RESEARCH ARTICLE
Trace Elements in Scalp Hair Samples from Patients with Relapsing-Remitting Multiple Sclerosis Elisa Tamburo1*, Daniela Varrica1, Gaetano Dongarrà1, Luigi Maria Edoardo Grimaldi2* 1 Dipartimento Scienze della Terra e del Mare (DiSTeM), University of Palermo, Palermo, Sicily, Italy, 2 U.O. Neurologia, Fondazione Istituto San Raffaele “G. Giglio” di Cefalù, Cefalù, Sicily, Italy * [email protected]
Abstract a11111
Background Epidemiological studies have suggested a possible role of trace elements (TE) in the etiology of several neurological diseases including Multiple Sclerosis (MS). Hair analysis provides an easy tool to quantify TE in human subjects, including patients with neurodegenerative diseases.
OPEN ACCESS
Objective
Citation: Tamburo E, Varrica D, Dongarrà G, Grimaldi LME (2015) Trace Elements in Scalp Hair Samples from Patients with Relapsing-Remitting Multiple Sclerosis. PLoS ONE 10(4): e0122142. doi:10.1371/journal.pone.0122142
To compare TE levels in scalp hair from patients with MS and healthy controls from the same geographic area (Sicily).
Academic Editor: Ralf Andreas Linker, FriedrichAlexander University Erlangen, GERMANY
ICP-MS was used to determine the concentrations of 21 elements (Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) in scalp hair of 48 patients with relapsing–remitting Multiple Sclerosis compared with 51 healthy controls.
Received: August 8, 2014
Methods
Accepted: January 26, 2015 Published: April 9, 2015
Results
Copyright: © 2015 Tamburo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
MS patients showed a significantly lower hair concentration of aluminum and rubidium (median values: Al = 3.76 μg/g vs. 4.49 μg/g and Rb = 0.007 μg/g vs. 0.01 μg/g;) and higher hair concentration of U (median values U: 0.014 μg/g vs. 0.007 μg/g) compared to healthy controls. The percentages of MS patients showing hair elemental concentrations greater than the 95th percentile of controls were 20% for Ni, 19% for Ba and U, and 15% for Ag, Mo and Se. Conversely, the percentages of MS patients showing hair elemental concentrations lower than the 5th percentile of healthy controls were 27% for Al, 25% for Rb, 22% for Ag, 19% for Fe, and 16% for Pb. No significant association was found between levels of each TE and age, disease duration or Expanded Disability Status Scale (EDSS) score. After stratification by gender, healthy subjects did not show any significant difference in trace element levels, while MS patients showed significant differences (pCu, the levels of these elements being from one to five orders of magnitude greater than all the other investigated TE. The median concentrations of Al and Sr were 4.49 and 1.70 μg/g, respectively; Se, Pb, Mn, Cr and Ni median values were between 0.1 and 1.0 μg/g, whereas the remaining elements had concentration levels below 0.1 μg/g. Although female controls exhibited higher median values compared to males for Ag, Cd, Co, Cu, Fe, Li, Mo, Ni, Pb, Rb, Sr, U, V and Zn, hair elemental concentration in females greater than the 95th percentile of males was observed only for Zn (30%), Ni (24%), Mo (20%), Ag (18%), Sr (17%) and Co (15%). Hair samples from MS patients showed similar orders of abundance and magnitude (Zn>>Fe>Cu). When we studied gender differences in the MS group, we observed higher median values in female’s hair compared to males for Ag, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, U, V and Zn. Interestingly, female/male differences were more relevant in MS patients compared to healthy subjects. From a statistical point of view, healthy subjects did not show any significant
PLOS ONE | DOI:10.1371/journal.pone.0122142 April 9, 2015
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Trace Elements in Scalp Hair of People Affected by Multiple Sclerosis
Table 4. Results of Mann-Whitney test for differences between MS patients, HC controls and confounding variables. p-value
Trace Elements in Scalp Hair Samples from Patients with Relapsing-Remitting Multiple Sclerosis Elisa Tamburo1*, Daniela Varrica1, Gaetano Dongarrà1, Luigi Maria Edoardo Grimaldi2* 1 Dipartimento Scienze della Terra e del Mare (DiSTeM), University of Palermo, Palermo, Sicily, Italy, 2 U.O. Neurologia, Fondazione Istituto San Raffaele “G. Giglio” di Cefalù, Cefalù, Sicily, Italy * [email protected]
Abstract a11111
Background Epidemiological studies have suggested a possible role of trace elements (TE) in the etiology of several neurological diseases including Multiple Sclerosis (MS). Hair analysis provides an easy tool to quantify TE in human subjects, including patients with neurodegenerative diseases.
OPEN ACCESS
Objective
Citation: Tamburo E, Varrica D, Dongarrà G, Grimaldi LME (2015) Trace Elements in Scalp Hair Samples from Patients with Relapsing-Remitting Multiple Sclerosis. PLoS ONE 10(4): e0122142. doi:10.1371/journal.pone.0122142
To compare TE levels in scalp hair from patients with MS and healthy controls from the same geographic area (Sicily).
Academic Editor: Ralf Andreas Linker, FriedrichAlexander University Erlangen, GERMANY
ICP-MS was used to determine the concentrations of 21 elements (Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) in scalp hair of 48 patients with relapsing–remitting Multiple Sclerosis compared with 51 healthy controls.
Received: August 8, 2014
Methods
Accepted: January 26, 2015 Published: April 9, 2015
Results
Copyright: © 2015 Tamburo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
MS patients showed a significantly lower hair concentration of aluminum and rubidium (median values: Al = 3.76 μg/g vs. 4.49 μg/g and Rb = 0.007 μg/g vs. 0.01 μg/g;) and higher hair concentration of U (median values U: 0.014 μg/g vs. 0.007 μg/g) compared to healthy controls. The percentages of MS patients showing hair elemental concentrations greater than the 95th percentile of controls were 20% for Ni, 19% for Ba and U, and 15% for Ag, Mo and Se. Conversely, the percentages of MS patients showing hair elemental concentrations lower than the 5th percentile of healthy controls were 27% for Al, 25% for Rb, 22% for Ag, 19% for Fe, and 16% for Pb. No significant association was found between levels of each TE and age, disease duration or Expanded Disability Status Scale (EDSS) score. After stratification by gender, healthy subjects did not show any significant difference in trace element levels, while MS patients showed significant differences (pCu, the levels of these elements being from one to five orders of magnitude greater than all the other investigated TE. The median concentrations of Al and Sr were 4.49 and 1.70 μg/g, respectively; Se, Pb, Mn, Cr and Ni median values were between 0.1 and 1.0 μg/g, whereas the remaining elements had concentration levels below 0.1 μg/g. Although female controls exhibited higher median values compared to males for Ag, Cd, Co, Cu, Fe, Li, Mo, Ni, Pb, Rb, Sr, U, V and Zn, hair elemental concentration in females greater than the 95th percentile of males was observed only for Zn (30%), Ni (24%), Mo (20%), Ag (18%), Sr (17%) and Co (15%). Hair samples from MS patients showed similar orders of abundance and magnitude (Zn>>Fe>Cu). When we studied gender differences in the MS group, we observed higher median values in female’s hair compared to males for Ag, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, U, V and Zn. Interestingly, female/male differences were more relevant in MS patients compared to healthy subjects. From a statistical point of view, healthy subjects did not show any significant
PLOS ONE | DOI:10.1371/journal.pone.0122142 April 9, 2015
6 / 14
Trace Elements in Scalp Hair of People Affected by Multiple Sclerosis
Table 4. Results of Mann-Whitney test for differences between MS patients, HC controls and confounding variables. p-value
