Risk of stillbirth in United States patients with diagnosed intrahepatic cholestasis of pregnancy.

BACKGROUND: Intrahepatic cholestasis of pregnancy is associated with a 4- to 10-fold increase in the risk of stillbirth in the absence of intervention, leading to recommendations for antenatal assessment, ursodiol use, and often preterm or early term delivery. OBJECTIVE: This study aimed to determine whether current management strategies for intrahepatic cholestasis of pregnancy mitigate the elevated risk of stillbirth at a population level. STUDY DESIGN: This was a retrospective cohort study using the 2015-2020 National Readmissions Database, an administrative database developed by the United States Agency for Healthcare Research and Quality. Our study identified delivery hospitalizations, gestational age at delivery, occurrence of intrahepatic cholestasis of pregnancy and stillbirth, and comorbid conditions using the International Classification of Diseases diagnosis and procedure codes. Moreover, this study compared the timing of delivery and stillbirth rates of pregnant patients with intrahepatic cholestasis of pregnancy vs those without intrahepatic cholestasis of pregnancy at the time of delivery hospitalization. RESULTS: This study identified a cohort of 9,987,705 delivery hospitalizations in the National Readmissions Database, corresponding to a weighted national estimate of 18,609,207 births. Of these births, 152,040 (0.8%) were noted to have an intrahepatic cholestasis of pregnancy diagnosis. Patients with an intrahepatic cholestasis of pregnancy diagnosis were older, with small differences in comorbidities, such as a higher rate of gestational diabetes mellitus, than patients without an intrahepatic cholestasis of pregnancy diagnosis at delivery hospitalization. The overall rates of stillbirth were lower among those with intrahepatic cholestasis of pregnancy than among those without intrahepatic cholestasis of pregnancy (252 vs 386 per 100,000 deliveries; risk difference, 133 fewer per 100,000 deliveries; 95% confidence interval, 98-170), a finding that persisted after adjustment for insurance status, socioeconomic factors, and comorbid conditions (risk difference, 160 fewer stillbirths per 100,000 deliveries; 95% confidence interval, 127-194). Furthermore, although patients with intrahepatic cholestasis of pregnancy were more likely to deliver before term than those without intrahepatic cholestasis of pregnancy (30.1% vs 9.3%; P<.001), increased rates of stillbirth were not noted at any point after stratification of the cohort by gestational age at delivery. CONCLUSION: Patients with intrahepatic cholestasis of pregnancy diagnosis codes delivered earlier than those without intrahepatic cholestasis of pregnancy diagnosis codes, but the percentage of births affected by stillbirth was lower, even when stratifying for gestational age at birth. These results may provide reassurance to patients receiving an intrahepatic cholestasis of pregnancy diagnosis that current management does mitigate stillbirth risk in intrahepatic cholestasis of pregnancy.

Formin-like 1 mediates effector T cell trafficking to inflammatory sites to enable T cell-mediated autoimmunity.

Lymphocyte migration is essential for the function of the adaptive immune system, and regulation of T cell entry into tissues is an effective therapy in autoimmune diseases. Little is known about the specific role of cytoskeletal effectors that mediate mechanical forces and morphological changes essential for migration in complex environments. We developed a new Formin-like-1 (FMNL1) knock-out mouse model and determined that the cytoskeletal effector FMNL1 is selectively required for effector T cell trafficking to inflamed tissues, without affecting naïve T cell entry into secondary lymphoid organs. Here, we identify a FMNL1-dependent mechanism of actin polymerization at the back of the cell that enables migration of the rigid lymphocyte nucleus through restrictive barriers. Furthermore, FMNL1-deficiency impairs the ability of self-reactive effector T cells to induce autoimmune disease. Overall, our data suggest that FMNL1 may be a potential therapeutic target to specifically modulate T cell trafficking to inflammatory sites.

Ena/VASP proteins regulate activated T-cell trafficking by promoting diapedesis during transendothelial migration.

Vasodilator-stimulated phosphoprotein (VASP) and Ena-VASP-like (EVL) are cytoskeletal effector proteins implicated in regulating cell morphology, adhesion, and migration in various cell types. However, the role of these proteins in T-cell motility, adhesion, and in vivo trafficking remains poorly understood. This study identifies a specific role for EVL and VASP in T-cell diapedesis and trafficking. We demonstrate that EVL and VASP are selectively required for activated T-cell trafficking but are not required for normal T-cell development or for naïve T-cell trafficking to lymph nodes and spleen. Using a model of multiple sclerosis, we show an impairment in trafficking of EVL/VASP-deficient activated T cells to the inflamed central nervous system of mice with experimental autoimmune encephalomyelitis. Additionally, we found a defect in trafficking of EVL/VASP double-knockout (dKO) T cells to the inflamed skin and secondary lymphoid organs. Deletion of EVL and VASP resulted in the impairment in α4 integrin (CD49d) expression and function. Unexpectedly, EVL/VASP dKO T cells did not exhibit alterations in shear-resistant adhesion to, or in crawling on, primary endothelial cells under physiologic shear forces. Instead, deletion of EVL and VASP impaired T-cell diapedesis. Furthermore, T-cell diapedesis became equivalent between control and EVL/VASP dKO T cells upon α4 integrin blockade. Overall, EVL and VASP selectively mediate activated T-cell trafficking by promoting the diapedesis step of transendothelial migration in a α4 integrin-dependent manner.