Molecular and clinical diversity in primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare and distinct entity within diffuse large B-cell lymphoma presenting with variable response rates probably to underlying molecular heterogeneity.

PATIENTS AND METHODS

To identify and characterize PCNSL heterogeneity and facilitate clinical translation, we carried out a comprehensive multi-omic analysis [whole-exome sequencing, RNA sequencing (RNA-seq), methylation sequencing, and clinical features] in a discovery cohort of 147 fresh-frozen (FF) immunocompetent PCNSLs and a validation cohort of formalin-fixed, paraffin-embedded (FFPE) 93 PCNSLs with RNA-seq and clinico-radiological data.

RESULTS

Consensus clustering of multi-omic data uncovered concordant classification of four robust, non-overlapping, prognostically significant clusters (CS). The CS1 and CS2 groups presented an immune-cold hypermethylated profile but a distinct clinical behavior. The 'immune-hot' CS4 group, enriched with mutations increasing the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor-κB activity, had the most favorable clinical outcome, while the heterogeneous-immune CS3 group had the worse prognosis probably due to its association with meningeal infiltration and enriched HIST1H1E mutations. CS1 was characterized by high Polycomb repressive complex 2 activity and CDKN2A/B loss leading to higher proliferation activity. Integrated analysis on proposed targets suggests potential use of immune checkpoint inhibitors/JAK1 inhibitors for CS4, cyclin D-Cdk4,6 plus phosphoinositide 3-kinase (PI3K) inhibitors for CS1, lenalidomide/demethylating drugs for CS2, and enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) inhibitors for CS3. We developed an algorithm to identify the PCNSL subtypes using RNA-seq data from either FFPE or FF tissue.

CONCLUSIONS

The integration of genome-wide data from multi-omic data revealed four molecular patterns in PCNSL with a distinctive prognostic impact that provides a basis for future clinical stratification and subtype-based targeted interventions.

[Infection associated cerebral vasculitis]

Infections are a frequent cause of cerebral vasculitis, important to diagnose because a specific treatment may be required. Infection-associated vasculitis can be caused by angiotropic pathogens (varicella zoster virus, syphilis, aspergillus). They can be associated with subarachnoidal meningitis (tuberculosis, pyogenic meningitis, cysticercosis). They can appear contiguously to sinuses or orbital infection (aspergillosis, mucormycosis). Finally, they also may be due to an immune mechanism in the context of chronic infections (hepatitis B virus, hepatitis C virus, human immunodeficiency virus). Cerebral vasculitis are severe conditions and their prognosis is directly linked to early recognition and diagnosis. Infectious causes must therefore be systematically considered ahead of cerebral vasculitis, and the appropriate investigations must be determined according to the patient's clinical context. We propose here an update on the infectious causes of cerebral vasculitis, their diagnosis modalities, and therapeutic options.

Chaos theory applied to the outbreak of COVID-19: an ancillary approach to decision making in pandemic context

While predicting the course of an epidemic is difficult, predicting the course of a pandemic from an emerging virus is even more so. The validity of most predictive models relies on numerous parameters, involving biological and social characteristics often unknown or highly uncertain. Data of the COVID-19 epidemics in China, Japan, South Korea and Italy were used to build up deterministic models without strong assumptions. These models were then applied to other countries to identify the closest scenarios in order to foresee their coming behaviour. The models enabled to predict situations that were confirmed little by little, proving that these tools can be efficient and useful for decision making in a quickly evolving operational context.

OS8.5 How to assess meningioma therapy activity: The CEVOREM independent central review experience

BACKGROUND

Meningioma therapy efficiency is used to being assessed by 6 months progression survival rate (PFS6), which remains the most consensual criterion. Nevertheless, different patterns of meningiomas intrinsic aggressiveness and growth rates directly impact the PFS6 leading to unreliability of drug effect assessment. Moreover, therapeutic response remains rare in meningiomas. These points lead to consider classical and updated RANO criteria as not fully adapted to meningiomas. Based on phase II CEVOREM trial experience, we aim to improve the assessment of drugs efficiency in meningiomas via the determination of growth rate before and under treatment.

MATERIAL AND METHODS

Twenty patients were included in Cevorem trial which tested the combination of octreotide and everolimus as previously described. MRI assessment was performed in the 3 to 6 preinclusion months, at inclusion then every 3 months. Progression was assessed by investigators according to RANO criteria. An independent central review was performed with 2 reviewers and 1 adjudicator: largest diameter, 2D maximal area as 3D volume were assessed by autosegmentation software (Brainlab). Results from central review were correlated to investigators assessment. 3D volume growth rate (3DVGR) was calculated using 2 different processes (one simple and one complex). Comparison of 3DVGR before vs. under treatment was performed. Meningioma growth under treatment was compared to theoretical meningioma growth based on preinclusion data using a model of meningioma growth.

RESULTS

PFS6 assessed via the independent central review was in accordance with PFS6 assessed by investigators following RANO criteria. Then, we analyzed 3DVGR before and during therapy. Standard deviation was higher using the complex 3DVGR calculation process. A decrease of more than 50% of the 3DVGR was observed in 30/36 tumors at 3 months with the both calculation modes and could be considered as a threshold of drugs activity. Median volume growth rate decreased from 88.3 or 17.2%/3 months before inclusion to -2.2 or à -0.6 %/3mo at 3 months depending of the calculation mode (p <0.0002). Nevertheless, in our study, decrease in 3DVGR was associated with a prolonged free progression period when 3DVGR decreased around 0 or negative. Comparison of theoretical meningioma growth curve based on preinclusion data with under treatment growth curve is ongoing. Some limits remain: 3DVGR calculation remains directly related to the volume assessment accuracy and 3DVGR can be very high particularly in case of very small initial tumor which cannot be mitigated by current mathematical models.

CONCLUSION

3DVGR measurement during versus before seems as a sensitive and reliable tool which provides valuable comparison in a phase 2 study to assess drugs activity in meningioma in complement to PFS6. 3DVGR assessment should be considered in future clinical trials.

[Management of tumoral epilepsy in meningioma surgery: Review of the literature and survey of French national practices]

Prophylaxis or treatment of tumor-associated seizures is adaily concern in neurosurgical practice but is often guided by the surgeon's habits rather than evidence from clinical trials, which is lacking. The present study reviews the literature on the incidence, clinical aspects and treatment of epilepsy and epileptic seizures in patients undergoing surgery for meningioma. Based on the published data, we then performed a French nationwide survey of neurosurgeons' practices regarding perioperative management of meningioma-related epilepsy and epileptic seizures.

Satisfaction with sexual life in people living with HIV/AIDS: the persistent weight of the fear of transmission

Sexual life is an important dimension of quality of life, which may be affected by the fear of transmission in people living with HIV/AIDS (PLWHA), despite the fact that antiretroviral therapy prevents person-to-person transmission. We, therefore, aimed to explore the sexual life satisfaction of PLWHA and its correlation with their fear of HIV transmission and self-esteem. Consecutive adult PLWHA from seven HIV care facilities in the Rhone-Alpes region, France, were asked to complete a self-administered, anonymous questionnaire concerning sociological and medical data, satisfaction with sexual life (18 questions), and self-esteem (Rosenberg score). Overall, 690 PLWHA answered the questionnaire (mean age 49.2 ± 11 years); 74.9% were men, of which 75.1% had sex with men. Overall, 68.0% of respondents feared transmitting HIV (a lot/a bit). A lower satisfaction with sexual life was significantly associated with being female, not having a stable sexual partner, being unemployed, having a low income, experiencing a fear of HIV transmission, having lower self-esteem, and not reporting an excellent/very good health status. These results strongly suggest that the information concerning the antiretroviral-induced suppression of infectivity should be widely diffused, as this may enhance the quality of sexual life in PLWHA.

Cultural Practices Shaping Zoonotic Diseases Surveillance: The Case of Highly Pathogenic Avian Influenza and Thailand Native Chicken Farmers

Effectiveness of current passive zoonotic disease surveillance systems is limited by the under-reporting of disease outbreaks in the domestic animal population. Evaluating the acceptability of passive surveillance and its economic, social and cultural determinants appears a critical step for improving it. A participatory rural appraisal was implemented in a rural subdistrict of Thailand. Focus group interviews were used to identify sanitary risks perceived by native chicken farmers and describe the structure of their value chain. Qualitative individual interviews with a large diversity of actors enabled to identify perceived costs and benefits associated with the reporting of HPAI suspicions to sanitary authorities. Besides, flows of information on HPAI suspected cases were assessed using network analysis, based on data collected through individual questionnaires. Results show that the presence of cockfighting activities in the area negatively affected the willingness of all chicken farmers and other actors to report suspected HPAI cases. The high financial and affective value of fighting cocks contradicted the HPAI control policy based on mass culling. However, the importance of product quality in the native chicken meat value chain and the free veterinary services and products delivered by veterinary officers had a positive impact on suspected case reporting. Besides, cockfighting practitioners had a significantly higher centrality than other actors in the information network and they facilitated the spatial diffusion of information. Social ties built in cockfighting activities and the shared purpose of protecting valuable cocks were at the basis of the diffusion of information and the informal collective management of diseases. Building bridges with this informal network would greatly improve the effectiveness of passive surveillance.

The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media.

When private actors matter: Information-sharing network and surveillance of Highly Pathogenic Avian Influenza in Vietnam

The effectiveness of animal health surveillance systems depends on their capacity to gather sanitary information from the animal production sector. In order to assess this capacity we analyzed the flow of sanitary information regarding Highly Pathogenic Avian Influenza (HPAI) suspicions in poultry in Vietnam. Participatory methods were applied to assess the type of actors and likelihood of information sharing between actors in case of HPAI suspicion in poultry. While the reporting of HPAI suspicions is mandatory, private actors had more access to information than public actors. Actors of the upstream sector (medicine and feed sellers) played a key role in the diffusion of information. The central role of these actors and the influence of the information flow on the adoption by poultry production stakeholders of behaviors limiting (e.g. prevention measures) or promoting disease transmission (e.g. increased animal movements) should be accounted for in the design of surveillance and control programs.

Analysis of Swine Movements in a Province in Northern Vietnam and Application in the Design of Surveillance Strategies for Infectious Diseases

While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a prerequisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta Province (northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades, that is between farms of equivalent sizes, whereas the other had pyramidal trades, that is from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that northern provinces were highly connected and showed some connection with central and southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector and to make recommendations for disease control.

Detection of Novel Reassortant Influenza A (H3N2) and H1N1 2009 Pandemic Viruses in Swine in Hanoi, Vietnam

From May to September 2013, monthly samples were collected from swine in a Vietnamese slaughterhouse for influenza virus isolation and serological testing. A(H1N1)pdm09 viruses and a novel H3N2 originating from reassortment between A(H1N1)pdm09 and novel viruses of the North American triple reassortant lineage were isolated. Serological results showed low seroprevalence for the novel H3N2 virus and higher seroprevalence for A(H1N1)pdm09 viruses. In addition, serology suggested that other swine influenza viruses are also circulating in Vietnamese swine.

A Systematic Scoping Study of the Socio-Economic Impact of Rift Valley Fever: Research Gaps and Needs

Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio-economic impact induced by RVF disease and the attempts to evaluate them. Of the 52 papers selected for this review, 13 types of socio-economic impact were identified according to the sector impacted, the level and temporal scale of the impact. RVF has a dramatic impact on producers and livestock industries, affecting public and animal health, food security and the livelihood of the pastoralist communities. RVF also has an impact on international trade and other agro-industries. The risk of introducing RVF into disease-free countries via the importation of an infected animal or mosquito is real, and the consequent restriction of access to export markets may induce dramatic economic consequences for national and local economies. Despite the important threat of RVF, few studies have been conducted to assess the socio-economic impact of the disease. The 17 studies identified for quantitative analysis in this review relied only on partial cost analysis, with limited reference to mid- and long-term impact, public health or risk mitigation measures. However, the estimated impacts were high (ranging from $5 to $470 million USD losses). To reduce the impact of RVF, early detection and rapid response should be implemented. Comprehensive disease impact studies are required to provide decision-makers with science-based information on the best intervention measure to implement ensuring efficient resource allocation. Through the analysis of RVF socio-economic impact, this scoping study proposes insights into the mechanisms underpinning its often-underestimated importance. This study highlights the need for comparative socio-economic studies to help decision-makers with their choices related to RVF disease management.

Molecular genetics of meningiomas: Building the roadmap towards personalized therapy

New advances have recently been made in the field of molecular genetics and mouse modeling of meningiomas, opening new perspectives for future treatments. Recent genome-wide genotyping and exome sequencing studies have confirmed the pivotal role of NF2 in meningioma tumorigenesis, concerning roughly half of the tumors, and unraveled new mutations in non-NF2 meningiomas concerning AKT1, SMO, KLF4 and TRAF7. The molecular mechanisms underlying tumorigenesis of high histological grades have been progressively deciphered with the recent discovery of TERT promoter mutations in progressing tumors. A better understanding of the genetics and clinical behavior of high-grade meningiomas is mandatory in order to better design future clinical trials. New genetically engineered mouse models of benign and histologically aggressive meningioma represent a substantial resource for the establishment of relevant pre-clinical trials. By studying the mechanisms underlying these new tumorigenesis pathways and the corresponding mouse models, we should be able to offer personalized chemotherapy to patients with surgery- and radiation-refractory meningiomas in the near future.

Identification of novel candidate genes for ependymoma progression in chromosomal regions over-represented at recurrence and detected by CGH array

2008

Background: The biology and genetics of ependymomas remain poorly understood. As opposed to other pediatric tumors, few recurrent chromosomal abnormalities or relevant pathways have been identified. Method: In order to gain new insight into the molecular mechanisms involved in ependymoma progression, we performed BAC array-based comparative genomic hybridization (aCGH) in a series of 59 tumors at diagnosis and at relapse (42 posterior fossa and 17 supratentorial). Specific chromosomal imbalances were confirmed by FISH. Expression of candidate genes was evaluated by RT-PCR and immunohistochemistry. Results: As compared to CGH (Cancer Genet Cytogenet 2002), aCGH detected more abnormalities since 18/33 samples at diagnosis and 22/26 at recurrence showed chromosomal imbalances. Three distinct patterns were observed : no imbalance (15 at diagnosis, 4 at relapse), large and numerous imbalances (7 at diagnosis, 12 at relapse) and small and rare imbalances (11 at diagnosis, 10 at relapse). At diagnosis, absence of chromosomal imbalance was correlated with young age (p=0.034) and shorter progression-free survival (p=0.014). At relapse, patients with large and numerous imbalances had a shorter survival (p=0.026). Specific chromosomal imbalances were significantly more frequent at recurrence: 9 qter gain (54% vs 21%), 1q gain (12% vs 0%) and 6q loss (27% vs 6%). Samples were available both at diagnosis and relapse for 16 patients. Whole genome changes were towards increase of genomic abnormalities (n=10) but also simplification (n=6), the former being associated with a higher risk of death from disease (Fisher exact, p=0.03). A candidate gene strategy was focussed on the frequently gained 9qter locus. Significant overexpression compared to normal brain was identified for Tenascin-C (median 35 fold, max 220 fold, p<0.0001) and Notch1 (median 6 fold, max 45 fold, p<0.0001). Notch pathway analysis by RT-PCR revealed potential regulatory loops between JAG1/2 or DLL1/3 and Notch1/2. Conclusion: aCGH pattern may identify subgroups of ependymomas with respect to prognosis. Notch pathway and Tenascin-C are important regulatory genes in ependymoma progression and may represent interesting new targets for therapy.

No significant financial relationships to disclose.

Effect of skin barrier disruption on immune responses to topically applied cross-reacting material, CRM(197), of diphtheria toxin

The high accessibility of the skin and the presence of immunocompetent cells in the epidermis makes this surface an attractive route for needle-free administration of vaccines. However, the lining of the skin by the stratum corneum is a major obstacle to vaccine delivery. In this study we examined the effect of skin barrier disruption on the immune responses to the cross-reacting material CRM(197), a nontoxic mutant of diphtheria toxin (DTx) that is considered as a vaccine candidate. Application of CRM(197), together with cholera toxin (CT), onto the tape-stripped skin of mice elicited antibody responses that had anti-DTx neutralizing activity. Vaccine delivery onto mildly ablated skin or intact skin did not elicit any detectable anti-CRM(197) antibodies. Mice immunized with CRM(197) alone onto the tape-stripped skin mounted a vigorous antigen-specific proliferative response. In contrast, the induction of cellular immunity after CRM(197) deposition onto mildly ablated or intact skin was adjuvant dependent. Furthermore, epidermal cells were activated and underwent apoptosis that was more pronounced when the stratum corneum was removed by tape stripping. Overall, these findings highlight the potential for transcutaneous delivery of CRM(197) and establish a correlation between the degree of barrier disruption and levels of antigen-specific immune responses. Moreover, these results provide the first evidence that the development of a transcutaneous immunization strategy for diphtheria, based on simple and practical methods to disrupt the skin barrier, is feasible.

Primary resistance to antituberculosis drugs: a national survey conducted in Côte d'Ivoire in 1995-1996. Ivoirian Study Group on Tuberculosis Resistance

SETTING

A national survey of resistance to the antituberculosis drugs used in Côte d'Ivoire was conducted in 1995-1996.

OBJECTIVE

To determine the rate of primary resistance to antituberculosis drugs.

METHODS

Consecutive new tuberculous patients with positive smear were recruited from tuberculosis centres and rural health centres. Drug susceptibility testing was performed according to the proportion method. Positive cultures were tested against streptomycin, isoniazid, rifampicin, and ethambutol. All resistant strains and 10% of all randomly sampled cultures were sent to an external laboratory for quality control. Human immunodeficiency virus (HIV) tests were performed for consenting patients at the tuberculosis centres.

RESULTS

Among the 430 samples, 320 were available for analysis. Primary resistance to antituberculosis drugs was observed for 13.4% of the patients (43/320); multidrug resistance (to at least isoniazid and rifampicin) was observed for 5.3% of the patients; 14.2% of HIV-negative and 16.2% of HIV-positive patients were resistant to at least one antituberculosis drug (P = 0.70).

CONCLUSION

This study is representative of antituberculosis drug resistance in Côte d'Ivoire. The rate of primary resistance is high and emphasises the need for a sentinel survey of tuberculous resistance. The National Tuberculosis Control Programme needs to make improvements in its management of tuberculosis cases.

6"'-Deamino-6"'-hydroxy derivatives, as intermediates in the biosynthesis of neomycin and paromomycin

From broths of a neomycin producing Streptomyces fradiae and of a mutant of Streptomyces rimosus forma paromomycinus respectively, 6"'-deamino-6"'-hydroxyneomycin and 6"'-deamino-6"'hydroxyparomomycin were obtained and their structures established by mass and 13C-NMR spectroscopy and by the study of hydrolytic fragments. These new compounds, which are both present as two epimers at C-5"', are suggested as intermediates in the biosynthesis of the parent antibiotics. The place and the mechanism of the 5"'-epimerisation and of the 6"'-amination are discussed.

Interspecific recombination among aminoglycoside producing streptomycetes

From auxotrophic double mutants of Streptomyces rimosus forma paromomycinus and Streptomyces kanamycerticus producing little or no antibiotic, stable prototrophic recombinants were obtained with low frequencies. Most of the recombinants differed from the parents in morphology and antibiotic production. The most frequent classes of recombinants behaved as streptomycetes of the "red" series and produced a wide range of neomycin yields, in contrast to the parents which produced paromomycin and a small proportion of neomycin, or kanamycin, respectively. Hypotheses on the nature of the genetic material exchanged are discussed.