1. Hypersensitivity Pneumonitis
Wael Batobara

2. Case 1 82 y Female smoker (30 pack) Seen in OPD because of
6/12 SOBE , Cough
No Orthopnea , PND ,LL swelling
No CP , Wheeze , Fever ,Sputum , Wt loss
No similar episode in the past
Able to walk 3 blocks & climb 20 stairs

3. History PMH : HTN , IHD ,Hypothyroidism
Medication: Thyroxine , Altace , Ranitidine
Ventolin
PSH : Partial gastrectomy for bleeding GU
Works as Cook
Travel to Arizona & North ON
No pets
No Contact with similar case

4. Examination Afebrile BP 120/70 RR14 Sat93% RA
No Clubbing or lymphadenopathy
Chest : N BS No wheeze
Fine crackles Bilaterally basally
CVS : N JVP S1+S2 +0
No Signs of Pulmonary HTN
Abd & LL : NAD

5. Investigation CBC & Coagulation N BUN , Creat & Lytes N LFT & UA N
Cardiac Enzyme & EKG & 2DE N
CXR & CT

6. Investigation ABG PH 6.42 PCO2 36 PO2 68 Hco3 24 Sat 93%
PFT : Isolated decrease in DLCO 60%
6MWT : 100 m HR 115 Sat 85%
Open Lung Bx  Non caseating granuloma
& organizing pneumonia
Sent to Mayo Clinic  Hypersensitivity
Pneumonitis

7. Course Patient was symptomatic persistently
H/O exposure To Wheat & Flour 24 lbs /week
Persistent decrease DLCO
& walking hypoxemia
Prednisolone 40 mg was initiated
Will be seen in OPD in follow up

8. Case 2 52 y Female Xsmoker (15pack) Seen In OPD because of
6 months H/O SOB ,Cough
Cough non productive
SOBE NO orthopnea ,PND
No fever , night sweating ,
chest pain , wheeze
No Wt Loss , anorexia

9. History NO CTD symptoms No leg pain or swelling
PMH Hypothyroidism & Migraine
No H/O CAP ,TB contact
NO IHD risk factor
Rx Thyroxine
Lives in Portage la Pairie
Works as animal rescue aids 25 y

10. Examination Afebrile BP 120/70 HR 80 RR 16 Sat 93% RA
No clubbing ,lymphadenopathy
JVP N
Chest Bilateral fine crackles No wheeze
CVS ,Abd & LL NAD
No CTD signs

11. Investigations CBC & Coagulation N BUN , Creat , Lytes N LFT N UA N
CXR , CT Chest
PFT

12. Patient Course Seen By Allergy / Immunology
+ve precipitant to avian protein
Hypersensitivity pneumonitis
Bird Fancier lung
Advised to avoid exposure
Steroids has not been started Given the mild symptoms & N exercise test

13. Hypersensitivity Pneumonitis
Syndrome of varying presentations
& natural history
Immunologic reaction to an inhaled
antigen mainly organic
Genetic predisposition
44 Pt with HP Vs 50 Asymptomatic
Vs 99 control
MHC 2 & TNF alpha levels difference
Am J Respir Crit Care Med 2001 Jun

14. Epidemiology Data from Farmers lung & Bird fancier lung
Great variation because of
geographical , seasonal & local practice
Bird fancier prevalence /
Farmer %
Life guard in swimming pools
Contaminated forced air system

15. Smoking Effect Less symptoms & immune response 102 pigeon breeder
1/23 smokers +ve IgG Vs 39/65 Non smokers
Clin Allergy 1985 Sep
92 dairy farmers Micropolyspora faeni antibody
Non smoker 27% Vs 7% smoker
Am Rev Respir Dis 1989 Sep

16. Smoking Effect 12 smoker Vs 31 non smokers farmers
No difference in age ,gender
,working environment & exposure duration
Acute FLD in non smoker 58% Vs 8%
Chronic insidious in Smokers 92% Vs 42%
10 y survival 91% Non Sm Vs 70% Sm
Persistent symptoms & radiological findings & higher reccurent episodes in Smokers
Intern Med 1995 Oct

17. Etiologies through droppings ,feathers
Farming ,Dairy or Cattle workers
Different from Organic Dust Toxic Syndrome
more common than HP occur with single
day exposure & non immunologic reaction
Bird ,Poultry & Animal handling
through droppings ,feathers
processed products or serum

20. Etiologies Grain and flour processing and loading
being colonized with organisms & easily aerosolized
Contaminated Ventilation & Water Source
Forced air systems , heated water reservoir
Spa Hot tubs, swimming pools water damaged carpet
MAC as a cause in immunocompetent
Construction & Lumber milling
Plastic , Painting & electronic industry

21. Classification Acute 6-12 hours of heavy exposure Misdiagnosed as CAP
Fever ,Chills ,Cough, SOB , CP & Malaise
Tachypnea & fine crackles

22. Classification Acute Symptoms will resolve with removal of
offending agent
Complete radiological resolution takes weeks
Elevated ESR & Immunoglobulin
+ve specific Precipitating IgG
BAL  Lymphocytosis
PFT  restrictive pattern

23. Classification Acute Radiologically HRCT > CXR
interstitial , micronodular
middle &lower zones
Bx  mononuclear infiltrate
poorly formed non caseating granuloma
peribronchial distribution

24. Classification Subacute , Intermittent Gradual symptoms & signs
More Wt loss
Improvement with removal of exposure
Improvement takes longer than acute

25. Classification Subacute , Intermittent DLCO decreased
Radiologically  Upper & middle zone
Ground glass & micronodules
Focal fibrosis & emphysema
Bx Granuloma more formed
Bronchiolitis +/- organizing Pneumonia
Interstitial Fibrosis

26. Classification Chronic Progressive Worsening cough & SOB
Removal of exposure yield partial relief
? Clubbing as bad prognosis
82 Pt followed for 5 years
16/44 +ve clubbing  worsening PFT
5/38 -ve clubbing  worsening PFT
Arch Intern Med 1990 Sep

27. Classification Chronic Progressive PFT  Restrictive +/- obstructive
Hypoxemia exertional or at rest
Radiologically  Volume loss
Honeycombing , Emphysema
Less Ground glass
Bx  difficult to differentiate from IPF

28. Diagnosis Exposure +ve aero/microbiological cultures
History
+ve aero/microbiological cultures
+ve serum precipitins
Compatible Clinical & Radiological Finding
Symptoms appearing or worsening after exposure
Reticular .nodular or ground glass
Restrictive / obstructive pattern

30. Diagnosis +ve Inhalation challenge test
Rexposure either in environment
or in PFT lab
BAL / Bx
Lymphocytosis & Low CD4/CD8 ratio
Granuloma / Mononuclear Infiltrate

31. Diagnosis Serum Precipitins Suggestive not diagnostic
High false –ve & +ve
Used to convince about hypersensitivity
Smoking Effect ?!

32. Diagnosis Inhalation Challenge Test 2 reactions:
Common  6-8 hours post challenge with
fever ,malaise ,SOB
neutrophilia & decreased FVC
Less common  immediate wheeze
& decreased FEV1
followed 6 hours later by
decreased FVC & DLCO

33. Diagnosis Inhalation Challenge Test 17 with HP Vs 11 ILD Vs Control
Challenged with pigeon serum
Increase in Temp
& Post Challenge decrease FVC ,PAo2 & Sat
All HP & 3 ILD +ve but none of control
Increase in Temp by 0.5 C
 100 PPV & 85 NPV
Decrease in FVC by 16%81%PPV & 83% NPV
No complication were observed
Am J Respir Crit Care Med 1998 Sep

34. Diagnosis Inhalation Challenge Test Methacholine challenge
37 dairy farmers & 11 controls
12 with FLD , 13 Asymptomatic with +Ab
12 Asymptomatic with –Ab
+ve in all farmers
No statistical difference in farmers subgroup in term of degree of responsiveness
Am J Respir Crit Care Med Jun

35. Diagnosis BAL Lymphocytosis  non specific but useful in
narrowing differential Dx
CD4/CD8 ? Prognostic
17 Pt study
HP with fibrosis Vs no Fibrosis
High CD8 acute presentation & less fibrosis
High CD4  chronic & more fibrosis
Chest 1993 Jul

36. Diagnosis Lung Bx Retrospective study
105 TBB 55 FLD Vs Control {other ILD}
Gold Standard Test for FLD was not open Bx
 History ,fine crackles ,Lymphocytic BAL
& resolution with removal of exposure
2 pathologist reading as
Probable FL ,Possible FL ,
non specific or alternative Dx
Chest Dec

37. Diagnosis Lung Bx Interobserver agreement was fair
Upto 48.5% of Bxnon specific
LHR for Probable FLD was
Possible FLD
Lymphocytic Infiltrates 9.1
Granuloma Chest Dec

38. Management Environmental Control Reduction of antigenic burden
wetting compost & Abx use
Design & Maintenance of Facilities
Keeping Humidity below 60%
Heating ,Ventilating & AC water
shouldn’t be recirculated
Early water damage control
Protective devices ?

39. Management Environmental Control
Relocation  ? If persistence of exposure will
lead to disease progression
61 Pt with FLD 37 /61 continued farming
5 y follow up on PFT
At 1 & 3 year reduction in DLCO,TLC more in continued exposure
At 5 no statically significance difference
Chest 1985 Jun

40. Management Steroids Accelerates initial recovery
but doesn’t change long term outcome
36 Pt FLD Prospective Randomized DB
8 weeks either Prednisolone (20Pt) Vs Placebo (16Pt)
At 1 month difference in DLCO
At 5 years not statically significant difference
in DLCO ,FEV1
At 5 years 5 of Prednisolone group had recurrence
Vs 1 of Placebo Not statically significant
Am Rev Respir Dis 1992 Jan

41. Management Steroids Prospective Randomized 3 arms 93 Pt FLD
12 weeks Vs 4 Weeks Vs Placebo
Follow up 18 months
No difference between 12 & 4 weeks outcomes
Eur J Respir Dis 1983 May

42. Thank You