Latex Allergy Issue
This is general information regarding proteins in latex and the problem of allergies in connection with using gloves. This information is not meant to replace consultation with a physician to address specific issues.
What are antigens and allergens?
An antigen is any substance that provokes an immune response when introduced into the body. It can come in the form of complex protein or carbohydrate of large molecular structure. This stimulates the lymphocytes to produce substances (i.e. antibodies) which would react specifically with the antigens.
Allergens are antigens that induce extreme immune reactions typically mediated through IgE (see below) antibodies. Allergic reactions occur under conditions of prolonged exposure to a highly concentrated foreign material. Potential allergens have no effect on non-sensitized people.
What are antibodies?
Antibodies are Immunoglobulins (Ig) which are proteins.
There are 5 classes of antibodies:
IgE is the factor in allergic reactions. A simplified case of reactions follows:
How does an allergy start?
Antigens enter the body, and this stimulates B and T cells which produce antibodies. The antibodies attach to mast cells and cause a gradual breakdown of the mast cells which release histamines and other mediators. Symptoms include vessel dilation, drop in blood pressure, increased heartbeat, breathlessness, urticaria and possible unconsciousness. This is the Type I reaction. There are also Type II, III and VI reactions.
How does this pertain to latex gloves?
Latex contains many different types of natural proteins. Some of these proteins are known to sensitize certain users. These residual proteins in gloves have been suspected of inducing Type VI reaction in sensitized users. The case for sensitization has not been fully established, but it is generally agreed that high contents of residual proteins in gloves may cause sensitization. The length of time for this to occur varies among individuals and also among different races, but frequency or cycles of wear is the determining factor in all cases.
What level of protein is 'safe'?
Studies conducted by the Rubber Research Institute of Malaysia found that in protein levels below 100 mg/g of glove material, 80% of sensitized users did not show allergic responses. This study was performed on a pool of healthcare workers, and the result is an indicative, but not definitive, threshold level.
Further research on this matter continues.
Are proteins caused by powder on the gloves?
No, the powder on the gloves does not induce the protein reactions described above. The powder is modified corn starch that is bioabsorbable (converted to glucose when absorbed by the body), and it has not been known to induce the kind of allergies usually associated with glove usage. However, there is some evidence that the powder may absorb protein from the host glove and therefore carry a percentage of this protein residue.
Why, then, are powder-free gloves less likely to cause reactions?
Removing powder from gloves is a "post-process,"
meaning that the removal of powder occurs after the glove has been fully
manufactured. This procedure is called chlorination. While powder
removal is the main objective, chlorination simultaneously removes a significant
amount of the residual protein from the glove.
Other powder removal processes simply substitute powder with a different coating agent like polyurethane or acrylic during production. While this eliminates powder from the gloves, the protein level remains the same as that of a pre-powdered glove. This can be misleading to end users.
What can be done to reduce protein in gloves?
The manufacturing process needs to be extended to include a protein reduction cycle. This means that an additional step of intensive leaching reduces the residual proteins before the gloves are coated with powder. At Terang Nusa, we have managed to lower the extractable protein level to less than 90mg/g for pre-powdered gloves as compared to a general level of 200-500mg/g in similar products on the market.
Can using Nitrile gloves eliminate allergy reaction?
Unlike latex, Nitrile material does not contain proteins. Therefore, anyone who is allergic to latex proteins will not have latex protein-induced allergies when using Nitrile gloves. This is an alternative product.
However, some users of Nitrile gloves have reported allergic reactions triggered by other antigens in the synthetic material but not by proteins.
What are the possible tests that can determine protein levels?
There are several test methods for protein and allergy
1. Modified Lowry
This is a colorimetric dye-binding assay based on differential color change in response to various concentrations of protein. It involves the extraction of residual water-soluble protein from NR Latex products followed by centrifugation and Phosphotungstic acid (PTA) to remove any interfering, water-soluble substances. This protein content is determined using a protein standard for quantification. Spectrophotometric measurement is made at a wavelength in the range of 600 to 750 Hz (nm).
2. ELISA (Enzyme Linked Immunesorbent Assay)
ELISA measures the antigenic protein level. One example of the available variations is the LEAP test (Latex ELISA for Antigenic Proteins). It uses antibodies to bind to the specific antigenic proteins. (These antibodies are derived from rabbits.) Antibodies bound to the proteins are then reacted with an added chemical resulting in a color development the intensity of which depends on the amount of antigenic protein.
3. RAST (Radioallergosorbent Test Johns Hopkins
The weakness of this test is that the pooled plasma of allergic patients will affect the outcome and relevancy of the tests.
Disclaimer: The Company is not responsible if some of the above information is obsolete. Sensitized users should refer to their physicians for advice before using any products.
Type of Latex Allergy Pictures: