I thought all of those people out there with milk allergies might
enjoy knowing that their asthma meds might contain milk.  I found out
after I started reacting to a new inhaler.

http://www.jacionline.org/article/PIIS0091674903026770/fulltext

Volume 113, Issue 3, Pages 558-560 (March 2004)
44 of 76

Contamination of dry powder inhalers for asthma with milk proteins
containing lactose

Anna Nowak-Wegrzyn , Gail G. Shapiro , Kirsten Beyer , Ludmila Bardina
and Hugh A. Sampson

To the Editor:
Milk allergy is one of the most common food allergies, affecting
approximately 2.5% of infants and young children. Most children,
approximately 80%, outgrow milk allergy by age 5 years; however, some
patients have persistent allergy.1 Lactose is obtained from cow's milk
and is commonly used as an inactive ingredient in many pharmaceutical
formulations including tablets, suspensions, and dry powder inhalers
for asthma (DPIs). Patients with severe milk allergy frequently ask
whether pharmaceutical products containing lactose are safe for them
to use and whether there is a possibility of milk contamination.

We became aware of anecdotal evidence that some patients with severe
milk allergy had allergic reactions after the ingestion of lactose-
containing medications. These reactions were attributed to milk
protein contamination in the lactose filler. In this report, we
describe a patient who had repeated and objectively documented
anaphylactic reactions after inhalation from a new lot of Advair
Diskus despite having tolerated Advair for months previously. We also
report the results of immunologic studies that demonstrate the
presence of milk proteins in DPI-containing lactose and in
pharmaceutical grade lactose (lactose USP).

An 8-year-old boy with severe milk allergy and persistent asthma was
maintained on Serevent (salmeterol) metered-dose inhaler (MDI) and
Flovent (fluticasone) MDI. However, when combined therapy became
available, he was successfully transitioned to Advair Diskus, a single
DPI containing both salmeterol and fluticasone. He had multiple
allergic reactions from ingestion or contact with minute amounts of
milk proteins in the past. The patient continued to receive Advair for
several months without any adverse reactions and with excellent asthma
control. However, after inhalation of three consecutive doses from a
new diskus, he immediately complained of chest tightness and feeling
of distress that were treated with oral diphenhydramine and inhaled
bronchodilator at home. The patient subsequently underwent a
supervised inhalation challenge in his allergist's office, where he
had immediate chest tightness, decline in FEV1 from 1.67 to 0.58 L/
min, and blood pressure drop from 90/58 to 64/40 mm Hg after the
inhalation of one dose from the incriminated Advair Diskus. He
recovered with intramuscular epinephrine, diphenhydramine, and
prednisone. The patient was switched back to Serevent MDI and Flovent
MDI without further complications.

Subsequently, powder was obtained from different lots of Advair.
Proteins were extracted with PBS and used for skin testing. Skin prick
testing was done with the use of a sterile smallpox needle (Hollister
Stier Laboratories, LLC) with the following results: commercial milk
extract 7/40 (Hollister Stier Laboratories, LLC), lactose USP 5/20
(obtained from commercial pharmacy), Advair lot No. 1 3/26, histamine
5/22, Advair lot No. 2 0/8, glycerinated saline 0/0 (mean wheal
diameter/mean erythema diameter, mm). Serum-specific milk- and casein-
IgE antibody concentrations were measured with the Pharmacia CAP
System, Pharmacia Diagnostics; the lower limit of detection is 0.35 kU/
L and the upper limit of detection is 100 kU/L. The patient's serum-
specific milk-IgE was 17.9 kU/L (milk-IgE antibody concentration >15
kU/L has 95% positive predictive value for an acute allergic reaction
to milk upon ingestion); casein-IgE was 24.3 kU/L.

Subsequently, Advair and other lactose-containing DPIs were tested for
the presence of milk proteins. Protein fractions from DPIs were
extracted with PBS, purified, and concentrated with the use of
precipitation technique Page-Perfect, Genotechnology, Inc, St Louis,
Mo. A sensitive inhibition-ELISA assay was performed as previously
described and detected milk proteins in the tested DPIs; however,
precise quantification of milk protein content was not possible
because of the apparent interference, presumably from large quantities
of lactose causing glycosylation of milk proteins with subsequent
changes in protein conformation. The presence of proteins that were of
similar molecular weight as milk β-lactoglobulin in the tested DPIs
containing lactose was detected with silver staining (Fig 1, A).
Subsequently, specific labeling with monoclonal antibodies against
milk proteins (generously provided by Dr Patrizia Restani from
Institute of Pharmacological Sciences in Milan, Italy) as well as
immunolabeling with sera from patients with severe milk allergy
detected caseins in Advair and β-lactoglobulin in Foradil. Both milk
proteins were also present in the lactose USP (Fig 1, B and C).

FIG 1. A, Silver staining of protein content in selected DPIs compared
with silver staining of cow's milk proteins. Proteins of molecular
weight similar to β-lactoglobulin are present in Lactose USP, Foradil,
and Flovent: 1, molecular weight standard; 2, α-casein; 3, β-casein;
4, κ-casein; 5, α-lactalbumin; 6, β-lactoglobulin; 7, lactose USP; 8,
Advair (12.5 mg lactose/dose); 9, Serevent (12.5 mg lactose/dose); 10,
Flovent (25 mg lactose/dose); 11, Foradil (25 mg lactose/dose). B,
Casein detection in Advair and Lactose USP by labeling with monoclonal
antibody against α-casein and β-casein; 1, molecular weight standard;
2, milk; 3, lactose USP; 4, Advair No. 1 (12.5 mg lactose/dose). C,
Immunolabeling with sera of patients allergic to milk. Patient 1 is
the patient described in the case report; patients 2 through 4 have
severe milk allergy and high serum milk-IgE antibody concentrations,
and patient 5 is not allergic to milk and serves as a negative
control; 1, molecular weight standard; 2, milk; 3, lactose USP; 4,
Advair No. 1 (12.5 mg lactose/dose). D, β-Lactoglobulin detection in
Foradil (25 mg lactose/dose) and lactose USP by labeling with
monoclonal antibody against β-lactoglobulin; 1, molecular weight
standard; 2, lactose USP; 3, Foradil (25 mg lactose/dose); 4,
Pulmicort (no lactose). E, Immunolabeling with sera of patients
allergic to milk. In addition to patients 2 through 4 from C, two
other subjects with severe milk allergy were included. Milk-tolerant
patient with milk-IgE <0.35 kU/L serves as negative control; 1,
molecular weight standard; 2, lactose USP; 3, Foradil (25 mg lactose/
dose); 4, Pulmicort (no lactose).

In this report, we described an asthmatic patient with documented
allergy to cow's milk, who had anaphylactic reactions to milk protein
contaminating Advair Diskus. Pharmaceutical grade lactose is obtained
from skim milk by coagulating and filtering out milk protein. The
efficiency of this process is apparently quite high, and the product
information inserts do not caution patients with milk allergy about
the possibility of an allergic reaction to milk proteins in lactose-
containing medications. Likewise, milk allergy is not included among
the contraindications against using lactose-containing pharmaceutical
formulations.

Dry powder inhalers are becoming mainstream asthma therapy. Both
rescue and maintenance anti-inflammatory medications are available in
the DPI formulation. It is expected that within several years DPIs
will capture a large share of the inhaled asthma medications market as
a result of the Montreal Protocol and chlorofluorocarbon phase-out.
Currently, except for Pulmicort Turbuhaler, all other DPIs available
in the United States contain from 12.5 mg (Serevent Diskus, Advair
Diskus) to 25 mg (Foradil Aerolizer, Flovent Rotadisk, Ventolin
Rotacaps) pharmaceutical grade lactose per dose.

The lactose excipient in DPIs improves the efficiency of the blister
pack opening upon breath activation and improves the delivery of the
drug into small airways. Lactose also indicates delivery of the drug
as the result of its sweet taste. Lactose USP is obtained from skim
milk according to strict industry standards. Casein is precipitated
with diluted hydrochloric acid. After removal of the casein by
filtration, the reaction of the whey is adjusted to a pH of
approximately 6.2 by addition of lime, and the remaining albuminous
matter is coagulated by heating (93.5°C); this is filtered out and the
liquid is set aside to crystallize.2

The possible routes of milk protein exposure from DPIs include both
inhalation and ingestion because >98% of lactose settles in the
oropharynx and is swallowed. Although the threshold dose of inhaled
milk protein has not been established, previous reports described
children with severe milk allergy having acute allergic reactions
after the ingestion of food products containing >10 parts per million
of total milk protein.3 It is well known that inhalation of cow's milk,
4 wheat,5 and fish6 can induce severe anaphylactic reactions in
allergic individuals. Repeated exposure to low doses of inhaled milk
proteins might also exacerbate chronic airway inflammation and lead to
poor asthma control in the absence of acute immediate reactions.

Occupational asthma as a result of exposure to inhaled allergens has
been reported in the bakery, confectionery, and pharmaceutical
industries. Furthermore, a recent report documented development of egg-
induced asthma and subsequent systemic symptoms caused by ingestion of
egg in 3 previously egg-tolerant bakery and confectionery workers
after the exposure to airborne egg allergens in the workplace.7 In
addition, anaphylactic reactions to inhaled rice flour in a child who
tolerated ingested rice were described.8 Considering the high
vascularity of the respiratory tract mucous membranes and lack of
protective mechanisms unique to the gastrointestinal tract, such as
digestive enzymes and low pH, one could hypothesize that the smaller
doses of inhaled food allergen would induce an allergic reaction
compared with an ingested allergen in highly sensitive individuals.

Another factor that may contribute to lower threshold for inhaled food
allergens is that allergenicity of milk proteins may be enhanced by
formation of the lactose-protein complexes. Nonenzymatic glycosylation
of milk proteins occurs during heat treatment (Maillard reaction),
leading to significant changes in the 3-dimensional structure of these
proteins. These conformational modifications might lead to large
glycoprotein complex formation and enhanced allergenicity. In fact,
intradermal skin test reactivity to β-lactoglobulin–lactose conjugates
has been shown to be 10- to 100-fold increased compared with native β-
lactoglobulin.9 Furthermore, large complexes may be randomly
distributed explaining why some lots of Advair contained larger
amounts of milk proteins compared with others. In addition, the purity
of lactose USP may differ among the manufacturers as well as among the
batches from the same source. A recent paper reported that none of the
24 children with well-characterized immediate cow's milk allergy
reacted on a blinded challenge with soy-based infant formula
containing lactose and that there was no detectable milk protein in a
single batch of lactose provided by an Italian manufacturer.10

Based on the experience of our patient, who tolerated several lots of
Advair before development of severe allergic reaction to an inhaler
from a different lot, there appears to be clinically significant and
apparently random variability between the lots of the DPIs in regard
to milk protein contamination. It is therefore advisable that lactose-
containing DPIs be used with caution in patients with severe milk
allergy. Considering the unpredictable lot-to-lot variability in milk
protein contamination, lactose-free DPI or alternative asthma inhalers
should be preferred choices for such patients. Furthermore, product
information inserts of the lactose-containing DPIs should include a
warning on possible allergic reactions to milk protein contamination

--------------------------------------------------------------------------------
References

References1. Sampson HA. Food allergy. J Allergy Clin Immunol.
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2. Gennaro AR, ed. Remington's pharmaceutical sciences. (18th ed.)
Easton (PA): Mack Publishing Co. 1980:1322-1323

3. Mofidi S, Bardina L, Chatchatee P, Wood RA, Sampson HA. Reactions
to food products labeled dairy-free: quantity of milk contaminant. J
Allergy Clin Immunol. 2000;105:S138 CrossRef

4. Fiocchi A, Bouygue GR, Restani P, Bonvini G, Startari R,
Terracciano L. Accuracy of skin prick tests in IgE-mediated adverse
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Suppl 1):26-32 MEDLINE

5. Armentia A, Rodriguez R, Callejo A, Martin-Esteban M, Martin-Santos
JM, Salcedo G, et al. Allergy after ingestion or inhalation of cereals
involves similar allergens in different ages. Clin Exp Allergy.
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6. Roberts G, Golder N, Lack G. Bronchial challenges with aerosolized
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MEDLINE | CrossRef

7. Anibarro B, Fontela JL, De La HF. Occupational asthma induced by
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Text | Full-Text PDF (1817 KB) | MEDLINE | CrossRef

8. Fiocchi A, Bouygue GR, Restani P, Gaiaschi A, Terracciano L,
Martelli A. Anaphylaxis to rice by inhalation. J Allergy Clin Immunol.
2003;111:193-195 Full Text | Full-Text PDF (83 KB) | MEDLINE

9. Spies JR. New antigens in lactose. Proc Soc Exp Biol Med.
1971;137:211-214 MEDLINE

10. Fiocchi A, Restani P, Leo G, Martelli A, Bouygue GR, Terracciano
L, et al. Clinical tolerance to lactose in children with cow's milk
allergy. Pediatrics. 2003;112:359-362 CrossRef
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a Division of Pediatric Allergy and Immunology, and the Jaffe
Institute for Food Allergy, Mount Sinai School of Medicine, New York,
NY, USA
b Northwest Asthma and Allergy Center, PS, Seattle, Wash, USA
doi: 10.1016/j.jaci.2003.11.015

© 2004 American Academy of Allergy, Asthma and Immunology. Published
by Elsevier Inc. All rights reserved.