Nickel sensitivity in patients with gastroesophageal reflux disease

A comprehensive summary of disease variants implicated in metal allergy

Allergic disease represents one of the most prominent global public health crises of the 21^st century. Although many different substances are known to produce hypersensitivity responses, metals constitute one of the major classes of allergens responsible for a disproportionately large segment of the total burden of disease associated with allergy. Some of the most prevalent forms of metal allergy - including allergic contact dermatitis - are well-recognized; however, to our knowledge, a comprehensive review of the many unique disease variants implicated in human cases of metal allergy is not available within the current scientific literature. Consequently, the main goal in composing this review was to (1) generate an up-to-date reference document containing this information to assist in the efforts of lab researchers, clinicians, regulatory toxicologists, industrial hygienists, and other scientists concerned with metal allergy and (2) identify knowledge gaps related to disease. Accordingly, an extensive review of the scientific literature was performed - from which, hundreds of publications describing cases of metal-specific allergic responses in human patients were identified, collected, and analyzed. The information obtained from these articles was then used to compile an exhaustive list of distinctive dermal/ocular, respiratory, gastrointestinal, and systemic hypersensitivity responses associated with metal allergy. Each of these disease variants is discussed briefly within this review, wherein specific metals implicated in each response type are identified, underlying immunological mechanisms are summarized, and major clinical presentations of each reaction are described.Abbreviations: ACD: allergic contact dermatitis, AHR: airway hyperreactivity, ASIA: autoimmune/ autoinflammatory syndrome induced by adjuvants, BAL: bronchoalveolar lavage, CBD: chronic beryllium disease, CTCL: cutaneous T-cell lymphoma, CTL: cytotoxic T-Lymphocyte, DRESS: drug reaction with eosinophilia and systemic symptoms, GERD: gastro-esophageal reflux disease, GI: gastrointestinal, GIP: giant cell interstitial pneumonia, GM-CSF: granulocyte macrophage-colony stimulating factor, HMLD: hard metal lung disease, HMW: high molecular weight, IBS: irritable bowel syndrome, Ig: immunoglobulin, IL: interleukin, LMW: low molecular weight, PAP: pulmonary alveolar proteinosis, PPE: personal protective equipment, PRR: pathogen recognition receptor, SLE: systemic lupus erythematosus, SNAS: systemic nickel allergy syndrome, Th: helper T-cell, UC: ulcerative colitis, UV: ultraviolet.

The effect of a low-nickel diet and nickel sensitization on gastroesophageal reflux disease: A pilot study

BACKGROUND/AIMS

Gastroesophageal reflux disease (GERD) is a common medical condition, frequently refractory to medical therapy. Nickel is a leading cause of allergic contact dermatitis. Although nickel is widely found in foods, the effect of nickel on GERD is unknown. This pilot study sought to evaluate the effect of a low-nickel diet on GERD and determine if epicutaneous patch testing to nickel could predict responsiveness to a low-nickel diet.

METHODS

This prospective, single-site pilot study recruited 20 refractory GERD patients as determined by GERD Health-Related Quality of Life (GERD-HRQL) scores. All patients had epicutaneous patch testing for nickel and were then instructed to follow a low-nickel diet for 8 weeks regardless of patch test results. GERD-HRQL was recorded at baseline and following 8 weeks of a low-nickel diet. Demographic and clinical data associated with GERD and nickel allergy were recorded. A Wilcoxon signed-rank test and nonparametric analysis of longitudinal data were run to determine statistical significance in pre- and post- GERD-HRQL scores in nickel patch test-positive and negative groups.

RESULTS

Nearly all (19/20 [95%]) participants reported reduced GERD symptoms after 8 weeks on a low-nickel diet. Mean total GERD-HRQL, regurgitation, and heartburn scores declined (27.05 ± 16.04, 11.45 ± 6.46, 10.85 ± 8.29). Participants with positive vs. negative patch testing to nickel responded equivalently to a low-nickel diet.

CONCLUSIONS

A low-nickel diet improves GERD symptoms, but responsiveness to a low-nickel diet does not correlate with epicutaneous patch testing to nickel.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT03720756.

Update of the risk assessment of nickel in food and drinking water

The European Commission asked EFSA to update its previous Opinion on nickel in food and drinking water, taking into account new occurrence data, the updated benchmark dose (BMD) Guidance and newly available scientific information. More than 47,000 analytical results on the occurrence of nickel were used for calculating chronic and acute dietary exposure. An increased incidence of post-implantation loss in rats was identified as the critical effect for the risk characterisation of chronic oral exposure and a BMDL 10 of 1.3 mg Ni/kg body weight (bw) per day was selected as the reference point for the establishment of a tolerable daily intake (TDI) of 13 μg/kg bw. Eczematous flare-up reactions in the skin elicited in nickel-sensitised humans, a condition known as systemic contact dermatitis, was identified as the critical effect for the risk characterisation of acute oral exposure. A BMDL could not be derived, and therefore, the lowest-observed-adverse-effect-level of 4.3 μg Ni/kg bw was selected as the reference point. The margin of exposure (MOE) approach was applied and an MOE of 30 or higher was considered as being indicative of a low health concern. The mean lower bound (LB)/upper bound (UB) chronic dietary exposure was below or at the level of the TDI. The 95th percentile LB/UB chronic dietary exposure was below the TDI in adolescents and in all adult age groups, but generally exceeded the TDI in toddlers and in other children, as well as in infants in some surveys. This may raise a health concern in these young age groups. The MOE values for the mean UB acute dietary exposure and for the 95th percentile UB raises a health concern for nickel-sensitised individuals. The MOE values for an acute scenario regarding consumption of a glass of water on an empty stomach do not raise a health concern.

Impact of Heavy Metals on Host Cells: Special Focus on Nickel-Mediated Pathologies and Novel Interventional Approaches

BACKGROUND

Heavy metals [arsenic, aluminium, cadmium, chromium, cobalt, lead, nickel (Ni), palladium and titanium] are environmental contaminants able to impact with host human cells, thus, leading to severe damage.

OBJECTIVE

In this review, the detrimental effects of several heavy metals on human organs will be discussed and special emphasis will be placed on Ni. In particular, Ni is able to interact with Toll-like receptor-4 on immune and non-immune cells, thus, triggering the cascade of pro-inflammatory cytokines. Then, inflammatory and allergic reactions mediated by Ni will be illustrated within different organs, even including the central nervous system, airways and the gastrointestinal system.

DISCUSSION

Different therapeutic strategies have been adopted to mitigate Ni-induced inflammatoryallergic reactions. In this context, the ability of polyphenols to counteract the inflammatory pathway induced by Ni on peripheral blood leukocytes from Ni-sensitized patients will be outlined. In particular, polyphenols are able to decrease serum levels of interleukin (IL)-17, while increasing levels of IL- 10. These data suggest that the equilibrium between T regulatory cells and T helper 17 cells is recovered with IL-10 acting as an anti-inflammatory cytokine. In the same context, polyphenols reduced elevated serum levels of nitric oxide, thus, expressing their anti-oxidant potential. Finally, the carcinogenic potential of heavy metals, even including Ni, will be highlighted.

CONCLUSION

Heavy metals, particularly Ni, are spread in the environment. Nutritional approaches seem to represent a novel option in the treatment of Ni-induced damage and, among them, polyphenols should be taken into consideration for their anti-oxidant and anti-inflammatory activities.

Nickel Sensitivity in Rosacea Patients: A Prospective Case Control Study

Background:

Rosacea is a frequently seen chronic disease. Certain allergens, some foods and beverages are known to trigger symptoms of rosacea.

Objective:

We aimed to assess if nickel sensitivity is more common in rosacea patients than the normal population.

Method:

Fourty patients with rosacea and 40 healthy age and sex-matched volunteers were included in the study. From European standard patch test series, test units with nickel were applied on the skin of the upper back. According to the scheme of the International Contact Dermatitis Research Group (ICDRG), test results were evaluated at 48th, 72th and 96th hours. Seven days later, reevaluation was done for late reactions. Statistical analyses were done by using Statistics package for Social Sciences (SPSS) 17 package program and p<0.05 was accepted as statistically significant.

Results:

Female/male ratio was 34/6 in patient group and 32/8 in control group. Mean age of the patient group and the control group were 39.97±12.65 (18-65 years), 40.82±11.79 (19-68 years), respectively. Age and sex distributions were found to be statistically similar. Nickel allergy in the patient and control group was found to be 52.5%, 22.5% respectively and the difference between groups was statistically significant (p=0. 006).

Conclusion:

Our results showed that there may be an association between nickel sensitivity and rosacea. Nickel sensitivity may be one of the underlying pathology or a triggering factor of the rosacea. Nickel restricted diet and avoiding the use of nickel-containing jewellery and piercings may extend the remission periods.