1 03.09.2014 Lung pathology
Acute pneumonias, acute viral respiratory infection Ivan Sakharau, assist. lect. Acute pneumonia
is an inflammatory lung disease affecting alveoli with accumulation of exudate in the alveoli or cellular infiltration in the interstitial tissue
3 03.09.2014 “Pneumonia”
from Ancient Greek πνευμονία (pneumonia, “lung disease”), from πνεύμων (pneumōn, “lung”)
4 03.09.2014 Classification
1. Etiology biological agents: bacteria, viruses, fungi, protozoa, mixed infections chemical factors: a vapours of chemicals, uremia physical factors: industrial dust, ionizing radiation
Ways of contamination: airborne aspiration from naso- and oropharynx hematogenous infection of extrapulmonary lesions from neighbour infected sites
5 03.09.2014 Classification 2. Pathogenesis Primary: there are laws on its own etiopathogenetic Secondary: a manifestation of another, as a rule, system or extrapulmonary disease
Risk factors: airway infection (usually viral) obstructive changes in bronchi immunodeficiencies, hypothermia, stress alcohol and tobacco inhalation of toxic substances and dusts wounds and injuries, post-operative period early childhood and old age
6 03.09.2014 Classification
3. Prevalence unilateral, bilateral acinar, miliary, lobular, segmental, polysegmentary, lobar, total
7 03.09.2014 Classification
4. Clinical and morphological features lobar pneumonia bronchopneumonia (focal p.) interstitial pneumonia
“Older terminology refers to lobar pneumonia or bronchopneumonia, but these terms have little clinical relevance today. In general, lobar pneumonia refers to consolidation of an entire lobe while bronchopneumonia is scattered solid foci in the same or several lobes” (Rubin's Pathology : Clinicopathologic Foundations of Medicine, 5th Edition)
8 03.09.2014 Differential clinical and morphological characteristics Feature Lobar pneumonia Bronchopneumonia Etiology Pneumococci (Streptococci Bacteria, viruses, fungi, pneumoniae I, II, III, IV types), mycoplasma, chlamidia, Klebsiella pneumoniae chemical and physical factors Pathogenesis • Preceding sensibilisation to After acute bronchitis and microbial agent bronchiolitis • Triggering factor (hypothermia, trauma) Clinical signs Acute onset, rapid Manifestations increase development gradually
9 03.09.2014 Differential clinical and morphological characteristics Feature Lobar pneumonia Bronchopneumonia Exudate Fibrinous or fibrino-purulent Serous, purulent, haemorrhagic, fibrinous, putrid, mixed Affected lung 1 lobe (right lower is most Acini, lobuli, segment(s) volume common), 2 lobes, 3 lobes Prevalent • Young adults, adults • All ages patients age • Always primary • Usually secondary (primary in infants and elderly patients) Staging 4 stages No
10 03.09.2014 Lobar pneumonia – clinical signs
11 03.09.2014 Lobar pneumonia – staging
1. Initial (1st day) a lobe rapidly becomes red and swollen protein-rich edema fluid containing numerous bacteria fills the alveoli (“microbial edema”) some amount of alveolar macrophages and leukocytes is seen fibrin is seen at the end of the day as a rule inflammation also develops in the pleura (pleuritis) bronchi remain intact during all stages (inflammation develops only in alveoli)
12 03.09.2014 Lobar pneumonia – initial stage
13 03.09.2014 Lobar pneumonia – initial stage
14 03.09.2014 Lobar pneumonia – staging
2. Red hepatization (2nd-3rd days) marked capillary congestion leads to massive outpouring of polymorphonuclear leukocytes and intra-alveolar hemorrhage affected lobe is of firm consistency and reminiscent of the liver
15 03.09.2014 Lobar pneumonia – red hepatization
16 03.09.2014 Lobar pneumonia – red hepatization
17 03.09.2014 Lobar pneumonia – staging
3. Grey hepatization (4th-6th days) lysis of polymorphonuclear leukocytes and erythrocytes macrophages phagocytose the fragmented blood cells lobe is still firm and grey due to fibrin in alveoli
18 03.09.2014 Lobar pneumonia – grey hepatization
19 03.09.2014 Lobar pneumonia – grey hepatization
20 03.09.2014 Lobar pneumonia – grey hepatization
21 03.09.2014 Lobar pneumonia – staging
4. Resolution (up to 2 weeks) fibrinolysis alveolar exudate is then removed while coughing lung gradually returns to normal
22 03.09.2014 Lobar pneumonia – complications
Pleuritis, often painful, is common, because the pneumonia readily extends to the pleura pleura is usually involved; sometimes “lobar pneumonia” is called “pleuropneumonia” Pleural effusion occurs frequently, but usually resolves Pyothorax results from infection of a pleural effusion, and may heal with extensive fibrosis
23 03.09.2014 Lobar pneumonia – pleuritis
24 03.09.2014 Lobar pneumonia – complications
Pulmonary fibrosis. The intra-alveolar exudate organizes to form intra-alveolar plugs of granulation tissue. Gradually, increasing alveolar fibrosis leads to a shrunken and firm lobe, a rare complication known as carnification
25 03.09.2014 Lobar pneumonia – pulmonary fibrosis
26 03.09.2014 Lobar pneumonia – complications
Lung abscess due to destruction of lung tissue by enzymes of leucocytes and macrophages. A cavity is formed filled with pus and surrounded by fibrous tissue.
27 03.09.2014 Lobar pneumonia – lung abscess
28 03.09.2014 Lobar pneumonia – complications
Gangrene due to necrosis of lung tissue. dark coloration is due to liberation of hemoglobin from hemolyzed red blood cells, which is acted upon by hydrogen
sulfide (H2S), resulting in formation of black iron sulfide that remains in the tissues
29 03.09.2014 Lobar pneumonia – gangrene
30 03.09.2014 Lobar pneumonia – complications
Spreading of the infection: Hematogenous: bacteremia occurs in the early stages of pneumococcal pneumonia in more than 25% of patients, and may lead to endocarditis, meningitis, brain abscess, arthritis or sepsis. Lymphogenous: pericarditis and mediastinitis.
31 03.09.2014 Lobar pneumonia – spreading of the infection
Pericarditis Meningitis
32 03.09.2014 Lobar pneumonia – spreading of the infection
Sepsis: septicopyemia
33 03.09.2014 Bronchopneumonia Various etiology: bacteria, viruses, fungi, mycoplasma, chlamidia, chemical and physical factors Affects acini, lobuli, segment(s) (and up to lobes) Develops after acute bronchitis and bronchiolitis low bronchial drainage leads to penetration of bacteria to respiratory parts of the lung (alveoli) morphological features differ due to various etiology
34 03.09.2014 Bronchopneumonia
35 03.09.2014 Bronchopneumonia
36 03.09.2014 Bronchopneumonia
37 03.09.2014 Bronchopneumonia
Can develop as autoinfection: after aspiration of upper airway content (aspiration p.) due to blood congestion (hypostatic p.) - confined to the bed or weakened patients after surgical intervention (postoperative p.) due to secondary immunodeficiency
38 03.09.2014 Bronchopneumonia – streptococcus
caused by hemolytic streptococci group A and B very often mixed infection (+ viral infection) often seen in patients with diabetes affects the lower lobes sero-purulent exudate with interstitial component sometimes abscesses and bronchiectases are formed
39 03.09.2014 Bronchopneumonia – streptococcus
40 03.09.2014 Bronchopneumonia – pneumococcus
caused by pneumococci (Streptococci pneumoniae I, II, III, IV types) exudate contain fibrin and PMN leucocytes
41 03.09.2014 Bronchopneumonia – pneumococcus
42 03.09.2014 Bronchopneumonia – staphylococcus
Staphylococcus aureus is a common pulmonary superinfection after influenza and other viral respiratory tract infections. nosocomial staphylococcal pneumonia typically occurs in chronically ill people who are prone to aspiration, and in intubated patients characterized by abscess development abscess can rupture into the pleural cavity and cause a tension pneumothorax and pleural effusions
43 03.09.2014 Bronchopneumonia – Pseudomonas aeruginosa
most often seen in patients who are immunocompromised often an infectious vasculitis, in which large numbers of organisms can be seen in blood vessel walls results in pulmonary infarction.
44 03.09.2014 Bronchopneumonia – fungi
caused by various fungi (Candida most often) marked alteration seen as necrosis proliferative inflammation and granuloma formation fungi elements in exudate and in the center of granulomas
45 03.09.2014 Bronchopneumonia – fungi
46 03.09.2014 Bronchopneumonia – viruses
most often in infants and children serous, fibrinous, hemorrhagic exudate hyaline membranes in alveoli alveolar epithelium contains viral inclusion and often is desquamated
47 03.09.2014 Pneumonias in children Etiology: viral, mycoplasma, bacterial, rickettsial, parasitic, fungal, mixed The most common microbial agents: Klebsiella, Pseudomonas aeruginosa, Proteus, E. coli, Staphylococcus Mixed viral-bacterial predominate Predisposing factors: congenital defects of respiratory tract and lungs congenital and acquired the immunodeficiencies immaturity of the lung tissue in preterm newborns aspiration of amniotic fluid in utero or during delivery mechanical ventilation surfactant deficiency
48 03.09.2014 Pneumonias in elderly patients Etiology: bacterial (Str.pneumoniae, Haemophilus influenzae, Legionella pneumophila, etc.), viral (flu), mycoplasma Autoinfection is of great value Predisposing factors: decreased immunity, impaired mucociliary clearance cardiopulmonary failure weakening of the cough reflex impaired swallowing process Atypical clinical presentation Suppurative and destructive complications
49 03.09.2014 Interstitial pneumonia
= “pneumonitis, alveolitis” Primary inflammation in the interalveolar and peribronchial stroma Etiology: viruses, mycoplasma, fungi, Pneumocystis Develop as hypersensitivity reaction I (immediate) and IV (delayed) types interstitial fibrosis in outcome
50 03.09.2014 Interstitial pneumonia
51 03.09.2014 Acute viral respiratory infection (AVRI)
group of acute inflammatory diseases of the respiratory system, similar in clinical presentation and morphology caused by pneumotropic viruses
“The common cold (also known as nasopharyngitis, rhinopharyngitis, acute coryza, or a cold) is a viral infectious disease of the upper respiratory tract which primarily affects the nose. Symptoms include coughing, sore throat, runny nose, sneezing, and fever which usually resolve in seven to ten days, with some symptoms lasting up to three weeks. Well over 200 viruses are implicated in the cause of the common cold; the rhinoviruses are the most common.” Wikipedia, “Common cold”
52 03.09.2014 AVRI - pathogenesis
1. Cytopathic effect: virus adsorption and penetration
Morphology: cytoplasmic and/or intranuclear inclusion giant cell formation cell degeneration, necrobiosis and necrosis desquamation regeneration and proliferation the formation of multilayered beds inflammatory infiltration (lymphocytes, plasma cells, macrophages, single neutrophils)
53 03.09.2014 AVRI - pathogenesis
2. Vasopathic effect: endothelium of capillaries is affected
Morphology: vascular paresis and dilatation hyperemia an increase in vascular permeability stasis thrombosis of capillaries edema, hemorrhage
54 03.09.2014 AVRI - pathogenesis
3. Immunosuppressive effect affect of immune organs, secondary ID
Morphology reactive hyperplasia of lymphatic tissue then – accidental transformation and atrophy of the thymus, lymphocyte depletion in peripheral immune organs
4. Spreading and generalization of infection through airways haematogenous
55 03.09.2014 Influenza (flu)
RNA viruses of the family Orthomyxoviridae According to virion internal proteins (M1 and NP) viruses divided into Influenza virus A, B, C Surface proteins – hemagglutinin (HA) and neuraminidase (NA) – determ serotypes Viruses affecting people contain three subtypes of HA (H1, H2, H3) two subtypes of NA (N1, N2) serovariants of A Influenza virus A (less often B) can change Ag-structure in vivo
56 03.09.2014 Known flu pandemics Name of Date Deaths Case fatality Subtype Pandemic pandemic rate involved Severity Index 1889–1890 1889–1890 1 million 0.15% possibly H3N8 N/A flu pandemic or H2N2 (Asiatic or Russian Flu) 1918 flu 1918–1920 20 to 100 2% H1N1 5 pandemic million (Spanish flu) Asian Flu 1957–1958 1 to 1.5 0.13% H2N2 2 million Hong Kong Flu 1968–1969 0.75 to 1 <0.1% H3N2 2 million Russian flu 1977–1978 no accurate N/A H1N1 N/A count 2009 flu 2009–2010 18,000 0.03% H1N1 N/A pandemic (Swine)
57 03.09.2014 Influenza (flu)
Airborne and transplacental transmission Incubation period 2-4 days Local changes are associated with the cytopathic and vasopathic effects of virus Catarrhal tracheobronchitis General changes associated with viremia and intoxication degenerative, inflammatory changes of inner organs, circulatory disorders.
58 03.09.2014 Influenza (flu) – clinical forms
1. Mild catarrhal laryngotracheobronchitis (upper airways) degeneration and desquamation of the respiratory epithelium hypersecretion of mucus edema complete restoration of the epithelium (on 5th day)
59 03.09.2014 Influenza (flu) – clinical forms
2. Moderate small bronchi, bronchioles and lung parenchyma serous-hemorrhagic inflammation interstitial infiltration in lung hyaline membranes and giant cells in alveoli squamous metaplasia of the bronchial epithelium
60 03.09.2014 Influenza (flu) – clinical forms
3. Severe – two types with marked intoxication (due to the cytopathic and vasopathic effects of virus). with pulmonary complications (due to the addition of a secondary infection).
61 03.09.2014 Influenza (flu) – Severe with marked intoxication
Trachea and bronchi: a pronounced serous-hemorrhagic inflammation and necrosis Lungs: massive hemorrhage, numerous small foci of serous-hemorrhagic pneumonia, acute emphysema and atelectases Inner organs: numerous hemorrhages Serous (serous-hemorrhagic) meningitis, meningoencephalitis, cerebral edema
62 03.09.2014 Influenza (flu) – Severe with pulmonary complications
Upper respiratory tract: sero-purulent or fibrino- hemorrhagic inflammation Bronchi: destructive panbronchitis (entire bronchial wall envolved) Lungs: bronchopneumonia with a tendency to abscess formation, necrosis, hemorrhage, development of atelectasis and emphysema, marked interstitial component
63 03.09.2014 Influenza A1N1
64 03.09.2014 Influenza A1N1
65 03.09.2014 Influenza A1N1
66 03.09.2014 Influenza A1N1
67 03.09.2014 Influenza A1N1
68 03.09.2014 Parainfluenza
group of four distinct serotypes of RNA viruses of the family Paramyxoviridae common in children under the age of 3 years and is characterized by subglottic swelling the most common cause of croup, which is characterized by stridor on inspiration and a “barking” cough
69 03.09.2014 Parainfluenza
infects and kills ciliated epithelial cells of upper respiratory tract in very young children this process frequently extends into the lower respiratory tract, causing bronchiolitis and pneumonitis in young children, where the trachea is narrow and the larynx is small, the local edema of laryngotracheitis compresses the upper airway enough to obstruct breathing and cause croup
70 03.09.2014 Adenovirus infection
Adenoviruses belong to group of DNA viruses of the family Adenoviridae can cause respiratory affection, gastroenteritis, conjunctivitis, cystitis
71 03.09.2014 Adenovirus infection specific presentation of adenovirus infection is “pharyngoconjunctival fever”:
high fever that lasts 4–5 days pharyngitis conjunctivitis enlargement of the lymph nodes of the neck headache, malaise, and weakness
72 03.09.2014 Adenovirus infection
73 03.09.2014 Adenovirus infection
74 03.09.2014 RSV infection
respiratory syncytial virus (RSV) is RNA viruses of the family Paramyxoviridae most children have been infected with the virus by age 2 in adults and older, healthy children, the symptoms of RSV are mild and typically mimic the common cold infection can be severe in some cases, especially in premature babies, transplant patients and other immunocompromised persons virus causes the cell membranes on nearby cells to merge, forming syncytia
75 03.09.2014 RSV infection
76 03.09.2014 Mycoplasma infection Mycoplasmas refers to a genus of bacteria that lack a cell wall the smallest self-replicating organisms at first, they were considered viruses; then intermediate between viruses and bacteria M. pneumoniae and some other mycoplasmas can cause human infection tracheobronchitis is most common in children primary atypical pneumonia can develop usually it occurs in younger age groups and may be associated with neurological and systemic (e.g. rashes) symptoms
77 03.09.2014 Mycoplasma infection
alveoli are filled with edematous fluid, macrophages, fewer lymphocytes and detached alveolocytes alveolocytes have foamy cytoplasm containing PAS positive granules (mycoplasmas)
78 03.09.2014 Mycoplasma infection
79 03.09.2014 Mycoplasma infection
80 03.09.2014 Thank you!
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