Aim: Thelaboratory 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
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.
Özet
Amaç: Yenidoğanlarda bilirubinin nörotoksik etkisini tam olarak göstermede, kullanılan laboratuvar ve görüntüleme metodları yeterince hassas değildir. Çalışmamızda 20mg/dl’in altındaki bilirubinin muhtemel nörotoksik etkisini gösterebilmek için, santral sinir sistemindeki hücresel hasarı gösteren hassas belirteçler olan nöron-spesifik enolaz ve kalsiyum bağlayıcı protein B kullanıldı. Çalışmamız nöron-spesifik enolaz ve kalsiyum bağlayıcı protein B düzeylerini ölçmenin, bu amaç için uygun olabileceği hipotezi üzerine kurgulandı.
Gereç ve Yöntemler: Çalışmada fototerapi tedavisi için hastaneye yatışı yapılan 33 term bebek (hasta gurubu) ve 29 sağlıklı term bebek (kontrol grubu) yer aldı. Fototerapi alması gereken bebeklerin serum bilirubin düzeyleri 20mg/dl’nin altında idi. Bütün bebeklerden, bilirubin, nöron-spesifik enolaz ve kalsiyum bağlayıcı protein B seviyelerini ölçmek için, en az 48 saat arayla iki serum örneği alındı.
Bulgular: Hasta ve kontrol gruplarının kalsiyum bağlayıcı protein B seviyeleri arasında anlamlı bir fark bulunmadı fakat nöron-spesifik enolaz değerleri arasında anlamlı bir fark bulundu. Hasta grubunda fototerapi öncesi ve sonrası nöron-spesifik enolaz ve kalsiyum bağlayıcı protein B değerleri arasında anlamlı bir değişim gözlenmedi.
Sonuç: Kalsiyum bağlayıcı protein B ve nöron-spesifik enolaz serum düzeyleri referans alındığında, 20mg/dl’in altındaki serum bilirubin değerlerinin nörotoksik etkisi olmadığı sonucuna vardık. Bu çalışmanın sonuçları, term bebeklerde kabul edilen güvenli bilirubin seviyesi olan 20mg/dl ile uyumludur.
Anahtar Kelimeler: Bilirubin Ensefalopati; Neonatal Hiperbilirubinemi; Nöron-Spesifik Enolaz; Kalsiyum Bağlayıcı Protein B.
Birincil Dil | İngilizce |
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Bölüm | Makaleler |
Yazarlar | |
Yayımlanma Tarihi | 10 Nisan 2015 |
Yayımlandığı Sayı | Yıl 2015 Cilt: 22 Sayı: 1 |