Quantification of circulating fetal DNA as a tool for potential monitoring of pregnant patients with antiphospholipid antibodies.

Apoptosis of tissues of fetal origin is thought to be one of the main sources of cell-free fetal DNA (cffDNA) in maternal circulation, impaired apoptosis is also involved in the mechanisms contributing to recurrent spontaneous miscarriages (RSM) associated with antiphospholipid syndrome (APS). The APS increases the risk for preeclampsia nine times. In preeclampsia, the elevated levels of cffDNA were described by different authors. To our knowledge, cffDNA in pregnant patients with APS was never studied. In our pilot study, we focused on the levels of cffDNA in four pregnant patients with treated primary APS and compared them with values obtained in twenty-one healthy subjects of comparable gestation age (the third trimester of pregnancy). We supposed that the increase of cffDNA concentration in our treated patients would signalize the elevated apoptosis of fetal tissues as in other pathological changes of placentation. The aim of our pilot study was to determine cffDNA concentrations in patients with treated APS and to compare them with values detected in healthy pregnant women of comparable gestation age in order to discover potential non-physiological elevations in patients. The elevated values of cffDNA were not observed in our patients (p value = 0.4363, Mann-Whitney test). All patients delivered healthy children. The measurement of concentrations of cffDNA seems to be a promising tool for monitoring of therapy effectiveness in pregnant women with APS but evaluation of randomized controlled trials would be necessary to determine the specificity and the sensitivity of this test.