Risk of early recurrent fetal loss and levels of thrombin-activatable fibrinolysis inhibitor.

INTRODUCTION: Though thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to hypercoagulability during pregnancy, limited data are available on the role of TAFI in women with recurrent fetal loss. MATERIAL/METHODS: We performed a case-control study aimed at evaluating any possible association between TAFI levels and early recurrent fetal loss (≥ 3, or 2 with at least one normal fetal karyotype, before the 10th week of gestation). 140 women with early recurrent fetal loss and 140 age-matched healthy controls with at least one normal pregnancy were included. The number of miscarriages was 2.59 and occurred at gestational age 6.89 weeks. TAFI levels were determined by a chromogenic assay measuring total potential activatable TAFI. RESULTS: TAFI levels were significantly lower in early recurrent fetal loss women (12.2 ± 2.3 µg/ml vs 13.2 ± 2.6 µg/ml in healthy controls, p=0.001). ORs of early recurrent fetal loss (crude and adjusted for possible confounding variables) were calculated after stratification of TAFI levels into quartiles. 25/140 (17.8%) early recurrent fetal loss women had TAFI levels above 14.0 µg/ml (4th quartile) vs 44/140 (31.3%) in healthy women (p=0.014). Crude and adjusted ORs of early recurrent fetal loss in women with TAFI levels in the 4th quartile vs those in the reference category (1st quartile=below 11.0 µg/ml) were 0.42 (95%CI: 0.22-0.82) and 0.39 (95%CI: 0.19-0.80), respectively. CONCLUSIONS: Our study provides evidence that high TAFI levels are associated with reduced risk of early recurrent fetal loss. Further studies are needed to better understand the actual role of TAFI in recurrent fetal loss.

Anti-HuD-induced neuronal apoptosis underlying paraneoplastic gut dysmotility.

BACKGROUND & AIMS: The role of autoimmunity underlying paraneoplastic gut dysmotility remains unsettled. Because anti-Hu antibodies may impair enteric neuronal function, we tested whether anti-HuD-positive sera from patients with paraneoplastic gut dysmotility or commercial anti-HuD antibodies activated the apoptotic cascade in a neuroblastoma cell line and cultured myenteric neurons. METHODS: Anti-HuD antibodies from patients with severe paraneoplastic gut dysmotility were characterized by immunofluorescence and immunoblot. SH-Sy5Y neuroblasts and cultured myenteric neurons were exposed to sera containing anti-HuD antibodies or 2 commercial anti-HuD antibodies. Cells were processed for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) technique to evaluate apoptosis. Immunofluorescence was used to identify activated caspase-3 and apaf-1, along with microtubule-associated protein 2. RESULTS: In SH-Sy5Y cells, the percentage of TUNEL-positive nuclei observed after exposure to anti-HuD-positive sera (32% +/- 7%) or anti-HuD antibodies (23% +/- 2%) was significantly greater than that of control sera or fetal calf serum (P < 0.001). The time-course analysis showed a significantly greater number of apoptotic neuroblastoma cells evoked by the 2 commercial anti-HuD antibodies at 24, 48, and 72 hours versus controls. The number of TUNEL-positive myenteric neurons exposed to anti-HuD antibodies (60% +/- 14%) was significantly greater than that of fetal calf serum (7% +/- 2%; P < 0.001). Apaf-1 and caspase-3 immunolabeling showed intense cytoplasmic staining in a significantly greater proportion of cells exposed to anti-HuD-positive sera or to commercial anti-HuD antibodies compared with controls. CONCLUSIONS: Anti-HuD antibodies evoked neuronal apoptosis that may contribute to enteric nervous system impairment underlying paraneoplastic gut dysmotility. Apaf-1 activation suggests participation of a mitochondria-dependent apoptotic pathway.