[Changes in T-cell subpopulations in normal pregnancy and in patients with spontaneous abortion]

From the immunological point of view, pregnancy is a privileged allograft, with complex mechanisms of adaptation within the maternal immune system preventing rejection. The importance of lymphocytes and their specific subsets for this mechanism is a controversial issue. This study was designed to examine changes within T-cell subsets during uneventful pregnancy and to evaluate their significance by comparison with findings in patients undergoing spontaneous pregnancy loss. When compared to non-pregnant control subjects, normal pregnant women showed significantly decreased numbers for peripheral T-lymphocytes, for helper/inducer-T-cells and for the helper/suppressor-T-cell ratio (T4/T8). In contrast, patients undergoing spontaneous abortion showed a significantly elevated T4/T8-ratio, if compared to normal pregnant women. The clinical relevance of these findings is uncertain. Nevertheless, in individual cases of spontaneous miscarriage, the analysis of T-cell subsets might indicate a possible immunological aetiology.