ศ.น.พ. อรรถ นานา คณะแพทยศาสตร์ศิริราชพยาบาล มหาวิทยาลัยมหิดล Extrinsic allergic alveolitis Hypersensitvity pneumonitis ปอดอักเสบภูมิไวเกิน ศ.น.พ. อรรถ นานา คณะแพทยศาสตร์ศิริราชพยาบาล มหาวิทยาลัยมหิดล

HP: Introduction immunologically induced lung disease diffuse inflammation of lung parenchyma & airways in previously sensitized patients sensitized to repeated inhalation of dusts containing organic & low molecular weight chemical antigens

HP: Introduction dusts derived from not atopic disease dairy & grain products animal dander & proteins wood bark water reservoir vaporizers not atopic disease not associated with increase IgE or eosinophils

HP: Selected etiological agents Disease Farmer’s lung ปอดชาวไร่ Bagassosis โรคชานอ้อย Bird-breeder’s lung Bird-fancier’s lung Pigeon-breeder’s lung Mushroom-worker’s lung คนเพาะเห็ด Humidifier/air conditioner lung ปอดเครื่องทำความชื้น ปอดอักเสบการระบาย อากาศ Source หญ้าแห้งที่ขึ้นรา ชานอ้อยที่ขึ้นรา มูลนก, ขน (พิราบ,นกแก้ว) ปุ๋ยที่ขึ้นรา,หญ้าแห้ง เครื่องทำความชื้น ท่อเครื่องปรับอากาศ Antigen Micropolyspora faeni Thermoactinomyces sacchari Avian proteins Thermoactinomyces vulgaris Thermoactinomyces vulgaris

HP: Epidemiology Varies 0.5-5% of farmers (Farmer’s lung disease) 8-30% of members of pigeon breeding clubs (pigeon breeder’s disease) Prevalence Farmer’s lung UK France Finland U.S.A. 420-3000 4370 1400-1700 540 cases/100,000 / “ persons at “ risk “

Bagassosis : A Report of 8 Cases จดหมายเหตุทางแพทย์ 2517:57;468-74. Pee Kamtorn, M.D.* Poonkasem Charoenpan, M.D.** Yosvi Sukumalchantra, M.D. , F.A.C.P. , F.R.C.P. (C) ,F.A.C.C.** Vijitr Boonpucknavig, M.D.*** Kalyanakit Kitiyakara, M.B. , B.S. , M.R.C.S. , L.R.C.P.**** Chirotchana Suchato, M.D.***** Chaivej Nuchprayoon, M.D.****** Bagassosis is classified as an extrinsic allergic pneumonia. It is considered to be the result of allergic reaction to moldy sugar cane inhalation(1) . Case Report All of the patients worked at a paper produc- tion factory in Karnchanaburi province and were

HP : Pathogenesis precipitating Ab against specific Ag immune - complex mediated process precipitating Ab against specific Ag 50% of asymptomatic persons exposed also have Ab

HP: Pathogenesis cell - mediated immunity more important response increase PMN in alveoli & small airways influx of mononuclear cells formation of granulomas cytokine from T- lymphocytes & macrophages

HP : Histologic findings diffuse interstitial infiltrate : lymphocytes, macrophages, mast cells, plasma cells scattered noncaseating granulomas cellular inflammation of bronchioles, + bronchiolar obstruction absent generalized vasculitis, necrotizing granulomata ~ duration or stage of disease, adequacy of biopsy sample

HP : Diagnostic criteria Major criteria 1. Symptoms c/w HP , appear or worsens within hours after Ag exposure 2. Confirmation of exposure to the offending agent by - Hx -investigation of the environment -serum precipitin test -BAL Ab

HP : Diagnostic criteria 3. Compatible CXR or HRCT 4. Lymphocytosis in BAL 5. Compatible histologic changes 6. Positive “natural challenge” or by controlled inhalational challenge

HP : Diagnostic criteria Minor criteria 1. Basilar crackles 2. Decreased diffusion capacity 3. Arterial hypoxemia, at rest or with exercise

HP : Diagnostic criteria Four major criteria Two minor criteria Other diseases have been excluded Adapted from Schuyler + Cormier Chest 1997; 111: 534-6.

HP : Diagnosis often unrecognized & misdiagnosed respiratory symptoms with Hx. of environmental occupational exposure respiratory symptoms with episodic radiographic infiltrates “Recurrent pneumonia”

HP : Radiographic findings vary to the stage of disease acute HP bilateral micronodular (1-4 mm.) infiltrates patchy ground-glass opacities decreased attenuation (air trapping from bronchiolitis) and mosaic pattern (expiratory view)

HP : Radiographic findings Subacute HP fine linear shadows, small nodules = reticulonodular appearance Chronic HP volume loss reticulonodular infiltrates honeycombing predominantly upper & mid lung zones

HP : Pulmonary function tests restrictive changes (superimposed obstruction in chronic HP) decreased diffusing capacity ABG: increased alveolar-arterial oxygen gradient frank hypoxemia (severe cases) oxygen desat. with exercise (clue in suspected case)

HP : BAL fluid intense lymphocytosis predominantly CD 8+ T-suppressor cells ~ timing of the last antigen exposure, stage of disease

HP: key features Acute Subacute Chronic Time frame 4-48 hr weeks to 4 M. 4 M. to years Clinical features fever, chills, cough hypoxemia, aches dyspnea , cough, episodic flares dyspnea, cough, fatigue, weight loss HRCT ground glass infiltrates micronodules, air trapping fibrosis, honey combing, emphysema Immunopathology alveolitis, immune complex granulomas, bronchiolitis lymphocytic infiltration, fibrosis,air space destruction Prognosis good

HP : Differential diagnosis Acute stage pneumonia acute tracheobronchitis organic dust toxic syndrome BOOP

HP : Differential diagnosis Subacute stage recurrent pneumonia granulomatous lung diseases pneumoconiosis Wegener’s granulomatosis

HP : Differential diagnosis Chronic stage IPF bronchiectasis COPD with pulmonary fibrosis MAC

HP: Management early diagnosis avoidance of further exposure protective devices :- personal respirators relocation to a new job reducing microorganism contamination in the environment altering handling & storage wetting compost using antibiotics to decrease fungal growth preventive maintenance on all A/C equipment

HP: key features Acute Subacute Chronic Time frame 4-48 hr weeks to 4 M. 4 M. to years Clinical features fever, chills, cough hypoxemia, aches dyspnea , cough, episodic flares dyspnea, cough, fatigue, weight loss HRCT ground glass infiltrates micronodules, air trapping fibrosis, honey combing, emphysema Immunopathology alveolitis, immune complex granulomas, bronchiolitis lymphocytic infiltration, fibrosis,air space destruction Prognosis good

Subacute HP, a 60-year-old dairy farmer had a 8-year history of intermittent dyspnea. CXR shows bilateral reticulonodular interstitial infiltration.

Chronic pigeon breeder’s disease Chronic pigeon breeder’s disease. This patient has extensive pulmonary fibrosis & cor pulmonale.

Chronic HP, Pigeon breeder’s disease Chronic HP, Pigeon breeder’s disease. Bilateral reticulonodular densities are present.

Acute HP, ground glass opacification

HRCT of a patient with Chronic HP demonstrating centrilobular nodules not associated with bronchovascular bundles.

Chronic HP, centrilobular nodules.

Chronic HP, honeycombing in right upper lung & traction bronchiectasis

Acute HP, mononuclear infiltration & noncaseating granulomas.

Chronic HP, mostly lymphocytic cellular infiltrate with epithelioid cells & numerous and clearly defined granuloma. (Wright-Giemsa)

Giant cells are characteristic feature of HP.

Chronic HP shows interstitial inflammation associated with fibrosis.