Question | Answer |
What are restrictive lung diseases? | A group of disorders characterized by bilateral, patchy, chronic involvement of the lung connective tissue, mainly the interstitium in the alveolar walls |
The interstitium is composed of | Basement membrane of the endothelial and epithelial cells ,
collagen and fibers and fibroblasts |
The hallmark feature of these disorders is | Reduced compliance (i.e., more pressure is required to expand the lungs because they are stiff), which in turn necessitates increased effort of breathing (dyspnea) |
Chest radiographs show | diffuse infiltration by small nodules, irregular lines, or "ground-glass" shadow |
When restrictive lung diseases progress, patients can develop: | Respiratory failure
Pulmonary hypertension
Cor pulmonale |
Advanced forms of these diseases may be difficult to differentiate because they result in: | Scarring and gross destruction of the lung, referred to as "honeycomb" lung |
Restrictive lung diseases are divided into two groups: | 1) Granulomatous diseases
2) Fibrosing diseases |
Sarcoidosis is an example of a: | Granulomatous disease |
Sarcoidosis is a multisystem disease of unknown etiology
characterized by: | noncaseating granulomas in many tissues and organs |
The histologic diagnosis of sarcoidosis is one of | Exclusion |
Epidemiology of sarcoidosis: | There is a consistent predilection for adults younger than 40
African Americans
Higher prevalence among nonsmokers |
Etiology of sarcoidosis: | A disease of disordered immune regulation in genetically predisposed persons exposed to certain environmental agents |
Immunologic abnormalities in sarcoidosis suggest the development of a cell-mediated response to an unidentified antigen. This process is driven by: | CD4+ helper T cells |
Immunologic abnormalities in sarcoidosis include: | 1) Intra-alveolar and interstitial accumulation of CD4+ TH1 cells
2) Increases in T cell-derived TH1 cytokines such as IL-2 and IFN-γ, resulting in T cell expansion and macrophage activation, respectively
3) Anergy to common skin test antigens like PPD |
The role of genetic factors in sarcoidosis is suggested by: | 1) Familial clustering of cases
2) Association with certain human leukocyte antigens (HLA) ( class I HLA-A1 and HLA-B8) |
After lung transplantation, sarcoidosis recurs in the
new lungs in what percentage of patients? | 75% |
Morphology of sarcoidosis: | Noncaseating epithelioid granuloma
Schaumann bodies, laminated concretions composed of
calcium and proteins
Asteroid bodies, stellate inclusions enclosed within giant
cells |
Involved organs in sarcoidosis: | The lungs in 90%
Intrathoracic hilar and paratracheal lymph nodes enlarged in 75% to 90%
1/3 present with lymphadenopathy
Skin lesions are encountered in 25%
Eye and lacrimal glands 1/5
Parotitis
Spleen, liver and Bone marrow |
In 5% to 15% of patients, the granulomas eventually are replaced by | diffuse interstitial fibrosis, resulting in a so-called honeycomb lung |
The hallmark of acute sarcoidosis is: | Erythema nodosum |
Erythema nodosum is characterized by: | Raised, red, tender nodules on the anterior aspects of the legs |
Subcutaneous nodules are | Painless, discrete
Reveal abundant noncaseating granulomas |
Ocular involvement takes the form | Iritis
Iridocyclitis
Unilateral or bilateral
Total loss of vision may develop
Inflammation of lacrimal glands
Suppression of lacrimation (Sicca syndrome) |
In parotitis, there is: | Unilateral or bilateral parotitis with painful enlargement of the parotid glands
Some patients develop xerostomia (dry mouth).
Combined uveoparotid involvement is designated Mikulicz syndrome. |
Hypercalcemia in sarcoidosis is caused by: | Increased calcium absorption secondary to production of active
vitamin D by the mononuclear phagocytes in the granulomas |
Clinical features of sarcoidosis: | In many affected persons the disease is
a. Asymptomatic
b. Discovered bilateral hilar
adenopathy
c. Incidental finding at autopsy
Peripheral lymphadenopathy
Cutaneous lesions
Eye involvement
Splenomegaly
Hepatomegaly
Resp. symptoms |
The presence of noncaseating granulomas is suggestive of sarcoidosis, but | Other identifiable causes of granulomatous inflammation must be excluded |
Clinical course of sarcoidosis: | Unpredictable course characterized by either progressive chronicity or periods of activity interspersed with remissions |
Recovery from Sarcoidosis: | Remissions spontaneous or initiated by steroid therapy- often are permanent
65% to 70% - recover with minimal or no manifestations
20% - permanent lung dysfunction or visual impairment
10% to 15% - progressive pulmonary fibrosis and cor pulmonale |