Response to letter to editor regarding “Serum Biochemical Markers of Central Nerve System Damage in Children with Acute Elemental Mercury Intoxicatıon” in Clinical Toxicology 2014: (doi: 10.3109/15563650.2013.860986)

To the Editor:

Pigatto et al. have some concerns about the use of dimercaptosuccinic acid (DMSA) as a chelating agent for children who have a blood mercury level higher than 10 μg/L and state that this treatment might have an effect on especially neuron-specific enolase (NSE) levels and refer their study that reports a potential relationship between serum NSE levels and blood mercury levels.¹ DMSA, as they also stated, has a significant effect on reducing the blood mercury level and as we emphasized in the methods section, we collected the blood samples before the beginning of the DMSA treatment in order to exclude the effect of the drug. The limitation of our study is the lack of monitorization of the effect of the therapy on the studied parameters. If we could take blood samples before and after the treatment, it could give a more reliable information. On the other hand, our aim was to present new biomarkers for the evaluation of mercury exposure and severity of damage in central nervous system.

Our results indicate that only blood or/and urine mercury levels are not reliable markers in the evaluation of neurotoxicity. GRIA1 and S100 B levels (with or without increased mercury levels in biological specimen and/or presence or absence of positive neurological symptoms) seem to be an important criteria for neurotoxic effect in mercury exposed people. According to our findings, in our group of mercury-exposed children, GRIA1 and S100B levels were found to be more sensitive than NSE. As a result, GRIA1 and S100B seem to be stronger candidate biomarkers than NSE in mercury-related neurotoxicity.

Declaration of interest

The authors report no declarations of interest. The authors alone are responisble for the content and writing of the paper.