Case Report of a Young Adult with Fatal COVID-19 and Abundant SARS-CoV-2 Nucleocapsid Protein and Lipofuscin Accumulation in Tissues.

This is a case report of a young adult who died of COVID-19 twelve days after admission, with coronavirus nucleocapsid protein and lipofuscin found in the heart and kidney tissues, providing further evidence of the role of SARS-CoV-2 in cellular senescence.

First-trimester plasma extracellular heat shock proteins levels and risk of preeclampsia.

Preeclampsia (PE) occurs annually in 8% of pregnancies. Patients without risk factors represent 10% of these. There are currently no first-trimester biochemical markers that accurately predict PE. An increase in serum 60- and 70-KDa extracellular heat shock proteins (eHsp) has been shown in patients who developed PE at 34 weeks. We sought to determine whether there is a relationship between first-trimester eHsp and the development of PE. This was a prospective cohort study performed at a third level hospital in Mexico City from 2019 to 2020. eHsp levels were measured during the first-trimester ultrasound in singleton pregnancies with no comorbidities. First-trimester eHsp levels and biochemical parameters of organ dysfunction were compared between patients who developed preeclampsia and those who did not. All statistical analyses and model of correlation (r) between eHsp and clinical parameter were performed using bootstrapping R-software. p-values <0.05 were considered significant. The final analysis included 41 patients. PE occurred in 11 cases. eHsp-60 and eHsp-70 were significantly higher at 12 weeks in patients who developed PE (p = 0.001), while eHsp-27 was significantly lower (p = 0.004). Significant differences in first-trimester eHsp concentration suggest that these are possible early biomarkers useful for the prediction of PE.

Cord Blood SARS-CoV-2 IgG Antibodies and Their Association With Maternal Immunity and Neonatal Outcomes.

Passive transplacental immunity is crucial for neonatal protection from infections. Data on the correlation between neonatal immunity to SARS-CoV-2 and protection from adverse outcomes is scarce. This work aimed to describe neonatal seropositivity in the context of maternal SARS-CoV-2 infection, seropositivity, and neonatal outcomes. This retrospective nested case-control study enrolled high-risk pregnant women with a SARS-CoV-2 RT-PCR positive test who gave birth at the Instituto Nacional de Perinatología in Mexico City and their term neonates. Anti-SARS-CoV-2 IgG antibodies in maternal and cord blood samples were detected using a chemiluminescent assay. In total, 63 mother-neonate dyads (mean gestational age 38.4 weeks) were included. Transplacental transfer of SARS-CoV-2 IgG occurred in 76% of neonates from seropositive mothers. A positive association between maternal IgG levels and Cycle threshold (Ct) values of RT-qPCR test for SARS-CoV-2 with neonatal IgG levels was observed. Regarding neonatal outcomes, most seropositive neonates did not require any mechanical ventilation, and none developed any respiratory morbidity (either in the COVID-19 positive or negative groups) compared to 7 seronegative neonates. Furthermore, the odds of neonatal respiratory morbidity exhibited a tendency to decrease when neonatal IgG levels increase. These results add further evidence suggesting passive IgG transfer importance.

Viral infections in stillbirth: a contribution underestimated in Mexico?

OBJECTIVES: To analyze the role of viral infections as etiology of stillbirths in Mexico and their epidemiological impact in the context of the global Every Newborn Initiative. METHODS: A comprehensive literature search was performed in electronic databases related to stillbirth and viral infections published prior to January 19th 2021. Stillbirths records and causes from National Mexican databases, during 2008-2019 period were also computed. RESULTS: Only two articles with a direct relationship between viral infection and stillbirth were found, and one article with an indirect serological association was identified. During the analyzed period there were 198,076 stillbirths, with a National stillbirth rate (SBR) ranging from 6.9 to 6.5 between 2008 and 2014, with a subsequent increase to reach 7.7 in 2019. Only 19 cases were attributed to viral causes and a specific virus was identified in 11. The main causes of early stillbirth were a fetus with premature rupture of membranes and light for gestational age, and for late stillbirth these were fetus affected by oligohydramnios and slow fetal growth. The percentage classified as unspecified deaths varied from 34.4-41.9%. CONCLUSIONS: In Mexico, there has been an increase in SBR during last years, but the goals of the Every Newborn Initiative is met. More than 14,500 stillbirths with at least 5,100 unspecified cases have been reported per year, and only 11 cases were attributable to a specific virus, highlighting the serious underestimation of cases and the need of implementation of routine viral diagnosis methods to improve the care of this global health problem.

Compartmentalized Innate Immune Response of Human Fetal Membranes against Escherichia coli Choriodecidual Infection.

An infectious process into the uterine cavity represents a major endangered condition that compromises the immune privilege of the maternal-fetal unit and increases the risk for preterm birth (PTB) and premature rupture of membranes (PROM). Fetal membranes are active secretors of antimicrobial peptides (AMP), which limit bacterial growth, such as Escherichia coli. Nevertheless, the antibacterial responses displayed by chorioamniotic membranes against a choriodecidual E. coli infection have been briefly studied. The objective of this research was to characterize the profile of synthesis, activity, and spatial distribution of a broad panel of AMPs produced by fetal membranes in response to E. coli choriodecidual infection. Term human chorioamniotic membranes were mounted in a two independent compartment model in which the choriodecidual region was infected with live E. coli (1 × 105 CFU/mL). Amnion and choriodecidual AMP tissue levels and TNF-α and IL-1ß secretion were measured by the enzyme-linked immunosorbent assay. The passage of bacterium through fetal membranes and their effect on structural continuity was followed for 24 h. Our results showed that E. coli infection caused a progressive mechanical disruption of the chorioamniotic membranes and an activated inflammatory environment. After the challenge, the amnion quickly (2-4 h) induced production of human beta defensins (HBD)-1, HBD-2, and LL-37. Afterwards (8-24 h), the amnion significantly produced HBD-1, HBD-2, HNP-1-3, S100A7, sPLA2, and elafin, whereas the choriodecidua induced LL-37 synthesis. Therefore, we noticed a temporal- and tissue-specific pattern regulation of the synthesis of AMPs by infected fetal membranes. However, fetal membranes were not able to contain the collagen degradation or the bacterial growth and migration despite the battery of produced AMPs, which deeply increases the risk for PTB and PROM. The mixture of recombinant HBDs at low concentrations resulted in increased bactericidal activity compared to each HBD alone in vitro, encouraging further research to study AMP combinations that may offer synergy to control drug-resistant infections in the perinatal period.

COVID-19 Infection in Pregnancy: PCR Cycle Thresholds, Placental Pathology, and Perinatal Outcomes.

(1) This study aimed to evaluate characteristics, perinatal outcomes, and placental pathology of pregnant women with or without SARS-CoV-2 infection in the context of maternal PCR cycle threshold (CT) values. (2) This was a retrospective case-control study in a third-level health center in Mexico City with universal screening by RT-qPCR. The association of COVID-19 manifestations, preeclampsia, and preterm birth with maternal variables and CT values were assessed by logistic regression models and decision trees. (3) Accordingly, 828 and 298 women had a negative and positive test, respectively. Of those positive, only 2.6% of them presented mild to moderate symptoms. Clinical characteristics between both groups of women were similar. No associations between CT values were found for maternal features, such as pre-gestational BMI, age, and symptomatology. A significantly higher percentage of placental fibrinoid was seen with women with low CTs (<25; p < 0.01). Regarding perinatal outcomes, preeclampsia was found to be significantly associated with symptomatology but not with risk factors or CT values (p < 0.01, aOR = 14.72). Moreover, 88.9% of women diagnosed with COVID-19 at <35 gestational weeks and symptomatic developed preeclampsia. (4) The data support strong guidance for pregnancies with SARS-CoV-2 infection, in particular preeclampsia and placental pathology, which need further investigation.

Prevalence, clinical features, and outcomes of SARS-CoV-2 infection in pregnant women with or without mild/moderate symptoms: Results from universal screening in a tertiary care center in Mexico City, Mexico.

The perinatal consequences of SARS-CoV-2 infection are still largely unknown. This study aimed to describe the features and outcomes of pregnant women with or without SARS-CoV-2 infection after the universal screening was established in a large tertiary care center admitting only obstetric related conditions without severe COVID-19 in Mexico City. This retrospective case-control study integrates data between April 22 and May 25, 2020, during active community transmission in Mexico, with one of the highest COVID-19 test positivity percentages worldwide. Only pregnant women and neonates with a SARS-CoV-2 result by quantitative RT-PCR were included in this study. Among 240 pregnant women, the prevalence of COVID-19 was 29% (95% CI, 24% to 35%); 86% of the patients were asymptomatic (95% CI, 76%-92%), nine women presented mild symptoms, and one patient moderate disease. No pregnancy baseline features or risk factors associated with severity of infection, including maternal age > 35 years, Body Mass Index >30 kg/m2, and pre-existing diseases, differed between positive and negative women. The median gestational age at admission for both groups was 38 weeks. All women were discharged at home without complications, and no maternal death was reported. The proportion of preeclampsia was higher in positive women than negative women (18%, 95% CI, 10%-29% vs. 9%, 95% CI, 5%-14%, P<0.05). No differences were found for other perinatal outcomes. SARS-CoV-2 test result was positive for nine infants of positive mothers detected within 24h of birth. An increased number of infected neonates were admitted to the NICU, compared to negative neonates (44% vs. 22%, P<0.05) and had a longer length of hospitalization (2 [2-18] days vs. 2 [2-3] days, P<0.001); these are potential proxies for illness severity. This report highlights the importance of COVID-19 detection at delivery in pregnant women living in high transmission areas.

Utility of two DNA extraction methods using formalin-fixed paraffin-embedded tissues in identifying congenital cytomegalovirus infection by polymerase chain reaction.

Formalin-fixed paraffin-embedded (FFPE) tissues are a source of biological material for molecular studies; several methods to extract DNA from FFPE tissues have been reported. This process is challenging because of formaldehyde-induced cross-linking between proteins and DNA as well as molecule fragmentation when unbuffered formalin is used for fixation. Here, 2 methods for DNA extraction from FFPE tissues, based on a chelating resin and silica membrane columns, were modified and compared in their capacity to detect human cytomegalovirus (HCMV) in congenital infections. Both methods were tested on 121 samples of brain, lung, spleen, and liver derived from 36 deceased preterm newborns. Twelve patients were selected, and UL55 and UL75 HCMV genes were detected by polymerase chain reaction in 16/36 samples. These 2 methods represent a useful tool for DNA recovery from FFPE tissues and HCMV molecular identification with the advantage of low cost, minimal steps, minimal sample use, being solvent-free, and being easy to implement in the laboratory.

Establishment of human embryonic stem cell line Amicqui-2 using poor-quality embryos from Mexican population.

Although investigation with human embryonic stem cells (HESC) is not decreasing, the derivation of new lines has been diminished. The preeminence of only a few HESC lines in research is accompanied by lack of universal applicability of results as well as by genetic under-representation. We previously reported the derivation of one line with male karyotype from Mexican population. Here, we derived one HESC line (Amicqui-2) with female karyotype from poor-quality embryos. These line comply the pluripotent requirements (normal karyotype, detection of pluripotency-associated markers, mycoplasma test and teratoma formation) and could be a valuable model for studying diseases specific to under-represented population.

Congenital Zika Syndrome and Extra-Central Nervous System Detection of Zika Virus in a Pre-term Newborn in Mexico.

BACKGROUND: During pregnancy, the Zika virus (ZIKV) replicates in the placenta and central nervous system (CNS) of infected fetuses; nevertheless, the ability of ZIKV to replicate in other fetal tissues has not been extensively characterized. METHODS: We researched whether dissemination of congenitally-acquired ZIKV outside the CNS exists by searching for the accumulation of the viral envelope protein, ZIKV ribonucleic acid (RNA), and infectious viral particles in different organs of a deceased newborn with Congenital Zika Syndrome. A real-time qualitative polymerase chain reaction (qPCR) was used to detect ZIKV RNA in the brain, thymus, lungs, kidneys, adrenal glands, spleen, liver, and small intestine. The same tissues were analyzed by indirect immunofluorescence and immunoperoxidase assays using the monoclonal antibody 4G2 to detect ZIKV envelope antigens. Isolation of infectious ZIKV in a cell culture was carried out using brain and kidney samples. RESULTS: A postmortem, virological analysis of multiple organs, such as the kidneys (epithelial cells in the renal tubules), lungs (bronchial epithelia), thymus (epithelial cells inside the Hassall's corpuscles), and brain (neurons, ependymal cells, and macrophages) revealed the presence of ZIKV RNA and envelope antigens. Other tissues of the deceased newborn tested positive by qPCR for Epstein-Barr virus and human herpesvirus 6, including the brain cortex (Epstein-Barr) and the thymus, kidneys, and adrenal glands (human herpesvirus 6). The kidneys were identified as a significant niche for viral replication, given that infectious particles were successfully isolated from renal tissues. CONCLUSIONS: Our findings demonstrate the ability of congenitally-acquired ZIKV to produce disseminated infections and the viral tropism towards epithelial cells.

Human amniotic epithelial cells as feeder layer to derive and maintain human embryonic stem cells from poor-quality embryos.

Data from the literature suggest that human embryonic stem cell (hESC) lines used in research do not genetically represent all human populations. The derivation of hESC through conventional methods involve the destruction of viable human embryos, as well the use of mouse embryonic fibroblasts as a feeder layer, which has several drawbacks. We obtained the hESC line (Amicqui-1) from poor-quality (PQ) embryos derived and maintained on human amniotic epithelial cells (hAEC). This line displays a battery of markers of pluripotency and we demonstrated the capacity of these cells to produce derivates of the three germ layers.

A fetus with hemifacial microsomia and sirenomelia. The same mesodermal defect spectrum?

Sirenomelia is the most severe malformation complex affecting the human caudal pole, although its etiology is unclear, a primary defect of blastogenesis has been proposed. Studies consider sirenomelia as the most severe form of caudal dysgenesis, VACTERL association, or axial mesodermal dysplasia, although others still support the idea of a different pathologic entity. We report the prenatal, clinical, and pathologic features of a fetus with cleft lip and palate, microtia, cardiac, renal and intestinal malformations, radial aplasia, and sirenomelia. Karyotype, chromosomal breakage studies, and SHH sequence analysis were normal. The occurrence of cephalic, midline-paramedial, and caudal malformations in the same patient imply the diagnosis of hemifacial microsomia and sirenomelia. These entities are part of the same mesodermal malformation spectrum and the clinical presentation depends on environmental and genetic interactions in embrionic development. Future clinical and genome wide studies will help to better delineate this spectrum.