Nickel allergy, a model of food cellular hypersensitivity?

Immune Effects of Nickel

Data on nickel immunomodulation are contradictory. The most consistent immune effects are suppression of immune responses. It has been show that T-lymphocytes and NK cells are more susceptible to nickel toxicity than are B lymphocytes or macrophages. Data reported about cytokine production in human and nickel reactive T-cell clones are also conflicting. Some authors studied cytokine production PBMC cultures of nickel allergic individuals after stimulation with NiSo4. They showed a higher synthesis of IL4, IL5 and IL13 but not of IFN gamma and TNFα in Ni allergic subjects. We found that the addiction of NiSo4 to the PBMC cultures of non sensitised subjects induces a reduction of release of IL5, IFN γ and TNFα. Our studies demonstrate a clear difference in NK cell activity between nickel-tolerant and intolerant individuals. In particular NK cell activity in reduced in sensitised patients respect to the normal subjects and the addition of Ni to the PBMC cultures induce a significant decrease of NK cell activity. The decrease was greater in cell derived from allergic subjects than non allergic. In conclusion, reported data show Ni has immunotoxic potential. Researches are in progress in an attempt to correlate the present data with other immune parameters and to measure the effects of a Ni free diet on the immune system of subjects with Ni intolerance. The comprehension of the mechanisms inducing these changes requires further studies in the uptake and intracellular distribution and binding of the metal.

Sensitization to nickel: etiology, epidemiology, immune reactions, prevention, and therapy

Nickel is a contact allergen causing Type I and Type IV hypersensitivity, mediated by reagins and allergen-specific T lymphocytes, expressing in a wide range of cutaneous eruptions following dermal or systemic exposure. As such, nickel is the most frequent cause of hypersensitivity, occupational as well as among the general population. In synoptic form, the many effects that nickel has on the organism are presented to provide a comprehensive picture of the aspects of that metal with many biologically noxious, but metallurgically indispensable characteristics. This paper reviews the epidemiology, the prognosis for occupational and non-occupational nickel allergic hypersensitivity, the types of exposure and resulting immune responses, the rate of diffusion through the skin, and immunotoxicity. Alternatives toward prevention and remediation, topical and systemic, for this pervasive and increasing form of morbidity are discussed. The merits and limitations of preventive measures in industry and private life are considered, as well as the effectiveness of topical and systemic therapy in treating nickel allergic hypersensitivity.

Latex allergies in the health care worker

A dramatic increase in the incidence of latex allergies in health care workers followed the surge in latex glove use accompanying the rise of human immunodeficiency virus (HIV) in the early 1980s. This increase in latex glove use was driven by the release of Universal Precautions issued by the Centers for Disease Control (CDC) in response to the rise of HIV and other blood-borne pathogens. Efforts to stem allergic responses in the workplace have relied on the substitution of other materials for latex. Unfortunately, there is so much latex in everyday life that avoiding this allergen is exceedingly difficult once one is sensitized. Additionally, there are numerous cross reactants that are present in the environment. The situation is further confounded by the introduction of genetically manipulated foods and agricultural products that contain defense proteins genetically inserted to protect plants from pests and pathogens. Many of these defense proteins are antigens that will cross react with latex. Sensitivity reactions, once developed, may progress to the point at which the health care worker is excluded from working. This report provides an overview of rubber products and cross reactants, allergic reactions, and latex sensitivity for the health care worker.