07_pepys -1-
3rd Jack Pepys Workshop
BGFA
Prevention of work-related asthma − Focus: Exposure
reduction
Rolf [email protected]
3rd Jack Pepys Workshop
07_pepys -2-
3rd Jack Pepys Workshop
BGFA
Questions 68 and 73
No. 68
Allergens in wheat flour?
Thresholds for sensitization of key occupational allergens?
No. 73
Relationships between exposure and sensitization for specific occupational agents, role of atopy?
07_pepys -4-
3rd Jack Pepys Workshop
BGFA
New information about sample processing
Conclusion Addition of Tween-20 → 3-100fold increased allergen
recovery
Allergens were stable at -20oC for 4 months
Stabilizing proteins not required
07_pepys -5-
3rd Jack Pepys Workshop
BGFA
New information about analytical methods
Conclusion Rabbit IgG inhibition assay recommended for routine
wheat allergen measurements.
Sandwich EIA more sensitive(e.g. for short task-related measurements)
07_pepys -6-
3rd Jack Pepys Workshop
BGFApH 4 - 8
128
717
163220
36
3721
22159
5b5a
23
1a
3c
1b
4b2
3a4a 18
3430
6b
6a
243b
19
67
97.4
45
29
21
12.5
6.5
Sander et al. J Allergy Clin Immunol 2001;107:907-13
Two-dimensional IgE immunoblot of baker (a)
Old information about wheat allergens
07_pepys -7-
3rd Jack Pepys Workshop
BGFA
13
21
1a1b
11 10 97.4
67
45
29
21
12.5
6.5
pH 4 - 8
Sander et al. J Allergy Clin Immunol 2001;107:907-13
Old information about wheat allergens
Two-dimensional IgE immunoblot of baker (b)
07_pepys -8-
3rd Jack Pepys Workshop
BGFApH 4 - 8
97.467
45
29
21
12.5
6.5
2315
16
8018
19
82
7578
83
32
31
39
79
84
87
92
91
77
8889
90
22
85
53
36
52
3721
4451
4250
4348
2054
45
13
65
41
38
46
4758
59
60
35
1
34
2
833
727
34
5772
1774
73
5655
66
6564
11
10 1 10 2
12
25
30
2614
9
1062
61
63
24
69 70 71
86 76
2829
40
49
6768
8193
98
50%30-40%20%10%
Sander et al. J Allergy Clin Immunol 2001;107:907-13
Old information about wheat allergens
Frequencies of IgE-binding wheat proteins
07_pepys -10-
3rd Jack Pepys Workshop
BGFA
Estimated additional sensitization risk for wheat flour dustDutch Expert Committee on Occupational Standards (DECOS) 0.1 % for an occupational exposure
to 0.012 mg/m³ inhalable dust
1.0% for an occupational exposure to 0.12 mg/m³ inhalable dust
10.0 % for an occupational exposure to 1.2 mg/m³ inhalable dust
as a time-weighted average concentration under normal working conditions of eight hours a day and five days a week, during a life-long employment exposure
07_pepys -11-
3rd Jack Pepys Workshop
BGFA
…….The available literature does not demonstrate a thrustworthy threshold for any of the flour dust-induced effects…….
Provisional recommendation of Scientific Committee for Occupational Exposure Limits (SCOEL) April 2007
07_pepys -12-
3rd Jack Pepys Workshop
BGFA
Answer to questions 68/73
Wheat flour contains a great number of single allergens
Atopy is a strong risk factor for wheat allergy
Despite progress in exposure assessment thresholds possibly cannot be determined.
07_pepys -13-
3rd Jack Pepys Workshop
BGFA
Question 32
Exposure control (e.g. NRL, detergent enzymes)or nonsensitizing substitutes for primaryprevention?
07_pepys -14-
3rd Jack Pepys Workshop
BGFA
Two reviews on NRL allergy in healthcare workers
Bousquet et al. JACI 2006;118:447-54……Although powder-free gloves allow a reduction in the level of airborne NRL allergens and glove-related symptoms, the lack of appropriate study does not allow any conclusions to be reached on powder-free gloves……
La Montagne et al. Occup Environ Med 2006; 63:359-364…….Substitution of powdered latex gloves with low protein powder-free NRL gloves or latex-free gloves greatly reduces NRL aeroallergens, NRL sensitization and NRL asthma among healthcare workers (sign level 2+)………
New information about the prevention of latex allergy
07_pepys -15-
3rd Jack Pepys Workshop
BGFA
Since 2004 2 longitudinal cohort studies(together >1000 person-years) without new sensitizations
Jones et al. Ann occup Hyg 2004;48:455-457
Filon et al. Occup Environ Med 2006;63:121-125
New information about the prevention of latex allergy
07_pepys -16-
3rd Jack Pepys Workshop
BGFA
Conclusion 195 personal air samples in 55 craft bakeries: Frequencies of measurable enzyme exposures
Amyloglucosidase 9% Fungal alpha-amylase 6% Bacterial alpha-amylase 7%
Similar enzyme air concentrations (about 5-10 ng/m3)
New information about exposure to enzymes
07_pepys -17-
3rd Jack Pepys Workshop
BGFA
Car body repair:
…. but none of the managers reported even considering switching to water-based paints until required to do so….
Sparer et al. SPRAY-study. J Occup Environ Hyg 2004;1:570-81
New information about substitution of isocyanates
07_pepys -18-
3rd Jack Pepys Workshop
BGFA
Substitution/avoidance of allergens (summary by RM) Substance Substitution?
HMW
flours no
baking enzymes complete avoidance
detergent enzymes
no
laboratory animals
no
farm animals no
latex (almost) complete avoidance
LMW
Pt salts catalyst replacement by Pd or less halogenated Pt species
Pt salts refinery no
acid anhydrides replacement by other substances
isocyanatesreplacement by other substances; technical modifications (MicroemissionTM)?
07_pepys -19-
3rd Jack Pepys Workshop
BGFA
Answer to question 32
(Almost) complete avoidance or substitutionmay be considered for some allergens.For most allergens exposure reduction willcontinue to be the only choice.
07_pepys -20-
3rd Jack Pepys Workshop
BGFA
Question 98
Should industry label compounds as sensitizers? How can management be improved?
07_pepys -21-
3rd Jack Pepys Workshop
BGFA
Old information on labelling of enzymes
Merget et al. Int Arch Allergy Immunol 2001;124:502-505
07_pepys -23-
3rd Jack Pepys Workshop
BGFA
Principle of lateral flow immunoassay (LFIA)
Bogdanovic et al.J Allergy Clin Immunol 2006;118:1157-63
07_pepys -24-
3rd Jack Pepys Workshop
BGFA
Good agreement between EIA and LFIA
Bogdanovic et al.J Allergy Clin Immunol 2006;118:1157-63
07_pepys -25-
3rd Jack Pepys Workshop
BGFA
Answer to question 98
It should be mandatory for industry to label sensitizing substances (more precisely).Management can be improved by quick and simple tests for the detection of allergens.
07_pepys -26-
3rd Jack Pepys Workshop
BGFA
Question 69
Exposure standards for isocyanates?Skin absorption of isocyanates?
07_pepys -27-
3rd Jack Pepys Workshop
BGFA
New information about exposure in car body repair shops
Pronk et al. Ann Occup Hyg 2006;50:1-14
07_pepys -32-
3rd Jack Pepys Workshop
BGFA
Beach et al. 2005Agency for Healthcare Research and Quality www.ahry.gov
New review about exposure cessation/reduction
Difference between FEV1 at follow-up and baseline by exposure status
07_pepys -33-
3rd Jack Pepys Workshop
BGFA
New question
What are the consequences of exposure reduction (without complete exposure cessation) in sensitized subjects?
07_pepys -35-
3rd Jack Pepys Workshop
BGFA
Beach et al. 2005Agency for Healthcare Research and Quality www.ahry.gov
New review about exposure cessation/reduction
Difference between bronchial hyperresponsiveness at follow-up and baseline by exposure status
07_pepys -36-
3rd Jack Pepys Workshop
BGFA
Beach et al. 2005Agency for Healthcare Research and Quality www.ahry.gov
New review about exposure cessation/reduction
Difference between asthma medication at follow-up and baseline by exposure status
07_pepys -37-
3rd Jack Pepys Workshop
BGFA
FeNO-results at the workplace and at homeN
O [
ppb]
200
150
100
50
0
350
300
250
1 2 3 4 5 6 7 8 9 10 11 12 13 14Week
Budesonide
Salbutamol