2Restrictive lung diseases (Diffuse Interstitial Lung Disease) A heterogeneous group of disorders characterized predominantly by diffuse and usually chronic involvement of the pulmonary connective tissueTestObstructiveRestrictiveFEV1↓↓↓VCslight↓ or NFEV1/ VCN or ↑
3Restrictive Lung Diseases Definition:Reduced lung complianceMore pressure needed to expand lungsLungs are stiffPulmonary function test: Low FEV1, Low FVC (the ratio FEV1/FVC is normal)
4Fibrosis Stiff lung Which level? principally the most peripheral and delicate interstitium in the alveolar wallsFibrosisStiff lungThis result in reduced expansion of lung with reduction in total lung capacity
5Restrictive lung diseases Characterized by reduced compliance of the lung.Caused by:2. parenchymal disease: Prominent changes in the interstitium (interstitial lung disease)1. Chest wall abnormalitiesKyphoscoliosissever obesityGuilian Barrre’ syndromeGuilian Barrre’ syndrome is an acute inflammatory demyelinating polyneuropathy , an autoimmune disease affecting the peripheral nervous system, usually triggered by an acute infectious process.exhibits as an ascending paralysis noted by weakness in the legs that spreads to the upper limbsWith prompt treatment by plasmapheresis or intravenous immunoglobulins, the majority of patients will regain full functional capacity.
6Restrictive lung diseases (Interstitial lung disease) Important signs and symptoms:- Dyspnea.- Hypoxia (caused by damage to the alveolar epithelium and interstitial vasculature produces abnormalities in the ventilation-perfusion ratio)- With progressive severe hypoxia,respiratory failure and cor pulmonale.- Chest radiographs show diffuse infiltration by small nodules, irregular lines, or "ground-glass shadows
8Chronic restrictive lung disease (Chronic interstitial lung disease) Are a heterogeneous group with little uniformity regarding terminology and classification.
9Chronic restrictive lung disease Major Categories of Chronic Interstitial Lung Disease (CILD)-Fibrosing:PneumoconiosisUsual interstitial pneumonia (idiopathic pulmonary fibrosis) Cryptogenic organizing pneumoniaAssociated with collagen vascular diseasesDrug and Radiation Reactions-Granulomatous: SarcoidosisHypersensitivity pneumonitis.Wegener’s granulomatosis-Eosinophilic granuloma-Smoking related: Desquamative interstitial pneumoniaRespiratory bronchiolitis-associated interstitial lung disease
10Chronic Interstitial Lung disease CILD Many entities are of unknown cause and pathogenesisSimilar clinical signs, symptoms, radiographic alterations and pathophysiologic changes.Patient have reduced forced vital capacity, however the FEV1/ FVC is normalAccount for about 15% of non-infectious lung diseases.
12Idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis) (Usual interstitial pneumonia) UIP A clinicopathologic syndrome with characteristic radiologic, pathologic and clinical features.Radiology: Bilateral lung nodular infiltratreHistology: diffuse interstitial fibrosis and inflammation.Clinical features:Dyspnea, advanced cases result in sever hypoxemia and cyanosis.Males are more affected than female2/3 of pt. older than 60 years
13PathogenesisSome form of alveolar wall injury result in interstitial edema and alveolitis. Type I pneumocyte is more susceptible to injury. Type II pneumocyte hyperplasia (regenerate). Fibroblast proliferation with progressive fibrosis of intra-alveolar exudate and interalveolar septa. IgG deposits are seen in alveolar wall.FGF, TGF-, PDGFIL-8 leukotriens
14Morphology of IPF Gross -The lungs are firm. -Pulmonary edema.The morphologic changes vary according to the stage of the disease.Early cases:-Intraalveolar exudate.-Hyaline membranes.-Infiltration of the alveolarsepta with mononuclearcells.-Hyperplasia of type IIpneumocytes-
15Morphology of IPF Advancing disease: -Organization of the intraalveolar exudates by fibrous tissue.-Thickening of the alveolar septa owing to fibrosis and variable amounts of inflammation.-Alternating areas of fibrosis and normal tissue.- Geographic variation- Temporal variationIn the end, the lung consists of spaces lined by cuboidal or columnarepithelium separated by inflammatory fibrous tissue (honeycomb lung).
21Prognosis of IPF Gradual onset of dyspnea with respiratory difficulty. Hypoxemia and cyanosis.Cor pulmonale and cardiac failure may result.The progression in individual cases is unpredictable.The median survival is about 2 to 4 years.
22PneumoconiosisNon-neoplastic lung reaction to inhalation of mineral dusts.Most common dusts are coal dust, silica, asbestos and beryllium.
23Pneumoconiosis Occupational Lung Diseases Dr. Atif Ali 2010
24Pneumoconiosis Pathogenesis The development of pneumoconiosis is dependent on:- The amount of dust retained in the lung and airways.a. Concentration of the dust in the ambient air.b. Duration of the exposure.c. Effectiveness of the clearance mechanisms.- The size (1-5) shape.- Their solubility and physiochemical activity.- The possible additional effects of other irritants, tobaccosmoking.The particles are impacted at alveolar duct macrophage, accumulate inflammatory response fibrosis.
26Coal worker’s pneumoconiosis (CWP) Occurs in coal workers after many years of underground mine work.Two forms:- The simple form:- Focal aggregations of coal dust-laden macrophages(coal macules, 1 to 2 mm) mainly in upper lobes.- Patients have slight cough and blackish sputum.- emphysema ( smoking related).- The complicated form:With heavier pulmonary burdens of coal dust, fibrous scarring appears (complicated CWP) also callled progressive massive fibrosis (PMF).
27Coal worker pneumoconiosis Morphology:Complicated CWP:-Black scars exceed 2 cm in diameter some times up to 10 cm-It consists of dense collagen and carbon pigments.-Cor pulmonale.-Miners who have rheumatoid arthritis and PMF are called Caplan’s syndrome.
28Coal miner with progressive massive fibrosis (unstained)
29Coal worker pneumoconiosis Clinical course:CWP is usually benign disease with little symptomMinor cases progress to PMFNo increased risk to bronchogenic carcinoma
31Silicosis Long exposure to silica particles. Nodular densely fibrosing pneumoconiosis.Encountered in a diversity of industries: mining of gold, tin, copper and coal, sandblasting, metal grinding, ceramic manufacturing, drilling and tunneling.Pathogenesis:Crystalline silica is highly fibrogenic.Scattered lymphocytes and macrophages are drawn rapidly with fibrosis.Some particles are transported to lymph nodes.
32Morphology of Silicosis Tiny collagenous nodules that enlarge forming stony-hard large fibrous scars usually in the upper lobes.The lung parenchyma between the scars may be compressed or emphysematous.Calcifications may appear (eggshell calcification) .Similar collagenous nodules within the lymph nodes.Fibrous pleural plaques may develop.
33Morphology of Silicosis Micro:-Hyalinized collagen fiber surround an amorphous center (fibrous nodules).- Scarring progress to PMF.-Scarring extending and encroching the pulmonary arteries.-Cor pulmonale.
34Clinical features of Silicosis depend on form of silicosis
35Forms of Silicosis Acute silicosis: Chronic silicosis: results from exposure to high dose of silica. Fluid in alveoli.Pt. Have rapid onset of tachypnea, cough and repiratory failure.Chronic silicosis:Inhalation of silica for long time with fibrotic nodules ( present in upper lobe of lung & in subpleural spacesComplicated silicosis:Progression of chronic silicosis with PMF with chronic hypoxiaOther pulmonary disease:Increased susceptibility to TBCaplan syndrome ( uncommon)Lung cancer
36Silica and lung cancerThe relationship between silica and lung cancer has been a contentious issue, but in 1997, based on evidence from several epidemiologic studies, the International Agency for Research on Cancer concluded that crystalline silica from occupational sources is carcinogenic in humans.However, this subject continues to be controversial.
38AsbestosisAsbestos is a family of crystalline hydrated silicates with a fibrous geometry.Two forms:Serpentine chrysotile (flexible fiber), more commonAmphibole (straight and stiff fiber), more pathogenicBoth forms are fibrogenic.
39Asbestosis Inhalation of asbestos leads to: - Asbestos pneumoconiosis. - Pleural effusion.- Pleural adhesions.- Parietal pleural fibrocalcific plaques.- Increased incidence of mesothelioma, bronchogenic carcinoma, laryngeal cancer.These consequences occurs decades after exposure has ended.An increased incidence of asbestos-related cancers in family members of asbestos workers has alerted the general public to the potential hazards of asbestos in the environment.
42Association of asbestos bodies with fibrosis (asbestosis)
43Pleural plaque in asbestos Parietal pleura over dome of diaphragm
44AsbestosisIn asbestosis, pt. develop progressively worsened dyspnea with cough and sputum progressing to cor pulmonale and death.Both bronchogenic carcinoma and mesothelioma develop in workers exposed to asbestos.The risk of bronchogenic carcinoma is fivefold and for mesothelioma is 1000 fold greater.The risk of bronchogenic carcinoma in 50 X increased in smoking asbestos workers (but not that of mesothelioma)
46Malignant Mesothelioma Rare cancer of mesothelial cellsArise from parietal or visceral pleuraCan arise from peritoneum and pericardium50% of pt. have history of exposure to asbestos at workIt also appeared in relatives of asbestos worker or in people living near asbestos factoryThe latent period between exposure and malignant mesothelioma is long (25 to 40 years)Nearly all cases are related to amphibole asbestosThese minerals cannot be removed from the lung and the risk for malignant mesothelioma is life longSimian virus 40 (SV40) T antigen is found in 60 to 80% of malignant mesotheliomaCharacteristic E/M finding : numerous long microvilli on cell surface