718 ABNORMALITIES IN FAT-SOLUBLE VITAMIN STATUS AT THE TIME OF DIAGNOSIS IN INFANTS WITH CYSTIC FIBROSIS IDENTIFIED BY NEWBORN SCREEN

Abstract

We have previously reported evidence of early protein malnutrition in some infants with cystic fibrosis (CF) identified by the newborn screening method using serum immunoreactive trypsinogen. We now report very early abnormalities in the status of fat-soluble vitamins in 6 of 10 infants (mean age, 5.7 weeks; range, 3-8 weeks) with CF identified by screening in 1984. Plasma retinol (PR) and γ and α-tocopherol (α-Toc) levels were measured by HPLC. Retinol binding protein (RBP) levels were measured by radial immunodiffusion. Total serum lipids, serum albumin, calcium, and phosphorus were measured by standard methods. Four infants had low levels of serum albumin (<3.2 g/dL), low levels of α-Toc (<3.0 μg/ml), and low total tocopherols/total serum lipid ratios (<0.6 mg/gm). Three of these infants had RBP levels of 1.5 mg/dl (normal, 1.4-3.3 mg/dL). PR levels were low in 5 infants (<20 μg/dL). PIVKA-II assays (by plasma immunoelectropheresis before and after BaCC3 absorption, representing noncarboxylated prothrombin specific for Vitamin K deficiency) were negative in all infants. Serum calcium and phosphorus levels were not low, suggesting adequate Vitamin D status. We conclude that as early as 6 weeks of age, some infants with CF have biochemical deficiencies of the fat-soluble vitamins A and E. However, these infants, all of whom had parenteral Vitamin K prophylaxis at birth, were not Vitamin K deficient.