PULMONARY TUBERCULOSIS

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1 PULMONARY TUBERCULOSIS GENERAL CONSIDERATIONS Communicable Granulomatous disease caused by Mycobacterium Tuberculosis. [M. avium- -30% of patients with AIDS] Tuberculosis is a chronic infection, potentially of lifelong duration isolated by Robert Koch in 1882 The morbidity and mortality of tuberculosis are high in developing countries. GENERAL CONSIDERATIONS The disease is confined to the lungs in most patients but may spread to almost any part of the body ETIOLOGY The tubercle bacillus (M.Tuberculosis) is aerobie, nonmotile,non-spore-forming, high in lipid content, and acid and alcohol-fast It grows slowly. It can t tolerate heat, but It can live in humid or dry or cold surroundings.

2 EPIDEMIOLOGY Tuberculosis is transmitted by airborne droplet nuclei (containing tubercle bacilli ) Many droplet nuclei are capable of floating in the immediate environment for several hours Large particles may be inhaled by a person breathing the same air and impact on the trachea or wall of the upper airway TUBERCULOSIS EPIDEMIOLOGY Certain disease states increase the risk. Diabetes mellitus, silicosis, Malnutrition or Alcoholism. Immunouppression (HIV). HUMAN IMMUNITY AFTER INFECTED TUBERCLE BACILLUS AND TUBERCULIN HYPERSENSITIVITY The natural immunity of human to TB is nonspecific After infected or given BCG vaccine, human will obtain specific immunity The immunity of tubercle bacillus is cell- mediated immunity The cellular immunity develops within 4 to 8 weeks after infected with bacillus Many immunologic cells involve in the formation of pulmonary tuberculosis. TWO TYPES OF CELLS ARE ESSENTIAL IN THE FORMATION OF TB Macrophages: directly phagocytize TB and processing and presenting antigens to T lymphocyte T lymphocytes(cd4+): induce protection through the production of lymphokines Many lymphokines are involved in tuberculosis, the interplay of these cytokines determine the hosts response for example IL-1 is related to fever IL-6 is related to hyperglobulinemia TNF is related to the killing of mycobacteria formation of granolomas other cytokines including IL-4,IL-5,IL-10 can promote humoral immunity Genetic factors play a key role in innate nonimmune resistance to infection with M. Tuberculosis These genes may have a role in determining susceptibility to tuberculosis PATHOGENESIS OF GRANULOMA FORMATION

DURING THE COURSE OF TB, THERE ARE THREE BASIC PATHOLOGIC CHANGES Including infiltration, hyperplasia, ulceration or calcification These changes happen in different stage of tuberculosis When host

3 DURING THE COURSE OF TB, THERE ARE THREE BASIC PATHOLOGIC CHANGES Including infiltration, hyperplasia, ulceration or calcification These changes happen in different stage of tuberculosis When host defense is destroyed and there is much more bacterias, caseating ulceration will exist Otherwise, when host defense is predominant and there is less bacteria, perhaps hyperplasia and calcification will happen THERE ARE FIVE COMMON CLINICAL PATTERNS OF TUBERCULOSIS Primary pulmonary tuberculosis (Primary Complex and Bronchial Lymphnode- Tuberculosis) Milliary Tuberculosis (acute, subacute and chronic hematogenous pulmonary tuberculosis) Secondary pulmonary tuberculosis Tuberculous pleuritis Extrapulmonary tuberculosis PRIMARY TUBERCULOSIS Definition of primary tuberculosis: The disease that develop in a previously unexposed (unsensitized) persons.

4 Morphology: Ghon complex Focus of primary TB: Lung, Intestine, lympnnodes (Cervical LN), skin, genital tract The Ghon complex: subpleural granuloma + marked hilar lymphadenopathy. Most often in children. Primary Tuberculosis: Caseating granuloma with Langhans giant cells: this may calcify. IMPLICATIONS OF PRIMARY TUBERCULOSIS It may resolve

5 It may progress to progressive primary tuberculosis. Some bacilli harbor in the apex of lung for survival (due to high Oxygen level). SECONDARY TB DEF: disease that arises in a previously sensitized host. Type: Reactivation of dormant primary lesions. Exogenous re-infection. SECONDARY TUBERCULOSIS (LOCATION) Location of lesions: classically localized to the apex of one or both upper lobes. Pattern of Secondary Tuberculosis Early lesion MICRO: CASEATING GRANULOMA

with fever, weight loss, anorexia, fatigue, night sweats wasting.

6 PROGRESSION OF SEC. PROGRESSIVE TB CLINICAL MANIFESTATIONS Systemic signs: Most patients present as cases of pulmonary tuberculosis with fever, weight loss, anorexia, fatigue, night sweats wasting. Respiratory signs: Cough may vary from mild to severe, and sputum may be scant and mucoid or copious and purulent. Hemoptysis may be due to cough of a caseous lesion or bronchial ulceration, chest pain, tachypnoea etc. Physical signs: nonspecific.

7 LABORATORY AND PHYSICAL EXAMINATIONS Chest radiography Sputum examination Tuberculin testing PCR test to detect TB TB antibody testing bronchoscopy RADIOLOGY Chest radiography is an important method to detect TB TB s characteristics of a chest radiograph favor the diagnosis of tuberculosis as following : (1) Shadows mainly in the upper zone patchy or nodular shadows The presence of a cavity or cavities, although these, of course, can also occur in lung abscess, carcinoma, etc (4)the presence of calcification. although a carcinoma or pneumonia may occur in an areas of the lung where there is calcification due to tuberculosis (5)bilateral shadows, especially if these are in the upper zones (6) the persistence of the abnormal shadows without alteration in an x-ray repeated after several weeks this helps to exclude a diagnosis of pneumonia or other acute infection SPUTUM EXAMINATION There are direct smear and culture Direct smear examination is only positive when large numbers of bacilli begin to be excreted A negative smear by no means excludes tuberculosis A negative smear in the presence of extensive disease and cavitation makes the diagnosis less likely.

8 Particularly if the negatives are frequently repeated TUBERCULIN TESTING A positive tuberculin test although it is of great use in children, but it has limited diagnostic significance in older age groups A reaction of less than 5 mm is considered negative 5-9 mm is considered positive (+) mm is considered positive (++) More than 20 mm is considered positive (+++) A positive tuberculin skin test indicates Tuberculous infection, with or without disease White blood count and ESR The white blood count is usually normal. In practice the white blood count is only useful in a minority of cases, When the patient is less ill and the radiological shadowing less extensive the count is often normal or high normal ESR is often elevated COMPLICATIONS Pneumothorax Bronchiectasis Empyema Extrapulmonary expansion Hemoptysis Chronic pulmonary heart disease NON TUBERCULOUS MYCOBACTERIAL DISEASE Stains implicated in the US are: M. avium-intracellulare. M. Kansasii. M. abscessus. Can mimic typical tuberculosis in presentation upper lobe cavitary disease. RISK FACTORS FOR NONTUBERCULOUS MYCOBACTERIAL DISEASE

9 COPD, cystic fibrosis, and pneumoconiosis. Immuno-suppression: In AIDS M. avium complex systemic symptoms. CLINICAL COURSE Similar to classic TB but more aggressive due to immunosuppression. PREVENTION Prevention of Tuberculosis : Vaccination BCG Vaccination can obtain immunity acquired for tubercle bacillus. Therefore, it is one of the most important tuberculosis prevention Vaccination target: infants children and youngster of tuberculin negative (vaccination is of course of no use in tuberculin-positive persons) REFERENCES BASIC PATHOLOGY BY ROBBINS Pg: *************************************************************************************

Maria Dalbey RN. BSN, MA, MBA March 17 th, 2015

Maria Dalbey RN. BSN, MA, MBA March 17 th, 2015 2 Objectives Participants will be able to : Understand the Pathogenesis of Tuberculosis (TB) Identify the Goals of Public Health for TB Identify Hierarchy