[Dissertations 25 years after date 35. Periodontal disease in Down syndrome: an immunological disorder].

In Down syndrome the prevalence of periodontal disease is high. Twentyfive years ago in a series of controlled experiments, based on an experimental gingivitis model, clinical, histological and immunological characteristics of a group children with Down syndrome and matched control children were evaluated. In the Down syndrome children the gingival inflammation occurred earlier and was more extensive. On the tissue level the early response was characterized by a polymorphonuclear leucocytes response. Chemotaxis assays were performed to rule out impaired function. It was found that random migration for the peripheral blood-polymorphonuclear leucocytes and chemotaxis in both groups of children were comparable; hence such a factor cannot be responsible the early polymorphonuclear leucocytes' response in the children with Down syndrome. The most striking feature in the group with Down syndrome was the delayed and impaired response of lymphocytes during plaque development compared to the controls. This impaired lymphocyte function was also observed in a pilot study on 1 child with Down syndrome. It showed a less pronounced T cell suppressor function and a lack of immune regulation. The high level of gingival inflammation in children with Down syndrome must therefore be related to their impaired adaptive immunity.