Assessment of serum S100B and neuron specific enolase levels to evaluate the neurotoxic effects of organic solvent exposure

To the Editor:

In the article by Züngün et al.,¹ the authors postulate that S100B and neuron-specific enolase levels can be used as markers of subclinical nervous system dysfunction in patients exposed to organic solvents. We commend the authors for attempting to find objective markers of dysfunction after solvent exposure, however, we have some concerns regarding the study.

The authors state that there is a statistically significant difference in S100B levels between a group of workers exposed to organic solvents and a control group. The control group was reported to have no exposure to organic solvents, but this was not verified through laboratory testing. Also, relevant baseline characteristics of the two groups, besides the age, creatinine and AST/ALT, are not provided. Additionally, although the difference in the median values of S100B is quoted as statistically significant (p = 0.036), it does not seem clinically relevant when the ranges are compared (0.03–0.19 vs. 0.03–0.14).

Finally, the only objective differences reported in Table 3 include positive EMG findings in those exposed. As the population studied involves welders, it is quite possible that this finding is simply the result of another work-related disease such as carpal tunnel syndrome.

In conclusion, although the authors have put in significant efforts to find a method of monitoring the effects of exposure to organic solvents, their findings do not support these tests as likely to be clinically useful.