Cytomegalovirus as a primary pulmonary pathogen in AIDS

A double whammy in an immunocompromised patient

Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection in immunocompromised patients, especially those with human immunodeficiency virus (HIV) infection. Cytomegalovirus (CMV) pneumonia most often occurs as a coinfection with another opportunistic pathogen especially in patients with severe immunosuppression. We present a case of PCP-CMV coinfection in a newly diagnosed HIV patient who was treated with the recommended therapy for both diseases and had a favorable outcome. The presence of CMV in the context of another opportunistic respiratory tract infection is often to be not treated, due to conflicting evidence of its therapeutic benefit. Our report highlights the importance of CMV treatment to achieve clinical stability and recovery in newly diagnosed patients with HIV and severely immuno-compromised status.

Invasive diagnostic strategies in immunosuppressed patients with acute respiratory distress syndrome

Immunosuppression predisposes the host to development of pulmonary infections, which can lead to respiratory failure and the development of acute respiratory distress syndrome (ARDS). There are multiple mechanisms by which a host can be immunosuppressed and each is associated with specific infectious pathogens. Early invasive diagnostic modalities such as fiber-optic bronchoscopy with bronchoalveolar lavage, transbronchial biopsy, and open lung biopsy are complementary to serologic and noninvasive studies and assist in rapidly establishing an accurate diagnosis, which allows initiation of appropriate therapy and may improve outcomes with relative safety.

Asymptomatic carriage of Pneumocystis jirovecii and cytomegalovirus in lungs of immunocompetent patients

PURPOSE

Pneumocystis jirovecii (PCP) and cytomegalovirus (CMV) are opportunistic pathogens which cause lung infection in immunocompromised individuals. However, scarce data are available regarding the carriage of CMV or PCP in immunocompetent, non critically ill patients. The purpose of this study was to evaluate the prevalence of PCP and CMV in broncholaveolar lavage of adult immunocompetent, non critically ill patients.

METHODS

BAL fluids from immunocompetent patients who underwent bronchoscopy were analyzed by polymerase chain reaction (PCR) for CMV and PCP DNA. We tested CMV antibodies in serum. In patients with positive CMV DNA in lavage fluid, we further analyzed peripheral blood for the presence of CMV DNA.

RESULTS

Ninety three patients were included. We did not detect PCP DNA in BAL in any patient. CMV DNA was found in BAL of 5 of 86 CMV IgG positive patients (5.8 %). Patients who were positive for CMV did not differ from patients with negative PCR for CMV regarding demographic and clinical features.

CONCLUSION

We did not find PCP colonization in our cohort of patients. However, we found significant prevalence of CMV DNA in BAL from immunocompetent patients, with no evidence of acute CMV infection. This finding may represent colonization by CMV in immunocompetent, non-critically ill individuals.

HIV/AIDS Related Respiratory Diseases

Lungs are the most commonly involved organ by HIV/AIDS related diseases, and pulmonary infections are the main reasons for the increasing death rate from AIDS. Pathogens of HIV related pulmonary infections include parasites, fungi, mycobacteria, viruses, bacteria and toxoplasma gondii. According to international reports, pathogens have different geographical distribution, which is also closely related to the socioeconomic status of the region to produce varied AIDS related diseases spectra. For instance, in the United States, pneumocystis carnii pneumonia (PCP), tuberculosis and recurrent bacterial pneumonia (at least twice within 1 year) occur frequently in HIV infected patients. An international report published 10 years ago indicated that PCP is the most common and serious pulmonary opportunistic infections in HIV infected patients. Now its incidence has dropped with the application of antiretroviral treatment and preventive measures. PCP will continue to occur initially in patients who are aware of their HIV infection. In addition, HIV related viral and parasitic infections have been reported both domestically and internationally. In this section, the clinical manifestations and imaging findings of HIV related pulmonary infections are analyzed and discussed, which provide effective diagnosis basis, so as to reduce the incidence of HIV-related pulmonary infections.

Evaluation of respiratory disease

The spectrum of HIV-associated pulmonary diseases is broad. Opportunistic infections, neoplasms, and noninfectious complications are all major considerations. Clinicians caring for persons infected with HIV must have a systematic approach. The approach begins with a thorough history and physical examination and often involves selected laboratory tests and a chest radiograph. Frequently, the clinical, laboratory, and chest radiographic presentation suggests a specific diagnosis or a few diagnoses, which then prompts specific diagnostic testing and treatment. This article presents an overview of the evaluation of respiratory disease in persons with HIV/AIDS.

Imaging lung manifestations of HIV/AIDS

Advances in our understanding of human immunodeficiency virus (HIV) infection have led to improved care and incremental increases in survival. However, the pulmonary manifestations of HIV/acquired immunodeficiency syndrome (AIDS) remain a major cause of morbidity and mortality. Respiratory complaints are not infrequent in patients who are HIV positive. The great majority of lung complications of HIV/AIDS are of infectious etiology but neoplasm, interstitial pneumonias, Kaposi sarcoma and lymphomas add significantly to patient morbidity and mortality. Imaging plays a vital role in the diagnosis and management of lung of complications associated with HIV. Accurate diagnosis is based on an understanding of the pathogenesis of the processes involved and their imaging findings. Imaging also plays an important role in selection of the most appropriate site for tissue sampling, staging of disease and follow-ups. We present images of lung manifestations of HIV/AIDS, describing the salient features and the differential diagnosis.

Review of HIV-Related Cytopathology

Exfoliative and aspiration cytologies play a major role in the management of patients with human immunodeficiency virus infection. Common cytology samples include cervicovaginal and anal Papanicolaou tests, fine needle aspirations, respiratory specimens, body fluids, Tzanck preparations, and touch preparations from brain specimens. While the cytopathologists need to be aware of specific infections and neoplasms likely to be encountered in this setting, they should be aware of the current shift in the pattern of human immunodeficiency virus-related diseases, as human immunodeficiency virus patients are living longer with highly active antiretroviral therapy and suffering fewer opportunistic infections with better antimicrobial prophylaxis. There is a rise in nonhuman immunodeficiency virus-defining cancers (e.g., anal cancer, Hodgkin's lymphoma) and entities (e.g., gynecomastia) from drug-related side effects. Given that fine needle aspiration is a valuable, noninvasive, and cost-effective tool, it is frequently employed in the evaluation and diagnosis of human immunodeficiency virus-related diseases. Anal Papanicolaou tests are also increasing as a result of enhanced screening of human immunodeficiency virus-positive patients for cancer. This paper covers the broad spectrum of disease entities likely to be encountered with human immunodeficiency virus-related cytopathology.

[Massive alveolar hemorrhage due to cytomegalovirus (CMV) and HIV infection]

Alveolar hemorrhage may be a complication of diseases with local and systemic manifestations. Both share the same pathophysiological concept: damage to the alveolar microcirculation. It is a clinical entity that generates a diagnostic challenge for the physician. Early recognition favors aggressive treatment, which can improve the outcome. Despite the technological advances in its diagnosis and treatment, it is still a condition having high morbidity and mortality. We present the case of a 42-year old woman diagnosed of massive alveolar hemorrhage induced by cytomegalovirus (CMV) and HIV infection. Its presentation is atypical because most reported cases have occurred as a pneumonic process, episodes of massive hemorrhage being uncommon. The diagnosis was documented by bronchoscopy with bronchoalveolar lavage and etiological diagnosis with molecular techniques using reverse transcription polymerase chain reaction.

[Pneumocystis and cytomegalovirus pneumonia in HIV patients - two clinical cases]

Cytomegalovirus is capable of causing disease in immunocompromised patients. In people infected by the Human Immunodeficiency Virus (HIV) it becomes an important agent when there is advanced immunosupression. Its role as a pulmonary pathogen in these patients has been questioned. In the case of pneumocystosis the presence of Cytomegalovirus doesn't seem to worsen prognosis, except in cases where corticosteroids are used. Authors present two cases of patients with HIV infection and advanced immunosupression who were admitted in the intensive care unit for respiratory failure. In both Pneumocystis jirovecii was isolated from.

[The radiology of opportunistic pneumonias. I: Epidemiological, laboratory and clinical background]

In the guidelines of the German Society of Pneumology on diagnosis and therapy of opportunistic pneumonias, chest x-ray is listed as the basic diagnostic method in congenital and acquired immunodepression. In case of discrepancy between radiographic and the clinical findings or in cases of bilateral infiltrates, infection refractory to therapy or a difficult course in patients requiring artificial ventilation, a CT, or if necessary, ultrasound or MRI should be carried out. Cross-sectional imaging allows more precise assessment of the radiological pattern, estimation of the degree of severity (number of infiltrated segments) and detection of complications (pleural effusion, empyema, thorax wall infiltration). Clinical and laboratory parameters, bacteriological and serological examinations as well as information on the underlying immunocompromising factors must be taken into account in the differential diagnosis. The radiographic finding is an important diagnostic parameter which is used in the determination of the degree of severity of the pneumonia. The pattern of findings is one of rationales for the use of antibiotic therapy. In the first part of this contribution the epidemiological, laboratory and clinical background of the diagnosis of opportunistic pneumonias is discussed.

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

The incidence rates of opportunistic diseases, hospital admission and death have fallen markedly since the advent of highly active antiretroviral therapy (HAART). We examined the impact of HAART on the pattern of HIV-related respiratory diseases necessitating hospitalization. We retrospectively compared the numbers and etiologies of respiratory diseases diagnosed in HIV-infected patients hospitalized in the chest department of a Paris university hospital during the three years preceding widespread prescription of HAART in France (era 1, starting in July 1993) and the first three years of widespread HAART prescription (era 2, starting in July 1996). Respectively, 207 and 119 HIV-infected patients were admitted for respiratory disease in era 1 and era 2. Only 31.1% of patients admitted during era 2 were receiving HAART. Pulmonary opportunistic infections other than Pneumocystis carinii pneumonia (PCP) (p = 0.0008) and exacerbations of chronic bronchial disease due to gram-negative bacilli (p = 0.04) virtually disappeared in era 2. In contrast, PCP, bacterial pneumonia, tuberculosis, pulmonary Kaposi's sarcoma and pulmonary non-Hodgkin lymphoma showed only a twofold decrease in era 2, while lung cancer was more frequent (p = 0.004). The frequency of severe respiratory diseases necessitating hospitalization of HIV-infected patients has fallen since the advent of HAART, and their etiologic distribution has changed.

Pulmonary involvement during cytomegalovirus infection in immunosuppressed patients

Although cytomegalovirus (CMV) pulmonary involvement after solid organ transplantation is infrequently seen nowadays, CMV pneumonitis is still a potential lethal complication. Introduction of the pp65 antigenemia assay enabled early and rapid diagnosis of CMV viremia in transplant patients prior to symptoms. Also, in asymptomatic patients with CMV viremia, a decreased pulmonary diffusion capacity could be demonstrated. In this review, we discuss clinical and subclinical pulmonary involvement of CMV infection in the immunocompromised host with an emphasis on transplant recipients. The clinical course, diagnosis, therapy, prophylaxis, and pathophysiology of CMV pneumonitis are discussed.

Update on lung disease in AIDS

Pulmonary disorders remain an important complication of HIV infection, even in the current era of potent antiretroviral therapy. Using an integrated approach that combines radiographic pattern recognition with knowledge of a patient's clinical symptoms, laboratory data, immune status level, demographic information, and drug therapy can enhance the interpretation of imaging studies in HIV-infected patients. Although chest radiography remains the mainstay of imaging the HIV-positive patient with respiratory symptoms, CT plays an increasingly important secondary role in selected cases.

HIV envelope protein inhibits MHC class I presentation of a cytomegalovirus protective epitope

CTL recognize peptides that derive from viral protein Ags by proteolytic processing and are presented by MHC class I molecules. In this study we tested whether coexpression of viral Ags in the same cell leads to competition between them. To this end, two L(d)-restricted epitopes derived from HIV-1 envelope gp160 (ENV) and from CMV pp89 phosphoprotein were coexpressed. HIV ENV strain IIIB, but not MN variant, impaired recognition by specific CTL of CMV pp89 epitope 9pp89. Susceptibility to inhibition after ENV coexpression was inversely related to the amount of antigenic 9pp89 peptide processed from different antigenic constructs. In line with it, competition decreased the yield of naturally processed antigenic 9pp89 peptide bound to MHC class I molecules in coinfected cells. Also, point mutants of the presenting MHC class I molecule differed in their competition pattern. Collectively, the data imply that competition operates at the step of MHC-peptide complex assembly or stabilization. We conclude that, although not the rule, in certain combinations there is interference between different Ags expressed in the same cell and presented by the same MHC class I allele. These studies have implications for vaccine development and for understanding immunodominance.

Herpesvirus type 1-8 in BAL fluid from HIV-1-infected patients with suspected pneumonia and from healthy individuals

Pneumonia is still a major problem in human immunodeficiency virus (HIV)-infected patients, and despite extensive investigation the aetiology remains unknown in many cases. The prevalence of the eight human herpesviruses was determined by polymerase chain reaction in 91 samples of bronchoalveolar lavage (BAL) fluid from 72 HIV-infected patients with 91 episodes of suspected pneumonia. The presence of herpesviruses was related to clinical and immunological findings and the prevalence of herpesviruses in HIV-infected patients was compared with the prevalence in BAL fluid from 50 healthy, immunocompetent individuals. Epstein-Barr virus, cytomegalovirus and human herpesvirus-8 (HHV8) were found in 5.5%, 36% and 5.5% of BAL fluid samples from HIV-infected patients. No herpesviruses were detectable in BAL fluid from healthy, immunocompetent individuals. The herpesviruses occurred mainly in patients with CD4+ counts <200 x 10(6) L(-1). All patients with herpesviruses recovered without specific antiviral treatment. Two patients with HHV8 had the diagnosis of Kaposi's sarcoma. It is concluded that cytomegalovirus, Epstein-Barr virus, and human herpesvirus-8 are frequently present in bronchoalveolar lavage fluid from severely immunocompromised human immunodeficiency virus-infected patients with pulmonary symptoms. In bronchoalveolar lavage fluid from healthy, immunocompetent individuals, herpesviruses are absent. Apart from human herpesvirus-8, the present results indicate that the herpesviruses do not play a serious pathogenic role in the development of pulmonary symptoms in human immunodeficiency virus-infected patients.

Current aspects of diagnosis and treatment of cytomegalovirus infections in infants

BACKGROUND

Human cytomegalovirus (CMV) is the most common cause of congenital and perinatal infections throughout the world. High prevalence of CMV infection is associated mainly with universal breast feeding practices rather than with crowding or poverty. Perinatal CMV infection usually follows a benign course in immunocompetent individuals, but the virus remains latent or persistent in the host cell thereafter.

OBJECTIVE

As a clinical diagnosis of CMV infection is generally not easy, rapid and accurate laboratory diagnosis of CMV infection is required for appropriate patient management. Numerous anti-CMV compounds including ganciclovir, foscarnet and cidofovir have been reported, most of them are unlikely in a clinical trial for perinatal CMV infection in immunocompetent individuals. Understanding the epidemiology of CMV is a key element in the development of strategies for prevention and treatment of infection.

STUDY DESIGN

This review focuses on recent advances in the diagnosis and treatment of perinatal CMV infections in infants.

CONCLUSIONS

Entirely new approaches to prevention and treatment of CMV infections in infants are necessary, including antiviral interventions and the development of a vaccine strategy.