Physiologic and Genetic Determinants of Occupational Lung Dysfunction - Experience in the Swine...

..Physiologic and Genetic Determinants of Physiologic and Genetic Determinants of Occupational Lung DysfunctionOccupational Lung Dysfunction

- Experience in the Swine Industry- Experience in the Swine Industry

Occupational and Environmental Medical Occupational and Environmental Medical Association of CanadaAssociation of Canada

Annual Scientific ConferenceAnnual Scientific Conference

October 5, 2010October 5, 2010

James A Dosman MDJames A Dosman MD

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CREDITS CREDITS

A SenthilselvanA Senthilselvan Ernie Barber Ernie Barber Chuck RhodesChuck Rhodes Tom HurstTom Hurst Shelley KirychukShelley Kirychuk Liliane ChLiliane Chéénardnard Yvon CormierYvon Cormier David SchwartzDavid Schwartz Leslie HolfeldLeslie Holfeld

Don CockcroftDon CockcroftFrank FrohFrank FrohLorne BabiukLorne BabiukPhil WilsonPhil WilsonBaljit SinghBaljit SinghAlan RosenbergAlan RosenbergLouise HagelLouise HagelKendra UlmerKendra UlmerVaneeta GroverVaneeta GroverJosh LawsonJosh LawsonMerry-Lynn MacDonaldMerry-Lynn MacDonald

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CREDITSCREDITS

The Medical Research The Medical Research Council of CanadaCouncil of Canada

National Health National Health Research and Research and Development ProgramDevelopment Program

The Canadian Institutes The Canadian Institutes of Health Researchof Health Research

Saskatchewan Health Saskatchewan Health Research FoundationResearch Foundation

Saskatchewan Saskatchewan LabourLabour

Saskatchewan Saskatchewan Agriculture and FoodAgriculture and Food

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OUTLINE OF PRESENTATION OUTLINE OF PRESENTATION 1.1. Characteristics of the industryCharacteristics of the industry

2. Respiratory health effects2. Respiratory health effects3. Mechanisms of dysfunction3. Mechanisms of dysfunction4.4. InterventionsInterventions

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THE SWINE INDUSTRY IN CANADATHE SWINE INDUSTRY IN CANADA

Annual sales: $4 BillionAnnual sales: $4 BillionNumber of pigs/yr: 31 MillionNumber of pigs/yr: 31 MillionNumber of people in industry: 30,000Number of people in industry: 30,000

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AN EVOLVING INDUSTRYAN EVOLVING INDUSTRY From the family farm From the family farm

with outdoor or small with outdoor or small scale production and scale production and a few hours per day a few hours per day exposureexposure

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AN EVOLVING INDUSTRYAN EVOLVING INDUSTRY Large scale indoor Large scale indoor

animal confinement animal confinement involving thousands of involving thousands of pigs and the “eight pigs and the “eight hour per day” hour per day” employed workeremployed worker

Photo: Prairie Swine Centre, Floral, SKPhoto: Prairie Swine Centre, Floral, SK

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AIR QUALITYAIR QUALITY (n=54 – winter)(n=54 – winter)

Total dust (mg/mTotal dust (mg/m3)3) 2.93 2.93 ±± 0.920.92Endotoxin EU/mEndotoxin EU/m33 11,443 11,443 ± 13,492± 13,492NHNH3 3 (ppm) 11.3 (ppm) 11.3 ± 4.2± 4.2COCO2 2 (ppm)(ppm) 2,632 2,632 ± 807± 807

Zejda et al, JOM 36:49-56, 1994Zejda et al, JOM 36:49-56, 1994

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DUSTS – CHARACTERISTICS (1)DUSTS – CHARACTERISTICS (1)

Animal feedAnimal feed Swine fecesSwine feces Swine danderSwine dander MoldMold

Pollen grainsPollen grains Insect partsInsect parts Mineral ashMineral ash

Median aerodynamic diameter, 2.2 um

Donham et al, Am J Ind Med, 10:294-297,1986.

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DUSTS – CHARACTERISTICS (2)DUSTS – CHARACTERISTICS (2)

Mold – 1.9 x 10Mold – 1.9 x 1033 cfu/mg cfu/mg33

Penicillium Alternaria

Aspergillus Fucarium

Verticillium Scopulariopsis

Donham et al, Am J Ind Med, 10:294-297, 1986

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DUSTS – CHARACTERISTICS (3)DUSTS – CHARACTERISTICS (3)

Bacteria 1.7 x 10Bacteria 1.7 x 1044 cfu/m cfu/m33

Predominant type – gram-positivePredominant type – gram-positiveGram-negative count – 8.4 x 10Gram-negative count – 8.4 x 1033

Donham et al, Am J Ind Med, 10:294-297, 1986

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DUST AND ENDOTOXINDUST AND ENDOTOXIN Dust particles are less Dust particles are less

than 5than 5µ in mean µ in mean aerodynamic diameter aerodynamic diameter and can penetrate and can penetrate

terminal bronchioles.terminal bronchioles.

Endotoxin adheres to Endotoxin adheres to dust particlesdust particles

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ENDOTOXINENDOTOXIN

Soluble lipopolysaccharides (LPS)Soluble lipopolysaccharides (LPS) Outer membrane gram negative bacteriaOuter membrane gram negative bacteria Aggregate to form micellesAggregate to form micelles Molecular weight 1,000,000 kdMolecular weight 1,000,000 kd

Reed CE, Milton DK. 2001. Mosby Inc.Reed CE, Milton DK. 2001. Mosby Inc.

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RESPIRATORY HEALTH EFFECTS RESPIRATORY HEALTH EFFECTS

AsthmaAsthma Chronic airflow limitationChronic airflow limitation Acute effects in new workersAcute effects in new workers Healthy worker effectHealthy worker effect

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CASE # 1, CAUCASIAN WOMAN, AGE 29 (1)CASE # 1, CAUCASIAN WOMAN, AGE 29 (1)

6 weeks -severe wheezing6 weeks -severe wheezing 3 months - quit work 3 months - quit work 1.5 months after quitting - 1.5 months after quitting -

seen in clinicseen in clinic Past history - no asthma, Past history - no asthma,

allergyallergy O/E - wheezes on forced O/E - wheezes on forced

expirationexpiration Dosman et al, Euro Resp J, 24:689, 2004Dosman et al, Euro Resp J, 24:689, 2004

• Chest X-ray clearChest X-ray clear• FEVFEV11 3.48; 10% BD 3.48; 10% BD• Allergy test: weeds, Allergy test: weeds,

grass, alfalfagrass, alfalfa• PCPC20 20 1.03 mg/ml1.03 mg/ml• Diagnosis:Diagnosis: asthma asthma• RxRx: fluticasone prop: fluticasone prop

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CASE # 1, CAUCASIAN WOMAN, AGE 29 (2)CASE # 1, CAUCASIAN WOMAN, AGE 29 (2)

Re-entry challenge - 2.5 Re-entry challenge - 2.5 mo after work cessation mo after work cessation

Spent less than 30 Spent less than 30 minutes in barn before minutes in barn before severe coughing and severe coughing and wheezing forced end of wheezing forced end of challengechallenge

Pre-challenge PCPre-challenge PC20 20 1.03 1.03 mg/mlmg/ml

3 hour post-challenge 3 hour post-challenge PCPC20 20 0.74 mg/ml0.74 mg/ml

Dx:Dx: occup asthma occup asthma

RxRx: fluticasone prop: fluticasone prop

Stay off workStay off workDosman et al, Euro Resp J, 24: 698-702, 2004Dosman et al, Euro Resp J, 24: 698-702, 2004

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CASE # 1, CAUCASIAN WOMAN, AGE 29 (3)CASE # 1, CAUCASIAN WOMAN, AGE 29 (3)

4 months after work 4 months after work cessationcessation

Mildly symptomaticMildly symptomatic Off fluticazone propOff fluticazone prop

PCPC20 20 1.23 mg/ml1.23 mg/ml

Dosman et al, Euro Resp J, 24: 698-702, 2004Dosman et al, Euro Resp J, 24: 698-702, 2004

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CASE # 1, CAUCASIAN WOMAN, AGE 29 (4)CASE # 1, CAUCASIAN WOMAN, AGE 29 (4)

7.5 mo after work 7.5 mo after work cessationcessation

No symptomsNo symptoms Not on treatmentNot on treatment Not working in barnNot working in barn

PCPC20 20 5.9 mg/ml 5.9 mg/ml

( nearly normal)( nearly normal) Dx: dischargedDx: discharged

Dosman et al, Euro Resp J, 24: 698-702, 2004Dosman et al, Euro Resp J, 24: 698-702, 2004

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CASE STUDY: Occupational asthma in newly CASE STUDY: Occupational asthma in newly employed workers in intensive swine employed workers in intensive swine confinement facilities”confinement facilities”

CASECASE ONSETONSET QUITQUIT OUTCOMEOUTCOME1.1. 29 yr f 1.5mo 29 yr f 1.5mo 3 mo 3 mo 7mo, no Rx 7mo, no Rx2.2. 38 yr f 1 mo38 yr f 1 mo 4 mo 4 mo 7mo, on Rx 7mo, on Rx3.3. 44 yr f 6 mo 24 mo 5.5mo, on Rx44 yr f 6 mo 24 mo 5.5mo, on Rx4.4. 39 yr f 39 yr f 12 mo 30 mo days no Rx 12 mo 30 mo days no Rx

Dosman et al, Euro Resp J, 24: 698-702, 2004Dosman et al, Euro Resp J, 24: 698-702, 2004

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CHRONIC AIRFLOW LIMITATIONCHRONIC AIRFLOW LIMITATION

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Saskatchewan Farmers SurveySaskatchewan Farmers Survey Organized by Mr. Frank FrohOrganized by Mr. Frank Froh

n=504 swine farmers

n=448 non-exposed Humboldt men

Dosman et al, J Occ Med 30: 715-720, 1988

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Swine farmers in Saskatchewan had more Swine farmers in Saskatchewan had more respiratory symptoms than control menrespiratory symptoms than control men

FarmersFarmers ControlsControls SigSig (n=504) (n=448)(n=504) (n=448)

age (yr) age (yr) 42.2 42.2 39.7` p 39.7` p<.05<.05smoking (pk yr) 13.6smoking (pk yr) 13.6 13.2 13.2 NS NSwheeze (%) wheeze (%) 29.2 29.2 10.3 10.3 p p<.001<.001sob (%)sob (%) 32.1 32.1 19.4 19.4 pp<.001<.001

Dosman et al, J Occ Med 30: 715-720, 1988Dosman et al, J Occ Med 30: 715-720, 1988

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Swine farmers in Saskatchewan had lower Swine farmers in Saskatchewan had lower values for lung function than control menvalues for lung function than control men

FarmersFarmers ControlsControls SigSig

TestTest n=504) (n=448) n=504) (n=448)FEVFEV11 (pred) (pred) 95.5 95.5 103.6 103.6 p p<.001<.001

FVC (pred) 97.3 106.8FVC (pred) 97.3 106.8 pp<.001<.001

Dosman et al, J Occ Med 30: 715-720, 1988Dosman et al, J Occ Med 30: 715-720, 1988

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INCREASED AIRWAY INCREASED AIRWAY RESPONSIVENESSRESPONSIVENESS

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20 Hutterite swine 20 Hutterite swine farmers (age 39.0farmers (age 39.0±11.1 ±11.1 yrs)yrs) had more had more increases in airways increases in airways responsiveness than responsiveness than did 20 blue collar city did 20 blue collar city workers (age 40.1workers (age 40.1±8.5 ±8.5 years)years)

Zhou et al, CHEST, 99:951-944, 1991Zhou et al, CHEST, 99:951-944, 1991

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ACROSS SHIFT CHANGESACROSS SHIFT CHANGES (n=54(n=54):):

Swine farmers had Swine farmers had significant reductions in significant reductions in expiratory flow rates over an expiratory flow rates over an 8-hour work shift8-hour work shift

Zhou, C, PhD Thesis, University of Zhou, C, PhD Thesis, University of Saskatchewan, 1994Saskatchewan, 1994

Over a four year period there Over a four year period there was significant accelerated was significant accelerated

lung function decline in swine lung function decline in swine farmers vs non-exposed farmers vs non-exposed

control subjectscontrol subjects

Senthilselvan et al, Chest, 111:1733- 41, 1997Senthilselvan et al, Chest, 111:1733- 41, 1997

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Annual Rate Change in FEVAnnual Rate Change in FEV11

1990/91 – 1994/95 (vs 171 controls)1990/91 – 1994/95 (vs 171 controls) ββ SESE SigSig

Grain FarmersGrain Farmers -16.4-16.4 7.337.33 p=0.03 p=0.03 (n=218),16 cc/year excess loss(n=218),16 cc/year excess loss

Swine FarmersSwine Farmers -26.1-26.1 7.447.44 p<0.0005 p<0.0005(n=217), 26 cc/year excess loss(n=217), 26 cc/year excess loss

Senthilselvan et al Chest 111:1733- 41, 1997Senthilselvan et al Chest 111:1733- 41, 1997

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The best predictor ofThe best predictor of annual decline inannual decline in FEVFEV1 1 over a fourover a four year period was 8 hryear period was 8 hr across-shift changeacross-shift change in FEVin FEV1 1 on the initialon the initial observationobservation

Kirychuk et al, Can Resp J, 5: 472-478, 1998Kirychuk et al, Can Resp J, 5: 472-478, 1998

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RESPIRATORY HEALTH STATUS RESPIRATORY HEALTH STATUS IN SWINE PRODUCERS RELATES IN SWINE PRODUCERS RELATES

TO ENDOTOXIN IN THE TO ENDOTOXIN IN THE PRESENCE OF LOW DUST PRESENCE OF LOW DUST

LEVELSLEVELS

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Respiratory Health Status in Swine Producers Respiratory Health Status in Swine Producers Relates to Endotoxin Exposure in the Presence of Relates to Endotoxin Exposure in the Presence of

Low Dust LevelsLow Dust Levels

n=54, Total Dust = 2.93 ± 0.92mg/m3

FVC FEV1

Airborne endotoxin -0.35* 0.17

Airborne endotoxin x hrs/day -0.42* 0.28**

**p<.05 *p=.06

Zejda et al, JOM 36: 49-56, 1994

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Acute exposure of naïve volunteers for 5 Acute exposure of naïve volunteers for 5 hours in a swine barn resulted in evidence hours in a swine barn resulted in evidence for acute inflammatory response at both for acute inflammatory response at both high and low dust levelshigh and low dust levels

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Dust and endotoxin Dust and endotoxin concentrations (concentrations (± SE)± SE)

treatmenttreatment controlcontrolTotal dustTotal dust (mg/m(mg/m33)) 0.15 0.15 ± 0,02 2.41 ± ± 0,02 2.41 ± 0.090.09**

EndotoxinEndotoxin (EU/m(EU/m3)3) 452.3 452.3 ± 65.8± 65.8 3983.5 3983.5 ± 498.3*± 498.3*

NHNH33 (ppm)(ppm) 18.3 ± 0.5 18.3 ± 0.5 26.0 ± 0.6 *26.0 ± 0.6 * *p<.001*p<.001

Senthilselvan et al, ARRCCM 156: 410-417, Senthilselvan et al, ARRCCM 156: 410-417, 19971997

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Summary: Acute exposure to dust, endotoxin Summary: Acute exposure to dust, endotoxin and NHand NH3 3 results in evidence for acute results in evidence for acute inflammatory response:inflammatory response:

Acute, reversible FEVAcute, reversible FEV1 1 declinedecline Elevation in total WBC, neutrophils and Elevation in total WBC, neutrophils and

lymphocyteslymphocytes Increase in cytokines in nasal wash and bloodIncrease in cytokines in nasal wash and blood Effects are reduced but not eliminated by Effects are reduced but not eliminated by

sprinkling canola oilsprinkling canola oil

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Mask StudyMask StudyNaïve subjects Naïve subjects exposed exposed 1. wearing a mask 1. wearing a mask 2. not wearing a 2. not wearing a maskmask

Dosman et al, Chest, 118: 852-860, Dosman et al, Chest, 118: 852-860, 20002000

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““Positive Human Health Effects of Positive Human Health Effects of Wearing a Respirator in a Swine Barn”Wearing a Respirator in a Swine Barn”

FEVFEV11 % change no mask % change no mask 8.12 8.12 ± 1.1± 1.1

FEVFEV11 % change with mask % change with mask 0.32 0.32 ± 0.62± 0.62

p<.001p<.001

Dosman et al, Chest, 118: 852-860, 2000Dosman et al, Chest, 118: 852-860, 2000

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N-95 mask provides N-95 mask provides similar protection similar protection than reducing dusts than reducing dusts and endotoxin 10 and endotoxin 10 foldfold

Baseline and interim lung function predicts healthy Baseline and interim lung function predicts healthy worker survival in swine farmersworker survival in swine farmers..

RESULTS OF A 14 YEAR FOLLOW UP IN SWINE FARMERSRESULTS OF A 14 YEAR FOLLOW UP IN SWINE FARMERS

Chenard et al, Chest, 131:245-254, 2006Chenard et al, Chest, 131:245-254, 2006

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There is a significant healthy worker effect There is a significant healthy worker effect among farmers who continue to work in among farmers who continue to work in swine confinement facilitiesswine confinement facilities

Survival in the industry may be predicted Survival in the industry may be predicted by baseline and interim lung function.by baseline and interim lung function.

Genetic make-up may be a factor in the Genetic make-up may be a factor in the healthy worker effecthealthy worker effect

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GENETICSGENETICS

Cellular innate recognition of endotoxin Cellular innate recognition of endotoxin depends on membrane bound receptors depends on membrane bound receptors including the Toll like receptorsincluding the Toll like receptors

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LPS

CD14

LBPMD-2

NEMOIKKαIKKβ

NucleusNucleus

NF-B

IκBβor IκBα

NF-B

TLR4

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LPS

CD14

LBPMD-2

NEMOIKKαIKKβ

NucleusNucleus

NF-B

IκBβor IκBα

NF-B

TLR4

TLR4 299 &/or TLR4 399mutation(s)

x

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Arbour et al, Nature Genetics, 25(2): 187-191, 2000

We tested the hypothesis that We tested the hypothesis that naïve volunteers with TLR4 naïve volunteers with TLR4

mutation will have less mutation will have less respiratory response when respiratory response when

exposed to endotoxin in a swine exposed to endotoxin in a swine barnbarn

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90 with TLR4Mutation

885 Wildtype

29 TLR4 29 Wildtype

Genotyped

DNA Collection from 975 Students

Subgroup SelectedMatching TLR4 GroupScreening for

Allergies

Acute Pig Barn Exposure

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Senthilselvan et al, JACI 2009; 123(5):1034-1040

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CONCLUSIONCONCLUSION

Genetic make up is a significant factor Genetic make up is a significant factor in the acute respiratory response to swine in the acute respiratory response to swine

barn dust.barn dust.

Endotoxin is a major contributor.Endotoxin is a major contributor.

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INTERVENTIONINTERVENTION

Respiratory Health Program for the Swine Respiratory Health Program for the Swine Industry in SaskatchewanIndustry in Saskatchewan

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Goal: Healthy and Goal: Healthy and safe workplace and safe workplace and workersworkers

Thank YouThank You

Slide Courtesy of Dr Shelly KyrichukSlide Courtesy of Dr Shelly Kyrichuk