Aluminium (Al) speciation in serum and urine after subcutaneous venom immunotherapy with Al as adjuvant

Neurotoxic effects of aluminum and manganese: From molecular to clinical effects

The existing data demonstrate that aluminum (Al) and manganese (Mn) possess neurotoxic effects upon overexposure due to induction of neuronal oxidative stress and apoptosis, synaptic dysfunction and neurotransmitter metabolism, neuroinflammation, and cytoskeletal pathology. However, systematic evidence regarding contribution of these metals to development of neurological diseases are lacking. Therefore, in this review we provide a summary of the existing data on contribution of Al and Mn exposure to brain diseases and its symptoms. Causal relations were demonstrated for development of parkinsonism upon exposure to high doses of Mn, whereas Al overload is considered the key contributor to dialysis encephalopathy. Certain studies demonstrate that Al and Mn overexposure is associated with neurodegenerative diseases including Alzheimer's and Parkinson's diseases, as well as neurodevelopmental disorders like autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Although laboratory studies demonstrate the potential contribution of Al and Mn to molecular pathogenesis of these diseases, clinical findings supporting the causal role of metals is these pathologies are yet insufficient. Therefore, estimation of the contribution of these metals to neurological disorders is essential for development of more effective early diagnostics and prevention of diseases under exposure to adverse neurological effects of Al and Mn compounds.

Comprehensive assessment of matrix effects in metallomics: Evaluating 27 metals in serum, heparine-plasma-, EDTA-plasma and citrate-plasma by ICP-MS analysis

BACKGROUND

Metallomics analysis is essential for studying environmental metal exposure and distinguishing between healthy and diseased individuals in large-scale studies. Inductively coupled plasma mass spectrometry (ICP-MS) is widely used due to its high sensitivity and ability to analyze multiple elements across a broad concentration range.

AIM

Developed to address key challenges in large-scale epidemiological studies, this method specifically focuses on evaluating the performance of metals measurement in biobank blood matrices that may not be optimized for metallomics, providing key insights for biobank planning METHODS: An ICP-MS-based analytical method using a "dilute and shoot" approach was developed to target 27 elements. The study assessed the behavior of these elements in serum and different plasma types (EDTA, citrate, and heparin) based on limits of detection (LOD), limits of quantification (LOQ), precision, accuracy, and quality controls.

RESULTS

Heparin plasma and serum provided the most consistent measurements, with most elements exhibiting a coefficient of variation below 15 %. Citrated and EDTA plasma displayed higher variability, likely due to contamination from collection tubes and metal-anticoagulant interactions. Among 13 certified elements, Mg, K, Fe, Cu, Se, Co, and Ni matched reference values, while Ca, Zn, Cr, Mn, and Al were lower, and Hg was higher. Of the 14 elements with indicative values, all except Cd, which was significantly lower, aligned with Seronorm™ references.

CONCLUSION

These findings highlight the impact of plasma matrices on metal measurements in biobank studies and emphasize the importance of selecting appropriate blood matrices and collection tubes to ensure accurate and reliable elemental analysis in large-scale epidemiological research.

Early-life exposure to aluminum and fine motor performance in infants: a longitudinal study

BACKGROUND

Aluminum (Al) is a well-established neurotoxicant. However, little is known about its effects on the neurodevelopment of infants.

OBJECTIVES

To examine early-life exposure to Al in relation to neurodevelopment in healthy infants.

METHODS

Nail Al concentrations were measured among 747 newborn babies within 6 months of delivery in the Shanghai Birth Cohort. Neurodevelopment was assessed using Ages and stages questionnaire (third edition, ASQ-3) at ages 6 and 12 months. General linear regression models were performed to estimate the associations between Al concentrations and ASQ-3 scores.

RESULTS

After adjustment for potential confounders, early-life exposure to Al was not associated with any neurodevelopmental performance at age 6 months. However, Al level was associated with an increased risk of having a low fine motor score (quartile 4 vs. quartile 1, mean difference (MD): -1.63; 95% confidence interval (CI): -3.22, -0.05; P-trend < 0.01) at 12 months. No association was found for communication, gross motor, problem-solving, or personal-social score at 12 months.

SIGNIFICANCE

Early-life exposure to Al may be associated with poor fine motor skills in a dose-response manner among apparently healthy infants at age 12 months.

Detection of Al3+ and Fe3+ ions by nitrobenzoxadiazole bearing pyridine-2,6-dicarboxamide based chemosensors: effect of solvents on detection

Hybrid chemosensors, based on a pyridine-2,6-dicarboxamide fragment while containing a 4-nitrobenzoxadiazole group, are used for the sensing of Al³⁺ and Fe³⁺ ions where detection was significantly controlled by the selection of a solvent.

Aluminium levels in hair and urine are associated with overweight and obesity in a non-occupationally exposed population

BACKGROUND

Data on the association between aluminium (Al) exposure and obesity and/or metabolic syndrome are insufficient. The objective of the present study was to investigate the association between hair and urine Al levels and obesity.

METHODS

A total of 206 lean and 205 obese non-occupationally exposed subjects (30-50 y.o.) were enrolled in the study. Hair and urine Al levels were assessed with ICP-MS. Laboratory quality control was performed using the certified reference materials of human hair, plasma, and urine.

RESULTS

Hair and urinary Al levels in obese subjects were significantly higher by 31% and 46% compared to the control levels, respectively. The presence of hypertension (41% cases), atherosclerosis (8%), type 2 diabetes mellitus (10%), and non-alcoholic fatty liver disease (NAFLD) (53%) in obese patients were not associated with Al levels in the studied subjects. An overall multiple regression model established urinary Al levels (β = 0.395; p < 0.001), hypertension (β = 0.331; p < 0.001) and NAFLD (β = 0.257; p = 0.003) were significantly and directly associated with BMI. Hair Al levels were found to be border-line significantly related to BMI after adjustment for several confounders (β = -0.205; p = 0.054).

CONCLUSIONS

Aluminium body burden is associated with increased body weight, although the causal relationship between Al exposure and obesity is not clear. Both clinical and experimental studies are required to further investigate the impact of Al exposure on metabolic parameters in obesity and especially direct effects of Al in adipose tissue.

Increased urinary excretion of aluminium after ingestion of the food additive sodium aluminium phosphate (SALP) - a study on healthy volunteers

Food is an important source of human aluminium (Al) exposure and regular consumption of foods containing Al-based food additives may result in high Al intakes above health-based tolerable intakes. However, some additives are Al salts with low solubility, and little is known about bioavailability of Al in these additives. We investigated urine Al concentrations in healthy adult volunteers (N = 18, women/men) before (base-line) and after 7 days of ingestion of pancakes with a low Al content (median: <0.5 mg Al/kg) and high Al content (median: 860 mg/kg). The high-Al pancakes contained the common additive sodium aluminium phosphate (SALP). The participants did not know if the pancakes contained SALP or not during the experiment. After adjusting for creatinine content of the urine samples, median base-line Al concentrations before pancake ingestion were in the range 30-40 µmol Al/mol creatinine. Urine Al concentrations after ingestion of low-Al pancakes (average intake: <0.042 Al mg/day) did not differ significantly from the base-line levels. After ingestion of high-Al pancakes (72 mg Al/day) the median Al concentration in urine was more than 2-fold higher than at the base-line sampling before the high-Al pancake ingestion. At the end of the experiment the volunteers ingested an Al-containing antacid (Al-OH, 1800 mg Al/day) for 7 days as a positive control of Al absorption. This caused a 10-fold increase in median urine Al concentration compared to base-line. Our results strongly suggest that Al in the form of SALP in a pancake mix is bioavailable for absorption in humans, which should be taken into account in risk assessment of Al in food in countries with a high use of SALP as a food additive.