Serum Protein Values in Premature Infants

The present investigations were stimulated by an interest in the effect of feeding larger amounts of protein to premature infants than provided by human milk. Twenty-one premature infants between 1500 and 2400 gm in weight and 1 and 56 days of age were studied. The total serum protein and the serum-protein components were determined by paper electrophoresis. During an initial 8 weeks of the experiment the infants received human milk; later 10 of them received additional protein from a skimmed-milk preparation containing 89% casein. During the first 8 weeks the concentration of total protein in the serum decreased from 5.63 to 4.03 gm/100 ml. The decrease was in the albumin fraction (from 3 to 2 gm/100 ml) and the gammaglobulin fraction (from 1 to 0.5 gm/100 ml). The other globulin fractions remained constant. Casein added to the diet resulted in concentrations of total serum protein and serum albumin at higher levels, but the decrease with increasing age was not prevented. The decrease in gamma globulin, concurrent with increasing age, was not prevented by additional casein, on the contrary resulted in a further decrease. The author relates this to other studies in which a lower frequency of infection was found in premature infants fed on human milk than in infants fed on human milk with additional protein.