Humoral immunity in Down's syndrome.

Carried out on 57 outpatients, the study was aimed to prove the existence of a disgammaglobulinemia in Down's syndrome. The event could not be attributed to hospitalization. Data indicate increased A and G immunoglobulinemias. In agreement with other authors Ig A level was found to be very high especially after the age of 5. Ig M titre in patients was reduced in comparison with that of the controls, regardless of the age group. Increase timing of IgA and Ig G concentrations tends to be more marked for the Ig A fraction. In patients ranging from 0 to 5 years the Ig A serum level is deficient.