Download Document

CHRONIC PNEUMONIAS
Chronic Pneumonias
 Often SYNONYMOUS with the 4 classic fungal or
granulomatous pulmonary infections .
 If you see pulmonary granulomas, think of a
CHRONIC process, often years.
Include :
 Tuberculosis
 Histoplasmosis
 Blastomycosis
 Coccidiodomycosis : (kok-sid-e-oy-doh-my-KOH-sis)
1- Histoplasmosis,Coccidiodomycosis,Blastomycosis
 Usually normal host, also immunocompromised
 Presentation & pathology very similar to T.B.



Acute primary pulmonary infection
Chronic cavitary pulmonary infection
Disseminated miliary infection
 Lesion is granuloma with necrosis & giant cells
 Identify the organisms
Infections in immunocompromised
patients:
1- Candidiasis :
 Common superficial oral or vaginal mucosal or
skin infections.
 Maybe invasive in special patients.
AIDS , renal transplant, neutropenia , heart
valvular diseases.
 Selective involvement of esophagus in AIDS
2-Cryptococcosis : (krip-toh-ko-koh-sis)
 Opportunistic infection specially in AIDS.
 Gelatinous organisms, initiates minimal
inflammation.
 Pulmonary, CNS, Disseminated disease.
 Usually inhalation to lung, spread to meninges in
gelatinous masses.
3- Aspergillosis :
 1- Invasive pulmonary aspergillosis :
 Immunocompromised
host:
Multifocal necrotizing pneumonia
May invade Blood Vessles  dissemiation
with vasculitis, occlusion,& infarction.
 2-Aspergilloma : (mycetoma) growing in existing
cavities , specially in TB & bronchiectasis.
 3-Allergic bronchopulmonary aspergillosis:
Asthmatic attack or hypersensitivity pneumonitis :

Transient pulmonary infiltrates, eosinophilia
IgE
ASPERGILLOMA
4 - Mucormycosis:
 Hyphae localized in nose  brain.
 In lung localized cavity or miliary.
 Immunocompromised host, specially in diabetics.
5- Pneumocystis carinii pneumonia :
 ? Protozoa, ? Fungus
 Majority of humans show positive serology , but no
disease
 Opportunistic infection in AIDS , often with CMV
(reactivation)
Pathology :
 Interstitial lymphocytic infiltration.
 Pink frothy exudate in alveoli.
 Cysts or trophozoites in exudate.
Diagnosis :
Organism best detected by special stains & PCR on
the following samples :
 Bronchoalveolar
lavage
 Transbronchial biopsy
Silver Stain (+)
Methenamine SILVER stain
for Pneumocystis Carinii
Clinical Picture :
 Fever, dry cough, dyspnea, hypoxia
 Chest X ray : Bilateral perihilar & Basilar
nodular infiltrates
 Restrictive pulmonary function defects
 Recurrences are common
6- Cytomegalovirus ( CMV )
 Immunocompromised : Transplants & AIDS.
 Commonest pathogen in AIDS patients.
 Necrotizing
Interstitial Pneumonia with
inclusions.
 Retinitis
 Gastrointestinal ulcerations & diarrhea
Thank you
Tuberculosis
Ancient Disease - New Threat






TB is an ancient infectious disease
caused by
Mycobacterium tuberculosis.
It has been known since 1000 B.C.
1900’s Approximately all of Europe’s
adult population infected with TB
No treatment
Up till the ’50s Sanatorium with
Emphasis on rest, good nutrition, and
fresh mountainous air
Isolation led to  in transmission
Meeting held in London (1977)
It was concluded that by 1990
Tuberculosis would be rare and by
2010 it will only be of historical
interest to the medical fraternity!
TUBERCULOSIS




Infects one third of world population..!
3 million deaths due to TB every year
Under privileged population
Since 1985 incidence is increasing in
west
 AIDS, Diabetes, Immunosuppressed
patients.
 Drug resistance






Communicable disease caused usually by
M. hominis ,bovis, avium,…etc.
May affect any organ lung is most affected .
Route of infection : Inhalation  Lung
OR Ingestion  Intestine
Not all exposed get infected
Genetic makeup linked to NRAMP1
polymorphism
Mostly self limited ,  viable organisms

Since TB is a disease of respiratory
transmission, optimal conditions for
transmission include:
 overcrowding
 poor personal hygiene
 poor public hygiene
 Poor nutrition
Transmission

Pulmonary tuberculosis is a disease of
respiratory transmission, Patients with
the active disease (bacilli) expel them
into the air by:
 coughing,
 sneezing,
 or any other way that will expel
bacilli into the air
Environmental Factors Increase
Risk for Transmission





Exposure in small, enclosed spaces
Inadequate ventilation
Re-circulated air containing infectious
droplets
Inadequate cleaning and disinfection of
equipment
Improper specimen-handling
procedures
Pathogenesis :




TB bacilli taken up by alveolar macrophages
through action of receptors on their surface
Bacilli inhibit microbial killing by interfering
with phagolysosomal function
Proliferation of bacilli inside alveolar
macrophages, then released→bacteremia
Majority are symptomless





Inside LN, cell mediated immunity after 3w
CD4+TH1 subset→ IFN γ activate
macrophages → mediators → bacterial
killing
Immune response leads to caseation
Caseation is tissue necrosis, later healing
Outcome of the disease depends on the
balance of immunity to tissue destruction
Signs and symptoms

Early symptoms
Common cold symptoms
 Listlessness, fatigue, fever, a minimally
productive cough of yellow or green
sputum and a general feeling of malaise.


Later symptoms

Night sweats, fever, cough with purulent
secretions and haemoptysis, dyspnoea,
chest pain, and hoarseness appear.
Types of TB infection :
1. Primary TB :Infection in unsensitized
or immunocompromised host
2. Secondary ( reactivation TB)
3. Progressive pulmonary TB
4. Miliary TB
5. Isolated organ TB
1- Primary TB :


Subpleural caseating granuloma 
Ghon focus
Caseation , surrounded by chronic
inflammatory cells, epitheloid cells &
Langhan’s giant cells
Enlarged hilar LNs with caseation 
Ghon Complex
Ghon focus + nodal involvement
GHON COMPLEX
Caseating granulomata
Caseating granulomata

WHAT HAPPENS LATER ???
Outcome of Primary TB :
- In 95% cell mediated immunity 
healing in 3 weeks
- Fibrosis  calcification
Ranke complex
- Uncommonly disseminated disease
Progressive Primary TB
2. Secondary (Reinfection TB)
Arises in a previously sensitized host in
one of following :



Progressive post primary ( < 5% )
Reactivation of old focus
Reinfection with a virulent strain
Infection is characterized by :




Location usually at apex about 2 cm.size
CAVITATION is common
Lymph node enlargement less prominent
Sputum is positive for TB bacilli in most
cases
Symptoms :
 Hemoptysis common, fever , loss of
weight night sweats, pleuritic pain….
 Extrapulmonary manifestations if present
 May be asymptomatic !
Outcome :
May heal or become progressive
3. Progressive Pulmonary TB


This can occur after primary or secondary
TB , along the following routes :
Tracheobronchial tree & lymphatics
 Tuberculous bronchopneumonia OR
Miliary pulmonary disease.
 Pleural involvement leads to effusion,
empyema or obliterative fibrous pleuritis
Spread through trachea to larynx
leads to Laryngeal TB


Swallowing infected sputum leads to
intestinal TB
Spread through pulmonary veins 
Heart systemic circulation 
generalized spread
4. Systemic Miliary TB


Numerous tiny tubercles in any organ
Most affected :

Liver

Bone marrow

Spleen

Adrenals

Meninges

Kidneys….etc
Systemic Miliary TB
5. Isolated Organ TB


Spread through blood  low grade
bacteremia leads to granulomatous
infection in any organ
Symptoms depend on the organ:
 Tuberculous salpingitis & endometritis
lead to sterility
 Vertebral TB  POTT’s Disease
 Adrenal gland  Addisons disease
Tuberculous lymphadenitis± Scrofuloderma
 Renal infection  Tuberculous chronic
Pyelonephritis, nephrotic syndrome…
 Male Genital system  Tuberculous
epididymo-orchitis & prostatitis sterility


Chronic TB  SECONDARY AMYLOIDOSIS
Adrenal TB - Addison Disease
Spinal TB - Potts Disease
Tuberculosis in HIV :




Bacterial pneumonias in general are
commoner & more serious than in
immunocompetent patients
Tuberculosis in initial phases of HIV is
usually secondary reactivation TB
In late stages : Miliary TB & Atypical TB
M.avium common in late stages 
poorly formed granuloma without caseation
Diagnosis of TB



Clinical picture
X ray picture
Sputum :
 Direct examination for Acid Fast
Bacilli
(ZN, Auramine-rhodamine stains, PCR)
 Culture of sputum about 6 weeks
Chest X-ray in primary TB
Later :

Chest x-rays: Multi nodular infiltrate
above or behind the clavicle with or
without pleural effusion unilaterally or
bilaterally.
Diagnosis (continued)

Sputum investigation:
Cultures will reveal the presence of
mycobacterium tuberculosis
 Patients stay infectious for as long as
the bacilli are excreted in the sputum

AFB - Ziehl-Nielson stain
Diagnosis (continued)

Skin test : Tuberculin test
Injecting PPD into skin 
positive ( 48- 72hrs.)
PPD Testing
PPD Testing
Problems of interpretation of test :



It indicates hypersensitivity to bacilli but
does not differentiate infection from active
disease
False negative in Miliary TB , AIDS,
sarcoidosis some viral diseases , Hodgkin’s
disease , malnutrition…
False positive in atypical mycobacterial
infection

Parasitic Infections in the Lung :
Hydatid Disease :







Common in mediterranean & middle east countries
Infection by larval stage of Eccinococcus
Granulosis
Tape worm. Adult is in dogs  eggs 
Intermediate stage ( Larva) in sheep & humans
Mainly affects liver but other organs too
Lung, Brain,…. Etc
May be accompanied by eosinophilia
Diagnosis by MRI & CT
Forms a large unilocular cyst lined
by eosinophilic laminated membrane
from which scoleces develop
( Daughter cysts)
 In lung may be incidentally discovered
 May be infected or ruptured
 Treatment is surgical removal
