The relationship between caries index and stimulation of lymphocytes by Streptococcus mutans in mothers and their neonates

Abstract

A group of 31 mothers and their neonates were examined by the in-vitro lymphocyte transformation test to determine sensitization by Streptococcus mutans, plaque antigens and dextran and to correlate these with the caries indices of the mothers. A significant correlation was found between the caries index (DMF) and the proliferative response to Strep. mutans with both maternal ( p < 0.01) and neonatal ( p < 0.01) lymphocytes. The responses of maternal and neonatal lymphocytes to Strep. mutans showed some specificity as significant relationships were not found between the DMF and lymphocyte proliferation induced by plaque, Actinomyces viscosus, Veillonella alcalescens or purified protein derivative of Mycobacterium tuberculosis. In contrast, the degree of stimulation of neonatal lymphocytes induced by all tested antigens was significantly correlated ( p < 0.01) with the degree of stimulation of maternal lymphocytes. This, however, did not apply to the B-cell mitogen dextran which induced a significant response with neonatal but not maternal lymphocytes. IgG antibodies to Strep. mutans were found in both maternal and neonatal sera, but IgNt antibodies were present only in maternal sera, so that direct stimulation of the foetus with streptococcal antigens is unlikely to have occurred. The possibility needs to be examined that the passive transfer of IgG antibodies and a factor sensitising lymphocytes to Strep. mutans from the mother to the foetus might influence colonization of Strep. mutans during the initial 6–12 months of the infant's life.