Chemistry: analytical and immunological testing – Involving iga – igd – ige – or igm
Reexamination Certificate
2001-10-12
2003-05-13
Le, Long V. (Department: 1641)
Chemistry: analytical and immunological testing
Involving iga, igd, ige, or igm
C530S379000, C436S008000, C436S018000, C436S017000, C436S513000, C436S518000, C435S007100, C424S085100, C424S085100, C424S093200, C424S010400, C422S053000
Reexamination Certificate
active
06562630
ABSTRACT:
BACKGROUND
The purpose of this invention is to expand the number of incitants that can be utilized in allergy testing to determine which antigens or combinations of antigens are causing patient symptoms. As ozone levels and industrial pollution increase, the population at large is becoming more susceptible to adverse reactions from many sources. These include additives in food, food articles, pollens, molds, terpenes, chemicals, weeds, trees, and grasses.
Outdoor air pollution has long been thought to enhance, or at times even cause disease processes. Hippocrates mentions it in his work Air, Waters, and Places. Increased industrialization and mechanization that began around 1950 accelerated the growth of anthropogenic (manmade) pollution. According to a recent estimate, there are presently over 70,000 chemicals now in commercial production and another 700-3,000 new chemicals are being introduced every year. The U.S. Environmental Protection Agency lists 188 hazardous air pollutants either known or suspected of causing cancer, serious human health effects or ecosystem damage.
As the human immune system is taxed to detoxify from exposure to pollution, the body has become sensitized to a wider range of chemicals and natural pollutants. As a result, individuals are experiencing a wide range of both chronic and acute symptoms related to these exposures.
Presently, allergy testing commonly takes the form of intracutaneous skin tests, patch tests and blood testing such as the Radioallergosorbent Test (RAST). Skin testing comprises introducing allergens to a portion of the patients' dermis and then measuring the patients' response to the allergen. Various methods are known and used to measure the patient's response. For example, the size and color of any induced weal can be measured. U.S. Pat. No. 5,413,113 to Milne, incorporated herein by reference, describes methods of measuring galvanometric skin response to an allergen.
The skin patch is a similar method of testing for allergies and irritants. A suspected allergen or irritant is applied to normal skin under occlusion for a period of time, this application being in a controlled manner and with a suitable formulation and concentration of the test substance. Allergic eczema or irritative eczema reactions indicate a patient's sensitivity to the suspect substance. Usually the test substance is applied in a dispersion of petrolatum or aqueous solution. Means of holding the test substance in contact with the patient's dermis include the use of a foil cup or polymeric film as disclosed in U.S. Pat. No. 4,836,217 to Fischer, et al. and incorporated herein by reference.
Over 2000 substances are known as common test substances in the testing for allergens. In 1984 the American Academy of Dermatology established a list of test substances. The earlier list included: Benzocain (5% petrolatum), imidazolidinyl urea (2% aq), Thiuram mix (1% petrolatum), cinnamic alcohol (5% petrolatum) dibucaine (1% petrolatum), mercaptobenzothiazole (1% petrolatum), neomycin sulfate (20% petrolatum), p-phenylenedimine (1% petrolatum), tetracaine (1% petrolatum), p-tert.butylphenol formaldehyde resin (1% petrolatum), Thiomersal (0.1% petrolatum), formaldehyde (2% aq.), hydroxycitronellal (4% petrolatum), Carba mix (3% petrolatum), cinnamic aldehyde (2% petrolatum), rosin (colophony) (20% petrolatum), PPD mix (black rubber mix) (0.6% petrolatum), wool (lanolin) alcohols (30% petrolatum), cyclomethycaine (1% petrolatum), eugenol (4% petrolatum), Quaternium-15 (2% petrolatum), isoeugenol (4% petrolatum), mercapto mix (1% petrolatum), epoxy resin (1% petrolatum), potassium dichromate (0.5% petrolatum), caine mix less benzocaine (3% petrolatum), ethylenediamine dihydrochloride (1% petrolatum), benzoyl peroxide (1% petrolatum), balsam of Peru (25% petrolatum), Quaternium-15 (2% aq.), oak moss (abs. mousse de chene) (5% petrolatum), nickel sulfate (2.5% petrolatum). This list has subsequently been revised by the North American Contact Dermatits Group. As of 1999 this list has expanded to 50 substances with an additional 15 to be added by the year 2001. Similar lists of testing substances are available for Europe and Japan.
In skin tests, a number of apparatus have been described that introduce the allergen test substance into contact with a patient's dermis. For example, U.S. Pat. No. 3,289,670, incorporated herein by reference, discloses an apparatus that produces multiple cutaneous sites by abrading the skin and applying test substances. Intracutaneous injection of multiple test substances is disclosed in U.S. Pat. No. 4,270,548 to Brennan, incorporated herein by reference. In contrast to the test substances used in patch tests, intracutaneous allergy testing often concentrates on airborne allergies such as tree allergens, mold allergens, grass allergens, ragweed allergens, weed allergens, dust, epidermals (dander, animal hair, feathers, etc) and foods.
The intracutaneous extracts used for food testing include testing for the food groups including: whole cow's milk, whole egg, legumes, chocolate, grains (wheat, rye, barley, corn), citrus fruits (orange, grapefruit, lemon), potato family (potato, tomato, green pepper), seafood (with fish family) and cucumber (cucumber, cantaloupe, watermelon).
Intracutaneous test substances are commonly provided in either an aqueous form or in a glycerin-saline base. The aqueous form comprises a preservative in addition to the allergen and normal saline solution. For example, the 0.5% methyl paraben and 0.05% propylparaben can be added to the aqueous forms. Other aqueous preservatives include phenol and albumin. The glycerin-saline base is comprised of 50% glycerin so that additional preservative is not required. The preservative is added to increase the shelf-life of the test substance. This allows standardized test substances to be produced in a controlled environment and distributed to clinicians in an economical fashion.
However, it has been noted that some patients are sensitive to the preservatives used in the test substance preparations. The American Journal of Contact Dermatology reports of cases of allergic contact dermatitis from patient skin contact with paraben preservatives. Similarly, other patients may be allergic to glycerin, phenol or albumin. When such patients receive a series of allergy tests, they show “false positives” caused by their allergic reaction to preservative and not the named test substance.
Typical preparation of allergen extracts for intradermal use begins with a powder or ground solid form of the allergen. This powder is then dissolved or dispersed into an aqueous or normal saline solution and then filtered. Due to the nature of these powders, they often comprise the named allergen along with other foreign matter. This foreign matter is deemed to be a contaminant that lowers the specificity of the allergen extract. Patients may be allergic to the foreign matter contaminants while not being allergic to the named allergen, thus showing a “false positive.”
Of the different forms of contaminants, mold, bacteria and endotoxin can be present. Special efforts must be made to insure that these forms are reduced to acceptable levels.
An additional consideration in the preparation of allergen extracts is the ability to prepare extracts of consistent biological activity. Medical clinicians rely upon this consistency in order to obtain reproducible, valid test results. Allergen extracts that are excessively active may cause allergic shock dangers to patients while extracts that are excessively inactive will not properly identify allergic responses.
As a result, there is a need for prepared allergen extracts with adequate shelf life that comprise the named test substance without added preservatives and that further have a known biological activity.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide allergen testing preparations and testing protocols that are more sensitive and accurate than existing methods.
It is a further object of the present inventio
Aboukhair Nabil K.
Bryant Thomas H.
Davis Deborah A
Le Long V.
Roberts Abokhair & Mardula LLC
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