Systemic nickel allergy syndrome: nosologic framework and usefulness of diet regimen for diagnosis

New Insights and Evidence on "Food Intolerances": Non-Celiac Gluten Sensitivity and Nickel Allergic Contact Mucositis

The clinical examination of patients often includes the observation of the existence of a close relationship between the ingestion of certain foods and the appearance of various symptoms. Until now, the occurrence of these events has been loosely defined as food intolerance. Instead, these conditions should be more properly defined as adverse food reactions (AFRs), which can consist of the presentation of a wide variety of symptoms which are commonly identified as irritable bowel syndrome (IBS). In addition, systemic manifestations such as neurological, dermatological, joint, and respiratory disorders may also occur in affected patients. Although the etiology and pathogenesis of some of them are already known, others, such as non-celiac gluten sensitivity and adverse reactions to nickel-containing foods, are not yet fully defined. The study aimed to evaluate the relationship between the ingestion of some foods and the appearance of some symptoms and clinical improvements and detectable immunohistochemical alterations after a specific exclusion diet. One hundred and six consecutive patients suffering from meteorism, dyspepsia, and nausea following the ingestion of foods containing gluten or nickel were subjected to the GSRS questionnaire which was modified according to the "Salerno experts' criteria". All patients underwent detection of IgA antibodies to tissue transglutaminase, oral mucosal patch tests with gluten and nickel (OMPT), and EGDS, including biopsies. Our data show that GSRS and OMPT, the use of APERIO CS2 software, and the endothelial marker CD34 could be suggested as useful tools in the diagnostic procedure of these new pathologies. Larger, multi-center clinical trials could be helpful in defining these emerging clinical problems.

Datterino Trial: A Double Blind, Randomized, Controlled, Crossover, Clinical Trial on the Use of Hydroponic Cultivated Tomato Sauce in Systemic Nickel Allergy Syndrome

A low-nickel (Ni) diet, a key treatment for Systemic Nickel Allergy Syndrome (SNAS), is difficult in the long term and strongly impacts quality of life (QoL). Hydroponic agriculture could be an alternative to allow the reintroduction of tomato, an essential food in the global diet. In a first interventional, randomized, double-blind, single-center crossover study, we compared the possible effects of eating tomato puree deriving from hydroponic agriculture versus tomato puree from conventional cultivation, collecting data on subjective control of SNAS symptoms, adherence to treatment, and impact on QoL. Thirty subjects were randomly assigned to one of the following treatment groups: (1) a 12-week low-Ni diet plus 100% Italian Datterino tomato puree deriving from hydroponic technology; (2) a 12-week low-Ni diet plus 100% Italian Datterino tomato puree deriving from conventional cultivation. Then, after a 2-week washout period on the low-Ni diet, each patient crossed over to the other treatment. Patients reported lower symptom scores after eating Datterino tomato puree deriving from hydroponic technology; specifically, bloating (p = 0.0111, p = 0.0060), flatulence (p = 0.0090), abdominal cramps (p = 0.0207), constipation (p = 0.0395), and diarrhea (p = 0.0105). Overall, the adherence rate was high for both treatment arms. At baseline, QoL was poor, but significant improvement was observed after two treatments. In our study, precision medicine and precision agriculture merge in a holistic approach to the challenges of food allergies.

Betaine Ameliorates Brain Damage in a Rat Model of Ischemia/Reperfusion Injury

Brain ischemia and reperfusion (I/R) injury may lead to a poor prognosis for ischemic stroke, which could be alleviated by anti-oxidants with diminished oxidative stress. Betaine is a natural nutrient found in beetroot and seafood to improve cognitive performance in the elderly. The present study investigated whether betaine could protect the brain from I/R injury. Results showed that betaine treatment could reduce H₂O₂-induced cell death in the PC12 cell line. Pretreatment with betaine reduced the brain infarct volume and neuronal apoptosis in a rat I/R injury model induced by two-hour middle cerebral artery occlusion (MCAO). Biochemical analyses indicated that betaine treatment decreased pro-inflammatory cytokine production and reduced oxidative stress after I/R injury. Betaine increased the expression of anti-oxidative enzymes, such as glutathione peroxidase 4 (Gpx4) and superoxide dismutase 1 (Sod1), and anti-oxidative non-enzymatic genes, such as 3-mercaptopyruvate sulfurtransferase (Mpst), methionine sulfoxide reductases b1 (Msrb1), and Msrb2. These data suggest that betaine exerts a neuroprotective effect in I/R injury through enzymatic and non-enzymatic anti-oxidative systems and anti-inflammatory mechanisms.

High consumption of Nickel-containing foods and IBS-like disorders: late events in a gluten-free diet

As reported in the recent literature, Nickel has become an important part of our daily life since the last decades. We can find it in skincare products, occupational exposures and foods. Only recently, research has started to show a link between Nickel and many health disorders, including adverse reactions to food containing nickel. Nowadays, the relationship between nickel-containing foods and well-being is becoming a topic of growing interest in clinical practice and will play an even larger role in the future. The use of foods with a high nickel content, largely present in a gluten free diet, could explain the lack of clinical remission in celiac patients and dispel a diagnosis of refractory celiac disease.

Diet Intervention Study through Telemedicine Assistance for Systemic Nickel Allergy Syndrome Patients during the COVID-19 Pandemic

Background: Restrictions due to the COVID-19 pandemic limited patients’ access to hospital care. The aims of this study were to assess dietary nutritional status, quality of life (QoL), and adherence to dietary therapy before and after 30-day personalized diet therapy through telenutrition tools in patients with systemic nickel allergic syndrome (SNAS). Methods: Each SNAS patient underwent the following allergological procedures: (a) face-to-face visit (nutritional visit and QoL evaluation) with prescription of one out of five personalized and balanced dietary plans different for calorie intake, (b) video call visit for dietary evaluation and assessment of adherence to diet after 15 days, and (c) video call visit for dietary and QoL evaluation and assessment of adherence to diet therapy after 30 days (end of study). Results: We enrolled 20 SNAS patients. After 15 and 30 days, we found a statistically significant improvement in anthropometric findings after diet therapy, a significant adherence rate to low-nickel diet (60% and 80%, respectively), and an improvement in QoL with an increase in almost all psychometric indices. Conclusions: Our study demonstrates that telenutrition can be a valid tool to monitor nutritional status and adherence to balanced low-Ni diet positively affecting QoL in SNAS patients during the COVID-19 pandemic.

Nickel Hypersensitivity to Atrial Septal Occluders: Smoke Without Fire?

Nickel is one of the most common contact allergens worldwide; it is used as the main component of the devices used for atrial septal defects (ASDs) and patent foramen ovale (PFO) closure. Developing nickel hypersensitivity after PFO/ASD occlusion is significantly rarer described in medical literature than typical nickel contact sensitization. The exact pathophysiological mechanism of this "device syndrome" remains unknown, and many question the real incidence or even the existence of this clinical entity. Nevertheless, it has been associated with a wide spectrum of symptoms, including chest pain, migraines, palpitation, and dyspnea. Skin patch tests are the first-line approach to diagnose nickel hypersensitivity. However, diagnostic criteria for the device syndrome have not been developed, and diagnosis in reported cases is established by a process of elimination. Management-drug therapy (corticosteroids, clopidogrel, etc.) or even surgical explantation in severe cases-of patients developing such clinical manifestations after percutaneous PFO/ASD occlusion is empirical. Undoubtedly, endocardiac device-related nickel hypersensitivity requires more focused research to discover the underlying mechanism as well as to develop reliable prognostic tests for detecting high-risk patients and preventing severe nickel hypersensitivity reactions.

The Association Between Intestinal Bacteria and Allergic Diseases-Cause or Consequence?

The incidence of allergic disorders has been increasing over the past few decades, especially in industrialized countries. Allergies can affect people of any age. The pathogenesis of allergic diseases is complex and involves genetic, epigenetic, and environmental factors, and the response to medication is very variable. For some patients, avoidance is the sole effective therapy, and only when the triggers are identifiable. In recent years, the intestinal microbiota has emerged as a significant contributor to the development of allergic diseases. However, the precise mechanisms related to the effects of the microbiome on the pathogenesis of allergic diseases are unknown. This review summarizes the recent association between allergic disorders and intestinal bacterial dysbiosis, describes the function of gut microbes in allergic disease development from both preclinical and clinical studies, discusses the factors that influence gut microbial diversity and advanced techniques used in microbial analysis. Ultimately, more studies are required to define the host-microbial relationship relevant to allergic disorders and amenable to new therapeutic interventions.

Nickel Sensitivity Is Associated with GH-IGF1 Axis Impairment and Pituitary Abnormalities on MRI in Overweight and Obese Subjects

Nickel (Ni) is a ubiquitous metal, the exposure of which is implied in the development of contact dermatitis (nickel allergic contact dermatitis (Ni-ACD)) and Systemic Ni Allergy Syndrome (SNAS), very common among overweight/obese patients. Preclinical studies have linked Ni exposure to abnormal production/release of Growth Hormone (GH), and we previously found an association between Ni-ACD/SNAS and GH-Insulin-like growth factor 1 (IGF1) axis dysregulation in obese individuals, altogether suggesting a role for this metal as a pituitary disruptor. We herein aimed to directly evaluate the pituitary gland in overweight/obese patients with signs/symptoms suggestive of Ni allergy, exploring the link with GH secretion; 859 subjects with overweight/obesity and suspected of Ni allergy underwent Ni patch tests. Among these, 106 were also suspected of GH deficiency (GHD) and underwent dynamic testing as well as magnetic resonance imaging for routine follow up of benign diseases or following GHD diagnosis. We report that subjects with Ni allergies show a greater GH-IGF1 axis impairment, a higher prevalence of Empty Sella (ES), a reduced pituitary volume and a higher normalized T2 pituitary intensity compared to nonallergic ones. We hypothesize that Ni may be detrimental to the pituitary gland, through increased inflammation, thus contributing to GH-IGF1 axis dysregulation.

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.

Beneficial Effects of a Low-Nickel Diet on Relapsing IBS-Like and Extraintestinal Symptoms of Celiac Patients during a Proper Gluten-Free Diet: Nickel Allergic Contact Mucositis in Suspected Non-Responsive Celiac Disease

Background and Aim: Nickel (Ni)-rich foods can induce allergic contact mucositis (ACM) with irritable bowel syndrome (IBS)-like symptoms in predisposed subjects. Ni ACM has a high prevalence (>30%) in the general population and can be diagnosed by a Ni oral mucosa patch test (omPT). Many celiac disease (CD) patients on a gluten-free diet (GFD) often show a recrudescence of gastrointestinal and extraintestinal symptoms, although serological and histological remission has been achieved. Since a GFD often results in higher loads of ingested alimentary Ni (e.g., corn), we hypothesized that it would lead to a consequent intestinal sensitization to Ni in predisposed subjects. We wanted to (1) study Ni ACM prevalence in still symptomatic CD patients on a GFD and (2) study the effects of a low-Ni diet (LNiD) on their recurrent symptoms. Material and Methods: We recruited 102 consecutive CD patients (74 female, 28 male; age range 18–65 years, mean age 42.3 ± 7.4) on a GFD since at least 12 months, in current serological and histological remission (Marsh–Oberhuber type 0–I) who complained of relapsing gastrointestinal and/or extraintestinal symptoms. Inclusion criteria: presence of at least three gastrointestinal symptoms with a score ≥5 on the modified Gastrointestinal Symptom Rating Scale (GSRS) questionnaire. Exclusion criteria: IgE-mediated food allergy; history of past or current cancer; inflammatory bowel diseases; infectious diseases including Helicobacter pylori; lactose intolerance. All patients enrolled underwent Ni omPT and followed a LNiD for 3 months. A 24 symptoms questionnaire (GSRS modified according to the Salerno Experts’ Criteria, with 15 gastrointestinal and 9 extraintestinal symptoms) was administered at T0 (free diet), T1 (GFD, CD remission), T2 (recurrence of symptoms despite GFD), and T3 (GFD + LNiD) for comparisons. Comparisons were performed using Wilcoxon signed-rank test. RESULTS: Twenty patients (all female, age range 23–65 years, mean age 39.1 ± 2.9) out of 102 (19.6%) were finally included. All 20 patients enrolled (100%) showed positive Ni omPT, confirming an Ni ACM diagnosis. A correct GFD (T0 vs. T1) induced the improvement of 19 out of the total 24 (79.2%) symptoms, and 14 out of 24 (58.3%) were statistically significant (p-value < 0.0083 according to Bonferroni correction). Prolonged GFD (T1 vs. T2) revealed the worsening of 20 out of the total 24 (83.3%) symptoms, and 10 out of 24 (41.7%) were statistically significant. LNiD (T2 vs. T3) determined an improvement of 20 out of the total 24 (83.4%) symptoms, and in 10 out of 24 (41.7%) symptoms the improvement was statistically significant. Conclusions: Our data suggest that the recrudescence of gastrointestinal and extraintestinal symptoms observed in CD subjects during GFD may be due to the increase in alimentary Ni intake, once gluten contamination and persisting villous atrophy are excluded. Ni overload can induce Ni ACM, which can be diagnosed by a specific Ni omPT. Improvement of symptoms occurs after a proper LNiD. These encouraging data should be confirmed with larger studies.

Impact of nickel oral hyposensitization on quality of life in systemic nickel allergy syndrome

Nickel (Ni) oral hyposensitization treatment (NiOHT) is an effective management approach for Ni allergy. No health-related quality of life (HRQoL) data exist for the pre- and post-treatment with NiOHT in systemic nickel allergy syndrome (SNAS). The aims of this study were (a) to explore HRQoL in SNAS patients, (b) to assess changes of HRQoL after 1 year of NiOHT; (c) to evaluate psychological status of patients. SNAS patients completed the Short-Form 36-Item Health Survey and Psychological General Well-Being Index before and 1 week after the end of NiOHT. Moreover, psychological state was assessed with the Minnesota Multiphasic Personality Inventory (MMPI-2). A total of 52 patients self-reported pre- and post-treatment questionnaires. HRQoL was poor at baseline. After 1 year of NiOHT, all outcome measure scores improved by about 20% with respect to baseline data (P < 0.01 for all indices, except depressed mood). Finally, 33 patients performed the MMPI-2. High rates for hypochondriasis and depression were noted. Furthermore, most of the patients had high scores for anxiety, depression, and health concerns. This is the first study showing that NiOHT improves HRQoL of SNAS patients, which can be considered a “personalized medicine” approach.

Nickel allergy in lipid transfer protein sensitized patients: Prevalence and clinical features

Nickel (Ni), the main responsible for allergic contact dermatitis worldwide, is also involved in systemic condition called "Systemic Nickel Sulfate Allergy Syndrome (SNAS)." Likewise, IgE-mediated reactivity to Lipid Transfer Protein (LTP) represents the main cause of primary food allergy in adults of Mediterranean countries. We evaluated the prevalence of SNAS in LTP allergic patients and investigated patients' clinical features with double sensitization (LTP and Ni). A retrospective, single-center, observational study was conducted performing a complete allergological work-up including: (1) skin prick tests; (2) serum specific IgE for plant food allergens and rPru p3 (LTP); (3) patch test with 5% Ni sulfate in petrolatum. We enrolled 140 LTP allergic patients of which 36 patients (25.7% of sample) showed additional positivity to Ni patch test. Patients with double sensitization were more frequently females and reported fewer cutaneous symptoms. Higher values of sIgE for peach, apple, peanut, walnut, grain, corn, and garlic were found in LTP allergic patients, while higher values for hazelnut in the other subgroup. The prevalence of SNAS in the LTP allergic population is clinically relevant. Moreover, the clinical and immunological profiles of patients with double sensitization were different from patients monosensitized to LTP.

Overweight and obese patients with nickel allergy have a worse metabolic profile compared to weight matched non-allergic individuals

Background

A lack of balance between energy intake and expenditure due to overeating or reduced physical activity does not seem to explain entirely the obesity epidemic we are facing, and further factors are therefore being evaluated. Nickel (Ni) is a ubiquitous heavy metal implied in several health conditions. Regarding this, the European Food Safety Authority has recently released an alert on the possible deleterious effects of dietary Ni on human health given the current levels of Ni dietary intake in some countries. Pre-clinical studies have also suggested its role as an endocrine disruptor and have linked its exposure to energy metabolism and glucose homeostasis dysregulation. Ni allergy is common in the general population, but preliminary data suggest it being even more widespread among overweight patients.

Objectives

The aim of this study has been to evaluate the presence of Ni allergy and its association with the metabolic and endocrine profile in overweight and obese individuals.

Methods

We have evaluated 1128 consecutive overweight and obese outpatients. 784 were suspected of being allergic to Ni and 666 were assessed for it. Presence of Ni allergy and correlation with body mass index (BMI), body composition, metabolic parameters and hormonal levels were evaluated.

Results

We report that Ni allergy is more frequent in presence of weight excess and is associated with worse metabolic parameters and impaired Growth Hormone secretion.

Conclusions

We confirm that Ni allergy is more common in obese patients, and we report for the first time its association with worse metabolic parameters and impaired function of the GH-IGF1 axis in human subjects.

Effects of Metal Micro and Nano-Particles on hASCs: An In Vitro Model

As the knowledge about the interferences of nanomaterials on human staminal cells are scarce and contradictory, we undertook a comparative multidisciplinary study based on the size effect of zero-valent iron, cobalt, and nickel microparticles (MPs) and nanoparticles (NPs) using human adipose stem cells (hASCs) as a model, and evaluating cytotoxicity, morphology, cellular uptake, and gene expression. Our results suggested that the medium did not influence the cell sensitivity but, surprisingly, the iron microparticles (FeMPs) resulted in being toxic. These data were supported by modifications in mRNA expression of some genes implicated in the inflammatory response. Microscopic analysis confirmed that NPs, mainly internalized by endocytosis, persist in the vesicles without any apparent cell damage. Conversely, MPs are not internalized, and the effects on hASCs have to be ascribed to the release of ions in the culture medium, or to the reduced oxygen and nutrient exchange efficiency due to the presence of MP agglomerating around the cells. Notwithstanding the results depicting a heterogeneous scene that does not allow drawing a general conclusion, this work reiterates the importance of comparative investigations on MPs, NPs, and corresponding ions, and the need to continue the thorough verification of NP and MP innocuousness to ensure unaffected stem cell physiology and differentiation.

Irritable Bowel Syndrome and Nickel Allergy: What Is the Role of the Low Nickel Diet?

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) is characterized by chronic abdominal pain or discomfort accompanied by abnormal bowel movements. In sensitized subjects, ingested nickel (Ni) may induce gastrointestinal symptoms similar to IBS, in addition to typical systemic cutaneous lesions (systemic nickel allergy syndrome [SNAS]). A low nickel diet could improve the systemic manifestations. We evaluated prevalence of nickel allergy in IBS and effects of low Ni diet on (1) gastrointestinal symptoms control, (2) intestinal barrier function, (3) quality of life, and (4) psychological status of patients with IBS and Ni-sensitized patients.

METHODS

Twenty consecutive patients affected by IBS and suspected SNAS underwent intestinal permeability tests. Gastrointestinal symptoms were evaluated using the visual analogue scale before and after 3 months low Ni diet. Subjects with increased intestinal permeability at baseline repeated nuclear examination after the diet.

RESULTS

The most frequent profile was diarrhea-predominant IBS (8/20). The low Ni diet induced a significant and constant improvement of gastrointestinal symptoms and an equally significant improvement of visual analogue scale. Mean urinary output of ⁵¹Chromium ethylene-diamine-tetra-acetate (⁵¹Cr-EDTA) was 5.91%/24 hr (± 2.08), significantly different from the control group (2.20%/24 hr ± 0.60, P < 0.0001).

CONCLUSION

This pilot study shows that low Ni diet improves gastrointestinal symptoms in patients with IBS and SNAS.

Food Avoidance Diets for Dermatitis

Food allergy is relatively common in both children and adults, and its prevalence is increasing. Early exposure of food allergens onto skin with an impaired epidermal barrier predisposes to sensitization and prevents the development of oral tolerance. While immediate-type food allergies are well described, less is known about delayed-type food allergies manifesting as dermatitis. This is due, in part, to limitations with current diagnostic testing for delayed-type food allergy, including atopy patch testing. We conducted a systematic review of food avoidance diets in delayed-type food allergies manifesting as dermatitis. While beneficial in some clinical circumstances, avoidance diets should be used with caution in infants and children, as growth impairment and developmental delay may result. Ultimately, dermatitis is highly multifactorial and avoidance diets may not improve symptoms of delayed-type food allergy until combined with other targeted therapies, including restoring balance in the skin microbiome and re-establishing proper skin barrier function.

Serum diamine oxidase activity in patients with histamine intolerance

INTRODUCTION

Intolerance to various foods, excluding bona fide coeliac disease and lactose intolerance, represents a growing cause of patient visits to allergy clinics.Histamine intolerance is a long-known, multifaceted clinical condition triggered by histamine-rich foods and alcohol and/or by drugs that liberate histamine or block diamine oxidase (DAO), the main enzyme involved in the metabolism of ingested histamine. Histamine limitation diets impose complex, non-standardized restrictions that may severely impact the quality of life of patients.

METHODS

We retrospectively evaluated 14 patients who visited allergy outpatient facilities in northern Italy with a negative diagnosis for IgE-mediated food hypersensitivity, coeliac disease, conditions related to gastric hypersecretion, and systemic nickel hypersensitivity, and who previously underwent a histamine limitation diet with benefits for their main symptoms. Serum diamine oxidase levels and the clinical response to diamine oxidase supplementation were investigated.

RESULTS

We found that 10 out of 14 patients had serum DAO activity<10 U/mL, which was the threshold suggested as a cutoff for probable histamine intolerance. Moreover, 13 out of 14 patients subjectively reported a benefit in at least one of the disturbances related to food intolerances following diamine oxidase supplementation. The mean value (±SD) of diamine oxidase activity in the cohort of patients with histamine intolerance symptoms was 7.04±6.90 U/mL compared to 39.50±18.16 U/mL in 34 healthy controls (P=0.0031).

CONCLUSION

In patients with symptoms triggered by histamine-rich food, measuring the serum diamine oxidase activity can help identify subjects who can benefit from a histamine limitation diet and/or diamine oxidase supplementation.Properly designed, controlled studies investigating histamine intolerance that include histamine provocation are indispensable for providing insights into the area of food intolerances, which are currently primarily managed with non-scientific approaches in Italy.

Guidelines for the use and interpretation of diagnostic methods in adult food allergy

Food allergy has an increasing prevalence in the general population and in Italy concerns 8 % of people with allergies. The spectrum of its clinical manifestations ranges from mild symptoms up to potentially fatal anaphylactic shock. A number of patients can be diagnosed easily by the use of first- and second-level procedures (history, skin tests and allergen specific IgE). Patients with complex presentation, such as multiple sensitizations and pollen-food syndromes, frequently require a third-level approach including molecular diagnostics, which enables the design of a component-resolved sensitization profile for each patient. The use of such techniques involves specialists' and experts' skills on the issue to appropriately meet the diagnostic and therapeutic needs of patients. Particularly, educational programs for allergists on the use and interpretation of molecular diagnostics are needed.

Zerovalent Fe, Co and Ni nanoparticle toxicity evaluated on SKOV-3 and U87 cell lines

We have considered nanoparticles (NPs) of Fe, Co and Ni, three transition metals sharing similar chemical properties. NP dissolution, conducted by radioactive tracer method and inductively coupled plasma mass spectrometry, indicated that NiNPs and FeNPs released in the medium a much smaller amount of ions than that released by Co NPs. The two considered methodological approaches, however, gave comparable but not identical results. All NPs are readily internalized by the cells, but their quantity inside the cells is less than 5%. Cytotoxicity and gene expression experiments were performed on SKOV‐3 and U87 cells. In both cell lines, CoNPs and NiNPs were definitely more toxic than FeNPs. Real‐time polymerase chain reaction experiments aimed to evaluate modifications of the expression of genes involved in the cellular stress response (HSP70, MT2A), or susceptible to metal exposure (SDHB1 and MLL), or involved in specific cellular processes (caspase3, IQSEC1 and VMP1), gave different response patterns in the two cell lines. HSP70, for example, was highly upregulated by CoNPs and NiNPs, but only in SKOV‐3 cell lines. Overall, this work underlines the difficulties in predicting NP toxicological properties based only on their chemical characteristics. We, consequently, think that, at this stage of our knowledge, biological effects induced by metal‐based NPs should be examined on a case‐by‐case basis following studies on different in vitro models. Moreover, with the only exception of U87 exposed to Ni, our results suggest that metallic NPs have caused, on gene expression, similar effects to those caused by their corresponding ions. Copyright © 2015 The Authors. Journal of Applied Toxicology published by John Wiley & Sons, Ltd.

We have considered Fe, Co and Ni nanoparticles and studied their dissolution by radioactive tracer method and ICP‐MS. We have also performed cytotoxicity and gene expression experiments on two different cell lines. The obtained results convinced us that, at this stage of our knowledge, metal‐based nanoparticles should be examined on a case‐by‐case basis on different in vitro models. Moreover, our results suggest that metal‐based nanoparticles have caused similar effects to those caused by their corresponding ions.

Toxicity of nickel ions and comprehensive analysis of nickel ion-associated gene expression profiles in THP-1 cells

The aim of the present study was to explore the toxic effects and underlying mechanisms of nickel ions during therapeutic nickel‑based alloy‑treatment in congenital heart disease by investigating the metal‑induced cytotoxicity to the human monocyte‑derived macrophage cell line THP‑1. THP‑1 cells were treated with NiCl2·6H2O (25, 50, 100, 200, 400 and 800 µM) for 24, 48 and 72 h, respectively. MTT was applied to detect THP‑1 cell proliferation following NiCl2 treatment. Apoptosis of THP‑1 cells was quantified using flow cytometry. Illumina sequencing was used for screening the associated genes, whose mRNA expression levels were further confirmed by quantitative real‑time polymerase chain reaction. High concentrations of nickel ions had a significant suppressive effect on cell proliferation at the three concentrations investigated (200, 400 and 800 µM). Treatment with nickel ions (25‑400 µM) for 48 h reduced cell viability in a dose‑dependent manner. The mRNA expression levels of RELB, FIGF, SPI‑1, CXCL16 and CRLF2 were significantly increased following nickel treatment. The results of the present study suggested that nickel ions exert toxic effects on THP‑1 cell growth, which may indicate toxicity of the nickel ion during treatment of congenital heart disease. The identification of genes modified by the toxic effects of nickel on THP‑1 cells (EPOR, RELB, FIGF, SPI‑1, TGF‑β1, CXCL16 and CRLF2) may aid in the development of interventional measures for the treatment/prevention of nickel ion‑associated toxic effects during the treatment of congenital heart disease.

High prevalence of nickel allergy in an overweight female population: a pilot observational analysis

Context

In our Allergy Unit, we incidentally observed that a low Nickel diet, prescribed for delayed allergy to Nickel sulfate, reduced body mass index (BMI) and waist circumference in overweight patients.

Objectives

This pilot cross-sectional analysis was undertaken to compare the prevalence of Nickel allergy of overweight individuals versus the general population. We also had the chance to report the efficacy of a low Nickel diet on BMI and waist circumference in Nickel-sensitive overweight subjects.

Methods

Eighty-seven overweight subjects, with a BMI >26 Kg/m², were consecutively enrolled in a health prevention program, and screened for the presence of Nickel allergy. The enrolled population was mostly females (72/87) (82.8%). Forty-three overweight women and two men showed a Nickel allergy and started a low Nickel diet. After 6-months of dieting, 24 overweight allergic women could be traced and changes in BMI and waist circumference were calculated.

Main Outcome Measurements

Prevalence of Nickel allergy in overweight.

Results

Prevalence of Nickel allergy in overweight female was 59.7%, compared with a prevalence rate of 12.5% in the general population. A significant reduction in BMI was observed in 24 out of 43 overweight females with Nickel allergy after 24 weeks of a low Nickel diet. Relative to baseline, mean BMI decrease was 4.2±0.5 (P <0.001) and the mean decline in waist circumference was 11.7±0.6 cm (P< 0.001).

Conclusions

This pilot observational analysis showed a substantially higher prevalence of Nickel allergy among overweight females, especially those with metabolic syndrome and fatty liver disease. A normocaloric low Nickel diet was effective in reducing BMI in this population. Further research is strongly needed to confirm these preliminary findings.

Probiotic supplementation in systemic nickel allergy syndrome patients: study of its effects on lactic acid bacteria population and on clinical symptoms

AIMS

The study aimed to evaluate the effects of probiotic Lactobacillus reuteri DSM 17938 strain supplementation in patients suffering from systemic nickel allergy syndrome, in terms of modulation of faecal LAB population linked to a reduction of GI and cutaneous symptoms and to an increase of patient's quality of life.

METHODS AND RESULTS

A preliminary double-blind randomized placebo-controlled study was planned and a culture-independent method based on denaturing gradient gel electrophoresis (DGGE) analysis coupled to the 16S rRNA gene sequencing was applied to investigate on the dynamics of faecal LAB communities before and during a low-Ni diet, supplemented with the probiotic strain. Moreover, the severity and the frequency of GI and cutaneous reactions as well as patient's clinical condition perception (VAS scores) were estimated by statistical analysis. PCR-DGGE fingerprinting obtained using LAB-specific primers revealed significant shift in faecal community with an increase in biodiversity in patients supplemented with probiotic Lact. reuteri strain. In addition, GI reactions such as symptoms related to meals and type of stools significantly improved only in patients treated with Lact. reuteri, while severity and frequency of cutaneous symptoms (urticaria, itch and eczema) and recurrent abdominal pain (RAP) as well as VAS scores statistically decreased in both groups.

CONCLUSIONS

Our preliminary findings suggest that probiotic Lact. reuteri could be a useful supplementation during a low-Ni diet of patients with SNAS, to increase LAB population diversity, which could contribute to restore the intestinal homoeostasis conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

To date, no information is available on probiotics application and on their effects, in terms of intestinal microbiota modulation, on patients suffering from SNAS. Therefore, the identification of dominant LAB community and the study of its shift during the probiotic supplementation could enhance the knowledge of the SNAS syndrome.

Drastic nickel ion removal from aqueous solution by curcumin-capped Ag nanoparticles

A completely green synthesis protocol has been adopted to obtain silver nanoaggregates capped by the natural compound (1E, 6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-diene), also known as curcumin. The synthesis has been monitored by infrared, Raman, visible and fluorescence spectroscopies. Characterization confirms that curcumin reduces and caps the nanoparticles, and such a procedure allows its solubility in water and drastically increases curcumin stability. Silver nanoparticles (AgNPs)/curcumin complex has been dispersed in a water solution containing a known nickel ion concentration. After three days, a grey precipitate is observed and nickel concentration in the solution is reduced by about 70%.

Nickel oral hyposensitization in patients with systemic nickel allergy syndrome

BACKGROUND

This is the first randomized, double-blind, placebo-controlled trial (EUDRACT No. 2009-013923-43) evaluating nickel oral hyposensitizing treatment (NiOHT) in patients with "systemic nickel allergy syndrome" (SNAS), characterized by Ni-allergic contact dermatitis and systemic reactions after eating Ni-rich food.

METHODS

Adults with positive Ni-patch test, who reported symptoms suggesting SNAS, which improved after Ni-poor diet, and were positive to Ni-oral challenge were eligible. Patients were randomly assigned to three treatments (1.5 μg, 0.3 μg, or 30 ng Ni/week) or placebo for a year, with progressive reintroduction of Ni-rich foods form the 5(th) month. Out of 141 patients randomized, 113 completed the trial. Endpoints were efficacy and tolerability of treatment.

RESULTS

During Ni-rich food re-introduction, the 1.5 μg Ni/week group had a mean VAS score significantly higher than placebo (p = 0.044), with significant improvement of gastrointestinal symptoms (p = 0.016;) and significantly fewer rescue medications. Cutaneous manifestations also improved but without reaching statistical significance. After the treatment, oral challenge with higher Ni doses than at baseline were needed to cause symptoms to flare-up in significantly more patients given 1.5 μg Ni/week than placebo (p = 0.05). Patients reported no side-effects.

CONCLUSIONS

NiOHT is effective in SNAS, in particular on gastrointestinal manifestations, with trend toward improvement of cutaneous symptoms.