Butyrylcholinesterase activity and lymphocyte subpopulations in peripheral blood of Kuwaiti women experiencing recurrent spontaneous abortion.

This study has evaluated the hypothesis that activity of the detoxifying enzyme butyrylcholinesterase (BuChE) correlates with levels of serum anti-cardiolipin antibodies (ACA) and T lymphocytes in peripheral blood of women experiencing recurrent spontaneous abortion (RSA). Peripheral venous blood from 16 non-pregnant, RSA-afflicted women and 8 healthy non-pregnant women was analyzed for frequency of T lymphocyte subpopulations by two-color flow cytometry and for serum BuChE using butyrylthiocholine iodide/spectrophotometry. RSA-afflicted women with high serum ACA, but not those with normal ACA levels, exhibited significantly increased percentages of CD4+CD25+ cells (p<0.01) and CD4+HLA-DR+ cells (p<0.05) relative to healthy women. CD4+CD25+(high) cells were significantly lower (p<0.05), while CD4+CD25+(low) cells were significantly higher (p<0.01), in women with elevated ACA compared to healthy women and to RSA women with normal ACA. Relative to healthy, non-pregnant subjects, serum BuChE activity in RSA patients was elevated, both for those with normal ACA (p<0.001) and elevated ACA levels (p<0.01). Among healthy controls, a significant positive correlation was observed between frequency of CD3+NK cells and BuChE activity (p<0.01), but not for RSA-afflicted subjects. A positive correlation between BuChE activity and frequency of CD4+CD25+ cells, as well as CD4+CD25+(high) cells, was observed in the RSA-afflicted subject group with elevated ACA (p<0.05), which may be related to induction of BuChE by toxic metabolites resulting from pathogenic T cell activity. It is concluded that, among RSA patients, high serum ACA correlates with elevated levels of activated T cells and reduced CD4+CD25+(high)/CD4+CD25+(low) cells in comparison to healthy women or those afflicted with RSA but with normal ACA. BuChE activity is observed to be elevated in RSA patients irrespective of serum ACA status.