Spontaneous lymphocyte proliferation and the periodontal status of young adults

The objective of this study was to determine if the level of incorporation of 3H‐thymidine in unstimulated cultures of peripheral blood lymphocytes obtained from young adults differs as a function of their periodontal status. Kinetic studies using normal PBL indicated that the rate of 3H‐thymidine uptake in unstimulated cultures began to increase markedly by day 5 of culture, peaked about day 7, and then declined. When this spontaneous lymphocyte proliferative response in young adults with a healthy periodontium (HP) was compared with the response obtained from young adults with severe periodontitis (SP) and individuals with juvenile periodontitis (JP), it was observed that responses in the SP group were markedly depressed at day 5 and day 7. In contrast, responses in the JP group were nearly identical to the HP controls. Periodontal treatment of the SP group appeared to restore normal responsiveness. We believe the most likely bases for these responses to be autologous mixed lymphocyte culture reactions. The suppression of the spontaneous response in the untreated SP group may reflect changes in regulatory T‐cell function induced by a state of active disease.