Transfer of tuberculin immunity from mother to infant.

The purpose of our study was to investigate transfer of tuberculin immunity from mother to infant via breast milk by studying newborn lymphocyte blastogenesis induced by purified protein derivative antigen at 1-5 days of age, 4-6 wk of age, and 3 months of age. Our study consisted of four mother-infant groups: breast-feeding and bottle-feeding infants of tuberculin-positive and tuberculin-negative mothers. A difference in the groups was found only at 4-6 wk of age where 17% (4/23) of breast-feeding infants and 13% (2/15) of bottle-feeding infants of tuberculin positive mothers had lymphocyte blastogenesis to purified protein derivative. None of the infants of tuberculin negative mothers had purified protein derivative-induced blastogenesis. Analysis of covariance with tests for equality of slopes showed that the responses of tuberculin-positive mothers were significantly different from the responses of tuberculin-negative mothers (p less than 0.05). These studies suggest transplacental transfer of tuberculin immunity evident at 4-6 wk of age which wanes by 3 months of age. We could not find evidence of transfer via human milk.