Monocyte Phagocytosis and Loss of Periodontal Attachment In Down Syndrome

Objectives: this study investigated the phagocytic function of peripheral granulocytes and monocytes from adult individuals with Down syndrome (DS) and assessed the relation between phagocytic function and periodontal status.

Methods: 55 DS individuals (18-56 years old), 74 mentally retarded (MR) individuals and 88 medically healthy controls (HC) participated in the study. Clinical periodontal measures including attachment level (AL) were recorded. Whole blood was collected for granulocyte/monocyte phagocytosis tests. Phagocytic function was determined by flow cytometry in terms of percentage of cells actively involved in phagocytosis, and phagocytic intensity (magnitude of the bacterial staining per cell).

Results: in DS individuals phagocytic intensity of both granulocytes and monocytes was comparable to HC subjects. In all subjects, monocyte phagocytic intensity showed a low positive association with AL (r=0.2, p=0.003). Regression analysis controlling for risk factors for periodontitis and factoring DS and MR status upheld the association between monocyte phagocytosis intensity and AL (p<0.05), showed an independent adverse effect of DS on AL (p<0.05) and a significant interaction between monocyte phagocytic intensity and DS status on AL (p<0.05).

Conclusions: monocyte phagocytic intensity in DS individuals is unimpaired and contributes to loss of periodontal attachment in these individuals.

Supported by NIDCR: DE15012-02