[Changes in T-lymphocyte subsets of peripheral blood in unexplained habitual abortion]

T-lymphocyte subsets of peripheral blood were examined by flow cytometry (FCM) in 20 cases of unexplained habitual abortion (UHA) before and after active immunization treatment, with 10 normal pregnant (NP) women and 20 normal nonpregnant (NNp) women as control.

there was no difference in the percentage of CD3 cells between the UHA cases and NNP. Before immunization the percentage of CD8 cells was significantly lower (P < 0.001) and the ratio of CD4/CD8 was increased (P < 0.05) in UHA as compared with the NNP. However, after immunization, the percentage of CD8 cells greatly increased (P < 0.05) and CD4/CD8 ratio decreased significantly (P < 0.05) nearly to that of NP. These findings suggest that: (1) the increase of CD4/CD8 ratio due to the decreasing CD8 cells is the underlying immunomechanism of UHA; (2) immunization may induce the proliferation of CD8 cells and the lowering of CD4/CD8 ratio. Therefore, CD8 cells might play an important role in maintaining the balance of fetal-maternal immunological relationship; (3) the ratio of CD4/CD8 may served as parameter for observing the clinical efficacy of immunization therapy.