Levels of Neuron-Specific Enolase and S-100B in the Serum of Neonates in Early Diagnosis of Possible Neurotoxic Effects of Hyperbilirubinemia/ Hiperbilirubineminin Olası Erken Nörotoksik Etkilerini Belirlemede, Yenidoğanların Serumunda Neuron-Spesifik Eno

Abstract Aim: The laboratory and imaging methods are not sufficiently sensitive to determine precisely the neurotoxic effects of bilirubin in neonates. The neuron-specific enolase and calcium binding protein B, which are sensitive biomarkers of cellular damage in the central nerve system, were used in the present study to demonstrate possible neurotoxic effects of bilirubin below 20 mg/dL. We hypothesized that neuron-specific enolase and calcium binding protein B might be helpful for our purposes. Material and Methods: The present study included 33 full-term infants hospitalized for phototherapy treatment (patient group) along with 29 healthy full-term infants (control group). The serum bilirubin levels of the patient group were all below 20 mg/dl. Two serum samples were obtained from all 62 infants at an interval of at least 48hrs which were used for the measurement of bilirubin, calcium binding protein B, and neuron-specific enolase levels. Results: There was no significant difference in terms of the serum levels of calcium binding protein B between the patient and control groups but there was a significant difference of the serum levels of neuron-specific enolase between the groups. In addition, there were no significant changes in the levels of calcium binding protein B and neuron-specific enolase among the patient group before and after the phototherapy. Conclusion: We conclude that, considering the serum levels of calcium binding protein B and neuron-specific enolase, a serum bilirubin level of <20mg/dL had no neurotoxic effect on the central nerve system. The results of the present study are consistent with the accepted safe level of bilirubin, <20mg/dL, in a full-term newborn. Key Words: Bilirubin Encephalopathy; Neonatal Hyperbilirubinemia; Neuron-Specific Enolase; Calcium Binding Protein B. Ozet Amac: Yenidoganlarda bilirubinin norotoksik etkisini tam olarak gostermede, kullanilan laboratuvar ve goruntuleme metodlari yeterince hassas degildir. Calismamizda 20mg/dl’in altindaki bilirubinin muhtemel norotoksik etkisini gosterebilmek icin, santral sinir sistemindeki hucresel hasari gosteren hassas belirtecler olan noron-spesifik enolaz ve kalsiyum baglayici protein B kullanildi. Calismamiz noron-spesifik enolaz ve kalsiyum baglayici protein B duzeylerini olcmenin, bu amac icin uygun olabilecegi hipotezi uzerine kurgulandi. Gerec ve Yontemler: Calismada fototerapi tedavisi icin hastaneye yatisi yapilan 33 term bebek (hasta gurubu) ve 29 saglikli term bebek (kontrol grubu) yer aldi. Fototerapi almasi gereken bebeklerin serum bilirubin duzeyleri 20mg/dl’nin altinda idi. Butun bebeklerden, bilirubin, noron-spesifik enolaz ve kalsiyum baglayici protein B seviyelerini olcmek icin, en az 48 saat arayla iki serum ornegi alindi. Bulgular: Hasta ve kontrol gruplarinin kalsiyum baglayici protein B seviyeleri arasinda anlamli bir fark bulunmadi fakat noron-spesifik enolaz degerleri arasinda anlamli bir fark bulundu. Hasta grubunda fototerapi oncesi ve sonrasi noron-spesifik enolaz ve kalsiyum baglayici protein B degerleri arasinda anlamli bir degisim gozlenmedi. Sonuc: Kalsiyum baglayici protein B ve noron-spesifik enolaz serum duzeyleri referans alindiginda , 20mg/dl’in altindaki serum bilirubin degerlerinin norotoksik etkisi olmadigi sonucuna vardik. Bu calismanin sonuclari, term bebeklerde kabul edilen guvenli bilirubin seviyesi olan 20mg/dl ile uyumludur. Anahtar Kelimeler: Bilirubin Ensefalopati; Neonatal Hiperbilirubinemi; Noron-Spesifik Enolaz; Kalsiyum Baglayici Protein B.