Evaluation of T Cell Response to SARS-CoV-2 in Kidney Transplant Recipients Receiving Monoclonal Antibody Prophylaxis and the Utility of a Bivalent mRNA Vaccine Booster Dose

Monoclonal antibodies have been administered to kidney transplant recipients (KTRs) with a poor or non-responder status to SARS-CoV-2 vaccination. The cellular response to SARS-CoV-2 has been poorly studied in this context. We assessed the T cell response to SARS-CoV-2 in 97 patients on the day of the injection of tixagevimab/cilgavimab using an IFNγ enzyme-linked immunospot assay (ELISPOT). Among the 97 patients, 34 (35%) developed COVID-19 before the injection. Twenty-nine (85.3%) had an ELISPOT compatible with a SARS-CoV-2 infection. There was no difference between KTRs under belatacept or tacrolimus treatment. Sixty-three patients (64.9%) had no known COVID-19 prior to the ELISPOT, but nine (14.3%) had a positive ELISPOT. In 21 KTRs with a positive ELISPOT who received a booster dose of a bivalent mRNA vaccine, median antibody titers and spike-reactive T cells increased significantly in patients under tacrolimus but not belatacept. Our study emphasizes the potential usefulness of the exploration of immune cellular response to SARS-CoV-2 by ELISPOT. In KTRs with a positive ELISPOT and under CNI therapy, a booster dose of mRNA vaccine seems effective in inducing an immune response to SARS-CoV-2.

Daratumumab for antibody-mediated rejection: Is it time to target the real culprit?

We report the case of a sensitized woman who underwent successful transplantation after a desensitization protocol, with an optically normal 8-day biopsy. At 3 months, she developed active antibody-mediated rejection (AMR) due to preformed donor-specific antibodies. It was decided to treat the patient with daratumumab, an anti-CD38 monoclonal antibody. The mean fluorescence intensity of donor-specific antibodies decreased, pathologic signs of AMR regressed, and kidney function returned to normal. A molecular assessment of biopsies was retrospectively performed. By doing so, regression of the molecular signature of AMR was evidenced between the second and third biopsies. Interestingly, the first biopsy revealed a gene expression profile of AMR, which helped retrospectively classify this biopsy as AMR, illustrating the relevance of molecular phenotyping of biopsy in high-risk situations such as desensitization.

Characterization of the skin-to-bone mechanical interaction on porcine scalp: A combined experimental and computational approach

Fasciae are soft tissues permitting a large but finite sliding between organs, but also between skin and its underlying elements. The contribution of fasciae has been seldomly reported in the literature, and is usually neglected or overly simplified within simulations. In the present contribution, we propose to use peeling tests in order to quantify the skin-to-bone interaction associated with a simple computational approach based on a geometrical modeling of the skin-to-bone interface. To this aim, a new experimental set up combined with a computational model to characterize the skin-to-bone interaction were proposed. The current work is devoted to the porcine scalp complex since it constitutes a common mechanical surrogate for the human scalp complex. The ad hoc computational approach and peeling set up were firstly evaluated on a validation material, before being used to characterize the skin-to-bone interaction within 6 porcine specimens harvested from the scalp. Our experimental setup allowed to measure the peeling response of porcine scalp, showing a three-regimes response including a plateau force. The computational approach satisfyingly reproduced the peeling response based uniquely on experimental-based parameters and on a discrete modeling of skin-to-bone interface. The presented methodology is a first attempt to propose a computationally efficient geometrically based model able to take into account the skin-to-bone interaction up to failure and corroborated by experimental data, and may be largely extended to the modeling of soft interactions between biological human tissues in the future.

A preliminary quantification of the clinical gesture during vacuum assisted delivery on a training dummy

BACKGROUND

The vacuum assisted delivery represents, in France, the most used operative vaginal delivery technique. The purpose was to provide a preliminar quantification of the operator's hand kinematics while performing a vacuum assisted delivery.

METHODS

A group of 21 participants composed of 12 trainees and 9 obstetricians were recorded performing a vacuum assisted delivery on a training dummy, the matching fetal presentation was a left occiput anterior position.

FINDINGS

The mean movement was composed of a first phase corresponding to a descendant pull, followed by an ascendant finish of the gesture. No significative difference were found between the trainees and the obstetricians' mean gesture.

INTERPRETATION

This is the first quantification of the clinical gesture associated with the vacuum assisted delivery.

Impact of Calcineurin Inhibitor-Based Immunosuppression Maintenance During the Dialysis Period After Kidney Transplant Failure on the Next Kidney Graft Outcome: A Retrospective Multicenter Study With Propensity Score Analysis

The impact of immunosuppressive therapy (IS) strategies after kidney transplant failure (KTF) on potential future new grafts is poorly established. We assessed the potential benefit of calcineurin inhibitor (CNI)-based IS maintenance throughout the dialysis period on the outcome of the second kidney transplant (KT). We identified 407 patients who underwent a second KT between January 2008 and December 2018 at four French KT centers. Inverse probability of treatment weighting was used to control for potential confounding. We included 205 patients with similar baseline characteristics at KTF: a total of 53 received at least CNIs on the retransplant day (G-CNI), and 152 did not receive any IS (G-STOP). On the retransplant date, G-STOP patients experienced a longer pretransplant dialysis time, were more often hyperimmunized, and underwent more expanded-criteria donor KTs than G-CNI patients. During the second KT follow-up period, rejection episodes were similar in both groups. The 10-year survival rates without death and dialysis were 98.7% and 59.5% in G-CNI and G-STOP patients, respectively. In the multivariable analysis, CNI-based IS maintenance was associated with better survival (hazard ratio: 0.08; 95% confidence interval: 0.01-0.58, p = 0.01). CNI-based IS maintenance throughout the dialysis period after KTF may improve retransplantation outcomes.

[Whole-body training using HUBER® system in physical therapy rehabilitation: a systematic review]

INTRODUCTION

HUBER®, an isometric strengthening device, has been promoted as rehabilitation tool for a wide population of patients presenting heterogenous profiles.

METHODS

Medline and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Only interventional studies aiming to assess the effectiveness of HUBER® device (any versions, any protocol of intervention used) on physical rehabilitation outcomes of adults were included. Quality of studies was assessed using Cochrane RoB tools.

RESULTS

Out of 142 references, six interventional studies were included in this systematic review. The number of participants included per study varied from 12 to 53, length of intervention varied from 4 to 8 weeks and number of sessions per week varied from 2 to 4. Different profiles of participants were included. Globally, training sessions using the HUBER® device showed moderate beneficial effects on the following outcomes: morphological characteristics, strength, balance and muscle power. The overall quality of the included studies was, however, rated as moderate to low.

CONCLUSION

Because of its capacity to collect various physiological parameters simultaneously, the HUBER® device seems to be an interesting rehabilitation tool.

Conversion From Intravenous In-Hospital Belatacept Injection to Subcutaneous Abatacept Injection in Kidney Transplant Recipients During the First COVID-19 Stay-at-Home Order in France

The first COVID-19 stay-at-home order came into effect in France on 17 March 2020. Immunocompromised patients were asked to isolate themselves, and outpatient clinic visits were dramatically reduced. In order to avoid visits to the hospital by belatacept-treated kidney transplant recipients (KTRs) during the initial period of the pandemic, we promptly converted 176 KTRs at two French transplant centers from once-monthly 5 mg/kg in-hospital belatacept infusion to once-weekly 125 mg subcutaneous abatacept injection. At the end of follow-up (3 months), 171 (97.16%) KTRs survived with a functioning graft, 2 (1.14%) had died, and 3 (1.70%) had experienced graft loss. Two patients (1.1%) experienced acute T cell-mediated rejection. Nineteen patients (10.80%) discontinued abatacept; 47% of the KTRs found the use of abatacept less restrictive than belatacept, and 38% would have preferred to continue abatacept. Mean eGFR remained stable compared to baseline. Seven patients (3.9%) had COVID-19; among these, two developed severe symptoms but survived. Only one patient had a de novo DSA. Side effects of abatacept injection were uncommon and non-severe. Our study reports for the first time in a large cohort that once-weekly injection of abatacept appears to be feasible and safe in KTRs previously treated with belatacept.

Triple positive profile in antiphospholipid syndrome: prognosis, relapse and management from a retrospective multicentre study

Objective

Antiphospholipid syndrome (APS) is defined by the association of thromboembolic and/or obstetrical clinical manifestations and the presence of antiphospholipid antibodies. The objective of our study was to evaluate the impact of the triple-positive profile in a cohort of 204 APS patients.

Methods

We conducted a retrospective study, including patients with primary or secondary APS, meeting the Sydney criteria with at least one thrombotic and/or obstetrical complication. Clinical characteristics and the risk of relapse (defined by the occurrence of a new thrombotic event and/or a new adverse obstetrical event) between triple-positive and non-triple-positive APS patients were compared.

Results

204 patients were included in our study, 68 were triple-positive and 136 were single or double positive. 122 patients (59.8%) had primary APS. 67 patients (32.8%) had obstetrical APS, with a higher rate among triple-positive patients (45.6% vs 26.5%, p=0.010), and 170 patients (83.3%) had thrombotic APS, without difference between triple-positive and others. Thrombotic events were more often venous (56.4%) than arterial (37.7%). Triple-positive patients had more placental complications than others (17.6% vs 2.9%, p=0.001) and more non-criteria events (48.5% vs 25.7%, p=0.002). Among non-criteria events, there was a higher frequency of Sneddon syndrome in triple-positive patients (7.4% vs 0.7%, p=0.028). The relapse rate was higher in triple-positive patients than in others (63.2% vs 39,7%, p=0002). In multivariate analysis, the triple-positive profile was associated with a higher risk of relapse (HR 1.63; 95% CI 1.04 to 2.55; p=0.031).

Conclusion

The triple-positivity is associated with a higher risk of relapse and obstetrical complications.

Identifying high-risk profile in primary antiphospholipid syndrome through cluster analysis: French multicentric cohort study

INTRODUCTION

Antiphospholipid syndrome (APS) is an autoimmune disease characterised by thrombosis (arterial, venous or small vessel) or obstetrical events and persistent antiphospholipid antibodies (aPL), according to the Sydney classification criteria. Many studies have performed cluster analyses among patients with primary APS and associated autoimmune disease, but none has focused solely on primary APS. We aimed to perform a cluster analysis among patients with primary APS and asymptomatic aPL carriers without any autoimmune disease, to assess prognostic value.

METHODS

In this multicentre French cohort study, we included all patients with persistent APS antibodies (Sydney criteria) measured between January 2012 and January 2019. We excluded all patients with systemic lupus erythematosus or other systemic autoimmune diseases. We performed hierarchical cluster analysis on the factor analysis of mixed data coordinates results with baseline patient characteristics to generate clusters.

RESULTS

We identified four clusters: cluster 1, comprising 'asymptomatic aPL carriers', with low risk of events during follow-up; cluster 2, the 'male thrombotic phenotype', with older patients and more venous thromboembolic events; cluster 3, the 'female obstetrical phenotype', with obstetrical and thrombotic events; and cluster 4, 'high-risk APS', which included younger patients with more frequent triple positivity, antinuclear antibodies, non-criteria manifestations and arterial events. Regarding survival analyses, asymptomatic aPL carriers relapsed less frequently than the others, but no other differences in terms of relapse rates or deaths were found between clusters.

CONCLUSIONS

We identified four clusters among patients with primary APS, one of which was 'high-risk APS'. Clustering-based treatment strategies should be explored in future prospective studies.

Hepaticojejunostomy for bile duct injury: state of the art

BACKGROUND

Hepaticojejunostomy (HJ) is the gold standard procedure for the reconstruction of the bile duct in many benign and malignant situations. One of the major situation is the bile duct injury (BDI) after cholecystectomy, either for early or late repair. This procedure presents some specificities associated to a debated management of BDI.

PURPOSE

This article provides a state-of-the-art of the hepaticojejunostomy procedure focusing on bile duct injury including its indications and outcomes CONCLUSION: Performed at the right moment and respecting the technical rules, HJ provides a restoration of the biliary patency in the long term of 80 to 90%. It is the main surgical technique to repair BDI. Complications and failure of this procedure can be difficult to manage. That is why the primary repair requires an appropriate multidisciplinary approach associated with an expert high quality surgical technique.

Belatacept rescue conversion in kidney transplant recipients with vascular lesions (Banff cv score >2): a retrospective cohort study

BACKGROUND

Immunosuppression in kidney transplant recipients with decreased graft function and histological vascular changes can be particularly challenging. The impact of a late rescue conversion to belatacept on kidney graft survival in this context has never been studied.

METHODS

We report a bicentric retrospective cohort study comparing a calcineurin inhibitor (CNI) to belatacept switch versus CNI continuation in 139 kidney transplant recipients with histological kidney vascular damage (cv ≥2, g + cpt ≤1, i + t ≤1) and low estimated glomerular filtration rate (≤40 mL/min/1.73 m²). Primary outcome was death-censored graft survival.

RESULTS

During the study follow-up, 10 graft losses (14.5%) occurred in the belatacept group (n = 69) versus 26 (37.1%) in the matched CNI group (n = 70) (P = .005). Death-censored graft survival was significantly higher in the belatacept group (P = .001). At 3 years, graft survival was 84.0% in the belatacept group compared with 65.1% in the control group. Continuing CNI was an independent risk factor for graft loss [hazard ratio (HR) 3.46; P < .005]. The incidence of cellular rejection after the conversion was low (4.3% in both groups) and not significantly different between groups (P = .84). Patients switched to belatacept developed significantly less donor-specific antibodies de novo. Belatacept was an independent risk factor for the occurrence of opportunistic infections (HR 4.84; P < .005).

CONCLUSION

The replacement of CNI with belatacept in patients with decreased allograft function and vascular lesions is associated with an improvement in graft survival and represents a valuable option in a context of organ shortage. Caution should be exercised regarding the increased risk of opportunistic infection.

Regression trees to identify combinations of farming practices that achieve the best overall intrinsic quality of milk

Many studies over the last 30 years have shown the effects of farming practices on milk compounds. Combinations of practices may have antagonistic or synergistic effects on milk compounds, but these combination effects remain underinvestigated. Research needs to focus on overall intrinsic milk quality (including sensory, technological, health, and nutritional dimensions) and identify the combinations that can optimize it. The aim of this study was to identify which combinations of farming practices achieved the best scores for sensory, technological, health, and nutritional dimensions and for overall intrinsic milk quality. Ninety-nine private farms were visited once each to sample their bulk tank milk and survey their farming practices. The surveyed practices concerned herd characteristics, feeding management, housing conditions, and milking and milk storage conditions on the day of test. Analyses of bulk tank milk were designed to evaluate the overall intrinsic quality of the milk for 2 target products: raw milk cheese and semi-skimmed UHT milk. Regression trees were then used to identify the combinations of farming practices that achieved the best scores on each dimension and on overall intrinsic quality of the milk. Breed and diet (type of forage) were the most influential factors for sensory and health dimensions and for technological and nutritional dimension scores, respectively, in the cheese assessment. Overall cheese quality was highly positively correlated with these 4 dimension scores. Therefore, breed and diet emerged as the most influential practices in the regression tree for overall cheese quality. However, the combinations of practices that resulted in the best quality scores differed according to dimension studied and product targeted. This suggests that advice on farming practices to improve intrinsic milk quality needs to be adapted according to the end-purpose of the collected milk. This innovative approach combining on-farm data and regression trees provides farm managers with a valuable and practical tool to prioritize practices in terms of their role in shaping milk quality, and to identify the combinations of practices that promote good milk quality and practice thresholds or modalities needed to achieve it.

Impacts of production conditions on goat milk vitamin, carotenoid contents and colour indices

The content, composition and variation of vitamin compounds in goat milk have been little studied. An experimental design was based on 28 commercial farms, selected considering the main feeding system (based on main forage and especially pasture access), goat breed (Alpine vs Saanen) and reproductive management (seasonal reproduction), in the main French goat milk production area. Each farm received two visits (spring and autumn) that included a survey on milk production conditions and bulk milk sampling. Milk vitamins (A, E, B₂, B₆, B₉, B₁₂) and carotenoid concentrations plus colour indices were evaluated. A stepwise approach determined the variables of milk production conditions that significantly altered milk indicators. The main forage in the diet was the major factor altering goat milk vitamin and carotenoid concentrations and colour indices. Bulk milk from goats eating fresh grass as forage was richer in α-tocopherol (+64%), pyridoxal (+35%) and total vitamin B₆ (+31%), and b* index (characterising milk yellowness in the CIELAB colour space) was also higher (+12%) than in milk from goats eating conserved forages. In milk from goats eating fresh grass, concentrations of pyridoxamine, lutein and total carotenoids were higher than in milk of goats fed corn silage (+24, +118 and +101%, respectively), and retinol and α-tocopherol concentrations were higher than in milk of goats fed partially dehydrated grass (+45 and +55%). Vitamin B₂ concentration was higher in milk of goats eating fresh grass than in milk of goats fed hay or corn silage as forage (+10%). However, bulk milk when goats had access to fresh grass was significantly poorer in vitamin B₁₂ than when fed corn silage (-46%) and in γ-tocopherol (-31%) than when fed conserved forage. Alpine goats produced milk with higher vitamin B₂ and folate concentrations than Saanen goats (+18 and +14%, respectively). Additionally, the milk colour index that discriminates milks based on their yellow pigment contents was 7% higher in milk from Alpine than Saanen herds, but milk from Saanen goats was richer in lutein (+46%). Goat milks were richer in vitamins B₂ and B₁₂ and folates, but poorer in vitamin B₆ in autumn than in spring (+12, +133, +15 and -13%, respectively). This work highlights that goat milk vitamin and carotenoid concentrations and colour indices vary mainly according to the main forage of the diet and secondly according to the breed and season.

Analysis of suction-based gripping strategies in wildlife towards future evolutions of the obstetrical suction cup

The design of obstetrical suction cups used for vacuum assisted delivery has not substantially evolved through history despite of its inherent limitations. The associated challenges concern both the decrease of risk of soft tissue damage and failure of instrumental delivery due to detachment of the cup. The present study firstly details some of the suction-based strategies that have been developed in wildlife in order to create and maintain an adhesive contact with potentially rough and uneven substratum in dry or wet environments. Such strategies have permitted the emergence of bioinspired suction-based devices in the fields of robotics or biomedical patches that are briefly reviewed. The objective is then to extend the observations of such suction-based strategies toward the development of innovative medical suction cups. We firstly conclude that the overall design, shape and materials of the suction cups could be largely improved. We also highlight that the addition of a patterned surface combined with a viscous fluid at the interface between the suction cup and scalp could significantly limit the detachment rate and the differential pressure required to exert a traction force. In the future, the development of a computational model including a detailed description of scalp properties should allow to experiment various designs of bioinspired suction cups.

6-sulfo LacNAc monocytes are quantitatively and functionally disturbed in systemic sclerosis patients

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis, microangiopathy and autoantibodies. We previously reported that circulating follicular helper T (cTfh) cells are increased in SSc and induce plasmablast differentiation. However, mechanisms leading to cTfh cell expansion and activation in SSc remain to be established. Tfh cells require IL-12 for their expansion and differentiation. 6-sulfo LacNAc monocytes (slanMo), a subset of monocytes, have a higher capacity to produce IL-12 and to induce CD4 + T cell proliferation in comparison with dendritic cells (DC) or classical monocytes. The aim of this study was to perform a quantitative and functional analysis of monocytes and DC and to correlate them with cTfh cell expansion and clinical manifestations in SSc. Using flow cytometry, we analyzed different monocyte subsets including slanMo and DC from 36 SSc patients and 26 healthy controls (HC). In vitro culture experiments of sorted slanMo were performed for functional analysis and cytokine production. We observed that slanMo, intermediate and non-classical monocytes were increased in SSc in comparison with HC. Furthermore, the increase in slanMo cells was more potent in patients with diffuse SSc. We observed a significant positive correlation between slanMo and cTfh cell levels in SSc patients but not in HC. Other monocyte subsets did not correlate with cTfh cell expansion. In addition, we observed that in vitro, slanMo cells from SSc patients produced less IL-12 than slanMo from HC. SlanMo are increased in SSc and may participate in the activation of cTfh cells in SSc.

CD86 occupancy in belatacept-treated kidney transplant patients is not associated with clinical and infectious outcomes

The CD86 occupancy assay has been developed to measure the number of CD86 molecules unbound to belatacept, but its association with clinical outcomes has not been assessed yet. All kidney transplant patients switched to belatacept in our center between 2016 and 2018 were included. Blood samples were collected before each infusion for 1 year to assess CD86 occupancy by CD86 antibody cytometry staining on the surface of CD14⁺ monocytes. Results were expressed as the median fluorescence intensity (MFI) value of CD86 staining. At each infusion, the MFI_{Day of infusion} /MFI_{Day 0} ratio was calculated. Forty-one patients were consecutively included. After every 2-week infusion period, CD86 MFI ratio dropped from 1.00 to 0.73 [0.57-0.98], p = .07. However, this ratio progressively increased to 0.78 [0.53-1.13] at 1 year, which was not statistically different from pre-switch ratio, p = .4. Over the first year, the MFI ratio coefficient of variation was 31.58% [23.75-38.31]. MFI ratio was not different between patients with or without opportunistic infections: 0.73 [0.60-0.88] versus 0.80 [0.71-1.00], p = .2, or between patients with or without EBV DNAemia, p = .2. Despite previous in vitro results, the CD86 occupancy assay suffers from a high intra-individual variability and does not appear to be relevant to clinical outcomes.

Non-criteria manifestations in primary antiphospholipid syndrome: a French multicenter retrospective cohort study

Background

From this retrospective study, we aimed to (1) describe the prevalence and characteristics of non-criteria features in primary antiphospholipid syndrome (p-APS) and (2) determine their prognostic value.

Methods

This retrospective French multicenter cohort study included all patients diagnosed with p-APS (Sydney criteria) between January 2012 and January 2019. We used Kaplan-Meier and adjusted Cox proportional hazards models to compare the incidence of relapse in p-APS with and without non-criteria manifestations.

Results

One hundred and seventy-nine patients with p-APS were included during the study time, with a median age of 52.50 years [39.0; 65.25] and mainly women (n = 112; 62.6%). Among them, forty-three patients (24.0%) presented at least one non-criteria manifestation during the follow-up: autoimmune cytopenias (n = 17; 39.5%), Libman Sachs endocarditis (n = 5; 11.6%), APS nephropathy (n = 4; 9.3%), livedo reticularis (n = 8; 18.6%), and neurological manifestations (n = 12; 27.9%). In comparison to p-APS without any non-criteria manifestations (n = 136), p-APS with non-criteria features had more arterial thrombosis (n = 24; 55.8% vs n = 48; 35.3%; p = 0.027) and more frequent pre-eclampsia (n = 6; 14.3% vs n = 4; 3.1%; p = 0.02). The prevalence of triple positivity was significantly increased in patients with non-criteria features (n = 20; 47.6% vs n = 25; 19.8%; p = 0.001). Patients with p-APS and non-criteria manifestations (n = 43) received significantly more additional therapies combined with vitamin K antagonists and/or antiaggregants. Catastrophic APS (CAPS) tended to be more frequent in p-APS with non-criteria features (n = 2; 5.1% vs none; p = 0.074).

The p-APS with non-criteria manifestations had significantly increased rates of relapse (n = 20; 58.8% vs 33; 33.7%; p = 0.018) in bivariate analysis, but in survival analyses, the hazard ratio (HR) of relapse was not significantly different between the two groups (HR at 1.34 [0.67; 2.68]; p = 0.40).

Conclusions

The presence of non-criteria features is important to consider, as they are associated with particular clinical and laboratory profiles, increased risk of relapse, and need for additional therapies. Prospective studies are necessary to better stratify the prognosis and the management of p-APS.

Prediction of Cognitive Decline for Enrichment of Alzheimer's Disease Clinical Trials

BACKGROUND

A key issue to Alzheimer's disease clinical trial failures is poor participant selection. Participants have heterogeneous cognitive trajectories and many do not decline during trials, which reduces a study's power to detect treatment effects. Trials need enrichment strategies to enroll individuals who are more likely to decline.

OBJECTIVES

To develop machine learning models to predict cognitive trajectories in participants with early Alzheimer's disease and presymptomatic individuals over 24 and 48 months respectively.

DESIGN

Prognostic machine learning models were trained from a combination of demographics, cognitive tests, APOE genotype, and brain imaging data.

SETTING

Data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), National Alzheimer's Coordinating Center (NACC), Open Access Series of Imaging Studies (OASIS-3), PharmaCog, and a Phase 3 clinical trial in early Alzheimer's disease were used for this study.

PARTICIPANTS

A total of 2098 participants who had demographics, cognitive tests, APOE genotype, and brain imaging data, as well as follow-up visits for 24-48 months were included.

MEASUREMENTS

Baseline magnetic resonance imaging, cognitive tests, demographics, and APOE genotype were used to separate decliners, defined as individuals whose CDR-Sum of Boxes scores increased during a predefined time window, from stable individuals. A prognostic model to predict decline at 24 months in early Alzheimer's disease was trained on 1151 individuals who had baseline diagnoses of mild cognitive impairment and Alzheimer's dementia from ADNI and NACC. This model was validated on 115 individuals from a placebo arm of a Phase 3 clinical trial and 76 individuals from the PharmaCog dataset. A second prognostic model to predict decline at 48 months in presymptomatic populations was trained on 628 individuals from ADNI and NACC who were cognitively unimpaired at baseline. This model was validated on 128 individuals from OASIS-3.

RESULTS

The models achieved up to 79% area under the curve (cross-validated and out-of-sample). Power analyses showed that using prognostic models to recruit enriched cohorts of predicted decliners can reduce clinical trial sample sizes by as much as 51% while maintaining the same detection power.

CONCLUSIONS

Prognostic tools for predicting cognitive decline and enriching clinical trials with participants at the highest risk of decline can improve trial quality, derisk endpoint failures, and accelerate therapeutic development in Alzheimer's disease.

[Acute macular neuroretinopathy: En face OCT description, case series]

Acute macular neuroretinopathy (AMN) is a rare disease characterized by involvement of the outer retinal layers of the macula. The diagnosis of AMN is based on multimodal imaging, combining infrared reflectance (IR) imaging and optical coherence tomography with B-scan analysis (OCT-B). The en face OCT is a tomographic image processing technique, integrating data from entire A-scans to create a frontal retinal image of the desired area. Structural en face OCT imaging appears to be effective in delineating AMN lesions, using segmentation between the outer plexiform line and the ellipsoid line. In the future, analysis of the various modalities of a single OCT acquisition may be sufficient to diagnose AMN.

The association of Greig syndrome and mastocytosis reveals the involvement of the hedgehog pathway in advanced mastocytosis

Mastocytosis is a heterogeneous disease characterized by an abnormal accumulation of mast cells (MCs) in 1 or several organs. Although a somatic KIT D816V mutation is detected in ∼85% of patients, attempts to demonstrate its oncogenic effect alone have repeatedly failed, suggesting that additional pathways are involved in MC transformation. From 3 children presenting with both Greig cephalopolysyndactyly syndrome (GCPS, Mendelian Inheritance in Man [175700]) and congenital mastocytosis, we demonstrated the involvement of the hedgehog (Hh) pathway in mastocytosis. GCPS is an extremely rare syndrome resulting from haploinsufficiency of GLI3, the major repressor of Hh family members. From these familial cases of mastocytosis, we demonstrate that the Hh pathway is barely active in normal primary MCs and is overactive in neoplastic MCs. GLI3 and KIT mutations had a synergistic, tumorigenic effect on the onset of mastocytosis in a GCPS mouse model. Finally, Hh inhibitors suppressed neoplastic MC proliferation in vitro and extend the survival time of mice with aggressive systemic mastocytosis (ASM). This work revealed, for the first time, the involvement of Hh signaling in the pathophysiology of mastocytosis and demonstrated the cooperative effects of the KIT and Hh oncogenic pathways in mice with ASM, leading to the identification of new promising therapeutic targets.

SARS-CoV-2-specific Humoral and Cellular Immunities in Kidney Transplant Recipients and Dialyzed Patients Recovered From Severe and Nonsevere COVID-19

Kidney transplantation and dialysis are two major risk factors for severe forms of coronavirus disease 2019 (COVID-19). The dynamics of the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in this population remain largely unknown.

Methods

We report here the analysis of anti-SARS-CoV-2 antibody- and T cell-mediated immune responses in 26 kidney transplant recipients (KTRs) and 11 dialyzed patients (DPs) who recovered from COVID-19.

Results

After a mean time of 83 ± 26 d post-symptom onset for KTRs and 97 ± 31 d for DPs, 20 KTRs (76.9%) and 10 DPs (90.9%) displayed anti-S1 immunoglobulin G SARS-CoV-2 antibodies (P = 0.34), at similar titers in both groups. SARS-CoV-2-specific interferon-γ-producing T cells were evidenced in 26 KTRs (100%) and 10 DPs (90.9%). Total numbers of SARS-CoV-2-reactive T cells were high and not statistically different between the 2 groups. No correlation between the severity of the disease and the number of reactive T cells was found in KTRs. In 5 KTRs, also evaluated 10 mo after COVID-19, weak or absent antibody response was observed, whereas specific memory T-cell response was detected in all cases.

Conclusion

T-cell response persisted up to 3 mo post-symptom onset, even in KTRs in whom full immunosuppressive regimen was reinstated at recovery, and seems to be present up to 10 mo after infection. Our findings have implications in the understanding of the natural course of the disease in transplant patients and DPs.

Clinical and prognostic significance of antinuclear antibodies in primary antiphospholipid syndrome: A multicenter retrospective study

INTRODUCTION

The antiphospholipid syndrome (APS) (1) is defined by the development of vascular thrombosis, or pregnancy morbidity in the presence of persistent antiphospholipid antibodies (aPL). Antinuclear antibodies (ANA) can be detected in primary APS patients without any clinical systemic autoimmune disease. The presence of ANA antibodies could confer a specific phenotype in primary APS.

OBJECTIVE

To evaluate the characteristics of APS patients with antinuclear antibodies without other autoimmune disease (ANA positive APS patients) in comparison with primary APS without ANA or secondary APS patients with associated systemic lupus erythematosus (SLE).

METHODS

Clinical and biologic data from 195 APS were retrospectively collected and patients were classified as primary APS with positive ANA (ANA-positive APS), primary APS without any ANA (ANA-negative APS), and SLE-associated APS (SLE-APS).

RESULTS

Fourty patients (21%) were classified into ANA-positive APS group, 77 (39%) in ANA-negative APS and 78 (40%) in SLE-APS. In ANA-positive APS patients, 20 patients (51%) had arterial thrombosis, 14 (41%) had veinous thrombosis and 19% had obstetrical complications. There was no difference between the three groups for the frequency of thrombotic manifestations and obstetrical complications. ANA-positive APS patients had more non-criteria manifestations than ANA-negative APS (48% versus 25%; P≤0.01). ANA-positive APS had more triple aPL positivity (59% versus 18%; P<0.001) and more thrombosis and obstetrical recurrences (63% versus 36%; P<0.01) in comparison with ANA-negative APS patients. ANA-positive APS had more triple aPL positivity than SLE-APS patients (54% versus 33%; P<0.05). ANA-positive APS and SLE-APS patients had similar clinical manifestations, and recurrences. Despite a limited follow-up (28 months (11-50)) none of the ANA-positive APS develop SLE. Antiplatelet and anticoagulant therapies were similar for the three groups. SLE-APS patients received more immunomodulatory therapies.

CONCLUSION

ANA positivity in patients with APS enables to individualize a subset of patients with a more severe phenotype. Whereas the ANA positivity does not seem to be associated with the risk to develop SLE, prospective studies with a longer follow-up are necessary, in particular to evaluate the effect of additional therapies in this subset of APS.

An advanced method to design graded cylindrical scaffolds with versatile effective cross-sectional mechanical properties

The selection of the most-suited bone scaffold for a given clinical application is challenging, and has motivated numerous studies. They are mostly based on the characterization of cellular structures, generated from the three-dimensional repetition of a unit cell. However, the interest of circular graded bone scaffolds has been emphasized since they facilitate nutrient transport from the periphery to the core of the scaffold. In the present contribution, we present an advanced and versatile method to design graded circular porous 2D structures based on the conformal mapping of unit cells. We propose a method to generate 3D porous scaffolds by a multilayer repetition of the circular cross-section, resulting in tunable anisotropy depending on the clinical application. We then analyze the link between the porosities of the obtained structures and their effective elastic mechanical cross-sectional properties, making use of a novel and computationally efficient method allowing exhaustive parametric studies. The comparison of various conformal transformations and unit cell designs emphasizes the extent of mechanical properties and porosities that may be reached for a given constitutive material, including non-standard mechanical properties that open large perspectives towards the development of self-fitting scaffolds.

Antibody and T Cell Response to SARS-CoV-2 Messenger RNA BNT162b2 Vaccine in Kidney Transplant Recipients and Hemodialysis Patients

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with a high rate of mortality in patients with ESKD, and vaccination is hoped to prevent infection.

METHODS

Between January 18 and February 24, 2021, 225 kidney transplant recipients (KTRs) and 45 patients on hemodialysis (HDPs) received two injections of mRNA BNT162b2 vaccine. The postvaccinal humoral and cellular response was explored in the first 45 KTRs and ten HDPs.

RESULTS

After the second dose, eight HDPs (88.9%) and eight KTRs (17.8%) developed antispike SARS-CoV-2 antibodies (P<0.001). Median titers of antibodies in responders were 1052 AU/ml (IQR, 515-2689) in HDPs and 671 AU/ml (IQR, 172-1523) in KTRs (P=0.40). Nine HDPs (100%) and 26 KTRs (57.8%) showed a specific T cell response (P=0.06) after the second injection. In responders, median numbers of spike-reactive T cells were 305 SFCs per 10⁶ CD3+ T cells (IQR, 95-947) in HDPs and 212 SFCs per 10⁶ CD3+ T cells (IQR, 61-330) in KTRs (P=0.40). In KTRs, the immune response to BNT162b2 seemed influenced by the immunosuppressive regimen, particularly tacrolimus or belatacept.

CONCLUSION

Immunization with BNT162b2 seems more efficient in HDPs, indicating that vaccination should be highly recommended in these patients awaiting a transplant. However, the current vaccinal strategy for KTRs may not provide effective protection against COVID-19 and will likely need to be improved.

[Clinical and paraclinical examination of non-traumatic optic neuropathy in the adult population]

Optic neuropathies (ON) occur in a variety of clinical presentations depending on their pattern of occurrence, their topography and the amount of functional visual impairment. Management of an ON requires a sequence of steps: confirm its existence (positive diagnosis): the diagnosis of ON is usually clinical and must be considered in the case of decreased visual acuity, change in color vision, visual field defect, relative afferent pupillary defect (RAPD), and absence of macular pathology; rule out differential diagnoses: determine the cause; etiologic diagnosis is sometimes complex and takes shape from clinical and paraclinical building blocks. The etiology may be vascular, inflammatory or demyelinating, infectious, toxic, vitamin-deficient, compressive (neoplastic or non-neoplastic), hereditary, congenital, traumatic or even pressure-related (glaucoma or advanced intracranial hypertension). Cerebral and orbital imaging with fine cuts of the optic nerves is often a mandatory examination, which is sometimes useful to repeat; identify therapeutic emergencies.

[Ability of ophthalmic technicians to identify a normal ophthalmological examination]

INTRODUCTION

Ophthalmology care has been growing for several years. Since ophthalmic technicians have the opportunity to perform delegated procedures, it is important to evaluate their training.

OBJECTIVE

To evaluate the ability of 3rd year ophthalmic technician students and graduates to assess the normality of an ophthalmological examination and to determine a proposed time delay for seeing an ophthalmologist.

MATERIALS AND METHODS

One hundred records including ophthalmology examinations were shown to 8 ophthalmic technician students in their third year of study and to 3 graduated technicians. Three ophthalmologists determined the content of the files, the pathological nature or not of the case, as well as the proposed time for seeing an ophthalmologist. We calculated the sensitivity and specificity to recognize the normality of the case, as well as the concordance between the proposed time for seeing an ophthalmologist.

RESULTS

For recognition of a normal case, the sensitivity was 80%, and the specificity was 83% in the group of technician students, and 81% versus 80% respectively in the group of graduated technicians. For the proposed time of consultation for seeing an ophthalmologist, the kappa agreement coefficient was 0.30 in the group of students and 0.41 in the group of graduates (low and moderate agreement respectively).

CONCLUSION

The study showed a good ability of technicians to recognize the normality or not of clinical cases, but their ability to judge the appropriate timing of treatment by an ophthalmologist remains insufficient.

Prevalence of cardiovascular risk factors, the use of statins and of aspirin in Takayasu Arteritis

The aim of this study was to assess the prevalence of cardiovascular risk factors in TAK, to describe the use of aspirin and statins and the risk factors associated with vascular ischemic complications and relapses. We conducted a retrospective study on TAK patients diagnosed between 2010 and 2018. Demographic, clinical, laboratory data and treatments were evaluated at diagnosis and during the follow-up. We included fifty-two TAK patients with median age 37.5 years [range 16–53] and 43 (83%) women. At diagnosis, cardiovascular risk factors were present in 32 (62%) patients: hypertension (n = 20, 38%), hyperlipidemia (n = 8, 15%), tobacco use (n = 16, 31%). During the median 4-year follow-up [range 0.1–17 years], 17 (33%) patients had at least one ischemic event and 15 (29%) patients needed endovascular procedure. Whereas TAK patients with cardiovascular risk factors were more frequently on statins and anti-hypertensive drugs, they have higher rates of cumulative ischemic complications (5 (24%) versus 21 (67%); p = 0.004), but similar rates of aspirin-treated patients. Patients who have developed vascular ischemic events were more frequently smokers (53% versus 20%; p = 0.03). The vascular complication-free survival was not significantly different in TAK patients with or without statins or aspirin at diagnosis. During the follow-up, 27 (52%) patients had at least one relapse, and the relapse-free survival was not significantly different in patients treated with statins or aspirin. Cardiovascular risk factors in TAK have to be strictly controlled since these risk factors could be associated with increased risk of ischemic complications.

Regulatory B cell imbalance correlates with Tfh expansion in systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is an autoimmune disease with fibrosis, microangiopathy and immune dysfunction. B cell abnormalities characterised by autoantibody production and polyclonal B cell activation play an important role in the pathogenesis of SSc. We previously identified an expansion of functional and activated circulating T follicular helper (cTfh) cells in SSc patients. The aim of this study was to analyse the frequency of regulatory B (Breg) cell subsets and the correlation with Tfh in SSc patients.

METHODS

Circulating Breg cells CD24hiCD38hi and CD27+CD24hi levels and cTfh cells CD4+CXCR5+PD1+ were determined by cytometry in 50 SSc patients and 32 healthy subjects.

RESULTS

The frequency of Breg cells CD24hiCD38hi and CD24hiCD27+ was significantly reduced in patients with SSc as compared to controls (p=0.02 and p<0.001, respectively). In contrast, when examining the CD21low B cell subset, the frequency was significantly increased in SSc patients compared to healthy controls, (p<0.001). There was no difference in Breg cell levels in patients with diffuse SSc and limited SSc. However, CD24hiCD27+ Breg cell frequency was significantly decreased in SSc patients with pulmonary arterial hypertension (p=0.014), but not in patients with interstitial lung disease (p=0.058). Furthermore, we observed a negative correlation between cTfh and CD24hiCD27+ Breg cell levels in SSc patients but not in healthy controls (p=0.02).

CONCLUSIONS

These results suggest that Breg cell subsets may participate in the regulation of cTfh and disease severity. Decreased CD24hiCD27+ Breg cell frequency may contribute to the development of SSc.

Co-construction of a method for evaluating the intrinsic quality of bovine milk in relation to its fate

There are time-tested assessments for the environmental and economic aspects of sustainability. Its societal aspect has mainly been approached through the assessment of animal welfare. However, the intrinsic quality of milk is seldom taken into account. We developed a participatory construction method for the overall assessment of intrinsic milk quality in its different dimensions (sensory, technological, nutritional and health), according to the fate of the raw milk. Two assessment models were developed, for semi-skimmed standardized ultra-high temperature (UHT) milk and for pressed uncooked non-standardized raw milk cheese. They were constructed by a participatory approach involving experts in the dairy sector with the aim to obtain a diagnostic tool that could be used in the field to help farmers to manage the quality of their milk (by prioritizing improvements on major problems). They were shaped from prerequisite specifications (limited costs and time of application, desire to obtain a transparent tool with all the steps kept visible) and current technical and scientific knowledge. They were based on indicators obtained from raw bulk tank milk analyses (30 for UHT milk and 50 for cheese assessments), which were then aggregated into criteria, principles, dimensions and overall intrinsic quality at farm level. The assessment models had parts in common, for example, same four dimensions, common indicators for health and nutritional dimensions. They also had process-specific features: units chosen, criteria, indicators and weightings in relation to the final product specifications. For instance, sensory and technological dimensions are more complex and preponderant in the cheese assessment (three principles for cheese vs one for UHT milk in both dimensions). Another example is the lack of microbial pathogens (as potential health risk for consumer) in the UHT milk assessment because of pasteurization. The assessment models then underwent a sensitivity analysis and an application in 30 farms in indoor and grazing periods to finally obtain overall UHT milk and cheese quality scores at a 1-year level. The tool was found to be applicable at farm level. However, we observed low overall quality scores with a narrow dispersion, characteristic of a severe evaluation. Even so, the assessment models showed up seasonal differences of the UHT milk and cheese quality at both overall and dimensional levels. In the light of new scientific knowledge and future quality objectives, these are adaptable to other dairy products allowing for their specific features.