Racial Differences in S100b Levels in Persons with Schizophrenia
The calcium-binding protein S100b is secreted by glial cells in the brain and is also expressed by melanocytes. In nanomolar concentrations, S100b is considered to be a neurotrophic factor, but in micromolar concentrations, it is thought to reflect CNS injury and inflammation. Seen as a potential biomarker in traumatic brain injury, meta-analytic data from several studies report that S100b levels are significantly higher in persons with long standing schizophrenia, but also among first-episode patients compared to healthy control subjects. However, ethnic or racial differences are typically not mentioned when reporting levels of S100b. We assessed serum S100b levels in persons with schizophrenia (n = 136) who were participants in two independent research studies using the same enzyme-linked immunoassay (ELISA). African-American subjects had significantly higher levels of S100b (41.9 pg/ml ± 62.2) than Caucasian subjects (24.9 pg/ml ± 45.4) in the combined dataset (Mann-Whitney U = 1307, p < 0.001), as well as in each independent study. There were no significant differences in S100b levels between men and women. No significant correlations were observed between S100b levels and demographic or clinical variables. These data suggest that ethnicity or race should be given serious consideration when studying and interpreting S100b levels in persons with schizophrenia.
KeywordsSchizophrenia S100b African-American Caucasian Inflammation Race
The authors gratefully acknowledge Patricia Schlicht, RN, MA, who was the Research Nurse Coordinator for Study 1, and Joan Spinogatti, who handled IRB submission for Study 1, and coordinated author collaboration and drafts of the manuscript, including creating the figures and tables. We also thank Fang Liu who helped with data management, William W. Eaton, PhD, Nicola Cascella, MD and Alessio Fasano, MD who all helped with the study design for study 2.
Study 1 was funded by an award to K. N. Roy Chengappa (PI) by the Stanley Medical Research Institute, and Study 2 was funded by pilot funding from the Maryland Psychiatric Research Center to Deanna Kelly (PI).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- 4.Rothermundt M, Ohrmann P, Abel S, Siegmund A, Pedersen A, Ponath G, et al. Glial cell activation in a subgroup of patients with schizophrenia indicated by increased S100B serum concentrations and elevated myo-inositol. Prog Neuro-Psychopharmacol Biol Psychiatry. 2007;31(2):361–4.CrossRefGoogle Scholar
- 5.Steiner J, Bielau H, Bernsteinc HG, Bogerts B, Wunderlich MT. Increased cerebrospinal fluid and serum levels of S100B in first-onset schizophrenia are not related to a degenerative release of glial fibrillar acidic protein, myelin basic protein and neurone-specific enolase from glia or neurones. J Neurol Neurosurg Psychiatry. 2006;77(11):1284–7.CrossRefGoogle Scholar
- 6.Rothermundt M, Ahn JN, Jörgens S. S100B in schizophrenia: an update. Gen Physiol Biophys. 2009; 28 Focus Issue:F76–81.Google Scholar