Letters to the Editor

Indian Pediatrics 2001; 38: 1070-1071  

Sialic Acid Levels in Healthy Preterm and Fullerm Infants

Sialic acid is part of gangliosides which are carbohydrate-rich complex lipids of large size and great complexity which are found in cell membrances, especially neuronal cell membrances(1). We studied serum total sialic acid (TSA) levels in healthy preterm and full-term infants to determine the relationship between gestational age and TSA.

The study includes 38 preterm and 31 fullterm healthy infants. The gestational age of the preterm and fullterm infants were between 23 and 36 weeks (32.20 ± 2.80 weeks) and 38 and 40 weeks (39.15 ± 0.81 

weeks), respectively. The weight of the preterm and full-term infants were between 600-2300 g (1567 ± 442 g) and 2800-3550 g (3206 ± 183 g), respectively. Serum TSA levels were studied on the first day of life in both the groups by spectrophotometric method(3). The approximate cost of estimating serum TSA in each case was one dollar.

Serum TSA levels were 89.65 ± 6.12 mg/dl and 101.63 ± 9.78 mg/dl in preterm and fullterm infants, respectively (p <0.05). There was a statistically significant positive correlation between gestational age and serum TSA levels in preterm group (r = 0.325, p <0.05). Serum TSA level increased in correlation with gestational age.

Although gangliosides were discovered some 50 years ago, their potential role in neuronal functions has been appreciated only recently. During development, their composition and concentration change in a variety of animal species(1). Sasaki et al.(2) showed that the mean plasma ganglioside concentration in preterm infants was lower than that of full term infants at birth and they suggest that plasma ganglioside concentration may reflect the development and maturation of the central nervous system to some degree, at least early in the neonatal period. Our findings demonstrated that mean serum TSA level in preterms was lower than that of fullterms and there was a positive correlation between gestational age and serum TSA levels in preterm infants.

1. Gorio A. Ganglioside enhancement of neuronal differentiation, plasticity and repair. Crit Reve Clin Neurobiol 1986; 2: 241-296.

2. Barry GT, Abbott V, Tsai T. Relationship of colonimic acid (poly N-acetylneurominic acid) to bacteria which contain neurominic acid. J Gen Microbiol 1962; 29: 335-352.

3. Sasaki H, Momoi T, Yamanaka C, Kaji M, Mikawa H. Developmental changes of plasma ganglioside concentration during the neonatal period. Early Hum Dev 1989; 20: 143-150.