DEVELOPMENT OF IMMUNOLOBULIN LEVELS IN MAN

The development of IgG, IgA, and IgM levels from birth, through the newborn period, infancy, childhood, and into adulthood has been studied with the use of 1,241 sera from 939 subjects. Rapid synthesis of IgM starts in the first week of postnatal life. This system expands to the adult levels by the age of about 1 year for boys and 2 years for girls. Boys and girls have similar IgM values until age 7, after which girls have higher values. IgA synthesis begins by 2 to 3 weeks of age, increases slowly, and attains adult levels by about 12 years. Rapid IgG synthesis probably begins by the first 4 to 6 weeks of life and adult levels are reached at about age 8 years. © 1968 The C. V. Mosby Company.