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Response: S100B protein and amniotic fluid by Tort et al.
Clinica Chimica Acta 335 (2003) 167 www.elsevier.com/locate/clinchim
Letter to the Editor Response: S100B protein and amniotic fluid by Tort et al.
the clue to reveal the biological role of this challenging protein.
Data on an increase of S100B in amniotic fluid consistently presented in our study [1] and by Portela et al. [2] suggest S100B measurements as an additional diagnostic tool for Down syndrome. In our opinion, the search for a possible biological role of S100B in amniotic fluid, far from being conclusively elucidated, as the function of S100B tout-court, promises to be even more interesting. In this respect, it is reasonable to believe that the correlation of amniotic S100B concentration with gestational age and ecographic parameters such as head circumference and biparietal diameter [3] reflects a still unknown function of this protein in amniotic fluid, possibly consistent with the hypothesis that S100B acts as a neurotrophic cytokine. In addition, S100B concentration has recently been shown to be higher (approximately double) in monoamniotic than in diamnotic twins and singleton pregnancies [4]. This finding appears to support the hypothesis that each fetus releases a physiologically defined aliquot of the protein, again in accordance with a possible role of S100B as a cytokine. In order to study of the role of amniotic S100B, the definition of its source is a necessary prerequisite. The fetal nervous system, where the protein has been shown to be present at the ages investigated [5] at present, appears to be the most reasonable source for much of amniotic S100B. At this stage of maturation, the presence of the protein in other sites where S100B is concentrated in adults, such as adipose tissue [6], has not been demonstrated. Nonetheless, placental tissues have also been shown to contain S100B in concentrations that vary in relation to gestational age [7], so that the possibility that the protein derives partly from the placenta has to be taken into account. The above data constitute the basis for future studies oriented at searching in the amniotic fluid
References [1] Gazzolo D, Bruschettini M, Corvino V, Lituania M, Sarli R, Bruschettini P, et al. Amniotic fluid levels of S100B protein in normal and trisomy-21 foetuses. Clin Chim Acta 2003;330: 131 – 3. [2] Portela LC, Tort ABL, Neto EC, Kessler RG, Penchaszadeh V, Souza DO, et al. High immunocontent of S100B protein in amniotic fluid of pregnancies with Down syndrome. Ultrasound Obstet Gynecol 2000;16:590 – 1. [3] Gazzolo D, Bruschettini M, Corvino V, Sarli R, Lituania M, Bruschettini PL, et al. S100B protein concentrations in amniotic fluid are correlated with gestational age and with cerebral ultrasound scanning parameters results in healthy fetuses. Clin Chem 2001;47:954 – 6. [4] Gazzolo D, Lituania M, Bruschettini M, Bruschettini PL, Michetti F. S100B protein concentrations in amniotic fluid are higher in monoamniotic than in diamniotic twins and singleton pregnancies. Clin Chem 2003;49:997 – 9. [5] Michetti F, Gazzolo D. S100B protein in biological fluids: a tool for perinatal medicine. Clin Chem 2002;48:2097 – 104. [6] Michetti F, Dell’Anna E, Tiberio G, Cocchia D. Immunochemical and immunocytochemical study of S100 protein in rat adipocytes. Brain Res 1983;262:352 – 6. [7] Marinoni E, Di Iorio R, Gazzolo D, Lucchini C, Michetti F, Corvino V, et al. Ontogenic localization and distribution of S100beta protein in human placental tissues. Obstet Gynecol 2002;99:1093 – 9.
0009-8981/03/$ - see front matter D 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0009-8981(03)00198-0
Diego Gazzolo* Department of Pediatrics, Giannina Gaslini Children’s University Hospital, I-16148, Genoa, Italy E-mail address: [email protected] Fabrizio Michetti Institute of Anatomy and Cell Biology, Catholic University, I-00168, Rome, Italy 9 April 2003 * Corresponding author.
Letter to the Editor Response: S100B protein and amniotic fluid by Tort et al.
the clue to reveal the biological role of this challenging protein.
Data on an increase of S100B in amniotic fluid consistently presented in our study [1] and by Portela et al. [2] suggest S100B measurements as an additional diagnostic tool for Down syndrome. In our opinion, the search for a possible biological role of S100B in amniotic fluid, far from being conclusively elucidated, as the function of S100B tout-court, promises to be even more interesting. In this respect, it is reasonable to believe that the correlation of amniotic S100B concentration with gestational age and ecographic parameters such as head circumference and biparietal diameter [3] reflects a still unknown function of this protein in amniotic fluid, possibly consistent with the hypothesis that S100B acts as a neurotrophic cytokine. In addition, S100B concentration has recently been shown to be higher (approximately double) in monoamniotic than in diamnotic twins and singleton pregnancies [4]. This finding appears to support the hypothesis that each fetus releases a physiologically defined aliquot of the protein, again in accordance with a possible role of S100B as a cytokine. In order to study of the role of amniotic S100B, the definition of its source is a necessary prerequisite. The fetal nervous system, where the protein has been shown to be present at the ages investigated [5] at present, appears to be the most reasonable source for much of amniotic S100B. At this stage of maturation, the presence of the protein in other sites where S100B is concentrated in adults, such as adipose tissue [6], has not been demonstrated. Nonetheless, placental tissues have also been shown to contain S100B in concentrations that vary in relation to gestational age [7], so that the possibility that the protein derives partly from the placenta has to be taken into account. The above data constitute the basis for future studies oriented at searching in the amniotic fluid
References [1] Gazzolo D, Bruschettini M, Corvino V, Lituania M, Sarli R, Bruschettini P, et al. Amniotic fluid levels of S100B protein in normal and trisomy-21 foetuses. Clin Chim Acta 2003;330: 131 – 3. [2] Portela LC, Tort ABL, Neto EC, Kessler RG, Penchaszadeh V, Souza DO, et al. High immunocontent of S100B protein in amniotic fluid of pregnancies with Down syndrome. Ultrasound Obstet Gynecol 2000;16:590 – 1. [3] Gazzolo D, Bruschettini M, Corvino V, Sarli R, Lituania M, Bruschettini PL, et al. S100B protein concentrations in amniotic fluid are correlated with gestational age and with cerebral ultrasound scanning parameters results in healthy fetuses. Clin Chem 2001;47:954 – 6. [4] Gazzolo D, Lituania M, Bruschettini M, Bruschettini PL, Michetti F. S100B protein concentrations in amniotic fluid are higher in monoamniotic than in diamniotic twins and singleton pregnancies. Clin Chem 2003;49:997 – 9. [5] Michetti F, Gazzolo D. S100B protein in biological fluids: a tool for perinatal medicine. Clin Chem 2002;48:2097 – 104. [6] Michetti F, Dell’Anna E, Tiberio G, Cocchia D. Immunochemical and immunocytochemical study of S100 protein in rat adipocytes. Brain Res 1983;262:352 – 6. [7] Marinoni E, Di Iorio R, Gazzolo D, Lucchini C, Michetti F, Corvino V, et al. Ontogenic localization and distribution of S100beta protein in human placental tissues. Obstet Gynecol 2002;99:1093 – 9.
0009-8981/03/$ - see front matter D 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0009-8981(03)00198-0
Diego Gazzolo* Department of Pediatrics, Giannina Gaslini Children’s University Hospital, I-16148, Genoa, Italy E-mail address: [email protected] Fabrizio Michetti Institute of Anatomy and Cell Biology, Catholic University, I-00168, Rome, Italy 9 April 2003 * Corresponding author.