Experiencing an Adverse Immune Response

Chemicals and Adverse Immune Response

The immune system plays a central role in the health of the individual. It protects us from disease by recognizing and eliminating or removing foreign material from our bodies. Exposure to a variety of chemicals can effect this system adversely; putting us at risk for illness and disease.

Immunoenhancement
Some chemicals can illicit an enhanced immune response resulting in tissue damage and immune mediated disease. Enhancement of the immune system can lead to chemical hypersensitivity and autoimmune disease.

Chemical Allergies and Hypersensitivity
A chemical allergy is an adverse reaction to a chemical resulting from previous sensitization to that chemical or to one that is structurally similar (1). A chemical allergy is initiated by the immune system and expressed as a hypersensitivity; after an initial allergic reaction to a chemical, very small subsequent exposures can evoke a severe response. A common example is hypersensitivity to bee stings. The range of hypersensitivity response is broad and can manifest itself in forms such as a skin rash, eye irritation, allergic asthma, or even anaphylactic shock and lung disease. Chemical allergies have the potential to be fatal. Some of the environmental chemical sensitizers are:

Polyisocyanates induce hypersensitivity response and are responsible for lung disease among industrial workers. Polyisocyanates are used in the manufacture of adhesives, paint hardeners, elastomers, and coatings (1). Occupational exposure occurs through inhalation or skin absorption and sensitization usually occurs through high doses. Unlike other hypersensitivity responses, the symptoms may persist for years after contact with the chemical (1).

Acid anhydrides used in the production of paints, varnish, coating materials, adhesives, casting and sealing materials can elicit a variety of hypersensitivity responses. These include asthma, anemia, hypersensitivity pneumonitis and contact dermatitis. Re-exposure via inhalation can lead to pulmonary disease. Various anhydrides can evoke this response.

Metals can evoke contact and pulmonary hypersensitivity responses. Nickel is a common contact sensitizer upon prolonged exposure, common through jewelry, coins, and clothing fasteners. A pulmonary response can occur via inhalation in an occupational setting during the mining, milling and smelting of nickel. Beryllium can produce contact and tuberculin type of hypersensitivity reactions. Exposure occurs most frequently in the aerospace, high-tech ceramic manufacturing, dental alloy manufacturing, electronics and nuclear weapons and reactor industries. Inhalation can result in acute pneumonitis, tracheobronchitis, chronic berrylium disease, and lung cancer. Non-worker exposures resulting in disease has been documented as a result from plant emissions and contact with family members clothing (1). A latent period following exposure is typical prior to the onset of lung disease. Only a small amount of fiber in the lung is necessary for sustaining an immune response in the pulmonary system. Other metals known to evoke hypersensitivity response include platinum, cobalt, and chromium.

Penicillin is the most common drug to elicit an allergic response. Exposure to penicillin is responsible for 75% of deaths due to anaphylaxis in the U.S. Anaphylactic reactions occur in about 10 to 40 of every 100,000 patients receiving injections (1). Severe reactions are less likely if administered orally.

Cosmetics, personal hygiene products and enzyme extracts from plants are also known to elicit hypersensitivity responses.

Autoimmune Disease
Autoimmune disease is not an exaggerated response to foreign matter. This syndrome occurs when foreign chemicals modify tissues or immune cells, affecting the regulation of immune response such as the production of antibodies and inflammatory response. The result is an immune response against our own tissues, tissue damage and disease. The mechanisms which allow this to occur in the body are complex, but there are genetic and environmental factors which affect an individuals susceptibility to autoimmune disease. Exposure to sulfa, penicillin, vinyl chloride, gold salts, silica, mercury, methyl dopa, and other compounds can induce this response by the immune system. Systemic lupus and rheumatoid arthritis are two autoimmune diseases. It should be noted that viral, hormonal, and emotional factors can also contribute to the development of autoimmune disease.

Immunosuppression
Some chemicals in our environment suppress the immune system. Suppression of the immune system can compromise the ability of the body to fight off cancer, disease, and infection from bacteria, virus, and parasites. Halogenated aromatic hydrocarbons (HAHs) such as PCBs and dioxin cause Immunosuppression. Recent findings show a genetic predisposition resulting in a heightened toxic response to HAHs within the population. This means that certain families are predisposed to immune suppression by HAHs. Children are more sensitive than adults to the effects of HAHs on the immune system. People undergoing immunosuppressive drug therapy, such as transplant patients, are at higher risk for secondary cancer according to a survey of kidney transplant patients, 50% surveyed developed cancer (2). Acquired immune deficiency (AIDS) highlights the importance of the immune system in the fight against infection and cancer.

References

1. Casarett & Doull's Toxicology: The Basic Science of Poisons. 5th Ed. 1996. Ed by Curtis D. Klaassen. McGraw-Hill, New York. pp 16, 391.

2. Shy CM, Alarie Y, Bates DV, Frank R, et al. 1974. Synergism or antagonism of pollutants producing health effects. Report to the U.S. Senate Committee of Public Works. pp. 483-499. NAS, Washington, DC.

This page was prepared by Theresa L. Pedersen, UCD EXTOXNET FAQ Team. August 1997.