POS0825 CLINICAL CHARACTERISTICS AND TREATMENT MANAGEMENT OF NON-INFECTIOUS SCLERITIS WITH CORTICOSTEROID-SPARING THERAPY. A RETROSPECTIVE STUDY FROM A TERTIARY EYE CARE CENTER

Background

Non-infectious scleritis refers to a rare and sight-threatening scleral inflammation. An association with an underlying systemic disease is noted in 30% to 40% of cases. Their management may require the use of nonsteroidal anti-inflammatory drugs, oral corticosteroids, and sometimes steroid-sparing immunosuppressive agents. Because of the low incidence and prevalence of scleritis, treatment guidelines are currently not available.

Objectives

We analyzed in a retrospective observational study patients with scleritis referred to the Foundation Rothschild Hospital (Paris) from March 2011 to June 2021.

Methods

Characteristics, visual outcomes, ocular complications, associations with systemic diseases and efficacy of treatment were assessed in patients with non-infectious scleritis who needed steroid-sparing immunosuppressive agents.

Results

Among 731 patients diagnosed with scleritis, 54 patients (71 eyes, 7%) were treated by steroid-sparing immunosuppressive agents. Mean follow up was 111.9 ± 84.5 weeks. Mean age was 48.4 years ± 18.3, and 31 patients (57%) were female. Scleritis was anterior in 51 eyes (72 %), including 25 (35%) with diffuse scleritis, 24 (34%) with nodular scleritis and 2 (3%) with necrotizing scleritis. Scleritis was posterior in 20 eyes (28%). Bilateral involvement was noted in 17 patients (32 %). Ocular complications were observed in 52 eyes (73 %): scleral thinning in 25 eyes (35%), anterior uveitis in 24 eyes (34 %), loss of vision in 20 eyes (28%), posterior segment ocular complications in 18 eyes (25%), ocular hypertension in 17 eyes (24%) and corneal involvement in 16 eyes (23%). An underlying systemic disease was identified in 28 patients (52 %), and scleritis was the first manifestation of the systemic disease in 17 out of 28 patients. Rheumatoid arthritis was the most frequently identified disease (n=12), followed by granulomatosis with polyangiitis (n=8) and relapsing polychondritis (n=4). All patients received at least one immunosuppressive agent. Corticosteroid sparing with a daily dose ≤ 5 mg of prednisone was achieved in 85% of patients. Conventional immunosuppressive agents were used as the first steroid-sparing agent in 38 patients (70%) (methotrexate n=33, azathioprine n=4, mycofenolate mofetil (MMF) n=1) and as second steroid-sparing agent in 1 patient (MMF). This treatment led to control scleral inflammation in 23 (59%) patients after a mean delay of 10.0 ± 6.0 weeks. Biologic therapy was used in 33 (61%) patients (TNF alpha inhibitor n=17, IL6-R inhibitor n=7, anti-CD20 n=9), and as the first steroid-sparing agent in 16 (30%) (TNF alpha inhibitor n=4, IL6-R inhibitor n=4, anti-CD20 n=8). This treatment led to control scleral inflammation after a mean delay of 4,9 ± 3,7 weeks in 29 patients (87.9%).

Conclusion

Scleritis is a severe ocular inflammatory disease that requires repeated and thorough ophthalmologic and general examinations given the high frequency of complications and the possibility of an underlying systemic disease. This study reports real-life experience in management of non-infectious scleritis. Biological therapies seemed to be associated with a better outcome and a quicker reponse than conventional immunosuppressive agents. Further studies are warranted to develop specific guidelines

Disclosure of Interests

None declared

CRISPR-Cas9 globin editing can induce megabase-scale copy-neutral losses of heterozygosity in hematopoietic cells

CRISPR-Cas9 is a promising technology for gene therapy. However, the ON-target genotoxicity of CRISPR-Cas9 nuclease due to DNA double-strand breaks has received little attention and is probably underestimated. Here we report that genome editing targeting globin genes induces megabase-scale losses of heterozygosity (LOH) from the globin CRISPR-Cas9 cut-site to the telomere (5.2 Mb). In established lines, CRISPR-Cas9 nuclease induces frequent terminal chromosome 11p truncations and rare copy-neutral LOH. In primary hematopoietic progenitor/stem cells, we detect 1.1% of clones (7/648) with acquired megabase LOH induced by CRISPR-Cas9. In-depth analysis by SNP-array reveals the presence of copy-neutral LOH. This leads to 11p15.5 partial uniparental disomy, comprising two Chr11p15.5 imprinting centers (H19/IGF2:IG-DMR/IC1 and KCNQ1OT1:TSS-DMR/IC2) and impacting H19 and IGF2 expression. While this genotoxicity is a safety concern for CRISPR clinical trials, it is also an opportunity to model copy-neutral-LOH for genetic diseases and cancers.

Homozygous 16p13.11 duplication associated with mild intellectual disability and urinary tract malformations in two siblings born from consanguineous parents

The use of array-comparative genomic hybridization (array-CGH) in routine clinical work has allowed the identification of many new copy number variations (CNV). The 16p13.11 duplication has been implicated in various congenital anomalies and neurodevelopmental disorders, but it has also been identified in healthy individuals. We report a clinical observation of two brothers from related parents each carrying a homozygous 16p13.11 duplication. The propositus had mild intellectual disability and posterior urethral valves with chronic renal disease. His brother was considered a healthy child with only learning disabilities and poor academic performances. However, a routine medical examination at 25-years-old revealed a mild chronic renal disease and ureteropelvic junction obstruction. Furthermore, the father presented with a unilateral renal agenesis, thus it seemed that a "congenital anomalies of kidney and urinary tract" (CAKUT) phenotype segregated in this family. This may be related to the duplication, but we cannot exclude the involvement of additional genetic or non-genetic factors in the urological phenotype. Several cohort studies showed association between this chromosomal imbalance and different clinical manifestations, but rarely with CAKUT. The duplication reported here was similar to the larger one of 3.4 Mb previously described versus the more common of 1.6 Mb. It encompassed at least 11 known genes, including the five ohnologs previously identified. Our observation, in addition to expanding the clinical spectrum of the duplication provides further support to understanding the underlying pathogenic mechanism.

[Confined placental mosaicisms a priori from meiotic origin: analysis of 10 cases]

This retrospective monocenter study focused on confined placental mosaicisms a priori from meiotic origin (i.e. non-mosaic type 3 confined placental mosaicisms). From a series of 14,967 chorionic villus samplings performed in our Fetal Medicine Center, 10 non-mosaic type 3 confined placental mosaicisms were identified. These abnormalities only involved chromosomes 15, 16 or 22. Pregnancies complicated by these confined placental mosaicisms were associated with prematurity and neonatal hypotrophy. Thus, when a confined placental mosaicism is suspected, this retrospective study highlighted the need to characterize the type of confined placental mosaicism to prevent the probable intra-uterine growth retardation and to adapt the obstetrical monitoring if necessary.

The association between the T309G polymorphism of the MDM2 gene and sensitivity to anticancer drug is dependent on the p53 mutational status in cellular models

Background:

We investigated, in the panel of 60 human tumour cell lines of the National Cancer Institute (NCI-60), whether the R72P polymorphism of TP53 and the T309G polymorphism of MDM2 were associated to the in vitro cytotoxicity of anticancer agents, extracted from the NCI database. For validation, the same study was performed independently on a second panel of tumour cell lines, JFCR-45.

Methods:

Both SNPs were identified in cell DNA using PCR-RFLP techniques confirmed by direct sequencing and by pyrosequencing. For the analysis of the results, the mutational status of p53 was taken into account.

Results:

In the NCI-60 panel, the TP53 rare-allele frequency was 32% and the MDM2 rare-allele frequency 39%. The MDM2 alleles were distributed according to Hardy–Weinberg equilibrium whereas this was only found, for the TP53 alleles, in p53 non-mutated cell lines. Comparable results were obtained in the JFCR-45 validation set. The TP53 SNP had low impact on anticancer drug cytotoxicity in either panel. In contrast, the MDM2 gene polymorphism had a major impact on anticancer drug cytotoxicity, essentially in p53 non-mutated cell lines. Presence of the rare allele was associated to significantly higher MDM2 protein expression and to increased sensitivity to DNA-interfering drugs. In the JFCR-45 panel, a similar effect of the MDM2 gene polymorphism was observed, but was less dependent on the p53 mutational status.

Conclusions:

We hypothesised that cell lines harbouring the MDM2 G allele presented a lower availability of p53 for DNA repair, translating into higher sensitivity to DNA-damaging agents.

Expression of the gene encoding the pro-apoptotic BNIP3 protein and stimulation of hypoxia-inducible factor-1α (HIF-1α) protein following focal cerebral ischemia in rats

Hypoxia is a common cause of cell death and is implicated in many disease processes including stroke and chronic degenerative disorders. In response to hypoxia, cells express a variety of genes which allow adaptation to altered metabolic demands, decreased oxygen demands, and the removal of irreversibly damaged cells. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that regulates the adaptive response to hypoxia in cells. In this study, we reported an early, time-related, gradual up-regulation of HIF-1alpha, and a moderate increase in vascular endothelial growth factor (VEGF)- and erythropoietin (Epo)-levels following transient focal ischemia. Moreover, we demonstrated, for the first time a specific localization of the pro-apoptotic regulator BNIP3 in striatal and cortical neurons after transient focal ischemia in rats. Prolonged intranuclear BNIP3 immunoreactivity was associated with delayed neuronal death. Experiments showed protein increases on Western blots of brain tissue with peaks at 48h after ischemia. Epo responds to ischemia in an early stage, whereas VEGF and BNIP3 accumulate in cells at later times after ischemia. This suggests the possibility that BH3-only proteins might be one of the major downstream effectors of HIF-1alpha in hypoxic cell death. These findings open the possibility that the hypoxia-regulated pro-apoptotic protein BNIP3 enters the nucleus and could interact with other proteins involved in DNA structure, transcription or mRNA splicing after focal brain ischemia.

Induction and redistribution of XAF1, a new antagonist of XIAP in the rat brain after transient focal ischemia

Apoptotic cell death occurs in neurons after cerebral ischemia. To investigate the molecular basis of this mechanism of cell death, we explored the expression and localization of Smac/DIABLO, a newly identified mitochondrial apoptogenic molecule, and XAF1, a recently identified antagonist of XIAP anti-caspase activity in the rat brain following focal ischemia. Transient focal cerebral ischemia was produced for 90 min in rats. We observed changes in the expression of Smac, XAF1, and XIAP during reperfusion. The expression level of Smac/DIABLO was negligible under normal conditions and was moderately increased by 6-24 h reperfusion on both immunohistochemical and Western blotting levels. In opposition to the orthodox method of Western blotting employing electrophoretic analysis and homogenization, the immunohistochemical investigations of XIAP provided spatial information. Immunohistochemical analysis showed that the subcellular localization of XIAP became more extensive within cells during reperfusion, as compared with the normal state. Under normal conditions, XIAP was localized predominantly in the cytoplasm and the perinuclear region. However, at 6, 12, 24, and 48 h post-reperfusion, XIAP exhibited a diffuse distribution, including nuclear and cytoplasmic compartments. Interestingly, the expression of XAF1 exhibited significant changes during reperfusion. XAF1 expression was increased and there was a cellular redistribution with a nuclear localization in the post-ischemic phase by 6-24 h. XAF1 expression apparently enhances neuronal susceptibility to degeneration either by suppressing the ability of XIAP to complex with caspases or by sequestering XIAP in nuclear inclusions. These finding indicate that Smac/DIABLO, XAF1, and XIAP are implicated in the pathophysiological mechanisms of reperfusion injury.

Direct quantification of protein partitioning in oil-in-water emulsion by front-face fluorescence: Avoiding the need for centrifugation

The quantification of proteins adsorbed at the oil-in-water interface is often difficult since it requires separation of fat globules from the aqueous phase that may damage the fat globule size and/or modify the interfacial composition. Front-face fluorescence spectroscopy was used to characterize the protein partitioning between the aqueous and oil phases of emulsions without separating these two phases. Different emulsions based on skim milk powder (SMP), two mono- and di-glyceride (MDG) mixtures (saturated and partially unsaturated), and three fats (hydrogenated and refined coconut oils and refined palm oil) were studied. The impact of an ageing period (24 h at 4 degrees C) was also investigated to typify the first step of ice cream processing. The emulsions were characterized for protein partitioning, immediately following emulsification and after ageing, using the Bradford spectrophotometric method, applied to the aqueous phase recovered after emulsion centrifugation. In parallel, the emulsions were characterized by their tryptophan emission fluorescence spectra. The area of the peaks at 333 nm, of the fourth-derivative fluorescence spectra corresponding to the amount of proteins present in the aqueous phase of emulsions, was well correlated with the Bradford measurements (r2=0.91). This amount was also calculated from the fluorescence calibration curve obtained with SMP in solution. In conclusion, front-face fluorescence spectroscopy appeared to be a powerful and simple technique allowing the quantification of different populations of protein in an emulsified system, i.e., in the aqueous phase and loaded at the fat globule interface.

Increased expression of transforming growth factor-beta after cerebral ischemia in the baboon: an endogenous marker of neuronal stress?

There has been an increasing interest in recent years in the evaluation of the neuronal and glial responses to ischemic insult. Some cytokines, including transforming growth factor-beta (TGF-beta), that are overexpressed after experimental stroke in rodents are thought to be implicated in the neuronal processes that lead to necrosis. Thus, such cytokines could predict tissue fate after stroke in humans, although data are currently sparse for gyrencephalic species. The current study addressed the expression pattern of TGF-beta1 in a nonhuman primate model of middle cerebral artery occlusion. Focal permanent ischemia was induced for 1 or 7 days in 6 baboons and the following investigations were undertaken: cerebral oxygen metabolism (CMRO2) positron emission tomography studies, magnetic resonance imaging, postmortem histology, and reverse transcription-polymerase chain reaction. The aim of the current study was to correlate the expression of TGF-beta1 to the underlying metabolic and histologic state of the threatened cerebral parenchyma. The authors evidenced increased TGF-beta1 mRNA levels (up to 25-fold) in those regions displaying a moderate (20% to 49%) reduction in CMRO2. The current findings suggest that the greatly enhanced expression of TGF-beta1 in the penumbral zones that surround tissue destined to infarction may represent a robust index of potentially salvageable brain. The current investigation, in the nonhuman primate, strengthens the authors' hypothesis, derived from rodent models, that TGF-beta1 may be involved in the physiopathology of human stroke.