Quiz #2 Flashcards
chronic bronchitis
hypertrophy of mucus secreting glands
Reid index- ratio of thickness of glands/total wall (>0.5)
mucus plugging - infections,
blocks ventilation
hypoxic vasoconstriction - low O2 and high CO2
can get pulmonary hypertension ad eventually right heart failure
shunting!
Symptoms of Chronic Bronchitis
Blue Bloater clinical defnitiion productive cough 3 months over 2 years associated with smoking
Emphysema
Pink Puffer - hyperventilate - maintains their O2 level so not hypoxic (unlike blue bloaters) - barrel chest
imbalance of proteases and antiproteases - alpha 1 antitrypsin is key, downregualted by smoking
destrcution of - too many proteases -destruction of upper lobe - centriacinar
people with alha anti tryp deficiency get lower lobe damage - panacinar
alveoli get damaged from excess protease, lose eleastic recoil, collapse and obstruction
hypersensitivity pneumonitits
Type 3/4 hypersensitivity reactions - exposure to organic antigen
It is suggested that HP is an immunologically mediated disease:
Most patients have specific antibodies in their serum suggesting type III hypersensitivity
Complement and immunoglobulins have been demonstrated in vessel walls by immunofluorescence also suggesting type III HS
Presence of noncaseating granulomas suggests T cell-mediated (type IV) delayed type hypersensitivity against the antigen.
obstructive lung disease
reduced FEV1, FVC, and FEV1/FVC ratio - air trapped inside, lung volumes increase
chronic bronchitits and emphysema - COPD
asthma
restrictive lung disease
lung volumes go down (cant get air in)
bronchiectasis
Bronchial obstruction: (tumors, foreign bodies, and mucus impaction).
Congenital or hereditary conditions: (cystic fibrosis, intralobar sequestration, immunodeficiency states, and primary ciliary dyskinesia and Kartagener syndromes)
Postinfectious conditions: (necrotizing pneumonia caused by bacteria (Mycobacterium tuberculosis, Staphylococcus aureus, Haemophilus influenzae, Pseudomonas), viruses (adenovirus, influenza virus, HIV), and fungi (Aspergillus species)
histologic findings in asthma
Thickened basement membrane
Inflammatory infiltrate consisting predominantly of eosinophils.
Charcot-Leyden crystals (arrow): These needle-shaped crystals are formed from eosinophil proteins. Note the bilobed eosinophils nuclei in the background.
Curschmann spiral (arrow): dense mucus with entrapped epithelial cells take the form of a small airway Creola body (arrow): Consists of an epithelial sheet which has formed into a three-dimensional figure.
sarcoidosis
THE MORPHOLOGIC DIAGNOSIS OF SARCOIDOSIS RELIES ON THREE FINDINGS:
1) Tight, well formed granulomas
2) Lymphangitic distribution of granulomas
3) and exclusion of an alternative cause by history, stains and cuture.
bilateral symmetric hilar lymphadenopathy and bilateral nodular infiltrates in her upper lobes.
– on chest x ray
Sarcoidosis is an immune-mediated multisystem disease. The most widely accepted explanation is that it is a Type IV delayed-type hypersensitivity reaction to an unidentified antigen in a genetically susceptible host. Epithelioid cell granulomas are a result of stimulation of the cell-mediated immunity. The process may resolve spontaneously or it may progress to form extensive noncaseous granulomas and fibrosis.
Both genders and all races and age groups, but has a predilection for young adults < 40 years of age. In the US african americans are 10 times more commonly affected than whites. Higher prevalence in nonsmokers.
Sarcoidal granulomas can involve any organ, but in more than 90% of patients, there is intrathoracic lymph-node enlargement, pulmonary involvement, skin or ocular (anterior uveitis is the most common) signs and symptoms. Sarcoidosis also involves salivary glands, spleen, liver, bone marrow, brain and heart.
idiopathic usual interstitial pneumonia (UIP)
Hallmark is that it is patchy with temporal heterogeneity. Which means that there is early and late lesions present as evidence of ongoing injury.
Causative agent is unknown. Believed that IPF is caused by repeated cycles of epithelial injury by some unidentified agent. Abnormal repair at these sites gives rise to the fibroblastic foci. It is believed that TGF-b1 released from injured type 1 alveolar cells is the driver for the fibrogenic process.
Poor prognosis with a mean survival of 3 years. Lung transplantation is the only definitive therapy availalble.
asbestosis
The left side shows asbestos bodies (arrows). An asbestos body is a fusiform or beaded rod with knobbed ends and a translucent center coated with iron-containing proteinaceous material (right image is an iron stain; stains iron blue).
Asbestos bodies are formed when macrophages attempt to phagocytose asbestos fibers; the iron is deposited from the ferritin in the macrophage.
Asbestosis is a fibrosing process due to interaction of asbestos fibers with lung macrophages.
It also functions as a tumor initiator and a promoter.
There are two distinct geometric forms of asbestos: serpentine (curly and flexible fibers) and amphibole (straight, stiff, and brittle fibers). Both amphiboles and serpentine are fibrogenic, but only the amphibole is associated with mesothelioma.
Development of asbestosis, like the other pneumoconioses, depends on the interaction of inhaled fibers with lung macrophages and other parenchymal cells. Asbestos fibers penetrate small airways and ducts. Macrophages attempt to ingest and clear the fibers and are activated to release chemotactic factors and fibrogenic mediators. Chronic deposition of fibers and release of mediators leads to inflammation and interstitial fibrosis.
Pulmonary Edema
can result from:
hemodynamic disturbances (increased pulmonary venous pressure and decreased oncotic pressure) or
from direct increases in capillary permeability as a result of microvascular injury.
The most common cause of hemodynamic edema is left-sided failure as in this patient.
In pulmonary edema resulting from direct microvascular injury the pulmonary capillary hydrostatic pressure is usually not elevated.
Pulmonary Hypertension
classified into five groups.
PAH where only small pulmonary arteries are affected (Like in this case 4).
PH due to left heart failure (Case 1)
PH from lung parenchymal diseases or hypoxemia (such as in UIP)
Chronic thromboembolic pulmonary hypertension (recurrent thromboemboli)
PH of multifactorial basis.
Heritable PAH has autosomal dominant with incomplete penetrance (10-20% family members develop overt disease). Mutations in the bone morphogenetic protein receptor type 2 (BMPR2) is the most common gene identified. BMPR2 is a cell surface protein belonging to the TGF-b receptor superfamily.
In normal vessels, BMPR2 signaling causes apoptosis and inhibition of proliferation of smooth muscle cells.
Mutation of BMPR2 promotes smooth muscle proliferation and survival.
Over 300 mutations have been identified in BMPR2 and it is found in >70% pts with heritable PAH.
The fact that only 10 to 20% individuals with BMPR2 have phenotypic disease points to the presence of modifier genes and/or environmental triggers
A two-hit model has been proposed in which a genetically susceptible individual with BMPR2 mutation requires additional genetic or environmental insults to develop the disease.
goodpasture syndrome
an autoimmune disease in which kidney and lung injury are caused by circulating autoantibodies against the α3 chain of collagen IV. When only RENAL DISEASE IS CAUSED BY THIS ANTIBODY IT IS CALLED ANTI-GLOMERULAR BASEMENT MEMBRANE DISEASE. The antibodies initiate inflammatory destruction of the basement membrane in renal glomeruli and pulmonary alveoli. Most patients are teenagers or in 20s and it is more common in males.
Pathogenesis: The trigger that initiates the anti-basement membrane antibodies is unknown. It is believed that some environmental insult such as viral infection or smoking is required to unmask the cryptic epitopes. As with other autoimmune disorders, a genetic predisposition is indicated by association with certain HLA subtypes.
Clinical Features Most cases begin clinically with respiratory symptoms, principally hemoptysis, and radiographic evidence of pulmonary infiltrates. Soon, manifestations of glomerulonephritis appear, leading to rapidly progressive renal failure. The most common cause of death is uremia.
most common cause of community-acquired acute bacterial pneumonia
Streptococcus pneumoniae.
