Pneumoconiosis

pneumonconiosis due to coal

1. PNEUMOCONIOSIS COAL MS/OOO38/014 Tuesday, February 21, 2017 1

2. OBJECTIVES To define pneumoconiosis and explain the etiology To list the types of pneumoconiosis To describe the various morphologies of pneumoconioses To outline the pathogenesis of the types of pneumoconioses To outline the clinical manifestations of coal pneumoconiosis To e xplain treatment prevention and control of pneumoconiosis Tuesday, February 21, 2017 2

3. Pneumoconioses Etiology Pneumoconioses are a group of lung diseases caused by inhalation and accumulation of inorganic or organic particles of mineral dust in the lungs . is a “long latency” disease which typically develops gradually over a number decades following exposure to these dusts The mineral dust pneumoconioses by- coal dust , silica , and asbestos Silica – silicosis Asbestos – asbestosis Coal – simple CWP and complicated CWP (PMF) Tuesday, February 21, 2017 3

4. Coal Mine Dust Lung Disease caused by inhalation of coal mine dust and the body’s reaction to it 1. Fibrotic diseases – damage/destroy lung tissue –   Coal workers' pneumoconiosis “CWP” –   Silicosis –   Mixed dust pneumoconiosis –   Dust-related diffuse fibrosis 2. Airflow diseases – block movement of air –   Bronchitis –   Emphysema –   Mineral dust small airway disease “COPD” 3. Infectious diseases – dust reduces immunity –   Tuberculosis/related Tuesday, February 21, 2017 4

5. COAL WORKERS PNEUMOCONIOSIS (CWP) Associated with coal mining industry Pneumoconiosis due to coal dust inhalation Coal – carbon, crystalline silica, variety of trace metals Types of coal – peat, lignite,(brown coal/immature coal) sub-bituminous, bituminous(black) anthracite(shiny/mature) Tuesday, February 21, 2017 5

6. Classification Asymptomatic anthracosis ( due to anthracite –coal) - pigment accumulates without a perceptible cellular reaction According to the severity of the lung scaring - two types: 1. simple (Simple CWP ) - no dysfunction 2. complicated CWP - (progressive massive fibrosis PMF) Tuesday, February 21, 2017 6

7. Anthracosis (urban dwellers) morphology Gross Streaks of anthracotic pigment in lymphatics and draining hilar lymph nodes Microscopy Carbon pigment in alveolar and interstitial macrophages, in connective tissue and lymphatics and lung hilus. Tuesday, February 21, 2017 7

8. Simple CWP – Pathogenesis CWP occurs when the body’s natural mechanism for defending against and processing inhaled dust becomes overwhelmed and in consequence, over reactive. Coal particles reach respiratory tract – terminal bronchioles engulfed by alveolar and interstitial macrophages, phagocytize coal particles, transport them up the mucociliary elevator to be expelled in the mucus or through the interstitial lymphatic clearance route – this the physiologic pathway. Tuesday, February 21, 2017 8

9. Pathogenesis cont’d The lungs are exposed to dust particles larger than 2-5 µm in diameter for a significant period ; The dust-laden macrophages accumulate in the alveoli, an immune response may be triggered ; Fibroblasts secrete reticulin and entrap the macrophages . When these macrophages migrate up the lymphatic vessels, the resultant interstitial fibrosis will cause the arterioles to become strangulated . As more macrophages die , more fibroblasts, reticulin and collagen are deposited along the vascular tree, compromising the vessels and ensuing ischemic necrosis. Tuesday, February 21, 2017 9

10. Pathogenesis cont’d Tuesday, February 21, 2017 10

11. Morphology - Simple CWP characterized by coal macules (1-2mm) and the somewhat larger coal nodule The coal macule consists of dust-laden macrophages ; small amounts of collagen fibers arrayed in a delicate network. The lesions are scattered throughout the lung, (the upper lobes and upper zones of the lower lobes are heavily involved). Centrilobular emphysema can occur Simple” pneumoconiosis is characterized by small, ill-defined , rounded opacities in the outer thirds of the lung fields and the mid and upper zones. Tuesday, February 21, 2017 11

12. Morphology cont’d Microscopy: Carbon laden macrophages & delicate collagen fibers. Adjacent to respiratory bronchioles initially (where dust settles), later interstitium & alveoli. Dilatation of respiratory bronchioles –focal dust emphysema Tuesday, February 21, 2017 12

13. Simple CWP - Gross Morphology GROSS HISTOLOGICAL Tuesday, February 21, 2017 13

14. Complicated CWP Also known as the “black lung disease” Occurs on a background of simple CWP Coalescence of coal nodules A form of Progressive Massive Fibrosis ( PMF) Generally requires many years to develop Disease can progress even if dust exposure ceases. Associated with increased incidence of clinical tuberculosis, chronic bronchitis and emphysema and independent of smoking In isolation, PMF does not appear to increase the risk of lung cancer Tuesday, February 21, 2017 14

15. Complicated CWP - Morphology It is characterized by usually multiple, intensely blackened scars larger than 2 cm , sometimes up to 10 cm in greatest diameter. On microscopic examination the lesions are seen to consist of dense collagen and pigment with the center of the lesions being necrotic Associated with pulmonary hypertension and corpulmonale . PMF appears as rounded, sausage-shaped or ovoid opacities greater than 1 cm in diameter, which are well demarcated from the adjacent lung and may vanish if the contents are expectorated A fibrotic mass is formed by exuberant fibroblast activity that tends to occur in the upper lobes of the bilateral lungs, showing an “angel’s wing” appearance on plain radiographs Tuesday, February 21, 2017 15

16. PMF - Morphology Tuesday, February 21, 2017 16

17. Caplan’s syndrome 1 st described in coal workers, may be seen in other pneumoconiosis Caplan syndrome results when PMF is associated with rheumatoid factor. - ?? Immunopathologic mechanism - Rheumatoid arthritis (RA) + Rheumatoid nodules (Caplan nodules) in the lung - Rheumatoid arthritis + pneumoconioses - Caplan’s nodule = necrosis surrounded by fibroblasts, monocytes and collagen - s/s RA > lung symptoms - The Caplan nodules exhibit a central area of coal dust and necrotic collagenous tissue lying in concentric rings and it is surrounded by an area of neutrophils with palisading fibroblasts Tuesday, February 21, 2017 17

18. Diagnosis - CWP A full and detailed medical , occupational and environmental history is taken followed by Physical examination , with a focus on the chest area Imaging procedures , such as chest X-rays and Computed Tomography (CT) scans , remain the primary diagnostic tools used to visualize the nodules and lung scarring and to evaluate the presence and progression of the disease. The radiographs obtained are to be compared against the standardized set of X-rays developed by the International Labor Organization (ILO) which reflects the amount of retained coal in the lungs Tuesday, February 21, 2017 18

19. Diagnosis cont’d Tuesday, February 21, 2017 19

20. Chest radiograph Tuesday, February 21, 2017 20

21. T he ILO 2011 classification system Tuesday, February 21, 2017 21

22. Other methods of diagnosis Use of pulmonary function tests (PFTs ) (i.e. Spirometry ) in order to determine the severity of the impairment of lung function Measurement of arterial blood gases (ABGs) can be used to the determine impairments between oxygen and carbon dioxide in the alveoli CBC count and a sputum culture can be performed, if needed, to eliminate the possibility of other infective processes The 6-minute walk test (6MWT ), a simple, additional test that can be performed as a mean of quantifying possible lung impairment due to CWP Bronchoscopy with a lung biopsy , an invasive technique that involves the removal of a small piece of lung tissue to be examined in the laboratory Tuesday, February 21, 2017 22

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24. Clinical picture and further complications Individuals suffering from simple CWP usually display: Chronic cough and shortness of breath on exertion may be reported, however usually due to industrial bronchitis or smoking Mild loss of lung function As CWP progresses to the more severe and complicated form, PMF, symptoms as follows may arise: Tightness in the chest Dyspnea Chronic Cough with black sputum Pulmonary dysfunction ( i.e . pulmonary hypertension ) Right- sided heart failure due to lung dysfunction Cyanosis Tuesday, February 21, 2017 24

25. PROGNOSIS Other constitutional symptoms such as fever and night sweats may occur if a superimposed mycobacterial infection is present Tuesday, February 21, 2017 25

26. Prevention, Treatment and Management P reventing exposure to coal dust prevents disease. This is important, as no effective treatments for CWP exist . The effects of simple and complicated CWP on the lungs are irreversible . There is so no specific treatment for the disease available so far, other than palliative and preventive methods. Chest radiographs are serially monitored in order to prevent further development of the disease As smoking can contribute to the condition, it is strongly advised that the individual stops smoking . Tuesday, February 21, 2017 26

27. References Robbins Basic Pathology 9 th Edition by Vinay Kumar, Abul K. Abbas, Jon C. Aster Towards Understanding Coal Workers Pneumoconiosis pdf by Alice Maria Ciobanu SID : 3395606 Coal Workers Pneumoconiosis – ‘An Old Disease That Is Still Among Us’ pdf by Wayne T. Sanderson, PhD, CIH, Professor and Chair University of Kentucky Annual Pilot Research Project (PRP) Symposium University of Cincinnati. Clinical Focus, Coal workers’ pneumoconiosis, an Australian perspective pdf by Graeme R Zosky, Ryan F ,Elizabeth J Silverstone, Fraser J Brims, Susan Miles, Anthony R Johnson, Peter G, Deborah H ( Rom and Markowitz; 2007) Tuesday, February 21, 2017 27

28. Thank you! Tuesday, February 21, 2017 28