 100 person-years) was not statistically significant. Discontinuation of TMP-SMX prophylaxis against PCP is not associated with a significant increase in the incidence of bacterial pneumonia among patients with a sustained CD4 cell count increase to >200 cells/microL.

Sinopulmonary complications of illicit drug use

Illicit drug use is frequently complicated by sinopulmonary illnesses. These complications fall into two major categories: (1) direct effects of drug exposure, and (2) indirect effects caused by HIV-induced immunosuppression. This article reviews the more common sinopulmonary syndromes associated with illicit drug use.

Lung abscess in adults: clinical comparison of immunocompromised to non-immunocompromised patients

Information related to the clinical characteristics and isolated microbes associated with lung abscesses comparing immunocompromised (IC) to non-immunocompromised (non-IC) patients is limited. A retrospective review for 1984-1996 identified 34 consecutive adult cases of lung abscess (representing 0.2% of all cases of pneumonia), including 10 non-IC and 24 IC patients. Comparison of age, gender, tobacco use, pre-existing pulmonary disease or recognized aspiration risk factors were not significantly different between the two groups. Upper lobe involvement accounted for the majority of cases, although multi-lobe involvement was limited to IC patients. There were no differences in the need for surgical intervention, and mortality was very low for both groups. Anaerobes were the most frequent isolates for non-IC patients (30%), whereas aerobes were the most frequent isolate for IC patients (63%). Importantly, certain organisms were exclusively isolated in the IC group and multiple isolates were obtained only from the IC patients.Thus, comparing non-IC to IC patients, clinical characteristics may be similar whereas important differences may exist in the microbiology associated with lung abscess. These findings have important implications for the clinical management of these patient groups, and support a strategy to aggressively identify microbial agents in abscess material.

Pneumocystis carinii isolated from lung lavage fluid in an infant with cystic fibrosis

Pneumocystis carinii (P. carinii) cysts were identified in bronchoalveolar lavage fluid from a 15-week-old child newly diagnosed with cystic fibrosis who presented with bronchitis, pneumonia, and weight loss. The child was not infected with human immunodeficiency virus (HIV), and there was no evidence of impaired immunity or exposure to individuals with known or suspected P. carinii disease. Culture of the lavage fluid also revealed pathogens typical of lung disease associated with cystic fibrosis. It is suspected that the presence of P. carinii in this patient represented a new acquisition, as has been described in immunocompetent infants and children. Whether P. carinii infection complicated cystic fibrosis-associated lung disease in this patient is unknown.

NF-kappa B modulates TNF-alpha production by alveolar macrophages in asymptomatic HIV-seropositive individuals

Local TNF-alpha production in different organs may affect HIV replication and pathogenesis. Alveolar macrophages (AMs) obtained by bronchoalveolar lavage from asymptomatic HIV-seropositive and HIV-seronegative individuals did not spontaneously release TNF-alpha, but LPS stimulation of these cells significantly increased TNF-alpha production. We tested whether NF-kappa B affects TNF-alpha production by AMs using N-tosyl-<cmd SC>l<cmd /SC> -phenylalanine chloromethylketone (TPCK) or N-benzoyl-<cmd SC>l<cmd /SC> -tyrosine ethyl ester (BTEE), which inhibit the degradation of I kappa B, or tricyclodecan-9-yl-xanthogenate-potassium (D609), which inhibits phospholipase C. Alveolar macrophages were exposed to LPS alone and with the chemical protease inhibitors TPCK, BTEE, and D609. NF-kappa B DNA binding induced by LPS treatment of AMs was inhibited by TPCK, BTEE, and D609. These agents also inhibited TNF-alpha mRNA and TNF-alpha protein production. After 24 h, the levels of TNF-alpha mRNA reached equilibrium, as assessed by RT-PCR. The levels of NF-kappa B mRNA remained constant under all conditions. The levels of I kappa B-alpha mRNA were similar after 30, 60, and 180 min, but the I kappa B-beta mRNA concentration was initially low and increased over time under all conditions. I kappa B-alpha and I kappa B-beta protein production was not affected by the chemical protease inhibitors. Our data show that TNF-alpha production by LPS-stimulated AMs from asymptomatic HIV-seropositive and -seronegative individuals is regulated via the phospholipase C pathway and by NF-kappa B DNA binding activity without obvious changes in I kappa B-alpha or I kappa B-beta protein concentrations.

Lymphocytic alveolitis, bronchoalveolar lavage viral load, and outcome in human immunodeficiency virus infection

Lymphocytic alveolitis portends a poor prognosis in human immunodeficiency virus (HIV)-infected subjects. Because alveolar lymphocytes consist predominantly of HIV-specific CD8(+) cytotoxic T lymphocytes (CTL), they could represent an appropriate immune response to infected cells in the lung, and be a surrogate marker for a high pulmonary viral burden. We assessed long-term outcome in a cohort of asymptomatic HIV-infected subjects who underwent bronchoscopy between 1990 and 1993 and had bronchoalveolar lavage fluid (BALF) available for determination of viral load by reverse transcription-polymerase chain reaction. The ability to detect HIV in BALF increased with disease progression. Lymphocytic alveolitis, although present at all stages of HIV infection, was most pronounced in patients with middle stage disease. The HIV viral load as measured by bronchoalveolar lavage correlated with the percentage of alveolar lymphocytes in patients with peripheral blood CD4(+) cell counts above 200/microliter. Including patients with CD4(+) cell counts < 200/microliter weakened this correlation, possibly because of replacement of CD8(+) CTL by CD8(+) suppressor cells in advanced disease. Free virus in BALF was a stronger predictor of HIV disease progression than was lymphocytic alveolitis. These data suggest that lymphocytic alveolitis in HIV-infected subjects occurs in response to viral antigens in the lung and that the poor prognosis associated with lymphocytic alveolitis reflects a high pulmonary viral burden.

Gamma interferon stimulates rat alveolar macrophages to kill Pneumocystis carinii by L-arginine- and tumor necrosis factor-dependent mechanisms

Pneumocystis carinii pneumonia remains a serious complication for immunocompromised patients. In the present study, P. carinii organisms interacted with gamma interferon (IFN-gamma)-stimulated alveolar macrophages (AMs) to activate the L-arginine-dependent cytocidal pathway involving reactive nitrogen intermediates (RNI) that were assayed as nitrite (NO2-). Unstimulated cultures of AMs produced negligible quantities of RNI. Addition of P. carinii organisms to IFN-gamma-primed AMs resulted in greatly enhanced production of RNI. NO2- levels increased from 0.8 +/- 0.4 to 11.1 +/- 3.8 microM as early as 6 h after P. carinii organisms were incubated with IFN-gamma-stimulated AMs and to 35.1 +/- 8.9 microM after a 24-h incubation, a near-maximum level. High levels of NO2- were produced by AMs primed with as little as 10 U of IFN-gamma per ml in the presence of P. carinii, and a 20-fold increase in IFN-gamma concentration resulted in only a further 65% increase in NO2- production. RNI-dependent killing of P. carinii was demonstrated by both a 51Cr release assay and a [35S]methionine pulse immunoprecipitation assay. Addition of either monoclonal tumor necrosis factor alpha (TNF-alpha) neutralizing antibody or 200 microM NG-monomethyl-L-arginine (L-NGMMA), a competitive inhibitor of the L-arginine-dependent pathway, significantly decreased NO2- production and reduced P. carinii killing. TNF-alpha alone had no effect on P. carinii viability. These results suggest that (i) the specific interaction of P. carinii organisms with IFN-gamma-primed AMs triggers the production of RNI, (ii) RNI are toxic to P. carinii, and (iii) TNF-alpha likely plays a central role in mediating P. carinii killing by IFN-gamma-stimulated AMs.

Chest imaging in AIDS

A review of imaging in the acquired immune deficiency syndrome (AIDS) is presented. The imaging features can be conveniently categorized according to whether the presenting complications are infective (bacterial, protozoal, or fungal), bronchiectasis, neoplastic (Kaposi's sarcoma, AIDS-related lymphoma, or lymphoproliferative disease), or a miscellaneous group (non-specific interstitial pneumonitis, persistent generalized lymphadenopathy, or bronchogenic carcinoma).

Surfactant protein-A reduces binding and phagocytosis of pneumocystis carinii by human alveolar macrophages in vitro

Surfactant protein-A (SP-A) levels are increased in Pneumocystis carinii pneumonia, but the role of SP-A in the pathogenesis of P. carinii pneumonia is not completely understood. This study investigated the effect of SP-A on the in vitro binding and phagocytosis of P. carinii by normal human alveolar macrophages (AM). Determination of binding and phagocytosis was done with a fluorescence-based assay, utilizing fluorescein isothiocyanate (FITC)-labeled P. carinii. Binding and phagocytosis of P. carinii to AM correlated inversely with the levels of SP-A present on the surface of the organisms (r = -0.6323, P = 0.0086; and r = -0.9827, P < 0.0001, respectively). The addition of exogenous SP-A to organisms with low surface-associated SP-A reduced P. carinii binding by 30% (P < 0.05) and reduced phagocytosis by 20% (P < 0.05), whereas this effect was reversed with ethylenediamine tetraacetic acid (EDTA) or anti-SP-A antibody. Furthermore, binding and phagocytosis were enhanced after enzymatic removal of P. carinii surface-associated SP-A, and this effect was reversed with the addition of exogenous SP-A. The observed inhibitory effect of SP-A on P. carinii binding and phagocytosis reflected binding of SP-A to the organisms rather than a direct effect of SP-A on the macrophages. These data suggest that increased levels of SP-A may contribute to the pathogenesis of P. carinii pneumonia through binding to the surface of the organism and interfering with AM recognition of this opportunistic pulmonary pathogen.

Pulmonary complications of HIV infection: autopsy findings

STUDY OBJECTIVES

To describe the pulmonary complications in patients with HIV infection, and the changes in the incidence of these complications over a 12-year period.

DESIGN

Retrospective review of autopsy records.

SETTING

Two university-affiliated medical centers.

PATIENTS

We studied autopsy findings from 233 patients with HIV infection who died between 1985 and 1996. Demographic data, risk factors for HIV infection, and the lengths of hospital stay were obtained. The histologic and microbiological findings of the respiratory system, and the extrapulmonary organ involvement by Kaposi's sarcoma (KS), Pneumocystis carinii, Mycobacterium tuberculosis, and Mycobacterium avium complex were reviewed.

RESULTS

Ninety-two percent of the patients were black and 75% were male. The two most common identified risk factors for HIV infection were homosexuality (34%) and injection drug use (27%). Bacterial pneumonia was the most frequent pulmonary complication (42%). The two most common causes of bacterial pneumonia were Pseudomonas aeruginosa and Staphylococcus aureus. P carinii pneumonia (PCP) was found in 24%, with extrapulmonary involvement in 13%. Pulmonary mycobacterial infections were seen in 33%, with multiple extrapulmonary involvement. The most common site affected by KS was the lung. Of all pulmonary complications, only the incidence of PCP decreased over the 12-year period.

CONCLUSIONS

Recognizing the high incidence rate of bacterial pneumonia, the high frequency of pulmonary KS and the not uncommon occurrence of extrapulmonary P carinii infection in patients with HIV helps in improving their care.

Neutrophil chemotactic activity in bronchoalveolar lavage fluid of patients with AIDS-associated Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) is accompanied by an acute inflammatory infiltration of the lung parenchyma. The cellular infiltrate is characterized by inflammatory cells including neutrophils, lymphocytes and macrophages. Furthermore, neutrophilia in bronchoalveolar lavage (BAL) fluid has been shown to confer a poor prognosis in PCP. We therefore investigated the potential of BAL fluid from 17 patients with PCP to induce neutrophil chemotaxis. BAL fluid from patients induced considerable neutrophil chemotactic activity compared to normal controls. Elevated levels of IL-8 were detected in patient samples as compared to controls. A specific anti-IL-8 antibody significantly reduced chemotactic activity of patient samples by more than 50%. In conclusion, IL-8 appears to be a significant participant of neutrophil chemotaxis in AIDS-associated PCP, and may participate in the recruitment of neutrophils to the lung during PCP.

Radiological features of pulmonary tuberculosis in 963 HIV-infected adults at three Central African Hospitals

Tuberculosis is one of the most important infectious complications in human immunodeficiency virus (HIV)-infected individuals in sub-Saharan Africa. In this radiological study, we detail the chest radiographic findings of Zairean and Zambian adults with a diagnosis of AIDS and tuberculosis as seen at three Central African Hospitals. Between 1992 and 1995, consecutive chest radiographs of 963 HIV-infected adults aged between 16 years and 56 years with microbiologically confirmed tuberculosis (TB) were reviewed: (1) 362 adults from Sendwe General Hospital, Lubumbashi, Zaire, (2) 175 from Mama Yemo Hospital, Kinshasa, Zaire, and (3) 426 adults from The University Teaching Hospital (UTH), Lusaka, Zambia. During the same period consecutive chest radiographs from 1000 age-matched HIV-negative adults with tuberculosis were collected for comparative purposes. Comparison of the two groups showed that the HIV-infected group of patients with tuberculosis had a significantly higher proportion of lymphadenopathy (26% vs 13%; P = 0.001), pleural effusions (16% vs 6.8%; P = 0.001), miliary shadowing (9.8% vs 5%; P = 0.001), an interstitial pattern (12% vs 7%; P = 0.01) and consolidation (10% vs 3%; P = 0.001). There was significantly less cavitation (33% vs 78%; P = 0.001) and atelectasis (12% vs 24%; P = 0.001) seen in the HIV-positive group compared to the HIV-negative group of patients. These patterns of radiographic changes were consistently seen across all three hospital sites. The radiographic appearances in HIV-infected individuals with TB is discussed.

Alveolar damage in AIDS-related Pneumocystis carinii pneumonia

OBJECTIVE

Pneumocystis carinii pneumonia is the most common and serious of the pulmonary complications of AIDS. Despite this, many basic aspects in the pathogenesis of HIV-associated P carinii pneumonia are unknown. We therefore undertook a light and electron microscopic study of transbronchial biopsy specimens to compare pathologic features of P carinii pneumonia and other HIV-related lung diseases.

DESIGN AND PATIENTS

Thirty-seven consecutive HIV-infected patients undergoing a diagnostic bronchoscopy.

RESULTS

P carinii pneumonia was characterized by an increase in inflammation, edema, exudate, fibrosts, type II pneumocyte proliferation, and cellular infiltration of the alveolar wall when compared with other lung diseases (all p < 0.05). Electron microscopy showed apposition of the trophozoite to the type I pneumocyte. Erosion of type I pneumocytes was observed in 13 of 15 patients with P carinii pneumonia, whereas none without P carinii pneumonia had this finding (p < 0.05). Erosion of the type II pneumocyte was not observed.

CONCLUSION

Inflammation, interstitial fibrosis, and alveolar epithelial erosion are characteristic features of P carinii pneumonia. The changes may form the pathologic basis for the respiratory failure seen in patients with P carinii pneumonia. Electron microscopy did not show any diagnostie advantage over conventional light microscopy using routine stains.

The role of alveolar macrophages in Pneumocystis carinii degradation and clearance from the lung

Although studies indicate that alveolar macrophages participate in host defense against Pneumocystis carinii, their role in organism degradation and clearance from the lung has not yet been established. We, therefore, quantified the uptake and degradation of 35S-labeled P. carinii by cultured macrophages, demonstrating significant degradation of P. carinii over 6 h. We further evaluated the role of macrophages in elimination of P. carinii from the living host. Rats received either intratracheal PBS, liposomal PBS (L-PBS), or liposomal dichloromethylene diphosphonate (L-Cl2MDP), a preparation which leads to selective depletion of macrophages. Over 72 h, L-Cl2MDP-treated animals had loss of > 85% of their alveolar macrophages. In contrast, L-PBS-treated rats had cellular differentials identical to rats receiving PBS. Macrophage-depleted rats and controls were next inoculated with P. carinii and organism clearance was determined after 24 h. P. carinii elimination was evaluated with both cyst counts and an ELISA directed against glycoprotein A (gpA), the major antigen of P. carinii. Both assays indicated that macrophage-depleted rats had substantial inpairment of P. carinii clearance compared to L-PBS- or PBS-treated rats. These data provide the first direct evidence that macrophages mediate elimination of P. carinii from the living host.

Fungal infections in patients with acquired immunodeficiency syndrome

The incidence and severity of fungal infections appear to increase with progression of HIV disease. Because of the significant morbidity and mortality associated with the mycoses discussed, knowledge of the clinical syndromes, early diagnosis, and prompt institution of therapy are crucial for a favorable outcome. For disseminated or invasive fungal infections, suppressive therapy must be continued to prevent relapse.

Pneumocystis carinii

Improved understanding of Pneumocystis carinii, in particular the widespread use of chemoprophylaxis, has resulted in a declining incidence of infection in patients infected with HIV since the late 1980s. Despite these advances, P. carinii pneumonia continues to represent an important cause of pulmonary disease in HIV-seropositive individuals who do not receive chemoprophylaxis or when breakthrough episodes occur. This article reviews the history, biology, clinical manifestations, prognostic markers, therapy, and chemoprophylaxis of P. carinii pneumonia in HIV-seropositive patients.

Molecular docking towards drug discovery

Fueled by advances in molecular structure determination, tools for structure-based drug design are proliferating rapidly. Lead discovery through searching of ligand databases with molecular docking techniques represents an attractive alternative to high-throughout random screening. The size of commercial databases imposes severe computational constraints on molecular docking, compromising the level of calculational detail permitted for each putative ligand. We describe alternative philosophies for docking which effectively address this challenge. With respect to the dynamic aspects of molecular recognition, these strategies lie along a spectrum of models bounded by the Lock-and-Key and Induced-Fit theories for ligand binding. We explore the potential of a rigid model in exploiting species specificity and of a tolerant model in predicting absolute ligand binding affinity. Current molecular docking methods are limited primarily by their ability to rank docked complexes; we therefore place particular emphasis on this aspect of the problem throughout our validation of docking strategies.

Pneumocystis carinii pneumonia in patients without acquired immunodeficiency syndrome: associated illness and prior corticosteroid therapy

OBJECTIVE

To determine the clinical spectrum of immunosuppressive conditions and systemic corticosteroid therapy associated with the development of Pneumocystis carinii pneumonia in a consecutive series of patients without acquired immunodeficiency syndrome (AIDS).

DESIGN

We retrospectively analyzed a consecutive series of 116 patients without AIDS who were assessed at Mayo Medical Center for a first episode of P. carinii pneumonia between 1985 and 1991.

METHODS

Medical records were examined to determine underlying immunosuppressive disorders, premorbid corticosteroid dosage and duration of therapy, associated infections, and subsequent respiratory failure and in-hospital mortality.

RESULTS

Conditions associated with a first episode of P. carinii pneumonia were hematologic malignant disorders (30.2%), organ transplantation (25.0%), inflammatory disorders (22.4%), solid tumors (12.9%), and miscellaneous conditions (9.5%). Regardless of the associated underlying disease, corticosteroids had been administered systemically in 105 patients (90.5%) within 1 month before the diagnosis of P. carinii pneumonia. The median daily corticosteroid dose was equivalent to 30 mg of prednisone; however, 25% of patients had received as little as 16 mg of prednisone daily. The median duration of corticosteroid therapy was 12 weeks before the development of pneumonia; however, P. carinii pneumonia developed after 8 weeks or less of corticosteroid therapy in 25% of these patients. Respiratory failure occurred in 43%, and in-hospital mortality was 34% for patients with P. carinii pneumonia in conditions other than AIDS.

CONCLUSION

Although these results do not suggest that premorbid administration of corticosteroids is the only factor that contributes to the development of P. carinii pneumonia in these patients, they show that, in this large consecutive series, systemic corticosteroid therapy, even in moderate doses, was administered to most patients during the month preceding the onset of P. carinii pneumonia. Consideration should be given to instituting P. carinii prophylaxis (when not contra-indicated) in patients for whom prolonged systemic corticosteroid therapy is prescribed.

Pulmonary complications of HIV disease: 10 year retrospective evaluation of yields from bronchoalveolar lavage, 1983-93

BACKGROUND

Pulmonary disease is a major contributor to morbidity and mortality in patients with HIV infection and AIDS. The aim of this study was to describe bronchoscopic findings and the spectrum of pulmonary pathogens in HIV seropositive patients undergoing investigation of respiratory disease over a 10 year period in a major UK referral centre.

METHODS

Recruitment was procedure based with data being captured when bronchoscopy was clinically indicated. Data were evaluated from 580 HIV seropositive patients (559 men, age 13-65 years) over a 10 year period from June 1983 to March 1993.

RESULTS

A total of 947 bronchoscopies was performed. The most frequent pulmonary pathogen isolated from bronchoalveolar lavage (BAL) fluid in 44% of all bronchoscopies was Pneumocystis carinii. Of all patients studied, 324 (55%) had at least one cytologically confirmed episode of P carinii pneumonia; this was AIDS defining in 219 (38%) of patients who underwent bronchoscopy. Between 1987 and 1993 the overall diagnostic yield from BAL fluid was 76%; 25% of all bronchoscopies yielded positive microbiological results, the most frequent isolates being Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas spp, and Haemophilus influenzae. Mycobacteria were identified in 8% of patients; M tuberculosis was the most common being identified in 3% of lavage samples and in 4% of patients. No drug-resistant M tuberculosis was found. Viral isolates (mainly cytomegalovirus) were identified in up to 31% of BAL fluid samples. Endobronchial Kaposi's sarcoma was seen in 15% of patients at bronchoscopy.

CONCLUSIONS

Of the 1956 newly diagnosed HIV seropositive patients receiving clinical care at St Mary's Hospital over this period, approximately 30% underwent bronchoscopy. Diagnostic rates for P carinii pneumonia, endobronchial Kaposi's sarcoma, and bacterial and mycobacterial infection have remained largely constant since 1989. Bronchoalveolar lavage produces high diagnostic yields generally, and P carinii pneumonia remains a common cause of pulmonary disease in these patients.

Acute lung disease in the immunocompromised host. Diagnostic accuracy of the chest radiograph

PURPOSE

To assess the diagnostic accuracy of the chest radiograph in the evaluation of acute pulmonary complications in immunocompromised patients.

METHODS

The study included the chest radiographs in 149 consecutive acute pulmonary complications seen in immunocompromised patients in whom a definitive diagnosis was made. Twenty-four complications were in patients with AIDS and 125 were in non-AIDS patients. The radiographs were separately reviewed in random order by two independent observers. The observers assessed pattern and distribution of radiographic findings and recorded their first-choice diagnosis.

RESULTS

The most common complication in patients with AIDS was Pneumocystis carinii pneumonia (n = 21). In the non-AIDS patients, the most common complications included invasive aspergillosis (n = 25), drug reaction (n = 21), and Pneumocystis pneumonia (n = 20). A correct first-choice diagnosis was made in 90% of patients with AIDS and 34% of non-AIDS patients. IN AIDS patients with Pneumocystis pneumonia, the correct first-choice diagnosis was made in 41 of 42 (98%) readings by the two observers. In non-AIDS patients with invasive pulmonary aspergillosis, drug reaction, and Pneumocystis pneumonia, the correct first-choice diagnosis was made in 38%, 26%, and 43% of readings, respectively.

CONCLUSION

The chest radiograph is helpful in the differential diagnosis of acute lung disease in the immunocompromised host, particularly in patients with AIDS.

Variable efficiency of three primer pairs for the diagnosis of Pneumocystis carinii pneumonia by the polymerase chain reaction

The efficiency of three different primer pairs, complementary to different Pneumocystis carinii DNA regions, was compared in the polymerase chain reaction (PCR) for the diagnosis of Pneumocystis carinii pneumonia (PCP) on bronchoalveolar fluid (BALF) from patients with AIDS. PCR coupled with dot-blot hybridization (BLOT) using primers and probe from the mitochondrial 23SrDNA region showed the highest sensitivity, with a lower detection limit of 0.5-1 organisms microliter-1. When testing 47 BALF, PCR plus BLOT of the mitochondrial 23SrDNA region showed also the best diagnostic efficiency (97% sensitivity, 100% specificity). Sensitivity was significantly higher than with PCR and BLOT of the 5SrDNA region (81.5% sensitivity; P = 0.025, McNemar test); and of the dehydrofolate reductase (DHFR) gene region (75.6% sensitivity; P = 0.019). Sensitivity was also significantly higher than indirect immunofluorescence (75.8% sensitivity; P = 0.008). Using DHFR primers and probe, specificity was also reduced. The diagnostic sensitivity in clinical specimens paralleled the detection limit in the standard dilutions. The use of repeated DNA sequences of proven specificity as target of PCR amplification favourably influences sensitivity and specificity. This comparative study demonstrates that primer selection plays a significant role in the diagnosis of PCP by PCR.

Pulmonary complications associated with illicit drug use. An update

STUDY OBJECTIVE

In earlier years, nonopportunistic infectious pulmonary complications of illicit drug use were most common. We designed this study to update the pulmonary complications associated with illicit drug use in the 1990s.

DESIGN

Concurrent and retrospective chart review.

SETTING

Inner-city municipal hospital.

PATIENTS

All illicit drug users with pulmonary complications seen by the pulmonary consult service were enrolled in the study. There were 105 hospital admissions of 97 patients in a 14-month study period.

RESULTS

Sixty percent of the patients had HIV infection. The most common pulmonary complications were Pneumocystis carinii pneumonia (30%) followed by community-acquired pneumonia (12%) and tuberculosis (9%).

CONCLUSIONS

The spectrum of pulmonary disease in illicit drug users has changed since 1988. Opportunistic HIV-related disease is much more common. Community-acquired pneumonia and tuberculosis remain relatively frequent complications. Septic pulmonary embolism is now rare.

Does cytomegalovirus predict a poor prognosis in Pneumocystis carinii pneumonia treated with corticosteroids? A note for caution

OBJECTIVE

To examine the importance of cytomegalovirus (CMV) in bronchoalveolar lavage (BAL) fluid of patients with HIV-associated Pneumocystis carinii pneumonia (PCP) treated with adjunctive corticosteroids (CS).

DESIGN

Analysis of clinical data during a 5-year period.

SETTING

Department of infectious diseases where clinical and paraclinical data on patients suspected of having PCP have been sampled prospectively.

PATIENTS

148 consecutive patients with a first episode of PCP in a 5-year period.

MAIN OUTCOME MEASURE

Vital status 3 months after diagnosis of PCP.

RESULTS

Patients with PCP treated with adjunctive CS who had CMV cultured from BAL fluid had a two times higher mortality within 3 months from bronchoscopy than others (p = 0.08). This difference could not be explained by differences in CD4 count, PO2 or PCO2 at time of bronchoscopy.

CONCLUSION

With the accepted usage of adjunctive CS in severe PCP, the role of CMV as a pulmonary copathogen may have changed. Active CMV infection may be an important cause of failing treatment of severe PCP in those treated with adjunctive CS.