title: Cytotoxic reactivity of human natural killer (NK) cells during normal pregnancy: a longitudinal study.
abstract: A longitudinal analysis of natural killer (NK) cell-mediated cytotoxicity of maternal peripheral blood lymphocytes was carried out at various stages (16-36 weeks) of normal human pregnancy, within 1 week following delivery and up to 40 weeks post-partum. NK cell-mediated lysis of K562 target cells (TC) in short term 51Cr-release assays was significantly depressed throughout pregnancy, returning to control levels 9-40 weeks post-partum. Natural cytotoxicity of unseparated maternal peripheral blood was also substantially depressed at all stages of pregnancy and, in addition, remained impaired in the late post-partum period. Longitudinal enumeration of Leu 3a+ and Leu 2a+ lymphocytes indicated an absence of helper/suppressor T-cell imbalance during pregnancy, and analysis of Leu 7+ cells showed no difference in population sizes between control and pregnancy groups. Comparison of blood and lymphocyte cytotoxicity in control and pregnancy samples suggested a complex regulation of NK reactivity during pregnancy. The potential role in vivo of both plasma-associated and cellular regulatory elements is discussed.
mesh_terms: D000293:Adolescent; D000328:Adult; D003602:Cytotoxicity, Immunologic; D005260:Female; D005865:Gestational Age; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy; D013601:T-Lymphocytes / Q000145:classification