The effect of institutionalisation on elevated IgD and IgG levels in patients with Down's syndrome.

Serum levels of IgA, IgD, IgE, IgG, IgM and levels of secretory IgA (S-IgA) in nasal specimens were quantitated by radial immunodiffusion in a group of forty-one institutionalised patients with Down's syndrome (all non-disjunctive trisomy-G karyotype) and their age, sex and race matched controls, consisting of institutionalised non-mongols and normal non-institutionalised subjects. Analysis of levels of all immunoglobulins by age and sex showed no differences within the populations. However, levels of IgA, IgD and IgG were found significantly higher in mongols than in the other two populations. The concentrations of IgM were lower in mongols than in other institutionalised retardates but higher than non-institutionalised normal controls. Levels of S-IgA or IgE were similar in all populations. It was shown that the length of institutionalisation was associated with elevated levels of IgA and depressed levels of IgM in mongols. However, elevated IgG levels in mongols did not appear to be associated with their length of institutionalisation. Similarly, elevated levels of IgD in mongols were not associated with their length of institutionalisation.