INTERSTITIAL LUNG DISEASE

Esam H. Alhamad, M.DAssistant Professor of Medicine

Consultant Pulmonary & Critical Care Medicine

ATS/ERS. Am J Respir Crit Care Med 2002;165:277-3

INTERSTITIAL LUNG DISEASEHypersensitivity Pneumonia

Idiopathic pulmonary Fibrosis

Smoking Associated ILD

Hypersensitivity Pneumonia

AntigensMammalian and avian proteinFungiThermophilic bacteriaCertain small molecular weight compounds

CLINCAL FORMSACUTE

SUBACUTE

• CHRONIC

ACUTE FORMSymptoms appear 4-8 hour after exposure

Fever, chills, malaise, tightness of the chestcough, dyspnea, expectoration, headache

Symptoms gradually decrease over the next24-48 hours, but recur after next exposure

SUBACUTE/CHRONIC FORMSContinuous low-level antigen exposure

(e.g few birds at home)

Insidious onset of the disease

Duration of symptoms 2-24 months

SUBACUTE/CHRONIC FORMSChronic progressive dyspneaFatigue, poor appetite, weight lossCough with mucoid sputumOccasional digital clubbingMay progress to fibrosis, respiratory failure,

cor pulmonale

CHEST X-RAY & HRCTGround glass opacitiesPoorly defined micronodulesPatchy air space opacificationFine and coarse reticular opacitiesHoneycombing ( chronic advanced cases)

PULMONARY FUNCTION TESTSRestrictive, obstructive, or mixed defectMost common finding Dlco40% airflow obstructionEmphysema more common than fibrosis

Alhamad et al. Clin Chest Med 2001; 22:715-750

BRONCHOALVEOLR LAVAGE T lymphocytes ~ 50%

CD8+ T-cells

CD4+ T-cells CD4+/CD8+ ratio CD4+/ CD8+

ratio

LUNG BIOPSYLymphocytes infiltrationGranulomaBronchiolitisEmphysemaFibrosis

DIAGNOSISClinical, radiologic and functional

abnormalities suggestive of an I.L.DHistory of exposure to HP antigensPositive specific antibodiesLung biopsy

Hypersensitivity pneumonitis

THERAPYAvoidance of antigen exposure

Corticosteroids