Studies on the Relation Between Serum and Spinal Fluid Bilirubin During Early Infancy1

Abstract
Simultaneous samples of serum bilirubin and spinal fluid bilirubin, protein and 410 mu heme peak have been obtained in 100 newborn infants and a number of older controls with jaundice. A positive correlation coefficient (r equals + 0.58) was obtained between the serum and spinal fluid bilirubin levels. The SB/SFB ratio was the lowest among the smallest and youngest infants. The ratio increased more with weight at birth than with age. The SB/SFB ratio was not significantly altered in infants with erythro-blastosis fetalis. Similarly, the concentration of bilirubin in the serum had little effect upon the SB/SFB ratio. A positive correlation coefficient (r equals + 0.67) was obtained between the spinal fluid bilirubin and total protein. The spinal fluid protein tended to be lower among the more mature infants. A positive correlation coefficient (r equals + 0.86) was obtained between the spinal fluid bilirubin and the 410 mu heme pigment. However, no significant difference existed in the 410 mu heme peak in the spinal fluid of infants with erythroblastosis fetalis and normal full term controls. The significance of these findings in the pathogenesis of kernicterus was discussed.