TREX-1 related Aicardi-Goutières syndrome improved by Janus kinase inhibitor.

Aicardi-Goutières syndrome (AGS) is a genetic interferonopathy classically characterized by early onset of severe neurologic injury with basal ganglia calcifications, white matter abnormalities, and progressive cerebral atrophy, along with lymphocytosis and raised interferon alpha (INFα) in the cerebrospinal fluid (CSF). Here, we report a 31/2 year-old patient born with prenatal onset AGS, first manifesting as intra-uterine growth retardation. Cranial ultrasonography and cerebral MRI revealed ventriculomegaly and periventricular and basal ganglia calcifications, along with cerebral atrophy. Perinatal infections and known metabolic disorders were excluded. Both CSF lymphocytosis and raised INFα were present. Molecular analysis disclosed two already described compound heterozygous pathogenic variants in TREX1 (c. 309dup, p.(Thr104Hisfs*53) and c. 506G > A, p.(Arg169His)). The evolution was marked by severe global developmental delay with progressive microcephaly. Promptly, the patient developed irritability, quadri-paretic dyskinetic movements, and subsequently tonic seizures. Sensorineural hearing loss was detected as well as glaucoma. Initially, he was symptomatically treated with trihexyphenidyl followed by levetiracetam and topiramate. At age 22 months, baricitinib (0.4 mg/kg/day) was introduced, leading to normal serum INFα levels. Clinically, dyskinetic movements significantly decreased as well as irritability and sleep disturbance. We confirmed that baricitinib was a useful treatment with no major side effect.

Tocilizumab reduces the unmanageable inflammatory reaction of a patient with Aicardi-Goutières syndrome type 7 during treatment with ruxolitinib.

BACKGROUND: Aicardi-Goutières syndrome (AGS) is a rare hereditary early-onset encephalopathy characterized by upregulation of the type I interferon pathway, poorly responsive to conventional immunosuppression. CASE PRESENTATION: We describe a 7-year-old Chinese boy who developed symptoms at the age of 6 months. He presented with a chilblain-like rash, leukopenia, neutropenia, elevated liver enzymesgrowth retardation, microcephaly, elevated acute phase reactants, intracranial calcification and leukodystrophy. At the age of 3 years old, whole-exome sequencing confirmed a de novo heterozygous gain-of-function mutation, c.1016 C > A (p.Ala339Asp), in the IFIH1 gene, and he was diagnosed with AGS7. He was treated with ruxolitinib accompanied by steroids and thalidomide for about four years. The rash, hematological manifestations, and the liver function were all improved, but the erythrocyte sedimentation rate remained consistently elevated until the addition of tocilizumab, a monoclonal antibody against interleukin 6. CONCLUSIONS: Ruxolitinib was not successful in suppressing the inflammatory process, and tocilizumab produced highly encouraging results in reducing the inflammatory reaction of AGS. The study makes a significant contribution to the literature because we may found a potential alternative therapeutic option for AGS.

JAK Inhibition in Aicardi-Goutières Syndrome: a Monocentric Multidisciplinary Real-World Approach Study.

The paradigm type I interferonopathy Aicardi-Goutières syndrome (AGS) is most typically characterized by severe neurological involvement. AGS is considered an immune-mediated disease, poorly responsive to conventional immunosuppression. Premised on a chronic enhancement of type I interferon signaling, JAK1/2 inhibition has been trialed in AGS, with clear improvements in cutaneous and systemic disease manifestations. Contrastingly, treatment efficacy at the level of the neurological system has been less conclusive. Here, we report our real-word approach study of JAK1/2 inhibition in 11 patients with AGS, providing extensive assessments of clinical and radiological status; interferon signaling, including in cerebrospinal fluid (CSF); and drug concentrations in blood and CSF. Over a median follow-up of 17 months, we observed a clear benefit of JAK1/2 inhibition on certain systemic features of AGS, and reproduced results reported using the AGS neurologic severity scale. In contrast, there was no change in other scales assessing neurological status; using the caregiver scale, only patient comfort, but no other domain of everyday-life care, was improved. Serious bacterial infections occurred in 4 out of the 11 patients. Overall, our data lead us to conclude that other approaches to treatment are urgently required for the neurologic features of AGS. We suggest that earlier diagnosis and adequate central nervous system penetration likely remain the major factors determining the efficacy of therapy in preventing irreversible brain damage, implying the importance of early and rapid genetic testing and the consideration of intrathecal drug delivery.

Janus Kinase Inhibitors in the Treatment of Type I Interferonopathies: A Case Series From a Single Center in China.

Objective: This study aimed to assess the efficacy and safety of 2 Janus kinase (JAK) inhibitors (jakinibs) tofacitinib and ruxolitinib in the treatment of type I interferonopathies patients including STING-associated vasculopathy with onset in infancy (SAVI), Aicardi-Goutières syndrome (AGS), and spondyloenchondrodysplasia with immune dysregulation (SPENCD). Methods: A total of 6 patients were considered in this study: 2 patients with SAVI, 1 patient with AGS1, 1 patient with AGS7, and 2 patients with SPENCD. Clinical manifestations, laboratory investigations, radiology examinations, treatment, and outcomes were collected between November 2017 and November 2021 in Peking Union Medical College Hospital. The disease score for patients with SAVI and AGS scale for patients with AGS were documented. The expression of 6 interferon-stimulated genes (ISGs) was assessed by real-time PCR. Results: Three patients (1 patient with SAVI, 2 patients with AGS) were treated with ruxolitinib and 3 patients (1 patient with SAVI, 2 patients with SPENCD) were treated with tofacitinib. The mean duration of the treatment was 2.5 years (1.25-4 years). Upon treatment, cutaneous lesions and febrile attacks subsided in all affected patients. Two patients discontinued the corticoid treatment. Two patients with SAVI showed an improvement in the disease scores (p < 0.05). The erythrocyte sedimentation rate normalized in 2 patients with AGS. The interferon score (IS) was remarkably decreased in 2 patients with SPENCD (p < 0.01). Catch-ups with growth and weight gain were observed in 3 and 2 patients, respectively. Lung lesions improved in 1 patient with SAVI and remained stable in 3 patients. Lymphopenia was found in 3 patients during the treatment without severe infections. Conclusion: The JAK inhibitors baricitinib and tofacitinib are promising therapeutic agents for patients with SAVI, AGS, and SPENCD, especially for the improvement of cutaneous lesions and febrile attacks. However, further cohort studies are needed to assess the efficacy and safety.

Autosomal dominant ADAR c.3019G>A (p.(G1007R)) variant is an important mimic of hereditary spastic paraplegia and cerebral palsy.

BACKGROUND: The type 1 interferonopathy, Aicardi-Goutières syndrome 6 (AGS6), is classically caused by biallelic ADAR mutations whereas dominant ADAR mutations are associated with dyschromatosis symmetrica hereditaria (DSH). The unique dominant ADAR c.3019G>A variant is associated with neurological manifestations which mimic spastic paraplegia and cerebral palsy (CP). CASE SUMMARIES: We report three cases of spastic paraplegia or CP diagnosed with AGS6 caused by the ADAR c.3019G>A variant. Two children inherited the variant from an asymptomatic parent, and each child had a different clinical course. The youngest case demonstrated relentless progressive symptoms but responded to immunomodulation using steroids and ruxolitinib. CONCLUSION: The ADAR c.3019G>A variant has incomplete penetrance and is a likely underrecognized imitator of spastic paraplegia and dystonic CP. A high level of clinical suspicion is required to diagnose this form of AGS, and disease progression may be ameliorated by immunomodulatory treatment with selective Janus kinase inhibitors.

Cerebrospinal fluid neopterin as a biomarker of treatment response to Janus kinase inhibition in Aicardi-Goutières syndrome.

Janus kinase (JAK) 1 inhibition represents a precision medicine approach in the treatment of Aicardi-Goutières syndrome (AGS), through targeting of type I interferon-mediated cell signalling. Blood interferon mRNAseq has been proposed as a biomarker of disease with utility in therapeutic monitoring. Objective cerebrospinal fluid (CSF) biomarkers tracking treatment efficacy are currently lacking. Here, we report a retrospective case series of 13 patients (median age 6y, range 2y 6mo-17y; five females, eight males) with AGS demonstrating significantly elevated CSF neopterin levels at first sampling (median 200nmol/L, range 45-2024nmol/L), compared to 13 age-matched controls with non-inflammatory neurological conditions (median 23nmol/L, range 5-34nmol/L, p<0.001). Five patients with AGS treated with JAK inhibitors demonstrated a median 81.5% reduction of CSF neopterin (range -36% to -88% change from baseline), compared to eight untreated patients with AGS demonstrating a median 7% reduction in CSF neopterin (range -63% to +117% change) (p=0.047). Our data indicate a biological effect of JAK inhibitors, and the potential role of CSF neopterin as a biomarker of treatment response.

Improving long-term outcomes in pediatric torcular dural sinus malformations with embolization and anticoagulation: a retrospective review of The Hospital for Sick Children experience.

OBJECTIVE: Torcular dural sinus malformations (tDSMs) are rare pediatric cerebrovascular malformations characterized by giant venous lakes localized to the midline confluence of sinuses. Historical clinical outcomes of patients with these lesions were poor, though better prognoses have been reported in the more recent literature. Long-term outcomes in children with tDSMs are uncertain and require further characterization. The goal of this study was to review a cohort of tDSM patients with an emphasis on long-term outcomes and to describe the treatment strategy. METHODS: This study is a single-center retrospective review of a prospectively maintained data bank including patients referred to and cared for at The Hospital for Sick Children for tDSM from January 1996 to March 2019. Each patient's clinical, radiological, and demographic information, as well as their mother's demographic information, was collected for review. RESULTS: Ten patients with tDSM, with a mean follow-up of 58 months, were included in the study. Diagnoses were made antenatally in 8 patients, and among those cases, 4 families opted for either elective termination (n = 1) or no further care following delivery (n = 3). Of the 6 patients treated, 5 had a favorable long-term neurological outcome, and follow-up imaging demonstrated a decrease or stability in the size of the tDSM over time. Staged embolization was performed in 3 patients, and anticoagulation was utilized in 5 treated patients. CONCLUSIONS: The authors add to a growing body of literature indicating that clinical outcomes in tDSM may not be as poor as initially perceived. Greater awareness of the lesion's natural history and pathophysiology, advancing endovascular techniques, and individualized anticoagulation regimens may lead to continued improvement in outcomes.

Risk factors for clozapine-induced central nervous system abnormalities in Japanese patients with treatment-resistant schizophrenia.

The purpose of this study was to assess the risk factors for clozapine-induced central nervous system (CNS) abnormalities (i.e., electroencephalogram [EEG] abnormalities, myoclonus, and seizures). We retrospectively analyzed data from 106 patients with schizophrenia who received clozapine treatment through our hospital. A review of the EEG recordings showed that 71 of these patients (67.0 %) developed CNS abnormalities after initiating clozapine treatment. EEG abnormalities, myoclonus, and seizures occurred in 53.8 %, 38.7 %, and 8.5 % of the patients, respectively. Multivariate logistic regression analysis showed that the risk factors for clozapine-induced CNS abnormalities were concomitant lithium usage (odds ratio, 4.560; 95 % confidence interval, 1.750-11.900) and shorter illness durations before clozapine initiation (odds ratio, 0.796; 95 % confidence interval, 0.649-0.976). However, plasma clozapine levels and the usage of antiepileptics did not exhibit associations with the risks of CNS abnormalities. Clinicians should monitor their patients for incident CNS abnormalities when administering lithium in combination with clozapine regardless of plasma clozapine levels or the usage of antiepileptics. This is especially true for patients with short illness durations.

Ruxolitinib in Aicardi-Goutières syndrome.

Aicardi-Goutières Syndrome (AGS) is a monogenic leukodystrophy with pediatric onset, clinically characterized by a variable degree of neurologic impairment. It belongs to a group of condition called type I interferonopathies that are characterized by abnormal overproduction of interferon alpha, an inflammatory cytokine which action is mediated by the activation of two of the four human Janus Kinases. Thanks to an ever-increasing knowledge of the molecular basis and pathogenetic mechanisms of the disease, Janus Kinase inhibitors (JAKIs) have been proposed as a treatment option for selected interferonopathies. Here we reported the 24 months follow-up of the fifth AGS patient treated with ruxolitinib described so far in literature. The treatment was globally well tolerated; clinical examinations and radiological images demonstrated a progressively improving course. It is however to note that patients presenting with mild and spontaneously improving course have been reported. Large natural history studies on AGS spectrum are strongly required in order to get a better understanding of the results emerging from ongoing therapeutic trials on such rare disease.

The translational value of animal models in orphan medicines designations for rare paediatric neurological diseases.

Rare diseases are characterized by a substantial unmet need mostly because the majority have limited, or no treatment options and a large number also affect children. Appropriate animal models, based on the knowledge of the molecular pathology of the human disease, are a significant element to support the medical plausibility of an orphan designation during the development of orphan medicines for rare neurological diseases. This observational, retrospective study aims to investigate the clinical or nonclinical nature of data submitted to support medical plausibility of orphan designations in the EU (2001-2019), for a group of rare and paediatric neurological diseases. From our sample of 30 diseases, 70% are rare with paediatric onset and 37% have approved orphan designations. The use of nonclinical data was significantly higher than clinical data (65% vs. 35%, p = 0.013) to support medical plausibility. Examples of diseases, with orphan designations based only in nonclinical data, are also discussed: Aicardi-Goutières syndrome and Centronuclear myopathy animal disease models, potentially used to support medical plausibility of medicines. Nonclinical appropriate models, assessing disease relevant endpoints, may contribute to increase the translational value of animal models, in paediatric and rare neurological area, to accelerate research and the effective development of treatment options.

TRPV4 antagonists ameliorate ventriculomegaly in a rat model of hydrocephalus.

Hydrocephalus is a serious condition that impacts patients of all ages. The standards of care are surgical options to divert, or inhibit production of, cerebrospinal fluid; to date, there are no effective pharmaceutical treatments, to our knowledge. The causes vary widely, but one commonality of this condition is aberrations in salt and fluid balance. We have used a genetic model of hydrocephalus to show that ventriculomegaly can be alleviated by inhibition of the transient receptor potential vanilloid 4, a channel that is activated by changes in osmotic balance, temperature, pressure and inflammatory mediators. The TRPV4 antagonists do not appear to have adverse effects on the overall health of the WT or hydrocephalic animals.

Interstitial Lung Disease and Psoriasis in a Child With Aicardi-Goutières Syndrome.

Aicardi-Goutières syndrome (AGS) is characterized by progressive neurologic decline, cerebral calcification, and variable manifestations of autoimmunity. Seven subtypes of AGS have been defined and aberrant activation of the type I interferon system is a common theme among these conditions. We describe a 13-year-old boy who presented with an unusual constellation of psoriasis, interstitial lung disease (ILD), and pulmonary hypertension in addition to cerebral calcifications and glomerulonephritis. He was found to have late-onset AGS due to a gain-of-function mutation in IFIH1 and over-activation of the type I interferon pathway was confirmed by RNA sequencing. The majority of his clinical manifestations, including ILD, psoriasis and renal disease improved markedly after treatment with the combination of corticosteroids, cyclophosphamide, and the Janus-kinase inhibitor tofacitinib. This case extends the clinical spectrum of AGS and suggests the need for lung disease screening in patients with AGS.

Biomarkers and Precision Therapy for Primary Immunodeficiencies: An In Vitro Study Based on Induced Pluripotent Stem Cells From Patients.

Ataxia telangiectasia (AT) and Aicardi-Goutières syndrome (AGS) are inherited disorders of immunity with prevalent neurological phenotype. Available treatments are only partially effective, and the prognosis is poor. Induced pluripotent stem cells (iPSCs) are obtained by reprogramming patient somatic cells, preserving the donor individual genetic heritage and creating patient-specific disease models, useful to investigate pathogenesis and drug effects and to develop precision therapies. The aim is to investigate the cytotoxicity of a panel of immunomodulators using iPSCs of patients with AT or different forms of AGS (AGS1, AGS2, and AGS7). iPSCs were obtained by reprogramming AT and AGS patients' cells and, as a control, the BJ normal human fibroblast line, using Sendai virus. Cytotoxic effects of two drugs proposed to treat respectively AT and AGS (dexamethasone and mepacrine) were tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after 72 hours' exposure. Data were obtained also for other immunomodulatory drugs (thioguanine, mercaptopurine, thalidomide, and lenalidomide). Relative expression of genes involved in the tested drug pathways was analyzed. AGS7-derived iPSCs displayed altered viability when treated with a low dose of mepacrine and higher expression of cyclic guanosine monophosphate-adenosine monophosphate synthase, which is the main target for mepacrine action. AGS7-derived iPSCs were also more sensitive to thioguanine, while AGS2 and AT iPSCs were less sensitive to this medication than the BJ-iPSC. All iPSCs were equally sensitive to mercaptopurine and resistant to dexamethasone, thalidomide, and lenalidomide. This work establishes an innovative in vitro model that is useful to investigate the mechanisms of drugs potentially effective in AT and AGS.

Toward a better understanding of type I interferonopathies: a brief summary, update and beyond.

BACKGROUNDS: Type I interferonopathy is a group of autoinflammatory disorders associated with prominent enhanced type I interferon signaling. The mechanisms are complex, and the clinical phenotypes are diverse. This review briefly summarized the recent progresses of type I interferonopathy focusing on the clinical and molecular features, pathogeneses, diagnoses and potential therapies. DATA SOURCES: Original research articles and literature reviews published in PubMed-indexed journals. RESULTS: Type I interferonopathies include Aicardi-Goutières syndrome, spondyloenchondro-dysplasia with immune dysregulation, stimulator of interferon genes-associated vasculopathy with onset in infancy, X-linked reticulate pigmentary disorder, ubiquitin-specific peptidase 18 deficiency, chronic atypical neutrophilic dermatitis with lipodystrophy, and Singleton-Merten syndrome originally. Other disorders including interferon-stimulated gene 15 deficiency and DNAse II deficiency are believed to be interferonopathies as well. Intracranial calcification, skin vasculopathy, interstitial lung disease, failure to thrive, skeletal development problems and autoimmune features are common. Abnormal responses to nucleic acid stimuli and defective regulation of protein degradation are main mechanisms in disease pathogenesis. First generation Janus kinase inhibitors including baricitinib, tofacitinib and ruxolitinib are useful for disease control. Reverse transcriptase inhibitors seem to be another option for Aicardi-Goutières syndrome. CONCLUSIONS: Tremendous progress has been made for the discovery of type I interferonopathies and responsible genes. Janus kinase inhibitors and other agents have potential therapeutic roles. Future basic, translational and clinical studies towards disease monitoring and powerful therapies are warranted.

Novel and emerging treatments for Aicardi-Goutières syndrome.

Introduction: Aicardi-Goutières syndrome (AGS) is the prototype of the type I interferonopathies, a new heterogeneous group of autoinflammatory disorders in which type I interferon plays a pivotal role. The disease usually manifests itself during infancy, primarily affecting the brain and the skin, and is characterized by cerebrospinal fluid chronic lymphocytosis and raised levels of interferon-alpha and by cardinal neuroradiological features: cerebral calcification, leukoencephalopathy and cerebral atrophy. Recently many aspects of the pathogenesis of AGS have been clarified, making it possible to hypothesize new therapeutic strategies.Areas covered: We here review recent data concerning pathogenesis and novel therapeutic strategies in AGS, including the use of Janus kinase inhibitors, reverse transcriptase inhibitors, anti-IFN-α antibodies, anti-interleukin antibodies, antimalarial drugs and other cGAS inhibitors.Expert opinion: Thanks to the identification of the molecular basis of AGS, many aspects of its pathogenesis have been clarified, making it possible to propose new therapeutic strategies for AGS and type I interferonopathies. A number of therapeutic options are now becoming possible, even though their efficacy is still to be proven. However, in spite of research advances coming from clinical trials and case series, there are still a number of open questions, which urgently need to be addressed.

Assessing the utility of antivirals for preventing maternal-fetal transmission of zika virus in pregnant mice.

Zika virus (ZIKV) infection during pregnancy has been associated with adverse outcomes and birth defects such as microcephaly in newborn children. Congenital malformations associated with ZIKV are believed to occur via direct infection of the fetus. Unfortunately, there are no licensed therapeutic or preventative tools to block maternal-fetal transmission of ZIKV. In this study, we developed a mouse model of ZIKV infection that specifically establishes vertical maternal-fetal transmission of ZIKV in 40-60% of fetuses when the dams acquire ZIKV infection during pregnancy. This mouse model somewhat mirrors the experience in humans at the peak of the epidemic in the Americas. Using this model, we demonstrate that a well-documented directly acting antiviral (DAA) compound that targets flaviviral RNA synthesis can completely prevent fetal infection when the treatment is started at the time of infection. Notably, we show that the treatment commenced at the time of peak viremia is still able to reduce the risk of fetal infection concomitant with significant reduction in placental viral load. Our results show for the first time the potential for clinical development of antiviral drugs for preventing vertical maternal-fetal transmission of ZIKV.

Brain histopathological study and prognosis in MOG antibody-associated demyelinating pseudotumor.

Our objective was to examine the brain biopsies by histopathology and investigate the prognosis of patients with myelin oligodendrocyte glycoprotein antibody-associated demyelinating pseudotumor. The clinical, MRI, and histological features of two patients with myelin oligodendrocyte glycoprotein antibody-associated demyelinating pseudotumor were reviewed. Both patients were treated with steroid plus rituximab and followed up. The brain biopsies of both cases revealed T cells, macrophages, and complement-mediated demyelination, which was in accord with multiple sclerosis-like pathology. Moreover, both cases showed favorable response to steroid plus rituximab therapy. Our cases add a new variant to the myelin oligodendrocyte glycoprotein-encephalomyelitis spectrum, which favorably responds to immunotherapy.

STING palmitoylation as a therapeutic target.

Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy (SAVI). Furthermore, excessive activity of the STING signaling pathway is associated with autoinflammatory diseases, including systemic lupus erythematosus and Aicardi-Goutières syndrome (AGS). Two independent studies recently identified pharmacological inhibitors of STING. Strikingly, both types of compounds are reactive nitro-containing electrophiles that target STING palmitoylation, a posttranslational modification necessary for STING signaling. As a consequence, the activation of downstream signaling molecules and the induction of type I interferons were inhibited. The compounds were effective at ameliorating inflammation in a mouse model of AGS and in blocking the production of type I interferons in primary fibroblasts from SAVI patients. This mini-review focuses on the roles of palmitoylation in STING activation and signaling and as a pharmaceutical target for drug development.

JAK-inhibitors. New players in the field of immune-mediated diseases, beyond rheumatoid arthritis.

Janus kinase (JAK)/signal transducers and activators of transcription (STATs) are a group of molecules associated with one of the major pathways through which many cytokines exert and integrate their function, and as such they are increasingly recognized as playing critical role in the pathogenesis subserving various immune-mediated diseases, including RA, PsA, SpAs, IBD, skin disorders (e.g. alopecia areata, atopic dermatitis), single-gene disorders like interferonopathies, and others. JAKs are the key initiating players of the JAK/STAT pathway. Upon binding of their respective effector molecules (cytokines, IFNs, growth factors and others) to type I and type II receptors, JAKs are activated, and through phosphorylation of themselves and of other molecules (including STATs), they mediate signal transduction to the nucleus. A class of drugs-called JAK inhibitors or JAKinibs-that block one or more JAKs has been developed in the last decade, and now numbers >20 members. Although, so far, JAK inhibitors have been marketed only for RA and PsA, these drugs have been tested in phase 2 and phase 3 clinical trials for other inflammatory conditions and beyond. In this review, we summarize the clinical data, including efficacy and safety, available for JAK inhibitors used in some immune-mediated conditions other than RA.