Factors Influencing the Serum Haptoglobin Level in Infancy

Some factors which possibly influence the serum haptoglobin levels in infancy were investigated with Jayle's activation method which measures the peroxidase activity of the haemoglobin-haptoglobin complex. The following results were obtained. Sampling haemolysis, not visually detectable, has little influence on the determinations. Bilirubin added in a moderate concentration to serum samples decreases the peroxidase activity but the influence is of little practical importance except possibly at very low haptoglobin levels. Cord serum added to a normal serum does not decrease the peroxidase activity of the latter. It is concluded that cord serum does not contain to an appreciable amount substances inhibiting the formation of the haemoglobin-haptoglobin complex or its peroxidase activity.
The possible existence in cord serum of haptoglobins forming a complex with haemoglobin without peroxidase activity could not be demonstrated with a specially devised starch gel electrophoretic method.
It was shown that infants 2 to 5 months old on an average have a higher serum haptoglobin level during acute infections than healthy infants of the same age. It is possible that the same holds true also for infants younger than 2 months. This was, however, not proved.