Serum ImmunoglobulinD in infants and children

Serum immunoglobulinD (IgD) concentration is usually low in healthy individ uals as compared to other immunoglobulin classes. Most studies on serum IgD are concerned with serum levels in healthy adults but reference values for young children and infants are not easily available. In order to establish age specific reference values we measured IgD levels in serum of 184 healt hy Icelandic children, age 0-14 years and 60 healthy blood donors age 18-63 , using the ELISA technique. Special attention was paid to the youngest age groups. Results showed low IgD values in infants and young children, gradu ally increasing until the age of 10 but then decreasing with age. We conclu de that IgD gradually increases with age in childhood as other immunoglobul in classes but later declines. These findings can be of importance in revea ling the function of IgD in the immune system as well as in the diagnosis o f the hyper-IgD syndrome.