What a differential a virus makes: a practical approach to thoracic imaging findings in the context of HIV infection--part 2, extrapulmonary findings, chronic lung disease, and immune reconstitution syndrome

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.

Chest ultrasonography in patients with HIV: a case series and review of the literature

INTRODUCTION

Pulmonary disease is common in HIV-infected patients. Diagnostic means, however, are often scarce in areas where most HIV patients are living. Chest ultrasonography has recently evolved as a highly sensitive and specific imaging tool for diagnosing chest conditions such as pneumothorax, pneumonia and pulmonary edema in critically ill patients. This article addresses the issue of imaging and differentiating common pulmonary conditions in HIV-infected patients by chest ultrasonography.

METHODS

We report chest ultrasound features of five different common pulmonary diseases in HIV-infected patients (bacterial pneumonia, Pneumocystis jirovecii pneumonia, tuberculosis, cytomegalovirus pneumonia and non-Hodgkin lymphoma) and review the respective literature.

CONCLUSIONS

We observed characteristic ultrasound patterns especially in Pneumocystis jirovecii pneumonia and pulmonary lymphoma. Further exploration of chest ultrasonography in HIV-infected patients appears promising and may translate into new diagnostic approaches for pulmonary conditions in patients living with HIV.

Imaging infection

Thoracic imaging is widely used to detect lower respiratory tract infections, identify their complications, and aid in differentiating infectious from noninfectious thoracic disease. Less commonly, the combination of imaging findings and a clinical setting can favor infection with a specific organism. This confluence can occur in cases of bronchiectatic nontuberculous mycobacterial infections in immune-competent hosts, invasive fungal disease among neutropenic patients, Pneumocystis jiroveci pneumonia in patients with AIDS, and in cytomegalovirus infections in patients with recent hematopoietic cell transplantation. These specific diagnoses often depend on computed tomography scanning rather than chest radiography alone.

Imaging of Pulmonary Infections

Pulmonary infection is one of the most frequent causes of morbidity and mortality throughout the world. Many infections occur in individuals with concomitant intrapulmonary or extrathoracic diseases; however, they commonly develop in otherwise healthy people. In the non-immunocompromised population, pneumonia is the most prevalent community-acquired infection and the second most common nosocomial infectious disorder. In immunocompromised patients, in children, and in the elderly, pneumonia, as well as other pulmonary infections, may develop into a life-threatening condition.

Human immunodeficiency virus-associated lung malignancies

This review of lung malignancies in human immunodeficiency virus (HIV) briefly highlights key epidemiologic and clinical features in the pulmonary involvement of AIDS-defining malignancies of Kaposi sarcoma and non-Hodgkin lymphoma. Then, focusing on non-AIDS defining lung cancer, the epidemiology and mechanisms, clinical presentation, pathology, treatment and outcomes, and prevention of HIV-associated lung cancer are discussed. Finally, the important knowledge gaps and future directions for research related to HIV-associated lung malignancies are highlighted.

Tuberculosis IRIS: a mediastinal problem

We present a case of a 39-year-old male patient with Acquired Immune Deficiency Syndrome (AIDS) who developed Mycobacterium tuberculosis related Immune Reconstitution Inflammatory Syndrome (IRIS) after initiation of Highly Active Antiretroviral Therapy (HAART) treatment. The inflammatory response resulted in mediastinal necrotic lymphadenopathy and subsequent perforation of the esophageal wall.

Mesenterial, omental, and peritoneal disorders in antiretroviral-treated HIV/AIDS patients: spectrum of cross-sectional imaging findings

In the era of highly active antiretroviral therapy, radiologists are increasingly confronted with a progressively aging HIV-infected population with improved immune function and survival, in whom a wide spectrum of infectious and neoplastic opportunistic disorders may be encountered. Furthermore, HIV / AIDS patients commonly have unspecific symptoms and physical signs, multicentric or coexisting diseases, so that diagnostic imaging studies are crucial to correctly identify and stage HIV-related abnormalities. Currently, volumetric multidetector CT (MDCT) provides comprehensive assessment and confident post-treatment follow-up of opportunistic abnormalities involving the mesentery, omentum, and peritoneum. In this pictorial essay, the cross-sectional imaging appearances of opportunistic disorders involving the mesentery, peritoneum, or both compartments in HIV / AIDS patients are reviewed, with emphasis on those MDCT findings that may be helpful for differential diagnosis along with knowledge of the degree of immune suppression as measured by the CD4 lymphocyte count. Familiarity with the varied spectrum of HIV-related opportunistic disorders encountered in antiretroviral - treated patients and their imaging appearances should allow radiologists to improve their confidence in the characterization of abnormal findings observed on abdominal cross-sectional imaging studies.