Vaccine strains of Rift Valley fever virus exhibit attenuation at the maternal-fetal placental interface.

Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and human placenta explant cultures, we sought to identify tissues at the maternal-fetal interface targeted by RVFV. Sheep villi and fetal membranes were highly permissive to RVFV infection resulting in markedly higher virus titers than human cultures. Sheep cultures were most permissive to wild-type RVFV and ΔNSm infection, while live attenuated RVFV vaccines (LAVs; MP-12, ΔNSs, and ΔNSs/ΔNSm) exhibited reduced replication. The human fetal membrane restricted wild-type and LAV replication, and when infection occurred, it was prominent in the maternal-facing side. Type-I and type-III interferons were induced in human villi exposed to LAVs lacking the NSs protein. This study supports the use of sheep and human placenta explants to understand vertical transmission of RVFV in mammals and whether LAVs are attenuated at the maternal-fetal interface.

A highly potent human neutralizing antibody prevents vertical transmission of Rift Valley fever virus in a rat model.

Rift Valley fever virus (RVFV) is an emerging mosquito-transmitted virus that circulates in livestock and humans in Africa and the Middle East. Outbreaks lead to high rates of miscarriages in domesticated livestock. Women are also at risk of vertical virus transmission and late-term miscarriages. MAb RVFV-268 is a highly potent recombinant neutralizing human monoclonal antibody that targets RVFV. Here we show that mAb RVFV-268 reduces viral replication in rat placenta explant cultures and prevents vertical transmission in a rat model of congenital RVF. Passive transfer of mAb RVFV-268 from mother to fetus occurs as early as 6 h after administration and persists through 24 h. Administering mAb RVFV-268 2 h prior to RVFV challenge or 24 h post-challenge protects the dams and offspring from RVFV infection. These findings support mAb RVFV-268 as a pre- and post-infection treatment to subvert RVFV infection and vertical transmission, thus protecting the mother and offspring.

Prenatal and fetal diagnosis of trisomy 18 after low-risk cell-free fetal DNA screening: A report of four cases.

INTRODUCTION: Non-Invasive Prenatal Screening (NIPS) is a useful screening method for common aneuploidies that can occur in pregnancies. It yields high sensitivities and specificities for the targeted conditions it tests for. Most commonly, these include Trisomies in chromosomes 21, 18, and 13, as well as aneuploidies in chromosomes X and Y. It does not, however, replace diagnostic testing. We review four cases seen by our institutions of patients who had NIPS performed with low-risk results and subsequently had fetuses affected with trisomy 18. METHODS: All fetal samples were evaluated by level II anatomic ultrasound and tested on amniocytes or products of conception through karyotype or chromosomal microarray following low-risk NIPS. RESULTS: None of the fetuses showed evidence of mosaicism and had features (both on ultrasound and postnatally) consistent with Trisomy 18. Postnatal fluorescence in situ hybridization performed on Formalin-Fixed Paraffin-Embedded tissue from 3 of the affected pregnancies' placentas identified mosaicism of trisomy 18. DISCUSSION: We discuss the possible explanations for the discrepancy between NIPS results and fetal karyotype, including, but not limited to placental mosaicism, placental size, and limitations of NIPS as a screening test.

Impact of Ki-67 Labeling Index on Prognostic Significance of the Chemotherapy Response Score in Women With Tubo-ovarian Cancer Treated With Neoadjuvant Chemotherapy.

The chemotherapy response score (CRS) proposed by Bohm and colleagues in 2015 has been validated as a reproducible method for determining histopathologic response of tubo-ovarian carcinoma to neoadjuvant chemotherapy and stratifies tumor response into 3 groups: CRS1 is defined as minimal/no response, CRS2 as moderate response, and CRS3 as marked response. Although described as a 3-tiered system, it essentially works as a 2-tiered system (CRS1/CRS2 vs. CRS3) for assessing prognosis. Here, we analyzed the prognostic value of CRS in a large cohort of tubo-ovarian carcinomas at a tertiary care center and evaluated the potential for Ki-67 labeling index on post-neoadjuvant chemotherapy samples to provide additional prognostic information. We included 170 patients with tubo-ovarian carcinoma treated with neoadjuvant chemotherapy followed by interval debulking surgery. We determined CRS for each case by reviewing slides from the interval debulking surgery resection specimen and calculated progression-free survival and overall survival. For each case with residual disease (CRS1 and CRS2, n=123, 72%), we also performed Ki-67 antibody staining and determined both average and highest Ki-67 labeling index. Consistent with prior studies, patients in our cohort with CRS1 and CRS2 showed significantly shorter progression-free survival and overall survival compared with CRS3. Further, in the subset of cases with CRS1 and CRS2, Ki-67 labeling index was predictive of OS at multiple cutoff points. An average Ki-67 labeling index of 20% (log rank test P-value: 0.0004) or a highest Ki-67 labeling index of 50% (log rank test P-value: 0.0002) could provide a practically useful cutoff. Multivariable cox proportional hazard model showed worse overall survival with both, average Ki-67 >20% (hazard ratios: 2.02, P-value: 0.00422, confidence interval: 1.25-3.28) and highest Ki-67 >50% (hazard ratios: 1.88, P-value: 0.0205, confidence interval: 1.1-3.2). We propose adding Ki-67 labeling index to CRS to provide additional prognostic separation between patients with CRS1 and CRS2.

The role of macrophages during acute kidney injury: destruction and repair.

Acute kidney injury (AKI) is defined by a rapid decline in renal function. Regardless of the initial cause of injury, the influx of immune cells is a common theme during AKI. While an inflammatory response is critical for the initial control of injury, a prolonged response can negatively affect tissue repair. In this review, we focus on the role of macrophages, from early inflammation to resolution, during AKI. These cells serve as the innate defense system by phagocytosing cellular debris and pathogenic molecules and bridge communication with the adaptive immune system by acting as antigen-presenting cells and secreting cytokines. While many immune cells function to initiate inflammation, macrophages play a complex role throughout AKI. This complexity is driven by their functional plasticity: the ability to polarize from a "pro-inflammatory" phenotype to a "pro-reparative" phenotype. Importantly, experimental and translational studies indicate that macrophage polarization opens the possibility to generate novel therapeutics to promote repair during AKI. A thorough understanding of the biological roles these phagocytes play during both injury and repair is necessary to understand the limitations while furthering the therapeutic application.