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Pathology of tuberculosis 2015-2016
    Required book      Robbins basic pathology 9th edition     Chronic pneumonias  tuberculosis     Chapter 12  lung     P...
Objectives By the end of the lecture you should be able to      List the causative agents of TB     Identify route of infe...
Tuberculosis     Is a communicable chronic granulomatous disease caused  by Mycobacterium tuberculosis     It usually invo...
Tuberculosis     Epidemiology     It is a leading cause of death globally as it accounts for    6  of deaths worldwide    ...
Tuberculosis     Epidemiology     Until the mid 1980s, in the USA   Western countries there  was a decline in TB infection...
Tuberculosis    predisposing factors     Tb flourishes in case of       poor population,     bad hygiene,     diabetes mel...
Tuberculosis     Microorganism     M. tuberculosis hominis     Responsible for most cases     Transmitted by inhalation of...
Tuberculosis     Routes of infection     Respiratory tract   Most cases are acquired by direct person to person transmissi...
Natural history of TB infecion     Getting Infection with M. tuberculosis is different from  developingTB disease.     Inf...
    Develop resistance
Tuberculosis - Pathogenesis    The sequence of events pattern of host response following an  infection depends on the stat...
Tuberculosis - Pathogenesis     Macrophages are the primary cells infected by M.  tuberculosis.     Inhaled M. Tuberculosi...
Tuberculosis - Pathogenesis    At this early stage of primary tuberculosis   3 weeks  in the  non-sensitized individual an...
Tuberculosis - Pathogenesis
Tuberculosis - Pathogenesis     While later in infection, the T lymphocytes-helper-1  cells   TH-1 cells immune response d...
Tuberculosis - Pathogenesis TH-1 response is stimulated by mycobacterial antigens  draining to Lymph Nodes and presented b...
Tuberculosis - Pathogenesis
Tuberculosis - Pathogenesis CD8  T cell lysis of infected macrophages with  killing of mycobacteria, Lysis of the macropha...
Notes     Defects in any of previous steps of Th-1 response lead to poorly formed granuloma, absence of resistance and dis...
Notes     Primary cell infected by TB bacilli is            Immunity mediated against TB bacilli is mainly mediated by    ...
Morphology Gross examination   Creamy yellow , granular, cheesy-like necrotic material
Primary Tuberculosis     Microscopic Morphology  Well-defined non-caseating granulomas are seen here. They have rounded ou...
Primary Tuberculosis     Microscopic Morphology     The site of active  involvement shows granulomatous inflammation with ...
Primary Tuberculosis     Microscopic Morphology     granulomatous     Epithelioid  inflammation   cells    minimal central...
Primary Tuberculosis     Microscopic Morphology  At high magnification, the granuloma demonstrates epithelioid macrophages...
Primary Tuberculosis     Microscopic Morphology  This is the acid fast stain of Mycobacterium tuberculosis  MTB . Note the...
Primary Tuberculosis                         Occurs in previously unexposed   therefore unsensitized persons In non immuni...
Primary Tuberculosis     Gross Morphology    Typically   inhaled bacilli implant in the distal airspaces of the  lower par...
Primary Tuberculosis     Gross Morphology     Ghon   s  complex   Parenchymal lesion   Hilar lymph node involvement
Primary Tuberculosis     Fate 1.Fibrosis   calcification    healing    in 95  of cases. Only 5   of the newly infected per...
Primary Tuberculosis     Fate    Progressive primary tuberculosis     A. Lower   middle lobe consolidation, pleural involv...
Primary Tuberculosis     Fate C. Haematogenous spread into blood vessels      Will produce      Isolated - organ tuberculo...
Tuberculosis     Natural History   Spectrum Majority