Protective effect of pre-existing natural immunity in a nonhuman primate reinfection model of congenital cytomegalovirus infection

Congenital cytomegalovirus (cCMV) is the leading infectious cause of neurologic defects in newborns with particularly severe sequelae in the setting of primary CMV infection in the first trimester of pregnancy. The majority of cCMV cases worldwide occur after non-primary infection in CMV-seropositive women; yet the extent to which pre-existing natural CMV-specific immunity protects against CMV reinfection or reactivation during pregnancy remains ill-defined. We previously reported on a novel nonhuman primate model of cCMV in rhesus macaques where 100% placental transmission and 83% fetal loss were seen in CD4+ T lymphocyte-depleted rhesus CMV (RhCMV)-seronegative dams after primary RhCMV infection. To investigate the protective effect of preconception maternal immunity, we performed reinfection studies in CD4+ T lymphocyte-depleted RhCMV-seropositive dams inoculated in late first / early second trimester gestation with RhCMV strains 180.92 (n = 2), or RhCMV UCD52 and FL-RhCMVΔRh13.1/SIVgag, a wild-type-like RhCMV clone with SIVgag inserted as an immunological marker, administered separately (n = 3). An early transient increase in circulating monocytes followed by boosting of the pre-existing RhCMV-specific CD8+ T lymphocyte and antibody response was observed in the reinfected dams but not in control CD4+ T lymphocyte-depleted dams. Emergence of SIV Gag-specific CD8+ T lymphocyte responses in macaques inoculated with the FL-RhCMVΔRh13.1/SIVgag virus confirmed reinfection. Placental transmission was detected in only one of five reinfected dams and there were no adverse fetal sequelae. Viral whole genome, short-read, deep sequencing analysis confirmed transmission of both reinfection RhCMV strains across the placenta with ~30% corresponding to FL-RhCMVΔRh13.1/SIVgag and ~70% to RhCMV UCD52, consistent with the mixed human CMV infections reported in infants with cCMV. Our data showing reduced placental transmission and absence of fetal loss after non-primary as opposed to primary infection in CD4+ T lymphocyte-depleted dams indicates that preconception maternal CMV-specific CD8+ T lymphocyte and/or humoral immunity can protect against cCMV infection.

Ensuring privacy protection in the era of big laparoscopic video data: development and validation of an inside outside discrimination algorithm (IODA)

BACKGROUND

Laparoscopic videos are increasingly being used for surgical artificial intelligence (AI) and big data analysis. The purpose of this study was to ensure data privacy in video recordings of laparoscopic surgery by censoring extraabdominal parts. An inside-outside-discrimination algorithm (IODA) was developed to ensure privacy protection while maximizing the remaining video data.

METHODS

IODAs neural network architecture was based on a pretrained AlexNet augmented with a long-short-term-memory. The data set for algorithm training and testing contained a total of 100 laparoscopic surgery videos of 23 different operations with a total video length of 207 h (124 min ± 100 min per video) resulting in 18,507,217 frames (185,965 ± 149,718 frames per video). Each video frame was tagged either as abdominal cavity, trocar, operation site, outside for cleaning, or translucent trocar. For algorithm testing, a stratified fivefold cross-validation was used.

RESULTS

The distribution of annotated classes were abdominal cavity 81.39%, trocar 1.39%, outside operation site 16.07%, outside for cleaning 1.08%, and translucent trocar 0.07%. Algorithm training on binary or all five classes showed similar excellent results for classifying outside frames with a mean F1-score of 0.96 ± 0.01 and 0.97 ± 0.01, sensitivity of 0.97 ± 0.02 and 0.0.97 ± 0.01, and a false positive rate of 0.99 ± 0.01 and 0.99 ± 0.01, respectively.

CONCLUSION

IODA is able to discriminate between inside and outside with a high certainty. In particular, only a few outside frames are misclassified as inside and therefore at risk for privacy breach. The anonymized videos can be used for multi-centric development of surgical AI, quality management or educational purposes. In contrast to expensive commercial solutions, IODA is made open source and can be improved by the scientific community.

Protective effect of pre-existing natural immunity in a nonhuman primate reinfection model of congenital cytomegalovirus infection

Congenital cytomegalovirus (cCMV) is the leading infectious cause of neurologic defects in newborns with particularly severe sequelae in the setting of primary CMV infection in the first trimester of pregnancy. The majority of cCMV cases worldwide occur after non-primary infection in CMV-seropositive women; yet the extent to which pre-existing natural CMV-specific immunity protects against CMV reinfection or reactivation during pregnancy remains ill-defined. We previously reported on a novel nonhuman primate model of cCMV in rhesus macaques where 100% placental transmission and 83% fetal loss were seen in CD4 + T lymphocyte-depleted rhesus CMV (RhCMV)-seronegative dams after primary RhCMV infection. To investigate the protective effect of preconception maternal immunity, we performed reinfection studies in CD4+ T lymphocyte-depleted RhCMV-seropositive dams inoculated in late first / early second trimester gestation with RhCMV strains 180.92 ( n =2), or RhCMV UCD52 and FL-RhCMVΔRh13.1/SIV gag , a wild-type-like RhCMV clone with SIV gag inserted as an immunological marker ( n =3). An early transient increase in circulating monocytes followed by boosting of the pre-existing RhCMV-specific CD8+ T lymphocyte and antibody response was observed in the reinfected dams but not in control CD4+ T lymphocyte-depleted dams. Emergence of SIV Gag-specific CD8+ T lymphocyte responses in macaques inoculated with the FL-RhCMVΔRh13.1/SIV gag virus confirmed reinfection. Placental transmission was detected in only one of five reinfected dams and there were no adverse fetal sequelae. Viral whole genome, short-read, deep sequencing analysis confirmed transmission of both reinfection RhCMV strains across the placenta with ∼30% corresponding to FL-RhCMVΔRh13.1/SIV gag and ∼70% to RhCMV UCD52, consistent with the mixed human CMV infections reported in infants with cCMV. Our data showing reduced placental transmission and absence of fetal loss after non-primary as opposed to primary infection in CD4+ T lymphocyte-depleted dams indicates that preconception maternal CMV-specific CD8+ T lymphocyte and/or humoral immunity can protect against cCMV infection.

Author Summary

Globally, pregnancies in CMV-seropositive women account for the majority of cases of congenital CMV infection but the immune responses needed for protection against placental transmission in mothers with non-primary infection remains unknown. Recently, we developed a nonhuman primate model of primary rhesus CMV (RhCMV) infection in which placental transmission and fetal loss occurred in RhCMV-seronegative CD4+ T lymphocyte-depleted macaques. By conducting similar studies in RhCMV-seropositive dams, we demonstrated the protective effect of pre-existing natural CMV-specific CD8+ T lymphocytes and humoral immunity against congenital CMV after reinfection. A 5-fold reduction in congenital transmission and complete protection against fetal loss was observed in dams with pre-existing immunity compared to primary CMV in this model. Our study is the first formal demonstration in a relevant model of human congenital CMV that natural pre-existing CMV-specific maternal immunity can limit congenital CMV transmission and its sequelae. The nonhuman primate model of non-primary congenital CMV will be especially relevant to studying immune requirements of a maternal vaccine for women in high CMV seroprevalence areas at risk of repeated CMV reinfections during pregnancy.

Diagnostic performance of MRI perfusion and spectroscopy for brainstem glioma grading

OBJECTIVE

This study investigated the roles of dynamic susceptibility contrast (DSC) perfusion and multivoxel magnetic resonance spectroscopy (MRS) in grading brainstem glioma (BSG).

PATIENTS AND METHODS

Our retrospective study comprised 12 patients, including 6 with pathology verified low-grade BSGs and 6 with high-grade BSGs. We examined differences in age, relative cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and the metabolite ratios of choline (Cho)/N-acetyl aspartate (NAA) and Cho/creatine (Cr) between these two groups using the Mann-Whitney U test and Chi-square test. Receiver operating characteristic (ROC) curve analysis was used to establish cutoff values and assess their usefulness in grading BSG.

RESULTS

The Cho/NAA metabolite ratio had the strongest preoperative predictive performance for identifying the correct histological grade among BSGs, with an area under the ROC curve (AUC) value of 0.944 (cutoff: 3.88, sensitivity [Se]: 83.3%; specificity [Sp]: 100%), followed by the Cho/Cr ratio (cutoff: 3.08; AUC: 0.917; Se: 83.3%; Sp: 100%), rCBF (cutoff: 3.56, AUC: 0.917; Se: 83.3%; Sp: 100%), rCBV (cutoff: 3.16, AUC: 0.889; Se: 100%; Sp: 66.7%), and age (cutoff: 9.5 years, AUC: 0.889; Se: 100%; Sp: 83.3%).

CONCLUSIONS

rCBF and rCBV values comparing solid tumors with the normal brain parenchyma and the metabolite ratios for Cho/NAA and Cho/Cre may serve as useful indices for establishing BSG grading and provide important information when determining treatment planning and prognosis in patients with BSG.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

Randomized comparison between perineural dexamethasone and combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block

BACKGROUND

This randomized trial compared perineural dexamethasone with combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block. We hypothesized that the combination of perineural adjuvants would result in a longer motor block.

METHODS

Fifty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (2 mg) or combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg). After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min), the onset time (defined as the time required to reach a minimal composite score of 14 points) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids or general anesthesia).Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block and postoperative analgesia.

RESULTS

No intergroup differences were observed in terms of success rate, onset time and surgical anesthesia. Compared with dexamethasone alone, combined dexamethasone-dexmedetomidine provided longer durations of motor block (21.5 (2.7) vs 17.0 (3.9) hours; p<0.001; 95% CI 2.6 to 6.4), sensory block (21.6 (3.6) vs 17.2 (3.6) hours; p<0.001; 95% CI 2.2 to 6.5), and postoperative analgesia (25.5 (9.4) vs 23.5 (5.6) hours; p=0.038; 95% CI 1.0 to 7.7).

CONCLUSION

Compared with perineural dexamethasone (2 mg) alone, combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg) results in longer durations of sensorimotor block and analgesia. Further studies are required to determine the optimal dosing combination for dexamethasone-dexmedetomidine.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT04875039.

POS1405 LESS THAN 50% FEMALES WITH CHRONIC RHEUMATIC INFLAMMATORY DISEASES CONTINUE A DMARD DURING PREGNANCY: A DESCRIPTIVE ANALYSIS OF THE NATIONAL FRENCH SOCIAL SECURITY DATABASE

Background

Treatment of patients with chronic rheumatic inflammatory diseases (CRID) during pregnancy has changed in the last decade, namely due to the availability of new DMARDs labelled to be used during pregnancy.

Objectives

To describe the anti-rheumatic drug use during pregnancy in women with CRID (i.e. rheumatoid arthritis (RA) or spondyloarthritis (SpA)) in France over the past decade.

Methods

This is a retrospective cohort study within the French Healthcare database (SNDS), which covers 98% of the French population. Adult women were included if they had RA or SpA according to CIM-10 codes, had started a singleton pregnancy between 2008 and 2017 (index date), and were continuously covered by this health insurance from 1-year before pregnancy onset to 1-year after end of the pregnancy or death (whichever comes first). The treatment exposures of interest were: NSAIDs, oral corticosteroids, csDMARD (methotrexate, leflunomide, sulfasalazine, azathioprine, hydroxychloroquine), biologics (anti-TNF, rituximab, abatacept, tocilizumab, ustekinumab, anakinra). Exposure during pregnancy was defined as at least one drug reimbursement from the 6 months before the last menstrual period (LMP) to the end of pregnancy period.

Results

Among the 35,737 adult women with a CIRD (40.7% with RA and 59.3% with SpA) who had a past history of DMARD reimbursement, 11,274 (41.7%) started a singleton pregnancy during the study period. In total, during preconception and pregnancy, 4,773 (42.3%) women were not delivered any DMARD nor corticosteroids, 769 (6.8%) were delivered corticosteroids alone, 3,639 (32.2%) a csDMARD alone and 2,862 (25.4%) a biologic (among whom 33.1% associated a csDMARD). Biologics delivered during pregnancy were mainly anti-TNFs (92.1%).

Exposure to NSAIDs was more frequent during the first trimester (30% patients) of pregnancy but occurred all along the pregnancy (6% and 2% in the second and third trimesters, respectively). Conversely, exposure to oral corticosteroids was stable during the pregnancy (33% to 27%); however, more than half of the prescriptions corresponded to doses higher than 10mg. Exposure to DMARDs including bDMARDs during pregnancy was more frequent during the first trimester, compared to the rest of the pregnancy (see graph).

Conclusion

Overall, less than 50% of women with a CRID who received a DMARD prior to the pregnancy continued to retrieve such treatment during pregnancy, and overall less than 20% were delivered biologics during pregnancy. Whether the withdrawal of DMARDs led to unfavorable maternal and pregnancy outcomes needs to be evaluated.

Acknowledgements

This study was conducted thanks to a grant from the French Ministry of Health - Programme Hospitalier de Recherche Clinique

Disclosure of Interests

Anna Moltó Consultant of: UCB, Abbvie, Lilly, Pfizer, BMS, MSD, Novartis, Biogen, Janssen, Grant/research support from: UCB, Aya Ajrouche: None declared, Diep Tran: None declared, Barbara Roux: None declared, Nathalie Costedoat-Chalumeau Grant/research support from: UCB, Elisabeth Elefant: None declared, Vassilis Tsatsaris: None declared, Jeanne Fresson: None declared, Brigitte Bader-Meunier: None declared, Bruno Fautrel: None declared, Florence Tubach: None declared

AB1391 19% PATIENTS WITH CHRONIC RHEUMATIC INFLAMMATORY DISEASES PRESENT AN UNFAVORABLE PREGNANCY OUTCOME: A DESCRIPTIVE ANALYSIS OF THE NATIONAL FRENCH SOCIAL SECURITY DATABASE

Background

patients with chronic rheumatic inflammatory diseases (CRID, i.e. rheumatoid arthritis (RA) or spondyloarthritis (SpA)) have been reported to have poorer pregnancy outcomes than the general population.

Objectives

to describe the pregnancy outcomes of singleton in patients with CRID in France in the past decade.

Methods

this is an analysis of the French Health Insurance claims database (SNDS), which represents 87% of the French population) from 2008 to 2016. To be included in the analysis patients had to be identified as RA or SpA according to existing diagnostic algorithms, to have at least one pregnancy declaration in the database, and to have continuous health insurance from 1-year before pregnancy onset to 1-year after end of the pregnancy or until death (if death occured before the 1-year-period after the end of pregnancy) to be included. Only the first singleton pregnancy occurring during the study period was included in this analysis. Both maternal and pregnancy outcomes were considered. Outcomes were identified either by ICM-10 codes or hospital discharge summaries discharge between 2008-2016.

Results

Among the 35 737 identified adult females with a CRID diagnosis (40.7% with RA and 59.3% with SpA), 27 722 (78%) had a pregnancy during the study period. 11 274 (42%) had received at least one DMARD prior to the pregnancy and were included in the analysis. Among them, only 4025 (36%) were exposed to DMARDs during pregnancy.

Mean (SD) age of females at the start of the pregnancy was 32 (5) years, and mean (SD) disease duration was 4 (4) years. Pregnancy ended before 13 WG in 21% and after 37 WG in 70% cases. Live-birth represented the most frequent pregnancy outcome (76.9%), and overall 34.7% patients presented at least one unfavorable outcome (see Table 1).

Table 1.Unfavourable outcomeN(%)Pregnancy outcomesMiscarriage (<22WG)579 (5.3%)Abortion91 (0.8%)Stillbirth48 (0.4%)Preterm delivery (>= 22WG and <37 WG)779 (7.1%)Low weight at birth (<3th percentile)287 (2.6%)Perinatal mortality (22WG to 6 days of life)2 (0%)Maternal outcomesSevere maternal infection*211 (1.9%)Newborn outcomesHospitalisation in neonatal intensive care > 48h in full-term newborns (after 37 WG)95 (0.8%)Neonatal mortality (27 first days of life)2 (0%)Severe infection * during first year603 (5.3%)

Conclusion

More than 75% pregnancies in patients with CRID resulted in a live-birth. Prevalence of miscarriage was surprisingly low, probably related to under-coding. Maternal and infant outcomes seemed comparable to general population. Whether medications had an impact on such outcomes is currently under evaluation.

Disclosure of Interests

None declared

Immunomodulatory potential of in vivo natural killer T (NKT) activation by NKTT320 in Mauritian-origin cynomolgus macaques

Invariant natural killer T-lymphocytes (iNKT) are unique immunomodulatory innate T cells with an invariant TCRα recognizing glycolipids presented on MHC class-I-like CD1d molecules. Activated iNKT rapidly secrete pro-and anti-inflammatory cytokines, potentiate immunity, and modulate inflammation. Here, we report the effects of in vivo iNKT activation in Mauritian-origin cynomolgus macaques by a humanized monoclonal antibody, NKTT320, that binds to the invariant region of the iNKT TCR. NKTT320 led to rapid iNKT activation, increased polyfunctionality, and elevation of multiple plasma analytes within 24 hours. Flow cytometry and RNA-Seq confirmed downstream activation of multiple immune subsets, enrichment of JAK/STAT and PI3K/AKT pathway genes, and upregulation of inflammation-modulating genes. NKTT320 also increased iNKT frequency in adipose tissue and did not cause iNKT anergy. Our data indicate that NKTT320 has a sustained effect on in vivo iNKT activation, potentiation of innate and adaptive immunity, and resolution of inflammation, which supports its future use as an immunotherapeutic.

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NKTT320 rapidly activates iNKT in vivo, modulating downstream immune function

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In vivo NKTT320 treatment modulates pro- and anti-inflammatory genes

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NKTT320 treatment results in activation of innate and adaptive immune subsets

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NKTT320 has promise as an immunotherapeutic with translational potential

Real-world Safety of Bevacizumab with First-line Combination Chemotherapy in Patients with Metastatic Colorectal Cancer: Population-based Retrospective Cohort Studies in Three Canadian Provinces

AIMS

To examine the real-world safety of adding bevacizumab to first-line irinotecan-based chemotherapy for patients with metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS

Patients diagnosed with CRC in three Canadian provinces (Ontario, Saskatchewan and British Columbia) who received publicly funded bevacizumab and/or irinotecan from 2000 to 2016 were identified from cancer registries. Propensity score 1:1 matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to contemporaneous and historical controls, adjusting for baseline demographic and clinical characteristics. Safety end points evaluated during first-line treatment plus 30 days included mortality within 30 days and all-cause-, chemotherapy- and bevacizumab-related hospitalisations. Chemotherapy- and bevacizumab-related visits were defined as hospitalisations for specific conditions commonly associated with chemotherapy (e.g. infections) or bevacizumab (e.g. arteriovenous thromboembolism) using most responsible diagnosis codes. In PSM and IPTW-weighted cohorts, we assessed event frequencies using odds ratios from logistic regressions and event rate ratios using negative binomial regression models. The results from each province and comparison were pooled using random-effects meta-analysis.

RESULTS

We identified 16 250 mCRC patients who received first-line irinotecan-based treatment. In PSM cohorts, bevacizumab was associated with fewer deaths within 30 days of treatment compared with contemporaneous (pooled odds ratio = 0.62; 95% confidence interval 0.50-0.75) and historical controls (pooled odds ratio = 0.73; 95% confidence interval 0.58-0.93). Hospitalisations were more frequent among patients treated with bevacizumab compared with historical controls but similar to contemporaneous controls. As patients receiving bevacizumab were exposed to a longer average treatment duration, across their full treatment duration, patients receiving bevacizumab had significantly lower rates of hospitalisations (contemporaneous pooled rate ratio = 0.56; 95% confidence interval 0.47-0.67; historical pooled rate ratio = 0.73; 95% confidence interval 0.56-0.95). Similar trends were observed for chemotherapy- and bevacizumab-related hospitalisations and in IPTW-weighted cohorts.

DISCUSSION

We did not observe any increase in rates of hospitalisation or death within 30 days of treatment among mCRC patients treated with bevacizumab plus chemotherapy versus chemotherapy alone; these findings should be interpreted with caution due to the risk of residual confounding.

Immune Profile of the Normal Maternal-Fetal Interface in Rhesus Macaques and Its Alteration Following Zika Virus Infection

The maternal decidua is an immunologically complex environment that balances maintenance of immune tolerance to fetal paternal antigens with protection of the fetus against vertical transmission of maternal pathogens. To better understand host immune determinants of congenital infection at the maternal-fetal tissue interface, we performed a comparative analysis of innate and adaptive immune cell subsets in the peripheral blood and decidua of healthy rhesus macaque pregnancies across all trimesters of gestation and determined changes after Zika virus (ZIKV) infection. Using one 28-color and one 18-color polychromatic flow cytometry panel we simultaneously analyzed the frequency, phenotype, activation status and trafficking properties of αβ T, γδ T, iNKT, regulatory T (Treg), NK cells, B lymphocytes, monocytes, macrophages, and dendritic cells (DC). Decidual leukocytes showed a striking enrichment of activated effector memory and tissue-resident memory CD4+ and CD8+ T lymphocytes, CD4+ Tregs, CD56+ NK cells, CD14+CD16+ monocytes, CD206+ tissue-resident macrophages, and a paucity of B lymphocytes when compared to peripheral blood. t-distributed stochastic neighbor embedding (tSNE) revealed unique populations of decidual NK, T, DC and monocyte/macrophage subsets. Principal component analysis showed distinct spatial localization of decidual and circulating leukocytes contributed by NK and CD8+ T lymphocytes, and separation of decidua based on gestational age contributed by memory CD4+ and CD8+ T lymphocytes. Decidua from 10 ZIKV-infected dams obtained 16-56 days post infection at third (n=9) or second (n=1) trimester showed a significant reduction in frequency of activated, CXCR3+, and/or Granzyme B+ memory CD4+ and CD8+ T lymphocytes and γδ T compared to normal decidua. These data suggest that ZIKV induces local immunosuppression with reduced immune recruitment and impaired cytotoxicity. Our study adds to the immune characterization of the maternal-fetal interface in a translational nonhuman primate model of congenital infection and provides novel insight in to putative mechanisms of vertical transmission.

Intrahost cytomegalovirus population genetics following antibody pretreatment in a monkey model of congenital transmission

Human cytomegalovirus (HCMV) infection is the leading non-genetic cause of congenital birth defects worldwide. While several studies have addressed the genetic composition of viral populations in newborns diagnosed with HCMV, little is known regarding mother-to-child viral transmission dynamics and how therapeutic interventions may impact within-host viral populations. Here, we investigate how preexisting CMV-specific antibodies shape the maternal viral population and intrauterine virus transmission. Specifically, we characterize the genetic composition of CMV populations in a monkey model of congenital CMV infection to examine the effects of passively-infused hyperimmune globulin (HIG) on viral population genetics in both maternal and fetal compartments. In this study, 11 seronegative, pregnant monkeys were challenged with rhesus CMV (RhCMV), including a group pretreated with a standard potency HIG preparation (n = 3), a group pretreated with a high-neutralizing potency HIG preparation (n = 3), and an untreated control group (n = 5). Targeted amplicon deep sequencing of RhCMV glycoprotein B and L genes revealed that one of the three strains present in the viral inoculum (UCD52) dominated maternal and fetal viral populations. We identified minor haplotypes of this strain and characterized their dynamics. Many of the identified haplotypes were consistently detected at multiple timepoints within sampled maternal tissues, as well as across tissue compartments, indicating haplotype persistence over time and transmission between maternal compartments. However, haplotype numbers and diversity levels were not appreciably different between control, standard-potency, and high-potency pretreatment groups. We found that while the presence of maternal antibodies reduced viral load and congenital infection, it had no apparent impact on intrahost viral genetic diversity at the investigated loci. Interestingly, some minor haplotypes present in fetal and maternal-fetal interface tissues were also identified as minor haplotypes in corresponding maternal tissues, providing evidence for a loose RhCMV mother-to-fetus transmission bottleneck even in the presence of preexisting antibodies.

Impact of CMV Infection on Natural Killer Cell Clonal Repertoire in CMV-Naïve Rhesus Macaques

Recent functional, gene expression, and epigenetic studies have suggested the presence of a subset of mature natural killer (NK) cells responsible for maintaining NK cell memory. The lack of endogenous clonal markers in NK cells impedes understanding the genesis of these cell populations. In humans, primates, and mice, this phenotype and memory or adaptive functions have been strongly linked to cytomegalovirus or related herpes virus infections. We have used transplantation of lentivirally-barcoded autologous hematopoietic stem and progenitor cells (HSPC) to track clonal hematopoiesis in rhesus macaques and previously reported striking oligoclonal expansions of NK-biased barcoded clones within the CD56⁻CD16⁺ NK cell subpopulation, clonally distinct from ongoing output of myeloid, B cell, T cell, and CD56⁺16⁻ NK cells from HSPC. These CD56⁻CD16⁺ NK cell clones segregate by expression of specific KIR surface receptors, suggesting clonal expansion in reaction to specific environmental stimuli. We have now used this model to investigate the impact of rhesus CMV(RhCMV) infection on NK clonal dynamics. Following transplantation, RhCMV^neg rhesus macaques display less dominant and oligoclonal CD16⁺ NK cells biased clones compared to RhCMV^pos animals, however these populations of cells are still clearly present. Upon RhCMV infection, CD16⁺ NK cells proliferate, followed by appearance of new groups of expanded NK clones and disappearance of clones present prior to RhCMV infection. A second superinfection with RhCMV resulted in rapid viral clearance without major change in the mature NK cell clonal landscape. Our findings suggest that RhCMV is not the sole driver of clonal expansion and peripheral maintenance of mature NK cells; however, infection of macaques with this herpesvirus does result in selective expansion and persistence of specific NK cell clones, providing further information relevant to adaptive NK cells and the development of NK cell therapies.

Deep learning as a predictive tool for fetal heart pregnancy following time-lapse incubation and blastocyst transfer

STUDY QUESTION

Can a deep learning model predict the probability of pregnancy with fetal heart (FH) from time-lapse videos?

SUMMARY ANSWER

We created a deep learning model named IVY, which was an objective and fully automated system that predicts the probability of FH pregnancy directly from raw time-lapse videos without the need for any manual morphokinetic annotation or blastocyst morphology assessment.

WHAT IS KNOWN ALREADY

The contribution of time-lapse imaging in effective embryo selection is promising. Existing algorithms for the analysis of time-lapse imaging are based on morphology and morphokinetic parameters that require subjective human annotation and thus have intrinsic inter-reader and intra-reader variability. Deep learning offers promise for the automation and standardization of embryo selection.

STUDY DESIGN, SIZE, DURATION

A retrospective analysis of time-lapse videos and clinical outcomes of 10 638 embryos from eight different IVF clinics, across four different countries, between January 2014 and December 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The deep learning model was trained using time-lapse videos with known FH pregnancy outcome to perform a binary classification task of predicting the probability of pregnancy with FH given time-lapse video sequence. The predictive power of the model was measured using the average area under the curve (AUC) of the receiver operating characteristic curve over 5-fold stratified cross-validation.

MAIN RESULTS AND THE ROLE OF CHANCE

The deep learning model was able to predict FH pregnancy from time-lapse videos with an AUC of 0.93 [95% CI 0.92-0.94] in 5-fold stratified cross-validation. A hold-out validation test across eight laboratories showed that the AUC was reproducible, ranging from 0.95 to 0.90 across different laboratories with different culture and laboratory processes.

LIMITATIONS, REASONS FOR CAUTION

This study is a retrospective analysis demonstrating that the deep learning model has a high level of predictability of the likelihood that an embryo will implant. The clinical impacts of these findings are still uncertain. Further studies, including prospective randomized controlled trials, are required to evaluate the clinical significance of this deep learning model. The time-lapse videos collected for training and validation are Day 5 embryos; hence, additional adjustment would need to be made for the model to be used in the context of Day 3 transfer.

WIDER IMPLICATIONS OF THE FINDINGS

The high predictive value for embryo implantation obtained by the deep learning model may improve the effectiveness of previous approaches used for time-lapse imaging in embryo selection. This may improve the prioritization of the most viable embryo for a single embryo transfer. The deep learning model may also prove to be useful in providing the optimal order for subsequent transfers of cryopreserved embryos.

STUDY FUNDING/COMPETING INTEREST(S)

D.T. is the co-owner of Harrison AI that has patented this methodology in association with Virtus Health. P.I. is a shareholder in Virtus Health. S.C., P.I. and D.G. are all either employees or contracted with Virtus Health. D.G. has received grant support from Vitrolife, the manufacturer of the Embryoscope time-lapse imaging used in this study. The equipment and time for this study have been jointly provided by Harrison AI and Virtus Health.

The association between platelet dysfunction and adverse outcomes in cardiac surgical patients

Haemostatic activation during cardiopulmonary bypass is associated with prothrombotic complications. Although it is not possible to detect and quantify haemostatic activation directly, platelet dysfunction, as measured with point-of-care-assays, may be a useful surrogate. In this study, we assessed the association between cardiopulmonary bypass-associated platelet dysfunction and adverse outcomes in 3010 cardiac surgical patients. Platelet dysfunction, as measured near the end of the rewarming phase of cardiopulmonary bypass, was calculated as the proportion of non-functional platelets after activation with collagen. Logistic regression and multivariable analyses were applied to assess the relationship between platelet dysfunction and a composite of in-hospital death; myocardial infarction; stroke; deep vein thrombosis or pulmonary embolism; and acute kidney injury (greater than a two-fold increase in creatinine). The outcome occurred in 251 (8%) of 3010 patients. The median (IQR [range]) percentage platelet dysfunction was less for those without the outcome as compared with those with the outcome; 14% (8-28% [1-99%]) vs. 19% (11-45% [2-98%]), p < 0.001. After risk adjustment, platelet dysfunction was independently associated with the composite outcome (p < 0.001), such that for each 1% increase in platelet dysfunction there was an approximately 1% increase in the composite outcome (OR 1.012; 95%CI 1.006-1.018). This exploratory study suggests that cardiopulmonary bypass-associated platelet dysfunction has prognostic value and may be a useful clinical measure of haemostatic activation in cardiac surgery.

Bioactive extracellular compounds produced by the dinoflagellate Alexandrium minutum are highly detrimental for oysters

Blooms of the dinoflagellate Alexandrium spp., known as producers of paralytic shellfish toxins (PSTs), are regularly detected on the French coastline. PSTs accumulate into harvested shellfish species, such as the Pacific oyster Crassostrea gigas, and can cause strong disorders to consumers at high doses. The impacts of Alexandrium minutum on C. gigas have often been attributed to its production of PSTs without testing separately the effects of the bioactive extracellular compounds (BECs) with allelopathic, hemolytic, cytotoxic or ichthyotoxic properties, which can also be produced by these algae. The BECs, still uncharacterized, are excreted within the environment thereby impacting not only phytoplankton, zooplankton but also marine invertebrates and fishes, without implicating any PST. The aim of this work was to compare the effects of three strains of A. minutum producing either only PSTs, only BECs, or both PSTs and BECs, on the oyster C. gigas. Behavioral and physiological responses of oysters exposed during 4 days were monitored and showed contrasted behavioral and physiological responses in oysters supposedly depending on produced bioactive substances. The non-PST extracellular-compound-producing strain primarily strongly modified valve-activity behavior of C. gigas and induced hemocyte mobilization within the gills, whereas the PST-producing strain caused inflammatory responses within the digestive gland and disrupted the daily biological rhythm of valve activity behavior. BECs may therefore have a significant harmful effect on the gills, which is one of the first organ in contact with the extracellular substances released in the water by A. minutum. Conversely, the PSTs impact the digestive gland, where they are released and mainly accumulated, after degradation of algal cells during digestion process of bivalves. This study provides a better understanding of the toxicity of A. minutum on oyster and highlights the significant role of BECs in this toxicity calling for further chemical characterization of these substances.

In vivo NKTT320-induced activation of invariant Natural Killer T-cells (iNKTs) and potential applications for use in AIDS pathogenesis modulation

iNKTs are unique, innate T cells with an invariant TCRα chain that recognize glycolipids presented by nonpolymorphic MHC class-I-like CD1d molecules. Activated iNKTs rapidly secrete a range of cytokines and thus have diverse functions including potentiation of anti-tumor and pathogen-specific humoral and cellular immunity and resolution of inflammation. iNKT depletion and dysfunction are common in pathogenic HIV/SIV infection and may hasten AIDS progression. In this study, we tested a novel monoclonal antibody, NKTT320, that specifically binds to the iNKT cell TCRα as a tool for direct in vivo iNKT activation in Mauritian cynomolgus macaques (MCM).

Dose-escalation NKTT320 pharmacokinetic studies were performed in 11 SIV-negative MCM. Plasma NKTT320 levels were measured by ELISA while kinetics of iNKT activation and effect on other immune cell subsets were evaluated by flow cytometry.

NKTT320 plasma levels peaked between 6.6–47.2 μg/ml within 24 hours of a single IV doses of 100–1000 μg/kg and declined below detection by 4–6 weeks. NKTT320 administration resulted in rapid iNKT activation and proliferation of CD4+ more than CD8+ iNKTs, without non-specific T cell activation. Transient elevation of several plasma analytes (IL-2, IL-6, IL-17, MCP-1, MDC and IP-10) and increased proliferation of non-T immune cell subsets were observed suggesting downstream potentiation of innate and adaptive immunity. Repeated doses of NKTT320 increased iNKT responsiveness indicating that treatment did not lead to iNKT anergy.

NKTT320-mediated iNKT activation may be a useful therapeutic tool to preserve and enhance iNKT function, thereby preventing immunodeficiency and aberrant immune activation in pathogenic SIV infection.

Survey of UK dentists regarding the use of CAD/CAM technology

Statement of the problem Digital workflows (CAD/CAM) have been introduced in dentistry during recent years. No published information exists on dentists' use and reporting of this technology.Purpose The purpose of this survey was to identify the infiltration of CAD/CAM technology in UK dental practices and to investigate the relationship of various demographic factors to the answers regarding use or non-use of this technology.Materials and methods One thousand and thirty-one online surveys were sent to a sample of UK dentists composing of both users and non-users of CAD/CAM. It aimed to reveal information regarding type of usage, materials, perceived benefits, barriers to access, and disadvantages of CAD/CAM dentistry. Statistical analysis was undertaken to test the influence of various demographic variables such as country of work, dentist experience, level of training and type of work (NHS or private).Results The number of completed responses totalled 385. Most of the respondents did not use any part of a digital workflow, and the main barriers to CAD/CAM use were initial costs and a lack of perceived benefit over conventional methods. Dentists delivering mostly private work were most likely to have adopted CAD/CAM technology (P <0.001). Further training also correlated with a greater likelihood of CAD/CAM usage (P <0.001). Most users felt that the technology had led to a change in the use of dental materials, leading to increased use of, for example, zirconia and lithium disilicate. Most users were trained either by companies or self-trained, and a third felt that their training was insufficient. The majority of respondents (89%) felt that CAD/CAM had a big role to play in the future.Conclusion Most of the respondents did not use any part of a digital workflow. However, the majority of surveyed dentists were interested in incorporating CAD/CAM into their workflow, while most believed that it will have a big role in the future. There are still some concerns from dentists about the quality of chairside CAD/CAM restorations while the costs are still in the main hugely prohibitive (especially for NHS dentistry).