Tobacco, alcohol, cannabis, and illicit drug use and their association with CD4/CD8 cell count ratio in people with controlled HIV: a cross-sectional study (ANRS CO3 AQUIVIH-NA-QuAliV)

BACKGROUND

To evaluate drug use (alcohol, tobacco, cannabis and other drugs) and its association with mean CD4/CD8 T cell count ratio, a marker of chronic inflammation, in virally suppressed people living with HIV-1 (PLWH) in Nouvelle Aquitaine, France.

METHODS

A multi-centric, cross-sectional analysis was conducted in 2018-19 in the QuAliV study-ANRS CO3 AQUIVIH-NA cohort. Tobacco, alcohol, cannabis, and other drug use (poppers, cocaine, amphetamines, synthetic cathinones, GHB/GBL) were self-reported. CD4 and CD8 T cell counts and viral load measures, ± 2 years of self-report, and other characteristics were abstracted from medical records. Univariable and multivariable linear regression models, adjusted for age, sex, HIV risk group, time since HIV diagnosis, and other drug use were fit for each drug and most recent CD4/CD8 ratio.

RESULTS

660 PLWH, aged 54.7 ± 11.2, were included. 47.7% [315/660] had a CD4/CD8 ratio of < 1. Their mean CD4/CD8 ratio was 1.1 ± 0.6. 35% smoked; ~ 40% were considered to be hazardous drinkers or have alcohol use disorder; 19.9% used cannabis and 11.9% other drugs. Chemsex-associated drug users' CD4/CD8 ratio was on average 0.226 (95% confidence interval [95% CI] - 0.383, - 0.070) lower than that of non-users in univariable analysis (p = 0.005) and 0.165 lower [95% CI - 0.343, 0.012] in multivariable analysis (p = 0.068).

CONCLUSIONS

Mean differences in CD4/CD8 ratio were not significantly different in tobacco, alcohol and cannabis users compared to non-users. However, Chemsex-associated drug users may represent a population at risk of chronic inflammation, the specific determinants of which merit further investigation.

TRIAL REGISTRATION NUMBER

NCT03296202.

Severe bacterial non-AIDS infections in persons with HIV: the epidemiology and evolution of antibiotic resistance over an 18-year period (2000-2017) in the ANRS CO3 AquiVih-Nouvelle-Aquitaine cohort

BACKGROUND

Severe non-AIDS bacterial infections (SBIs) are one of the leading causes of hospital admissions among persons with HIV (PWH) in regions with high ART coverage.

METHODS

This large prospective cohort study of PWH examined the types of infections, bacterial documentation, and evolution of antibiotic resistance among PWH hospitalized with SBIs over an 18-year period.

RESULTS

Between 2000 and 2017, 459 PWH had at least one SBI with bacterial documentation. Among the 847 SBIs, there were 280 cases of bacteremia, 269 cases of pneumonia, and 240 urinary tract infections. The 1025 isolated bacteria included Enterobacteriaceae (n = 394; mainly Escherichia coli), Staphylococcus aureus (n = 153) and Streptococcus pneumoniae (n = 82). The proportion of S. pneumoniae as the causative agent in pneumonia and bacteremia decreased sharply over time, from 34% to 8% and from 21 to 3%, respectively.The overall antibiotic resistance of S. aureus and S. pneumoniae decreased progressively but it increased for Enterobacteriaceae (from 24% to 48% for amoxicillin-clavulanate, from 4 to 18% for cefotaxime, and from 5% to 27% for ciprofloxacin). Cotrimoxazole prophylaxis was associated with higher nonsusceptibility of S. pneumoniae to amoxicillin and erythromycin, higher nonsusceptibility of Enterobacteriaceae to beta-lactams and fluoroquinolones, and a higher risk of extended-spectrum β-lactamase producing Enterobacteriaceae.

CONCLUSIONS

The bacterial resistance pattern among PWH between 2014 and 2017 was broadly similar to that in the general population, with the exception of a higher resistance profile of Enterobacteriaceae to fluoroquinolones. The use of cotrimoxazole as prophylaxis was associated with an increased risk of antibiotic resistance.

OS07.1.A A threshold of mitotic activity and post-surgery residual volume are independant prognostic factors in astrocytoma IDH-mutant

Background

The distinction between grade 2 and 3 is instrumental to choose between observational follow-up and adjuvant treatment in resected astrocytoma IDH-mutant. However, criteria of grade 2 versus 3 have not been updated since the WHO 2007 classification. There is no consensus on the method of evaluation of the mitotic activity or a cut-off of mitoses separating grade 2 and grade 3 tumors. The objectives were to evaluate the maximal mitotic activity on a series of resected astrocytoma IDH-mutant and assess its prognostic impact on survival.

Material and Methods

Maximal mitotic activity on consecutive high power fields corresponding to 3 mm2 was examined in 118 lower-grade astrocytoma IDH-mutant. The prognostic value for time-to-treatment (TTT) and overall survival (OS) of mitotic activity and other putative prognostic factors (including age, performance status, pre-surgical tumor volume, plurilobar involvement, post-surgical residual tumor volume, midline involvement) was assessed in tumors with (i) ATRX loss, and (ii) without CDKN2A homozygous deletion, lesional enhancement, histological necrosis nor microvascular proliferation.

Results

Among the 75 (64%) of tumors which had gone through observational follow-up after resection, the maximal mitotic activity, the post-surgical residual volume and the plurilobar involvement were independent prognostic factors of TTT (p &lt; 0.0001). A threshold of mitotic activity for grade 2 was fitted on TTT and OS prognosis. Using this threshold, patients with “grade 2 tumors” had a median TTT of 55 months versus 19 months for “grade 3” (p = 0.0057) and a median OS of 102 months versus 73 months respectively (p = 0.001). Residual volume &lt; 1 cm3 was associated with longer OS (113 months versus 88 months, p = 0.0021).

Conclusion

Mitotic activity and post-surgical residual volume can be combined to evaluate prognosis in resected astrocytoma IDH-mutant and could select the best candidates for observational follow-up.

The TeloDIAG: how telomeric parameters can help in glioma rapid diagnosis and liquid biopsy approaches

BACKGROUND

In glioma, TERT promoter mutation and loss of ATRX (ATRX loss) are associated with reactivation of telomerase or alternative lengthening of telomeres (ALT), respectively, i.e. the two telomere maintenance mechanisms (TMM). Strangely, 25% of gliomas have been reported to display neither or both of these alterations.

MATERIALS AND METHODS

The C-circle (CC) assay was adapted to tumor (formalin-fixed paraffin-embedded and frozen) and blood samples to investigate the TMM.

RESULTS

We constructed a CC-based algorithm able to identify the TMM and reported a sensitivity of 100% and a specificity of 97.3% (n = 284 gliomas). By combining the TMM, the mutational status of the isocitrate dehydrogenase 1/2 (IDH) gene (IDHmt), and the histological grading, we propose a new classification tool: TeloDIAG. This classification defined five subtypes: tOD, tLGA, tGBM_IDHmt, tGBM, and tAIV, corresponding to oligodendroglioma, IDHmt low-grade astrocytoma, IDHmt glioblastoma, and IDHwt glioblastoma (GBM), respectively; the last class gathers ALT+ IDHwt gliomas that tend to be related to longer survival (21.2 months) than tGBM (16.5 months). The TeloDIAG was 99% concordant with the World Health Organization classification (n = 312), and further modified the classification of 55 of 144 (38%) gliomas with atypical molecular characteristics. As an example, 14 of 69 (20%) of TERTwt, ATRXwt, and IDHwt GBM were actually tAIV. Outstandingly, CC in blood sampled from IDHmt astrocytoma patients was detected with a sensitivity of 56% and a specificity of 97% (n = 206 gliomas and 30 healthy donors).

CONCLUSION

The TeloDIAG is a new, simple, and effective tool helping in glioma diagnosis and a promising option for liquid biopsy.

OS02.6.A The TeloDIAG: How telomeric parameters can help in glioma rapid diagnosis and liquid biopsies approaches

BACKGROUND

The integration of molecular markers into the WHO 2016 classification has clarified the complex diagnosis of gliomas. Among these biomarkers, the TERT promoter mutation and the loss of ATRX (ATRX loss) are mutually exclusive alterations associated with re-activation of telomerase or alternative lengthening of telomeres (ALT), respectively. Strangely, 25% of gliomas display neither or both these alterations, a situation referred to as abnormal telomere maintenance mechanism (aTMM).

MATERIAL AND METHODS

To investigate the TMM actually involved in gliomas, the C-circle (CC) assay was adapted to tumor (FFPE and frozen) samples.

RESULTS

We constructed a CC-based algorithm able to identify the TMM of 284 gliomas with either TERT or ATRX alteration, with a sensitivity of 100% and a specificity of 97.3%, and succeeded in deciphering the TMM involved in 122 aTMM gliomas. Additionally, the combination of the TMM, the mutational status of the Isocitrate dehydrogenase 1/2 (IDH) gene, and the histological grading was used as base for a new classification: TeloDIAG. Six subtypes are defined in this classification: tOD, tLGA, tGBM_IDHmt, tGBM, and tAIV, corresponding to oligodendroglioma, IDHmt low grade astrocytoma, IDHmt glioblastoma, and IDHwt glioblastoma, respectively, the last class gathers ALT+ IDHwt glioma. The TeloDIAG diagnosis is 99% concordant with the WHO classification for glioma displaying typical molecular characteristics (N=312). It modified the classification of 38% (N=156) discordant tumors, such as IDHwt Astrocytoma, aTMM tumors, or gliomas with unexpected TMM (e.g. TERTwt oligodendroglioma, ATRX loss GBM). Interestingly, 20% (N=69) of TERTwt, ATRXwt, or IDHwt GBM were actually tAIV, which is remarkable as tAIV-glioma patients’ survival tended to be longer (21.2 months) than tGBM patients’ survival (16.5 months). Importantly, CC in blood sampled from IDHmt astrocytoma patients was detected with a sensitivity of 56% and a specificity of 95% (N = 206).

CONCLUSION

In sum, the TeloDIAG is a new, simple, and efficient tool helping in glioma diagnosis and a promising option for liquid biopsy

Émergence de variants E484 K suite à une monothérapie bamlanivimab chez des patients COVID-19 à haut risque d’évolution vers une forme sévère

Introduction

En France, une Autorisation d’Utilisation Temporaire de cohorte (ATUc) a été délivrée le 27/02/2021 pour l’utilisation du bamlanivimab en monothérapie dans le traitement précoce (< 5 jours du début des symptômes) de patients adultes avec un COVID-19 léger à modéré confirmé par PCR et à haut risque d’évolution vers une forme sévère. Les patients concernés étaient les patients de > 80 ans ou les patients de < 80 ans immunodéprimés (transplantation, chimiothérapie, traitement immunosuppresseur). Le risque d’émergence de variants potentiellement résistants à un monothérapie par anticorps monoclonal anti-Spike, en particulier les variants E484 K, avait été pris en compte lors de l’ATUc. Cependant, le bénéfice potentiel de ces traitements chez les patients à haut risque a été considéré comme supérieur au risque. Ici nous décrivons 6 patients ayant reçu de ce traitement, leur évolution et l’émergence de mutations de résistance sous pression de sélection.

Matériels et méthodes

Il s’agit d’une étude unicentrique en centre hospitalier universitaire. Le bamlanivimab a été administré à une dose unique de 700 mg en injection IV d’une heure chez 6 patients qui ont accepté d’utiliser le traitement dans le cadre de l’ATUc. Le suivi virologique des patients a consisté en un test RT-qPCR itératif réalisé le jour de la perfusion ou la veille, à J3 ± 1, à J5 ± 1, à J7 ± 1 puis tous les 3 jours jusqu’à ce que la PCR soit négative. La sélection de mutation de résistance a été vérifiée par séquençage du génome complet du SARS-CoV-2 chez tous les patients.

Résultats

Les six hommes traités avaient un âge médian de 65 ans (extrêmes 35-97), plus de 3 comorbidités à haut risque d’évolution vers une forme sévère et 5 étaient infectés par un variant UK (N501Y.V1, B.1.1.7). Le traitement a été administré dans les 4 jours suivant l’apparition des symptômes (médiane 2 jours). Les 6 patients ont eu une évolution clinique favorable, deux ont eu besoin d’oxygène au débit maximal de 4 L/min. Aucun patient n’a eu besoin d’oxygénothérapie haut débit, d’une ventilation non invasive ou d’une ventilation invasive. À J20 après l’administration, un seul présentait une PCR nasopharyngée négative et 5 présentaient l’apparition d’une mutation E484 K à différents moments après l’administration (J6, J7, J12, J14 et J26).

Conclusion

Chez ces patients à très haut risque d’évolution vers une forme sévère, la sélection de la mutation E484 K après administration de bamlanivimab en monothérapie était très fréquente et bien plus importante qu’observée dans les premiers essais cliniques. Ceci peut être expliqué en partie par l’infection par un variant UK pour 5/6 patients décrits ici. L’émergence de résistance lors des bithérapies devra être suivi attentivement, notamment avec l’émergence des nouveaux variants.

T helper 2 inflammatory markers are associated with recurrence in chronic rhinosinusitis with nasal polyps after endoscopic sinus surgery

BACKGROUND

Despite maximum medical treatment and endoscopic sinus surgery (ESS), chronic rhinosinusitis with nasal polyps (CRSwNP) can require revision surgery. With a growing literature on the diversity of cytokine inflammation patterns in CRSwNP, an endotype-driven approach could lead to the identification of cytokine profiles that predict recurrence.

METHODS

A monocentric longitudinal study was carried out until June 2019 following CRSwNP patients who underwent surgery for the first time between December 2010 and January 2012. The biomarker profiles were established on blood and nasal secretions at the time of the first surgery (Interleukin (IL)-5, IgE, IgA, eosinophilic cationic protein (ECP) and eosinophilic- derived neurotoxin (EDN)). Profiles were compared between the patients still controlled by medical treatment and the patients requiring revision surgery during the course of the follow-up period.

RESULTS

Among the 48 patients initially enrolled in our study, 8 required revision surgery (16,7%). Clinical features (asthma, allergy, aspirin intolerance, active smoking) and levels of blood markers measured at the time of the first surgery were comparable between the 2 groups of patients. Levels of IL-5, IgE and ECP in nasal secretions were significantly increased in the group of patients needing revision surgery.

CONCLUSIONS

Based on simple approach of nasal secretions sampling, we showed that a predominant T helper 2 proteins expression profile can be associated with recurrent CRSwNP after ESS. Initial immunoprofiling in CRSwNP disease may contribute to better predict the therapeutic response to optimal medical and surgical treatment, and help define the role of innovative targeted treatment, beside corticosteroids and ESS.

Characteristics of IDH-mutant gliomas with non-canonical IDH mutation

BACKGROUND

Approximately 10% of IDH-mutant gliomas harbour non-canonical IDH mutations (non-p.R132H IDH1 and IDH2 mutations).

OBJECTIVE

The aim of this study was to analyse the characteristics of non-canonical IDH-mutant gliomas.

MATERIALS AND METHODS

We retrospectively analysed the characteristics of 166 patients with non-canonical IDH mutant gliomas and compared them to those of 155 consecutive patients with IDH1 p.R132H mutant gliomas.

RESULTS

The median age at diagnosis was 38 years in patients with non-canonical IDH mutant gliomas and 43 years in glioma patients with IDH1 p.R132H-mutant tumours. Family history of cancer was more frequent among glioma patients harbouring non-canonical IDH mutations than in patients with IDH1 p.R132H mutations (22.2% vs 5.1%; P < 0.05). Tumours were predominantly localised in the frontal lobe regardless of the type of IDH mutation. Compared to IDH1 p.R132H-mutant gliomas, tumours with non-canonical IDH mutations were more frequently found in the infratentorial region (5.5% vs 0%; P < 0.05) and were often multicentric (4.8% vs 0.9%; P < 0.05). Compared to IDH1 P.R132H-mutant gliomas, tumours with non-canonical IDH1 mutations were more frequently astrocytomas (65.6% vs 43%, P < 0.05), while those with IDH2 mutations were more frequently oligodendrogliomas (85% vs 48.3%; P < 0.05). The median overall survival was similar in patients with IDH1 p.R132H-mutant gliomas and patients with non-canonical IDH-mutant gliomas.

CONCLUSION

Gliomas with non-canonical IDH mutations have distinct radiological and histological characteristics. The presence of such tumours seems to be associated with genetic predisposition to cancer development.

OS9.2 Radiomics analysis of lower-grade gliomas, a POLA Network study

BACKGROUND

Lower-grade gliomas (LGG) are divided into three histo-molecular groups: i) IDH-wildtype, ii) IDH mutant and 1p19q intact and iii) IDH mutant and 1p19q co-deleted. The current classification has improved the clinical stratification and its reproducibility. However, LGGs are still associated with an important degree of clinical heterogeneity. We sought to analyze the cross-talk between the spatial distribution and the quantitative imaging features (radiomics) with the clinical evolution and their molecular background (radiogenomics).

MATERIAL AND METHODS

We performed a retrospective multicentric study from 4 cohorts of high-grades gliomas (POLA Network, TCGA, REMBRANDT and LGG-1p19q), totaling 900 gliomas. We performed N4 and WhiteStripe imaging corrections to standardize MRI intensities. We used ITK-SNAP to obtain a mask of the different habitats of the tumor. Then we used PyRadiomics to obtain 2616 radiomic features per sample. We used plsRcox for fitting several Cox model in high-dimensional settings. We assessed the performance of the difference Cox model with the Harrel’s concordance index. We used a Sparse Canonical Correlation analysis to analyze the spatial distribution of the tumors.

RESULTS

Radiomics features allow identification in an unsupervised manner IDH-mutant gliomas with a median AUC of 0.96 [0.92–0.98]. Interestingly, in the analysis of survival, radiomics features provided additional information to clinical or genetics covariates and the model with only radiomics features obtained a C-Index of 0.78 [0.72–0.82]. In addition, survival model with the best performance in the prediction of overall survival was the one combining radiomics, clinics and genetics features with a C-Index 0.85 [0.82–0.92] and was validated in the other cohorts. The analysis of spatial distribution showed a very strong distribution of 1p19q co-deleted oligodendrogliomas in the frontal lobes.

CONCLUSION

Radiomics features may provide additional relevant clinical information by improving the prognosis of LGG. Radiomics allow non-invasive prediction of the most relevant molecular alterations of LGG.

P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

BACKGROUND

About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas.

MATERIAL AND METHODS

We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed.

RESULTS

Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p<0.05). In both IDH1 R132H-mutant and non-canonical IDH-mutant gliomas the most frequent location was the frontal lobe. Yet, compared to IDH1R132H-mutant gliomas those with a non-canonical IDH mutation had more frequently an infratentorial location (5,5% vs 0% p<0,05) and were more frequently multicentric (4,9%, versus 0.9%, p<0.05). Compared to IDH1R132H-mutant gliomas, gliomas with a non-canonical IDH1 mutation were more frequently astrocytomas (65.7% vs 45%, p<0.05) while those with an IDH2 mutation were more frequently oligodendrogliomas (82% vs 55%, p<0.05). The median overall survival in IDH1 R132H-mutant and non-canonical IDH-mutant gliomas was similar (122 versus 120 months).

CONCLUSION

Gliomas with non-canonical IDH mutations are associated with distinct clinical, radiological and histological characteristics. Their prognosis, however, is similar to that of gliomas with canonical IDH mutations.

Defining the human sperm microtubulome: an integrated genomics approach

Sperm motility notably depends on the structural integrity of the flagellum and the regulation of microtubule dynamics. Although researchers have started to use "omics" techniques to characterize the human sperm's molecular landscape, the constituents responsible for the assembly, organization, and dynamics of the flagellum microtubule have yet to be fully defined. In this study, we defined a core set of 116 gene products associated with the human sperm microtubulome (including products potentially involved in abnormal ciliary phenotypes and male infertility disorders). To this end, we designed and applied an integrated genomics workflow and combined relevant proteomics, transcriptomics, and interactomics datasets to reconstruct a dynamic interactome map. By further integrating phenotypic information, we defined a disease-interaction network; this enabled us to highlight a number of novel factors potentially associated with altered sperm motility and male fertility. Lastly, we experimentally validated the expression pattern of two candidate genes (CUL3 and DCDC2C) that had never previously been associated with male germline differentiation. Our analysis suggested that CUL3 and DCDC2C's products have important roles in the sperm flagellum. Taken as a whole, our results demonstrate that an integrated genomics strategy can highlight relevant molecular factors in specific sperm components. This approach could be easily extended by including other "omics" data (from asthenozoospermic men, for example) and identifying other critical proteins from the human sperm microtubulome.

Tau exon 2 responsive elements deregulated in myotonic dystrophy type I are proximal to exon 2 and synergistically regulated by MBNL1 and MBNL2

The splicing of the microtubule-associated protein Tau is regulated during development and is found to be deregulated in a growing number of pathological conditions such as myotonic dystrophy type I (DM1), in which a reduced number of isoforms is expressed in the adult brain. DM1 is caused by a dynamic and unstable CTG repeat expansion in the DMPK gene, resulting in an RNA bearing long CUG repeats (n>50) that accumulates in nuclear foci and sequesters CUG-binding splicing factors of the muscle blind-like (MBNL) family, involved in the splicing of Tau pre-mRNA among others. However, the precise mechanism leading to Tau mis-splicing and the role of MBNL splicing factors in this process are poorly understood. We therefore used new Tau minigenes that we developed for this purpose to determine how MBNL1 and MBNL2 interact to regulate Tau exon 2 splicing. We demonstrate that an intronic region 250 nucleotides downstream of Tau exon 2 contains cis-regulatory splicing enhancers that are sensitive to MBNL and that bind directly to MBNL1. Both MBNL1 and MBNL2 act as enhancers of Tau exon 2 inclusion. Intriguingly, the interaction of MBNL1 and MBNL2 is required to fully reverse the mis-splicing of Tau exon 2 induced by the trans-dominant effect of long CUG repeats, similar to the DM1 condition. In conclusion, both MBNL1 and MBNL2 are involved in the regulation of Tau exon 2 splicing and the mis-splicing of Tau in DM1 is due to the combined inactivation of both.

Management of subluxated lens in young patients

OBJECTIVES

To evaluate visual outcomes in patients treated for lens subluxation. Secondary objectives are to report best corrected visual acuity (BCVA) in LogMAR and compare the outcomes of patients managed conservatively with those treated surgically.

METHODS

Retrospective comparison of BCVA in patients under 50 years-old with lens subluxation, managed conservatively or surgically.

RESULTS

A total of 49 eyes of 28 patients were included. Demographic characteristics were similar in both groups. Twenty eyes were treated surgically (40.8%) compared to 29 with medical treatment (59.2%). Marfan syndrome (79.6%) was diagnosed in 39 eyes. LogMAR BCVA post intervention was 0.35±0.31 for medical treatment and 0.39±0.32 for the surgical group, with no significant differences (P=.63). Improvements in LogMAR lines were 2.7±4.2 and 4.11±4.2 (P=.35), respectively. Two eyes in the surgery group developed ocular hypertension (0.04%), none with retinal detachment.

CONCLUSIONS

The final BCVA showed no significant differences in this group of patients. BCVA depends on the visual potential of the rehabilitated eye rather than a specific type of intervention.

Mis-splicing of Tau exon 10 in myotonic dystrophy type 1 is reproduced by overexpression of CELF2 but not by MBNL1 silencing

Tau is the proteinaceous component of intraneuronal aggregates common to neurodegenerative diseases called Tauopathies, including myotonic dystrophy type 1. In myotonic dystrophy type 1, the presence of microtubule-associated protein Tau aggregates is associated with a mis-splicing of Tau. A toxic gain-of-function at the ribonucleic acid level is a major etiological factor responsible for the mis-splicing of several transcripts in myotonic dystrophy type 1. These are probably the consequence of a loss of muscleblind-like 1 (MBNL1) function or gain of CUGBP1 and ETR3-like factor 1 (CELF1) splicing function. Whether these two dysfunctions occur together or separately and whether all mis-splicing events in myotonic dystrophy type 1 brain result from one or both of these dysfunctions remains unknown. Here, we analyzed the splicing of Tau exons 2 and 10 in the brain of myotonic dystrophy type 1 patients. Two myotonic dystrophy type 1 patients showed a mis-splicing of exon 10 whereas exon 2-inclusion was reduced in all myotonic dystrophy type 1 patients. In order to determine the potential factors responsible for exon 10 mis-splicing, we studied the effect of the splicing factors muscleblind-like 1 (MBNL1), CUGBP1 and ETR3-like factor 1 (CELF1), CUGBP1 and ETR3-like factor 2 (CELF2), and CUGBP1 and ETR3-like factor 4 (CELF4) or a dominant-negative CUGBP1 and ETR-3 like factor (CELF) factor on Tau exon 10 splicing by ectopic expression or siRNA. Interestingly, the inclusion of Tau exon 10 is reduced by CUGBP1 and ETR3-like factor 2 (CELF2) whereas it is insensitive to the loss-of-function of muscleblind-like 1 (MBNL1), CUGBP1 and ETR3-like factor 1 (CELF1) gain-of-function, or a dominant-negative of CUGBP1 and ETR-3 like factor (CELF) factor. Moreover, we observed an increased expression of CUGBP1 and ETR3-like factor 2 (CELF2) only in the brain of myotonic dystrophy type 1 patients with a mis-splicing of exon 10. Taken together, our results indicate the occurrence of a mis-splicing event in myotonic dystrophy type 1 that is induced neither by a loss of muscleblind-like 1 (MBNL1) function nor by a gain of CUGBP1 and ETR3-like factor 1 (CELF1) function but is rather associated to CUGBP1 and ETR3-like factor 2 (CELF2) gain-of-function.

Analysis of exonic regions involved in nuclear localization, splicing activity, and dimerization of Muscleblind-like-1 isoforms

Muscleblind-like-1 (MBNL1) is a splicing regulatory factor controlling the fetal-to-adult alternative splicing transitions during vertebrate muscle development. Its capture by nuclear CUG expansions is one major cause for type 1 myotonic dystrophy (DM1). Alternative splicing produces MBNL1 isoforms that differ by the presence or absence of the exonic regions 3, 5, and 7. To understand better their respective roles and the consequences of the deregulation of their expression in DM1, here we studied the respective roles of MBNL1 alternative and constitutive exons. By combining genetics, molecular and cellular approaches, we found that (i) the exon 5 and 6 regions are both needed to control the nuclear localization of MBNL1; (ii) the exon 3 region strongly enhances the affinity of MBNL1 for its pre-mRNA target sites; (iii) the exon 3 and 6 regions are both required for the splicing regulatory activity, and this function is not enhanced by an exclusive nuclear localization of MBNL1; and finally (iv) the exon 7 region enhances MBNL1-MBNL1 dimerization properties. Consequently, the abnormally high inclusion of the exon 5 and 7 regions in DM1 is expected to enhance the potential of MBNL1 of being sequestered with nuclear CUG expansions, which provides new insight into DM1 pathophysiology.

All the 1p19q codeleted gliomas are mutated on IDH1 or IDH2

BACKGROUND

Recently, the gene encoding the human cytosolic NADPH-dependent isocitrate dehydrogenase (IDH1) was reported frequently mutated in gliomas. Rare mutations were also found in the sequence of the mitochondrial isoform IDH2.

METHODS

In a series of 764 gliomas genome-wide characterized, we determined the presence of mutations in the sequences of both IDH1 and IDH2 genes by direct sequencing.

RESULTS

We found that all tumors with complete 1p19q codeletion (n = 128) were mutated in the IDH1 (118) or IDH2 (10) gene. This 100% mutation rate contrasted strikingly with other gliomas exhibiting either variable 1p and 19q alterations (n = 159, IDH1/IDH2 mutation rate of 33%) or no 1p19q alteration (n = 477, IDH1/IDH2 mutation rate 32%). Our data also confirm the prognostic impact of IDH1/IDH2 mutation in gliomas whatever grade considered: patients harboring mutations of IDH1/IDH2 have an improved median overall survival. Moreover, in WHO grade II and III gliomas, 3 groups with significantly different outcomes were identified according to their 1p19q and IDH1/IDH2 statuses. Tumors carrying both alterations had longer overall survival than their nonmutated counterpart.

CONCLUSIONS

This exclusive association suggests a new mechanism of tumorigenesis. Perhaps the IDH1/IDH2 mutation is a prerequisite for the occurrence of the t(1;19) translocation, or it is required for the 1p19q codeleted cells to acquire a tumor phenotype.

Bevacizumab and irinotecan for recurrent oligodendroglial tumors

2054

Background: Treatment with a regimen of bevacizumab/irinotecan has been shown to be effective in recurrent grade 3 and 4 gliomas, but the effect of this regimen against recurrent oligodendroglial tumors has not been specifically studied. Methods: The bevacizumab/irinotecan regimen was retrospectively evaluated in a consecutive series of 25 patients with recurrent oligodendroglial tumors. All patients had failed previous treatment with radiation therapy and at least one line of temozolomide chemotherapy. Bevacizumab (10 mg/kg) and irinotecan (125 or 340 mg/m2 according to the antiepileptic regimen) were delivered every 14 days. Response was measured clinically and on monthly MRI. Results: The objective response rate was 72% (20% complete response, 52% partial response). After a median follow-up (from the first cycle) of 310 days (95% CI, 47–499), the median progression-free survival was 174 days (95% CI, 116–342), and the median overall survival was 328 days (95%CI, 217-not reached). The 6-month progression-free survival was 42 % (95 % CI, 26% to 67%). Among the 20 patients who progressed at the time of the analysis, the radiological pattern of progression was atypical in seven patients with an isolated multifocal or diffuse spread of the FLAIR signal, or an isolated meningeal spread or FLAIR abnormalities preceding contrast-enhancement recurrence. Among the 10 patients who are still alive, two are still on follow-up since 6 months with a complete response after, respectively, 10 and 12 months of treatment. Among the 17 patients in whom the status of the main molecular alterations of gliomas could be evaluated (search for deletions of chromosomes 1p, 19q, 9p, 10q, and amplification of EGFR, MDM2, CDK4), no relation could be found between the response rate and the type of genetic change (including 1p-19q co-deletion). The profile of tolerance was fair, with treatment discontinuation in 20% of patients. Intratumoral hemorrhages occurred in six patients (24%), but the treatment had to be discontinued because of symptomatic bleeding in only one patient (4%). Conclusions: This regimen is effective in recurrent oligodendrogliomas, and the overall tolerance is acceptable.

[Table: see text]

Polymorphism in Sp1 recognition site of the EGF receptor gene promoter and risk of glioblastoma

We investigated two polymorphisms of the epidermal growth factor receptor promoter as potential risk factors and prognostic markers for glioblastoma. The -216T allele (which results in a 30% higher activity) was more frequent in the patients compared with the control population (224/376 = 59.6% vs 165/352 = 46.8%; p = 0.0006) corresponding to an odd ratio of 1.67 (1.24; 2.25). A modest difference in median survival was also associated with the TT genotype.

Differential effects of chronic antidepressant treatments on micro- and delta-opioid receptors in rat brain

We performed an autoradiographic study of [D-Ala(2),MePhe(4),Gly-ol(5)]enkephalin (DAMGO)-sensitive [(3)H]naloxone binding to micro-opioid receptors and of [(3)H][D-Pen(2),D-Pen(5)]enkephalin (DPDPE) binding to delta-opioid receptors in the rat brain after 4- or 21-day treatments with paroxetine, reboxetine and moclobemide to investigate the participation of these receptors in the adaptive mechanisms occurring during the delay of action of new generation antidepressants. Paroxetine increased micro-opioid receptor binding site density in cingulate and insular cortices, dorsal endopiriform nucleus (4 days) and olfactory tubercle (21 days) and decreased it in thalamus (21 days). Reboxetine increased it in amygdala (4 days), hippocampus and thalamus (21 days) and decreased it in dorsal raphe (4 days). Moclobemide increased it in hippocampus (4 days) and decreased it in anterior olfactory nucleus, frontal cortex, amygdala and hypothalamus (21 days). Moclobemide increased delta-opioid receptor binding site density in frontal cortex and amygdala (4 days) and decreased it in amygdala and colliculi (21 days). Opioid receptors displayed distinct patterns of adaptations in response to the three antidepressants studied.

[Evaluation of retinal involvement in type 2 diabetics with microalbuminuria]

BACKGROUND

In patients with type 2 diabetes, the presence of microalbuminuria, reflecting a widespread vascular damage, can be a marker of nephropathy, retinophaty and cardiovascular diseases.

AIM

To study the relationship between microalbuminuria and the frequency, severity and outcome of retinopathy in patients with type 2 diabetes mellitus.

PATIENTS AND METHODS

One hundred patients with type 2 diabetes were subjected to a clinical examination, serial monitoring of blood pressure and quarterly measurement of microalbuminuria by RIA. Annually, a fundoscopy, a color photography of the posterior pole and retinal angiofluorescence were performed. Retinopathy was classified as basal (mild to moderate), preproliferative and proliferative. Sixty-four normoalbuminuric patients (urinary albumin of less than 30 mg/24 h) were included in group 1 and 36 patients with a urinary albumin over 30 mg/24 h in group 2. Fifty seven patients with normal blood pressure were randomly treated with enalapril or placebo and those with hypertension received enalapril or acebutolol to normalize blood pressure.

RESULTS

Sixty one percent of group 1 patients and 41% of group 2 patients has retinopathy (p < 0.05). The retinal lesions were proliferative in 41% of group 2 patients and in 8% of group 1 patient (p < 0.05). Retinopathy was present in 67% of hypertensive patients of group 2 and in 41% of hypertensive patients of group 1. An unfavorable evolution of retinopathy was observed in 22% of group 2 patients and in 5% of group 1 patient (p < 0.05).

CONCLUSIONS

In type 2 diabetic patients, the presence of microalbuminuria is a prediction of a higher frequency, severity and dismal evolution of diabetic retinopathy (Rev Méd Chile 2000; 128: 1085-92).

[Co-sleeping and sudden infant death syndrome]

Bedsharing has recently become a controversial subject. Some authors, mainly from North America, assign to bedsharing a positive effect on the efficacy and duration of breast-feeding. Moreover, it would protect against sudden infant death syndrome (SIDS). Conversely, other studies consider bedsharing as an additional risk factor for SIDS. From the literature data, there is some evidence for an increased risk of SIDS when bedsharing is associated with maternal smoking and alcohol consumption. Bedsharing cannot be recommended as an absolutely safe practice. Breast-feeding mothers should be aware of these potential hazards.

[Prematurity and sudden infant death syndrome. Polysomnography in question]

Systematic recording of cardiorespirographic events has been recommended by some authors in premature and/or very low birth weight infants before or shortly after hospital's discharge. Their objective is the recognition of babies at risk of sudden infant death syndrome (SIDS) and prevention by home monitoring. After an extensive review of the recent literature, prematurity itself does not appear as a risk factor of SIDS. Late apneas are common, but their prognostic significance remains uncertain. Although it is clear that bronchopulmonary dysplasia carries a greater risk of acute life threatening events and infantile death, their prevention mainly relies upon an adequate oxygen supplementation. As a consequence no more than the general infant population, premature infants require neither polysomnographic recording nor home monitoring.

Immunocytochemical localisation of NK3 receptors in the dorsal vagal complex of rat

Using immunohistochemistry, we demonstrate that neurons of the rat dorsal vagal complex (DVC) express NK3 receptors. The density of NK3-immunoreactive neurons depends of the different subnuclei of the nucleus tractus solitarii. The efferent vagal neurons of the dorsal nucleus of the vagus nerve highly express NK3. No NK3-immunoreactivity has been detected in the area postrema. Ultrastructural examination shows that NK3-immunoreactivity is principally present at non synaptic membrane of somatic and dendritic profiles. Therefore, neurokinin B and/or other ligands may act through a process of volume transmission on non synaptic NK3 receptors in the DVC.

Plasma exchange in Rasmussen's encephalitis

The authors observed a 4-year-old girl who has Rasmussen's encephalitis. She started with frequent localized and generalized seizures. Standard antiepileptic treatment was almost ineffective. The frequency of the generalized seizures decreased, but the myoclonic jerks of the left part of the body persisted. An EEG showed partial status epilepticus. The results of the CT scan were normal. Antibodies to viruses were absent from the blood and cerebrospinal fluid. An MR scan showed a T2-weighted hypersignal zone in the right frontal region. Intravenous bolus injections of corticosteroids and drips of immunoglobulins were inefficient, and we started plasma exchanges which have continued for 9 months. The clinical state stabilized, and the images on the MR scan improved, but the results of the EEG did not improve. The authors discuss the effect of the plasma exchange, the use of which is questionable in this disease.

[Gastroesophageal reflux and esophageal motility disorders in infants with vagal hyperreflectivity presenting severe syncope]

AIM

The aim of the study was to evaluate the prevalence of gastroesophageal reflux and abnormalities of esophageal motility in a population of neonates referred for apparently life threatening event (ALTE) and presenting vagal hyperreflectivity.

POPULATION AND METHODS

The study included 17 infants, who were examined after an ALTE. They were admitted at a mean age of 11.7 weeks (range 1-40 weeks). Vagal hyperreflectivity was confirmed in each infant by oculocardiac reflex. Before treatment, 24-hour intraesophageal pH-monitoring and esophageal manometry were performed.

RESULTS

pH-monitoring and esophageal manometry were both normal in only two patients. pH-monitoring showed pathological reflux (% of time with pH < 4 more than 4.8%) in 10/17 (59%) patients. Manometric studies showed esophageal dysmotility in 12/17 (71%) of patients. Hypertensive lower sphincter was noted in 11/17 (65%) infants. Patients with normal manometry were older than patients presenting with esophageal dysmotility (P < 0.05).

CONCLUSION

This study shows a high frequency of gastroesophageal reflux and dysmotility in infants with vagal hyperreflectivity. Hypertensive lower esophageal sphincter as well as vagal hyperreflectivity may correspond to dysmaturity of autonomous nervous system and facilitate the occurrence of ALTE.

Immunocytochemical localisation of NK3 receptors in the dorsal vagal complex of rat

Using immunohistochemistry, we demonstrate that neurons of the rat dorsal vagal complex (DVC) express NK3 receptors. The density of NK3-immunoreactive neurons depends of the different subnuclei of the nucleus tractus solitarii. The efferent vagal neurons of the dorsal nucleus of the vagus nerve highly express NK3. No NK3-immunoreactivity has been detected in the area postrema. Ultrastructural examination shows that NK3-immunoreactivity is principally present at non synaptic membrane of somatic and dendritic profiles. Therefore, neurokinin B and/or other ligands may act through a process of volume transmission on non synaptic NK3 receptors in the DVC.

[Respiratory syncytial virus infections and apnea in low birth-weight infants]

Respiratory syncytial virus infection was observed in 20 infants of less than 6 months of age who had a low weight at birth, were premature and/or presented with intra-uterine growth retardation. Except for rhinitis, which was present in all cases, the symptoms were closely correlated to the gestational age: beyond 48 weeks they were those of a common lower respiratory tract infection, but below 48 weeks attacks of apnea predominated, associated or not with signs of bronchitis. The apnea was of central origin, although there was no meningo-encephalitis; it regressed completely and without sequelae within a few days. In spite of similarities (notably of terrain) with disorders of respiratory command regarded as predictive of the sudden infant death syndrome risk, such children must be considered definitely cured after the initial episode. Including them in a long-term monitoring programme does not seem to be justified.

Lymphoplasmacytic myeloma: an immunological, immunohistochemical and electron microscopic study

An unusual case of a light chain plasma cell myeloma is described. The disease was initially characterized by a diffuse lymphoplasmacytic bone marrow involvement, but subsequently developed widespread extramedullary metastases with anaplastic tumors in the skin which histologically resembled a "histiocytic lymphoma." Electron microscopic examination, in vitro protein synthesis of bone marrow lymphoidal cells, chemical and immunochemical studies of serum and urine proteins, and intracellular immunoglobulin study by the immunoperoxidase technique on the skin biopsy and postmortem tumor tissue demonstrated evidence for lambda light chain synthesis and secretion. These findings provide further support to the notion that the wide spectrum of diverse morphologic patterns seen in lymphoplasmacytic disorders originates from the same progenitor B-lymphoid cell. Distinguishing anaplastic variant of plasma cell myeloma from other undifferentiated neoplasms offers a challenge.