Obliterative (Constrictive) Bronchiolitis
ABSTRACT Obliterative bronchiolitis (OB) (formerly termed bronchiolitis obliterans), is a rare fibrotic disorder involving terminal and respiratory bronchioles. The term constrictive bronchiolitis is synonymous with OB. Clinically, OB is characterized by progressive (often fatal) airflow obstruction, the absence of parenchymal infiltrates on chest radiographs, a mosaic pattern of perfusion on high-resolution computed tomographic scan, poor responsiveness to therapy, and high mortality rates. Most cases of OB occur in the context of a specific risk factor. Currently, most cases of OB occur in lung transplant recipients with chronic allograft rejection or hematopoietic stem cell transplant (HSCT) recipients with graft versus host disease (GVHD). Other causes of OB include connective tissue disease (CTD) (particularly rheumatoid arthritis); lower respiratory tract infections; inhalation injury; exposure or inhalation of toxic fumes, metals, dusts, particulate matter, or pollutants; occupational exposures; drug reactions; consumption of uncooked leaves of Sauropus androgynus; chronic hypersensitivity pneumonia; diffuse neuroendocrine cell hyperplasia; miscellaneous. When no cause is identified, the term cryptogenic obliterative bronchiolitis is used. This review discusses the salient clinical, radiographic, and histological features of OB and presents a management approach.
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ABSTRACT: Rationale: The chronic rejection of lung allografts is attributable to progressive small airway obstruction. Objectives: To precisely determine the site and nature of this type of airway obstruction. Methods: Lungs from patients with rejected lung allografts treated by a second transplant (n=7) were compared to unused donor (control) lungs (n=7) using multi-detector computed tomography (MDCT) to determine the percent of visible airways obstructed in each airway generation, microCT to visualize the site of obstruction and histology to determine the nature of this obstruction. Results: The number of airways visible with MDCT was not different between rejected and control lungs. However 10±7 % of observed airways > 2mm in diameter, 50±22% of airways between 1 and 2 mm in diameter and 73±10% of airways < 1mm in diameter were obstructed in the rejected lungs. MicroCT confirmed that the mean lumen diameter of obstructed airways was 647±317µm but showed no difference in either total number and cross sectional area of the terminal bronchioles or in alveolar dimensions (Lm) between groups (p>0.05). Additionally microCT demonstrated that only segments of the airways are obstructed. Histology confirmed a constrictive form of bronchiolitis caused by expansion of microvascular rich granulation tissue in some locations and collagen rich scar tissue in others. Conclusion: Chronic lung allograft rejection is associated with a progressive form of constrictive bronchiolitis that targets conducting airways while sparing larger airways as well as terminal bronchioles and the alveolar surface.American Journal of Respiratory and Critical Care Medicine 12/2013; 189(3). DOI:10.1164/rccm.201310-1894OC · 11.99 Impact Factor
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ABSTRACT: Worldwide, more than three million children are infected with HIV, 90% of whom live in sub-Saharan Africa. As the HIV epidemic matures and antiretroviral treatment is scaled up, children with HIV are reaching adolescence in large numbers. The growing population of adolescents with perinatally acquired HIV infection living within this region presents not only unprecedented challenges but also opportunities to learn about the pathogenesis of HIV infection. In this Review, we discuss the changing epidemiology of paediatric HIV and the particular features of HIV infection in adolescents in sub-Saharan Africa. Longstanding HIV infection acquired when the immune system is not developed results in distinctive chronic clinical complications that cause severe morbidity. As well as dealing with chronic illness, HIV-infected adolescents have to confront psychosocial issues, maintain adherence to drugs, and learn to negotiate sexual relationships, while undergoing rapid physical and psychological development. Context-specific strategies for early identification of HIV infection in children and prompt linkage to care need to be developed. Clinical HIV care should integrate age-appropriate sexual and reproductive health and psychological, educational, and social services. Health-care workers will need to be trained to recognise and manage the needs of these young people so that the increasing numbers of children surviving to adolescence can access quality care beyond specialist services at low-level health-care facilities.The Lancet Infectious Diseases 01/2014; 14(7). DOI:10.1016/S1473-3099(13)70363-3 · 19.45 Impact Factor
- European Respiratory Review 03/2015; 24(135):1-16. DOI:10.1183/09059180.00008014