Dynamics of drug resistance-associated mutations in HIV-1 DNA reverse transcriptase sequence during effective ART

Objectives

To investigate the dynamics of HIV-1 variants archived in cells harbouring drug resistance-associated mutations (DRAMs) to lamivudine/emtricitabine, etravirine and rilpivirine in patients under effective ART free from selective pressure on these DRAMs, in order to assess the possibility of recycling molecules with resistance history.

Patients and methods

We studied 25 patients with at least one DRAM to lamivudine/emtricitabine, etravirine and/or rilpivirine identified on an RNA sequence in their history and with virological control for at least 5 years under a regimen excluding all drugs from the resistant class. Longitudinal ultra-deep sequencing (UDS) and Sanger sequencing of the reverse transcriptase region were performed on cell-associated HIV-1 DNA samples taken over the 5 years of follow-up.

Results

Viral variants harbouring the analysed DRAMs were no longer detected by UDS over the 5 years in 72% of patients, with viruses susceptible to the molecules of interest found after 5 years in 80% of patients with UDS and in 88% of patients with Sanger. Residual viraemia with <50 copies/mL was detected in 52% of patients. The median HIV DNA level remained stable (2.4 at baseline versus 2.1 log10 copies/106 cells 5 years later).

Conclusions

These results show a clear trend towards clearance of archived DRAMs to reverse transcriptase inhibitors in cell-associated HIV-1 DNA after a long period of virological control, free from therapeutic selective pressure on these DRAMs, reflecting probable residual replication in some reservoirs of the fittest viruses and leading to persistent evolution of the archived HIV-1 DNA resistance profile.

Implementation of various approaches to study the prevalence, incidence and progression of disseminated neoplasia in mussel stocks

Marine mussel production is of substantial economic interest in numerous coastal areas worldwide, making crucial the study of pathologies that affect them. Disseminated neoplasia (DN) has recently been suggested to be linked to blue mussel, Mytilus edulis, mortality outbreaks observed in France since 2014, although the evidence remains indirect. In order to improve DN detection and monitoring, we compared the sensitivity of four diagnostic tools, namely haemocytology, histology, flow cytometry, and genetics. Haemocytological examination gave the best results in sensitivity and had the advantage of being non-invasive, allowing disease progression to be followed in affected mussels. Using this approach, we showed that DN progression is usually slow, and we provide evidence of remission events. We observed a high diversity of forms and mitotic features of neoplastic cells located in the vesicular connective tissue but rarely in the haemolymph. Circulating cells occur as four main types but are homogenous in morphology and DNA content within a single individual. Polyploidy proved very high, from 8 N to 18 N. Genetic analysis of haemolymph DNA showed that a Mytilus trossulus genetic signal was associated with almost all the DN cases here diagnosed by haemocytological examination, regardless of the DN type. This result corroborates DN is a transmissible cancer that first originated in a M. trossulus host and subsequently crossed into M. edulis. No pre-neoplastic conditions were detectable. The prevalence of the disease was quite low, which, together with the low morbidity observed in the lab, suggest DN is unlikely to be the direct cause of mortality outbreaks in France.

79Experience from heart or heart/lung transplantation from a single centre for adult congenital heart disease: too little, too late?

Introduction

Heart failure is the leading cause of death in adults with congenital heart disease (ACHD). Heart or heart and lung transplantation (H/HLTx) can be effective therapy for these patients, but unfavourable anatomy, end-organ damage, pulmonary vascular disease, HLA sensitization and lack of robust selection criteria currently limit its application.

Methods

Consecutive ACHD patients >16 years of age who were considered for H/HLTx at our tertiary centre between 2006 and 2018 constitute our study population. Baseline characteristics and outcome, including H/HLTx and death were obtained for all from designated databases, medical records and the UK Office for National Statistics.

Results

Of a total of more than 9,000 active ACHD patients, 130 (53.1% male, mean age 42.2, IQR 32.6–50.2 years) fulfilled inclusion criteria with a broad spectrum of underlying ACHD and considerable mortality across all anatomic subgroups [Table 1].

82% of patients had previous cardiac surgery (55.5% with ≥2 sternotomies or thoracotomies). Cardinal presenting features were poor functional capacity, low cardiac output, cyanosis and/or end-organ disease; “only” 47% had moderate or severe dysfunction of the systemic and 37% of the subpulmonary ventricle. Frequent comorbidities were atrial arrhythmia 68.7%, PH 30.4%, CKD 23.5%, liver dysfunction or cirrhosis 11.3%; 36.8% of patients had an ICD and 16.5% a CRT, whereas 79.8% were on diuretics, 70.5% MRA, 51.6% beta blockers, 32.6% ACEI, 18.9% ARB, 10.5% Digoxin and 29.5% on pulmonary vasodilators. HLA antibodies were positive in 47.3% (high sensitization >90% in 13.2%).

There was high overall mortality with 35.4% of patients dying over a median of 2.7 years (IQR 1.1–4.9). Only 13.6% from our cohort were transplanted, with a survival of 76.5% at a mean of 5.9 years from H/HLTx.

ACHD subgroup % of total % transplanted Mortality (%) Median follow-up (years) Univentricular heart 25.4 6.1 30.3 2.5 Systemic RV 21.5 7.4 35.7 2.6 Shunts with PAH / Eissenmenger 13.9 5.9 27.8 3 Tetralogy of Fallot with Pulmonary atresia 12.3 14.3 50 3.5 Left sided valvar disease, CoA, Marfan 10.8 14.3 50 0.6 CHD associated with cardiomyopathy 9.2 50 33.3 5.3 Other 6.9 22.2 22.2 2.2 RV: right ventricle; PAH: Pulmonary arterial hypertension; CoA: aortic coarctation.

Survival in end-stage heart failure

Conclusion

Of the small number of patients with heterogenous ACHD considered for H/HLTx in our contemporary practice, there was high overall mortality, whereas only a fraction of patients was actually transplanted. Better patient selection and timing are clearly warranted so that more ACHD patients benefit from this effective therapy.

Acknowledgement/Funding

None

P6325Gas exchange improvements during exercise correlate with hemodynamic changes in heart failure patients with a left ventricular assist device

Background

The implantation of left ventricular assist devices (LVAD) has established its role in therapy for patients with end stage heart failure.

Benefits in survival as well as an improved quality of life, compared to optimized medical therapy (OMT) alone, has been proven.

There are limited data in the literature on the metabolic changes during exercise in LVAD patients, and in most studies no increase in peak oxygen consumption on cardiopulmonary exercise test (CPET) could be shown early after surgery. However, recent data suggests an improvement in peak oxygen uptake (VO2) as a late effect after rehabilitation.

To further investigate these findings we sought to analyse CPET data from patients before LVAD implantation as well as in the early and late follow up in correlation with hemodynamic changes at these times.

Methods

We collected and retrospectively analysed data of heart failure patients who had undergone LVAD implantation, and in whom a right heart catheterization, a cardiopulmonary exercise test and an echocardiography had been performed at time before, as well as 6 Months and 12 months after LVAD implantation, respectively.

Results

Data of 43 patients implanted with an LVAD between 2011 and 2017 were analysed. There was significant improvement in cardiac output (3,2 vs 4,3 L/min, p<0,001) and VE/VCO2 slope (46 vs 38, p=0,001) 6 months after LVAD implant as well as a significant reduction in PCWP (26 vs 11 mmHg, p<0,001), PAP mean (40 vs 22 mmHg, p<0,001), RA mean (12 vs 8 mmHg, p=0,002) and PVR (4,2 vs 2,5 WU, p<0,001). However, there was no significant increase in peak VO2 after 6 months.

12 months after LVAD implantation there were no further significant changes in cardiac output, intracardiac pressures or VE/VCO2 slope, which all remained similar to the 6 months follow up. However, at that point, a significant increase in peak VO2 was seen, compared to baseline (1060 vs 1410ml/min, p=0,001) and to 6 months after surgery (Figure 1).

Conclusion

Cardiac output increases in heart failure patients early after LVAD implantation. Consequently, permanent ventricular off loading results in the reduction of intracardiac pressures and improvement in the VE/VCO2 slope 6 months after surgery. However, a significant rise in peak oxygen consumption could only be noted 12 months after surgery, suggesting either a delayed long-term effect of improved hemodynamics or other causes such as enhanced mobility or training due to improved quality of life.

P594Cardiac magnetic resonance imaging in lung transplant assessment: the clinical significance of right ventricular-pulmonary arterial coupling and right ventricular trabecular complexity

Introduction

Right ventricular (RV) dysfunction complicating lung disease is prognostic in patients undergoing lung transplantation. However key metrics are not clear.

Purpose

We assessed RV-pulmonary arterial (PA) coupling and RV trabecular complexity through cardiac magnetic resonance (CMR) imaging in patients undergoing lung transplant assessment.

Methods

Between 2013 and 2018, 91 consecutive patients underwent lung transplant assessment with echocardiography and CMR (1.5T - Siemens). RV trabecular complexity was assessed by its fractal dimension (FD) on CMR, using freely available code (FracAnalyse). RV functional adaptation to increased afterload was assessed with the RV-PA coupling index (stroke volume (SV)/RV end-systolic volume (ESV) ratio).

Results

91 patients (median age 53±15 years, 54% male) were analysed; 97% had underlying lung disease. Median follow up period was 23.8 months. Tricuspid regurgitation was echo-detected in 71 patients; 74% (53 patients) had echo-diagnosed pulmonary hypertension (PH). 85%, 10%, and 4% of PH patients were categorized to WHO PH classification Groups 3, 5 and 1 respectively. Mean LV and RV ejection fraction (EF) were 62±1.01% and 51±15.5%.

SV/ESV correlated to CMR indexed RV end-diastolic volume (RVEDVi), indexed RV end-systolic volume (RVESVi), RV EF, right atrial area and echo mean pulmonary artery pressure (mPAP) (r −0.437, r −0.646, r 0.824/all p<0.001; r −0.290/p 0.005; r −0.348/p 0.003 respectively). Global FD also correlated to these parameters (r 0.371, r 0.369/both p 0.001; r −0.245/p 0.021; r 0.352, r 0.403/both p<0.001). RV FD did not differ significantly in patients with PH. Survival was predicted by SV/ESV ratio, RVEF, RVEDVi, RVESVi, and mPAP on univariate analysis (Table).

All patients (n=91) Alive (n=77) Dead (n=14) Alive vs dead HR CI p value median/mean/counts (SEM/IQR) median/mean/counts (SEM/IQR) median/mean/counts (SEM/IQR) p value CMR RVESVI (ml/m2) 35 (20) 33 (18) 54 (41) <0.001 1.03 1.02, 1.04 <0.001 CMR RVEF (%) 51 (15.5) 53 (13) 38 (15) 0.001 0.93 0.90, 0.93 <0.001 RV-PA coupling SV/ESV 1.06 (0.64) 1.13 (0.61) 0.57 (0.38) <0.001 0.10 0.02, 0.46 0.003 6 minute walk test distance (m, n=90) 290 (188) 300 (190) 190 (264) <0.05 0.99 0.99, 1.00 0.13 Transplanted 22 15 7 0.04 2.39 0.80, 7.17 0.12 Echo mPAP (mmHg, n=71) 27 (10.7) 27 (9) 33 (14.8) <0.05 1.05 10.1, 1.05 0.008

Conclusion

RV functional adaptation to afterload assessed by CMR may predict survival among patients with underlying lung disease referred for lung transplant assessment. Fractal analysis of RV trabecular complexity correlated with metrics influencing RV remodelling and contractility, although not survival. Assessment in a larger cohort is required to determine utility of these metrics.

Complex medical history of a patient with a compound heterozygous mutation in C1QC

Introduction

C1q is an essential part of the classical pathway of complement activation. Genetic deficiencies, caused by homozygous mutations in one of the C1q genes, are rare and are strongly associated with development of systemic lupus erythematosus (SLE). Here we describe a C1q-deficient patient with a compound heterozygous mutation.

Material and methods

Serum was analysed with enzyme-linked immunosorbent assay (ELISA) and Western blot for the presence of C1q, and DNA and RNA sequencing was performed to identify the mutations and confirm that these were located on different chromosomes.

Results

The medical history of the patient includes SLE diagnosis at age 11 years with cerebral involvement at age 13, various infections, osteonecrosis and hemophagocytic syndrome. Using ELISA and Western blot, we confirmed the absence of C1q in the serum of the patient. Using DNA sequencing, two mutations in the C1QC gene were identified: c.100G > A p.(Gly34Arg) and c.205C > T p.(Arg69X). With RNA sequencing we confirmed that the mutations are located on different chromosomes.

Discussion

The patient described in this case report has a compound heterozygous mutation in C1QC resulting in C1q deficiency.

Deformable image registration for dose mapping between external beam radiotherapy and brachytherapy images of cervical cancer

For locally advanced cervical cancer (LACC), anatomy correspondence with and without BT applicator needs to be quantified to merge the delivered doses of external beam radiation therapy (EBRT) and brachytherapy (BT). This study proposed and evaluated different deformable image registration (DIR) methods for this application. Twenty patients who underwent EBRT and BT for LACC were retrospectively analyzed. Each patient had a pre-BT CT at EBRT boost (without applicator) and a CT and MRI at BT (with applicator). The evaluated DIR methods were the diffeomorphic Demons, commercial intensity and hybrid methods, and three different biomechanical models. The biomechanical models considered different boundary conditions (BCs). The impact of the BT devices insertion on the anatomy was quantified. DIR method performances were quantified using geometric criteria between the original and deformed contours. The BT dose was deformed toward the pre-CT BT by each DIR method. The impact of boundary conditions to drive the biomechanical model was evaluated based on the deformation vector field and dose differences. The GEC-ESTRO guideline dose indices were reported. Large organ displacements, deformations, and volume variations were observed between the pre-BT and BT anatomies. Rigid registration and intensity-based DIR resulted in poor geometric accuracy with mean Dice similarity coefficient (DSC) inferior to 0.57, 0.63, 0.42, 0.32, and 0.43 for the rectum, bladder, vagina, cervix and uterus, respectively. Biomechanical models provided a mean DSC of 0.96 for all the organs. By considering the cervix-uterus as one single structure, biomechanical models provided a mean DSC of 0.88 and 0.94 for the cervix and uterus, respectively. The deformed doses were represented for each DIR method. Caution should be used when performing DIR for this application as standard techniques may have unacceptable results. The biomechanical model with the cervix-uterus as one structure provided the most realistic deformations to propagate the BT dose toward the EBRT boost anatomy.

Plk4 Regulates Centriole Asymmetry and Spindle Orientation in Neural Stem Cells

Defects in mitotic spindle orientation (MSO) disrupt the organization of stem cell niches impacting tissue morphogenesis and homeostasis. Mutations in centrosome genes reduce MSO fidelity, leading to tissue dysplasia and causing several diseases such as microcephaly, dwarfism, and cancer. Whether these mutations perturb spindle orientation solely by affecting astral microtubule nucleation or whether centrosome proteins have more direct functions in regulating MSO is unknown. To investigate this question, we analyzed the consequences of deregulating Plk4 (the master centriole duplication kinase) activity in Drosophila asymmetrically dividing neural stem cells. We found that Plk4 functions upstream of MSO control, orchestrating centriole symmetry breaking and consequently centrosome positioning. Mechanistically, we show that Plk4 acts through Spd2 phosphorylation, which induces centriole release from the apical cortex. Overall, this work not only reveals a role for Plk4 in regulating centrosome function but also links the centrosome biogenesis machinery with the MSO apparatus.

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Drosophila Plk4 mutant NSCs show defects in centriole asymmetry and spindle positioning

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Apical centriole anchoring requires the PCM protein Spd-2 and the APC/C activator Fzr

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Movement of the centriole toward the basal side of the cell requires Plk4 activity

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At the mother centriole, Plk4 phosphorylates Spd2 to trigger PCM shedding and Fzr loss