Serum neuron-specific enolase levels in preterm and term newborns and infants 1-3 months of age

Neuron-specific enolase (NSE), assumed specific to neural tumors particularly to neuroblastoma in its first definition, was determined to increase in non-tumoral conditions subsequent to the observations of its increase in various tumors, which necessitates the standardization studies in normal individuals. Diagnosis chance of asymptomatic masses is increased, for the neuroblastoma is the most common tumor encountered in neonatal period and ultrasonography is frequently used in prenatal and newborn medicine. In this study, serum NSE levels were determined in healthy preterm, term and early infancy less than 3 months periods by age group. Necessary attention was paid for babies not to have any problem other than prematurity and physiological hyperbilirubinaemia. Serum NSE samples were taken in no earlier than 72 hours after the birth in order to eliminate hypoxia and stress at delivery. The determination of NSE levels was carried out by ECLIA method using Roche Elecysys 2010 device. Babies with over 30 ng/mL of NSE level were called for control to collect serum samples and examine their health conditions; consequently, NSE determination was repeated in necessary cases. Subjects diagnosed with additional problems were excluded from the study group, and the groups where the number of subjects was decreased were supplemented with new cases to reach the predetermined subject number. NSE levels were studied in 139 babies; in preterm and term periods each containing 39 and 40 babies , as well as in one-month, two-month and three-month infancy periods each containing 20 babies. The mean NSE level was determined in these groups as 21,83±15,06; 18,06±12,90; 8,92±4.13; 7,63±3,91; and 10,73±4,70 respectively, and the maximum serum levels were 59,36; 59,80; 16,80; 14,05; 21,40 ng/mL respectively. NSE levels of preterm and term babies were found significantly higher than babies aged one month or older (p<0,001). The maximum levels determined in groups were even more striking. As a result of this study, of which no equivalent was encountered in the literature, it was concluded that serum NSE levels were evidently higher in preterm and term babies compared to babies aged one month or older, and therefore, commercial kit reference values cannot be used for babies in these age groups.