Exam 2, Lung set 3

Question 1

Tx of TB

Answer 1

Standard = long course antibiotics
*increasing Abx resistance
Vaccinations -> the BCG (Bacillus Calmette-Guerin) attenuated

Question 2

Miliary TB

Answer 2

Disseminated TB - infix goes systemic, “millet” like seeds of bacilli in lungs & other organs, 1-3% of cases

Question 3

TB Sx

Answer 3

Can be Asx or…
Fever (esp late afternoon/night sweats)
Cough
Pleuritic chest pain
Dyspnea
Hemoptysis
Wt loss, cachexia
Fatigue

Question 4

Gohn Complexes

Answer 4

Form at initial infection site. In 2-3 wks does caseous necrosis. Drain toward hilar lymph nodes. May calcify and be seen on chest x-ray.

Dz can remain inactive here for months-decades. Can re-emerge “secondary TB” from poor nutritional status, concurrent infection, or other health problems that breakdown the Gohn complex.

May progress to cavitation of the lung and systemic dissemination

Question 5

TB infection pathogenesis

Answer 5

• CD4 helper cells secrete interferon
• Interferon activates NO/NO2 formation in macrophages
• Nitrogen intermediates would kill mycobacterium but phagosome fusion fails
• CD4/CD8 complexes lyse macrophages releasing TB
• Macro.-lysis contributes to development of granulomas
• Caseous granulomas characteristic of TB infection

Question 6

Histoplasmosis

Answer 6

• Fungal spores from bird or bat droppings
• “Histoplasmosis Capsulatum” tiny, live in macrophages
• Chronic infection Mimics TB, primary infection looks like viral URI
• *Granulomas are non-caseating, may calcify

Question 7

Blastomycosis

Answer 7

• Yeast spores in soil
• Mimics TB (all granulomatous diseases do), sx include productive cough, chest pain, wt. loss, fever & night sweats
• “Blastomyces dermatidis”
• Pulmonary granulomas often LARGE, distinct and calcified
• Affects other organs, primarily skin

Question 8

Coccidiomycosis

Answer 8

• Spores in soil, “Coccidioides IMMITIS”
• Mimics TB, teeny tiny live in macrophages forming thick-walled spherules inside them
• Large/calcified pulmonary granulomas
• Many other organs can be affected
• Sx of cough, high fevers, pleural effusion

-Almost everyone who inhales the fungus becomes infected & develops hypersensitivity to the fungus -> more than 80% of ppl in endemic areas test +

Question 9

Aspergillus

Answer 9

• Common mold, may be a source of allergies
• Becomes “invasive aspergillosis” in immunosuppressed/debilitated hosts
• “Aspergilloma” is when it infects a lung cavity

Question 10

Pneumocystis Pneumonia

Answer 10

• Caused by atypical fungi that make cysts, formerly P. carinii, now P. jiroveci
• Low virulence marks the transition from HIV to AIDS. Also affects patients on chemo, immunosuppressive drugs (esp. bone marrow transplant)
• Most common pneumonia in AIDS patients
• Sx: high fever, dry cough, dyspnea, wt. loss, night sweats.
• Always infects the lower lobes
• “Cotton wool” and “wooly exudates” are described radiologically and histologically

Question 11

Lung Transplant Pathology

Answer 11

• Infections (from EVERYTHING) are common b/c immnosuppressive drugs
• Acute rejection pneumonias take weeks-months
• Chronic rejection (half of all patients) by 3-5years

-Transplant can be necessary from Emphysema, Pulmonary Fibrosis, Cystic Fibrosis, Pulmonary Hypertension. Any end-stage lung disease in which the pt can tolerate long term immunosuppression. Often just one lung is enough